# "Titus" - freelance 0-4-0 in 7/8n2 - Progress and Updates



## xo18thfa (Jan 2, 2008)

Couple years back I found this very unusual freelance narrow gauge 0-4-0 named “Maguffin”. 



















Always liked this little engine, so it’s time to do one. Maguffin has a Colin Binnie 2 cylinder oscillator with a steam switch for a reverse. The drive train is geared with a ratio of 2:1 (I think). The boiler is a simple pot style with a gravity fed alcohol burner. The fuel tank is under the driver’s footplate. The usual plumbing accessories.

Don’t really know what the scale is. Call it 7/8n2

My version will retain the same general shape and proportions, but will have a single cylinder. The bore is 7/16 and the stroke 5/8”. The drive train is chain drive with a 3:1 ratio. The wheel diameter is 1.217”, turned to G1MRA practice. This power plant worked out very well on another engine I built, so I plan to use it again. I will use the same pot style boiler. Not sure yet what fuel to use. It might have a birdfeed drip alcohol system or gas fired.

This engine’s name is Titus.

Titus is a very basic engine. One cylinder, single acting. No reverse. No lubricator. No throttle. No safety valve. Oscillator engines act as their own safety. If the pressure gets too high, the cylinder lifts off the port face. 

Start first with the drivers. The drivers are from 1-3/8” diameter round steel bar. Brass or aluminum will work too. If you go with steel, use alloy 12L14. 12L14 is “free machining” quality. It cuts so smooth and easy. Other steels will work, but 12L14 is so nice to work with. It’s worth ordering a bar. Here’s the drawing for the drivers.

Wheel Drawing

Start by cutting billets about 1/2" thick. Chuck the billet in the 3-jaw with about 1/4" protrusion.










Turn the inner portion of the wheel blank first. Face off to good clean metal and turn a 9/16” diameter by 3/16” hub. Drill and ream to 3/16” for the axles










Reverse the wheel blank in the chuck. Face cut the wheel blank to a total thickness of .256”. This thickness includes the outer hub projection, tread and flange. Turn the tread to its final diameter of 1.217” and flange thickness of .060”










Turn the outer hub to .375” diameter and .020” projection.










Turn a decorative recess in the front of the driver. About 1/16” depth will do.










The driver blanks are done. So far all the cuts are either facing or straight. No special settings on the lathe. Measurements by either a good caliper or micrometer. Now it’s time to turn the treads and flanges to final shape. The drawing above is based on G1MRA practice.

We want the rim to be concentric with the axle. So, first check your 3-jaw chuck for run out with a dial indicator. I’m lucky my 3-jaw is within .001”, so I just use it as is. If you 3 jaw is out more than .003”, use a 4 jaw to turn the final tread.










Set the compound rest to 3 degrees. Bring the point of the tool just into the corner of the flange and tread. Take the cut by backing out










Reset the compound to 20 degrees and cut the flange in the same manner. Use a hand file to smoothly round over the flange edge.










Last thing on the drivers is to tap a 6 x 32 in the hub for an axle set screw. A good tapping handle set up in the drill press makes cutting threads very easy.










I’ve shown this tap handle many times before. It’s a 3/8” drill bit chuck on a sort length of rod. A little handle attached and an oilite bearing so it rotates smoothly. You need one of these so get a good one. Don’t mess with the cheap import version, they are junk. Get a good one.

Clamp the driver edgewise in the drill press vice. Drill for 6 x 32. Put the tap handle in the drill press vice and tap the hole. Use a drop of oil. 










Off to a good start.










That’s it for the drivers. Next time we will work on the drive chain sprockets.


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## snowshoe (Jan 2, 2008)

Now that is a neat little engine. Cant wait to see your progress.


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## Phippsburg Eric (Jan 10, 2008)

Now this is going to be fun to see! that is a neat little teapot!


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## Pete Thornton (Jan 2, 2008)

Nice work. 

That's one of Graham Stowell's whimsical creations. Google "maguffin" and you'll fnd a video of it running. More pictures of his amazing work at http://www.wis.co.uk/andy/16mm/unusual_locos.html


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## xo18thfa (Jan 2, 2008)

Thanks guys. Here's a few more pics of Maguffin and a sketch of Colin Binnie's steam motor


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## lotsasteam (Jan 3, 2008)

Looks like the gearing is from a servo with metal gears?


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## xo18thfa (Jan 2, 2008)

Ladder chain and sprockets form the drive train for Titus. The gear ratio is 3:1. Stock Drive Products (http://www.sdp-si.com/index.asp) has ladder chain and brass sprockets in stock and will sell in small amounts to us hobbyists. SDP’s ladder chain comes in several sizes. Size #21 with a pitch of 0.167” or size #19 with a pitch of 0.185” are the sizes to use.

I decided to make my own sprockets rather then purchase. They are a little pricey to buy, but available. Making the sprockets is not very difficult, but a little time consuming.

If you purchase, get these sprockets and chain in size #19:

Pinion: A 6B 8-1906, 6 Teeth, 0.125" Bore, 0.185 (Size 19) 
Gear: A 6B 8-1918, 18 Teeth, 0.1875" Bore, 0.185 (Size 19) 
Chain: A 6C 8-19, 0.185" (Size 19) Pitch, Steel ladder chain

For these sprockets, I went with size #21. I had some chain and plastic sprockets left over from another project. Unfortunately SDP does not sell #21 sprockets in metal, only in plastic. The concern is plastic will melt, so go with metal.

Start by making cutters to form the sprocket teeth. Use 1/4" diameter round tool steel alloy O-1 to make the cutters. O-1 is general-purpose tool steel that is easy to work with. I used plastic sprockets as patterns to make the form cutters. Grind or file the O-1 and hold the tool and sprocket up to the light. You will easily see the corrections to make. Your eyes are good at this. Hone the tools to remove scratches.










After getting the correct form, harden the O-1 by heating to cherry red heat and quench in oil. I use old salad oil. Seems to work fine. Temper the tool by reheating to 350F. To do this accurately heat some salad oil on a stove to 350F using a candy thermometer. Put the cutters in the hot salad oil for about 10 minutes so the heat completely soaks. Turn off the stove and let them cool down. The temper heat is very important. Use the candy thermometer to measure it, don’t try to guess it.

To form the gears, cut squares of 1/8” thick brass. Drill the center 5/16”. Make a mounting mandrel with a 1/2" shank and 5/16” shoulder.










Chuck up the mandrel and turn to final diameter. These were 1.106”










Clamp a dividing head to the bed of the lathe. Square it up. Mount the mandrel in a 1/2" in a collet. Secure the forming cutter in a holder, on the centerline of the dividing head.










This is a little homemade dividing head that uses the quick change gears from the Atlas 6” lathe for indexing. The collets are Morse Taper #2.










You probably can’t cut the whole tooth in one pass on a small mill. It took 3 passes for each tooth on mine. Set up a dial indicator the mill Y-Axis to get consistent accurate depths for each tooth.










Just take it slow and easy. Pay close attention to the indexing on the dividing head. They will come out fine










The teeth might come out with a sharp corner. Mine did. You will need to round over the ends of the teeth with a file. Otherwise the chain will hang up on the corners.

Turn a hub with a 3/16 hole and silver solder it to the gear. Tap for 6 x 32 just like the wheels.










Last thing on the gears is to turn the face width down from 1/8” thickness to 1/16”. Turn a 10 degree taper on both sides of the gear teeth to help the chain track better.

Make the pinions from solid round bar turned to the final diameter. Mine are .416”. Fit the stock into the collet.










Set up in the dividing head and cut as before. Use 4 passes per tooth, the cut is wider this time.










Chuck the pinion stock in the lathe. Drill a 1/8” hole thru for a hub. Part off pinions to 1/16” thickness










You’ll probably have to round over the tooth ends a little on the pinion too.

Turn and solder hubs on the pinions. Drill thru and ream to 5/32 for the crankshaft. Taper the sides of the pinion to 10 degrees as on the gear. Tap 4 x 40 for a set screw And you are done.










Here are the drawings for the sprocket hubs.

Sprocket Hub Drawings 

Cutting sprockets looks complicated, but it’s not that bad. Ladder chain is forgiving stuff. They might bind or climb at first. But it’s easy to see the problem spots and clean them up with a file. The biggest difficulty is getting a dividing head. You need one, no getting around that. Borrow one from a friend.

I made 6 gears and 10 pinions all together. It’s easy to make more. I also have a good length of #21 ladder chain. If anyone is interested in building Titus, I will set you up with sprockets and chain. -No cost- Just promise you build Titus, and carry it thru.

Next time we will get on the cranks.


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## xo18thfa (Jan 2, 2008)

Today we’ll do the cranks, axles and finish up the wheel sets. The cranks ended up far more difficult then they needed to be. When ordering material, I forgot to get steel for the cranks. So, had to use whatever was on hand. Then, discovered a design problem and had to do a modification -- DISASTER RECOVERY

Anyway, they are done. This is what I went thru. Hopefully, you will find a better way, Here is the drawing for the crank and pin.

Cranks and Crank Pins

Start by cutting slabs of 1” diameter 12L14 steel round bar a little over 1/4" thick. Chuck off centered in the four-jaw chuck and turn the inner hub projection. Drill and ream 3/16” to fit the axles.










Now face the crank to its final thickness. Griping an already thin piece of stock in the lathe chuck and turning it true is a difficult task. Turn a distance-backing piece that sets the stock in the lathe chuck parallel to the face of the chuck.










Chuck the crank in the 3-haw with the backing piece. The backing piece keeps the crank parallel to the chuck face. Turn the crank to final thickness.










Drill the crank for the crank pin. It is critical that the distance from the center of the axle to the center of the crank pin is the same for all cranks. Drill the crank pin by using a drilling jig that holds to crank securely by the axle hole. Here is the jig ready to go.










Install the crank on the jig. Secure it with an additional clamp. For clarity, I left the clamp off in this photo. Drill and ream to 1/8”










Next up are the crank pins. These are from 1/8” stainless, alloy 303. Alloy 303 is a free machine stainless. It machines almost as well as 12L14 and is very durable stuff. Other alloys of stainless are difficult to work with. They are difficult to machine and usually work harden when drilled. Cut and face to length. Drill for a 2 x 56 screw using the tap handle held in the tailstock.










A word about the crank pins. You will have to make a decision on how to secure the crank pins based on the material you have. You can either secure them by press fitting them in or using Loctite. The Crank pin stock I have is fairly oversized for 1/8”. I worried they were too big to press in without damaging something. So, I went with Loctite. These cranks were drilled with #30 (0.1285”) rather then 1/8”.

Put a final profile on the cranks with the grinder or file. Use Loctite #680 to secure the crank pins.  Tap the cranks for a 6 x 32 setscrew as before.










After finishing the cranks I discovered the throw ended up too long. The cranks strike the rails in a switch on the bottom of the stroke. I ran out of material making these, so they had to be salvaged. Heat the cranks in the oven to about 400 degrees F. That softens the Loctite so the crank pins will punch out. Plug the existing cranks pins holes by silver soldering some short lengths of 1/8” rod. File for the excess to flush.










Redrill the cranks to a shorter throw and Loctite the pins back in. Shape the cranks to a final profile and they are done (finally)










Last steps in finishing the wheel sets are the axles. Cut and face 3/16” diameter stainless steel rod to a length of 3.031 for the axles. Assemble everything and the wheel sets are done










Next time we will get started on the frame.


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## placitassteam (Jan 2, 2008)

Cute little engine! I really enjoy your detailed explanations of how you machine your parts. I wish I were half the machinist you are! Thanks for the posts.


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## xo18thfa (Jan 2, 2008)

Thanks Winn. All you have to do is start making chips.


Time to get on the frames and buffers and get Titus rolling on the track. The frame and buffers are from 0.062” hot rolled steel sheet. Hot roll is very rigid and will withstand a catastrophic fall should one happen. Cold rolled sheet tends to be softer and bends easily by hand. If you don’t have hot roll, hard cartridge brass from the hobby shop will work too.

I “cheated” on the frames and other flat parts by having them cut out by abrasive water jet. I did the drawing in .DXF format and took a travel drive to a CNC shop in Las Vegas. They knocked them out right away and at a reasonable price.

Cutting these out by hand, however, is not difficult. The key is doing them in pairs. Clamp two frame blanks together with a 0 x 80 screw and nut in each corner. Drill all holes and shape both pieces at the same time. Cut out portions in the frame are done by “chain drilling”, knocking out the center and finishing with files.

Here’s the frame drawing.
Frame Drawing 

Drill and cut out the buffers the same way as the frames. Here’s the drawing:
Buffer Drawing 

If you want to have these water jet cut, contact me off the board and I will email the files to you.

Assemble the frames by using 1/4" x 1/4" x 0.028” brass angle gussets and 0 x 80 machine screws. Set up the lathe as a horizontal saw to cut exact 1-1/4” lengths of brass angle. Chuck a .032” kerf cut off saw in the lathe. Use the tool post holder to secure the angle stock. Use a small stop block against the chuck jaw to set the angle stock. Here’s what that set-up looks like.










Remove the stop piece and advance the cross slide thru the saw. Perfect cut-offs every time. It’s a quick and easy set-up.










Drill the brass angle stock with #50 to match the frames and buffers. The frame is ready to assemble.










I bolted the angle gussets to the buffers first. The nuts are “small pattern nuts” from McMaster-Carr. They are 1/8” across the flats and look a lot better then standard nuts.










Assemble the frame on a flat surface. The inside with between the frames should come out to 2.250” or fairly close. The key thing for now is to get the frame flat and square.










Turn four axle bearings from brass. The process is just like turning the wheels. Turn a shoulder, just “TT” under 0.3125” to fit in the frames. . Drill the axles hole with #12 drill, which is 0.189”. That will give a good, smooth running fit with getting too sloppy. Use the parting tool to part the bearing off the bar stock.










Here’s the drawing for the axle bearing.
Axle Bearing Drawing 

There are several alloys of brass. The brass to use for the axle bearing is Alloy 360, or “free machining brass”. Brass 360 is excellent material, it is the 12L14 for brass. It has excellent machining qualities, turning, drilling, tapping, everything. The brass available in the hobby shops is a different alloy. It is Alloy 260, or “half hard brass” or “cartridge brass”. Brass 260 is miserable to machine. It sticks and galls the tool. It is very difficult to drill and impossible to tap. Except for sheet work like frames and cabs, stay away from it.

Next, turn a spreader for the lower center of the frame. The spreader is 3/16” diameter brass, 2.250” long. Drill and tap for 0 x 80.

The axle bearings go into the frame with soft solder. If you use hot rolled steel, the frames need a bath in acid to remove the black scale. A few seconds in ordinary swimming pool acid will clean scale and rust off steel and leave a clean surface. Flux the bearings and place in the frame. Insert a length of stainless steel rod thru the bearing to align them.










Cut off a very small piece of solder and place it on the inside flange. Heat the outside of the frame with just a whisper flame from the torch. Make sure the bearing flange is up against the flame. It takes very little solder and heat to get these in. After it cools, the alignment rod will spin freely.

Today’s solders are fairly good, but the fluxes are worthless. The water-soluble flux on the market today is terrible, completely useless. Soft soldering is best done with old-fashioned 50/50 (50% tin, 50% lead) solid wire solder and petroleum based flux. You are not going to find 50/50 at Lowe’s or Home Depot. Get it from a real plumbing outfit or order it. Lowe’s has a decent petroleum based paste flux. It’s messy to clean up, but does the job.

Temporarily install the wheel sets and give it a test roll.










Smooth as silk.

Next time we will get on the siderods, paint everything and wrap up the rolling chassis.


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## livesteam53 (Jan 4, 2008)

Bob, 
Looking like you know what your doing. It will be a nice locomotive. 
See you next month at Clark's 
Thanks for posting.


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## xo18thfa (Jan 2, 2008)

Hi Mark. Was good to see you at Clark's




Today we will get on the siderods, footplate, couplers and finish up the rolling chassis.

Disassemble the wheels and axles from the frame. Put the axles back in and use the calipers to get an accurate measurement between the axles. Left and right sides.










Using the actual measurements from the job, cut out the siderods and drill for bearings. The measurement on the siderods is probably the most critical on the engine. If the siderods don’t match the actual bearing locations on the frame, the engine will not roll smoothly. Make the siderods from the same material as the frame and the bearings from brass.










Here’s the drawings

Siderods and Bearings 

Check the measurement of the siderods. Insert the siderod bearings and some lengths of 1/8” rod.










Go in with the caliper and take a measurement. Do each side. 










If the siderods are within 0.005” or 0.006” or so of the axle bearings, you are in good shape. Go ahead and soft solder the siderod bearings to the siderods. 

If the siderods are too far off, correct them by turning an eccentric bearing. Chuck a length of bearing stock in the three-jaw chuck with a paper shim under one of the jaws.










Drill the bearing stock with #30 drill. Remove the paper shim and finish turning the bearing as you did before. The result is a bearing with an offset hole to the edge of the bearing.










The bearing in the above photo is greatly exaggerated, but it gives the idea of what to do. Insert the eccentric bearing in the siderod. Rotate the bearing and measure until you get the correct distance. Put a witness mark on the bearing and siderod. Soft solder the bearing to the siderod aligned with the witness mark. 

Now fabricate the couplers. A Ruby style coupler is on the rear.










Fabricate a decorative coupler for the front










Cut some 3/8” lengths of 1/4" brass angle and bolt them to the inside, back half of the frame. Use 0 x 80 machine screws. These are mounting brackets for the footplate.










The footplate is a 4” wide, 3-1/2” wide section of 1/32” thick sheet, either steel or brass. Drill and attach with 0 x 80 machine screws.










Once the rolling chassis is done, you will not want take it apart ever again. So, at this point, mask the rolling chassis parts for paint. Carefully mask off all bearing surfaces. Mask bearing holes with bits of cotton, tightly packed in. 










I used flat black for all the rolling chassis parts. Prime and finish paint according to the directions. These new spray paints call for all coats applied within one hour or after 48 hours. If you don’t follow that, the finish will crack and be a mess.

When everything is completely dry, assemble the rolling chassis and quartering the siderods. First assemble the wheels and axles back into the frame. Don’t forget the front drive sprocket. Check that the chassis rolls smoothly.

Quartering the wheels is not difficult. Since “Titus” is a simple 4-coupler, no quartering jigs are necessary. Install both cranks on one of the axles. Set them as close to 90 degrees apart as you can. The angle does not have to be exactly 90 degrees, but both axles have to be the same angle. Install the third crank on the other axle and loosely fit the fourth. Set the chassis on a test track or table top. Install both siderods. Adjust the fourth crank so everything appears as quartered as possible by eye. Roll the chassis slightly. The cranks will align themselves to quartered. Tighten the fourth crank.

There will probably be some little binds, but the chassis should turn over almost completely. If it does not, check the fourth crank and readjust if needed. Then check the binding buy looking at the siderods bearings, you will see the bind. Use a fine round file to relieve the siderod bearings. Just polish a little at a time until the chassis rolls smoothly. 

Rolling chassis is all done.










Next time we will start on the engine.


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## BigRedOne (Dec 13, 2012)

Wow! Coming along nicely.


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## HMeinhold (Jan 2, 2008)

Bob,

another nice little critter! Thanks for this new tutorial. One comment about soft soldering: I use Ruby fluid http://rubyfluidflux.com/
which works really well and does not leave residues.


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## xo18thfa (Jan 2, 2008)

Thanks for the Ruby fluid tip Henner. I'll get some. And thanks again for your tip on Citric Acid. 

I am still trying to figure out which way to go with the engine for Titus, just can't decide. So until that is done, we will get on the boiler first. The Titus boiler is a simple "pot" type, partially enclosed in a firebox and externally fired. The barrel diameter is 2 inches and length of 4 inches. A row of seven copper "porcupines" are along the bottom of the boiler barrel help heat transfer to the water. There are 5 bushings total. Water fill and steam out are "thru" bushings. Three are blind for mounting the barrel to the firebox and for the (dummy) chimney. The endplates are flat and soldered to the end of the barrel.


Here's the boiler plan.


Titus Boiler Drawing


A temporary pressure gauge on Nina and Chip reveal their operating pressures are about 6 PSI. So we will use 6 PSI as a planning figure for Titus.


The Australian Miniature Boiler Safety Committee (AMBSC) publishes a recommended practice pamphlet for miniature boilers. According to Part 3 of their practice, the Titus boiler is considered "low pressure". Low pressure boilers meet the following criteria:


- Maximum working pressure of 29 PSI
- Maximum diameter of 52mm
- Made of copper or brass, copper preferred
- May be soft soldered, silver brazing preferred


The AMBSC does not go into much detail on low pressure construction criteria. The practice has additional requirements for medium pressure boilers (up to 75 PSI) that we will use for guidance on the Titus boiler. 

The boiler barrel for Titus is 2.000" diameter, thin wall tube. The wall thickness is 0.032". This is a somewhat special pipe I ordered from McMaster-Carr (part # 8967K161). Regular 2" copper plumbing pipe would work fine too. Cut and square the pipe to 4" length. The endplates are flat. Cut the endplates from 1/16" thick copper sheet to a diameter of 2.125". The porcupines are 1-1/2" lengths of 1/8" diameter copper rod, 7 are needed.

The bushings are either bronze or brass. Bronze is most widely used and is recommended. The AMBSC practice allows for brass bushings. Machining the bushings is straight forward turning and tapping. Here is the drawing for the bushings.


Boiler Bushings


Here are all the boiler parts all cut out and ready to solder.










The porcupines go inside the boiler for most of their length. Only about 1/4" sticks out of the barrel.










Time to solder the boiler together. Silver soldering requires a torch and burner intended for the task. This is the torch I use. It is a Sievert brand propane-air burner that uses a regular bar-b-que propane tank. Sievert sells its burner tips separately. The #2943 burner is the best all-around for our work.










The silver solder alloy is available under several trade names. "Easy-Flo", Silvaloy", "Safety Silv" to name a few. The solder to use is 45% silver, 15% copper, 16% zinc and 24% cadmium and goes by the alloy number BAg-1. It is available from McMaster-Carr or most welding or jewelry making suppliers. Get the flux that matches BAg-1, Superior 601 is the stuff. After silver soldering, the remaining flux is removed chemically with citric acid. Sulfuric acid (battery acid) is also used to clean off flux, but it's very dangerous. Don't use it, use citric acid instead. Citric acid comes in powder form. Just mix it with water until no more dissolves. I heard citric acid is sold in health food stores. I got it from McMaster-Carr. So here's the materials










WARNING!!!!!!!!!! Cadmium is poisonous. Use only in well ventilated areas.


Silver soldering is kind of an art. It's hard to explain, just have to do it. Kozo Hiraoka has excellent tutorials in his books. Read up on it, then practice. It's best to solder big parts together first, then add the little parts. Solder the ends on first, one at a time. Then do the top bushings and finally the bottom. Four heats all together. Here is the barrel ready for the first heat.










Here's the top bushings after finishing with the torch. The flux keeps the copper bright and shiny. The unfluxed areas turn black. A dip in the citric acid bath cleans every off. Brush with a brass wire brush and the boiler will look like a brand new penny.










After soldering the boiler, hydro test it for leaks. Standard practice is to hydro test to two times the working pressure. This boiler will run at about 6 PSI, so test to 15 PSI. Attach a large pressure gauge to one bushing. Fill the boiler completely full of cold water and plug the remaining bushing.

There are two ways to hydro test a boiler. One way is with a water pump. Most common method. The other way is to warm up the boiler with a candle. The candle method works fine and is the method I used. The boiler has to be completely full of water, no air gaps at all. Apply the candle. It will take a while to build pressure, but it will get there. Here's the boiler ready for test.










And at 15 PSI.










Most of the time a leak is obvious right away. Water sprays out and pressure won't build. Stop the test and re-solder the leak. This boiler had a very unusual leak. A micro pinhole leak that did not pop open until it was at 10 PSI. Got the leak fixed, re-tested and ready to install.

Next time we will install the boiler on the chassis.


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## John Allman (Jan 2, 2008)

Bob - I have really enjoyed this. You make it seem like I am right next to you. Thank you for taking the time to do so. 
John


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## Joe Johnson (Jan 2, 2008)

Thanks Bob!


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## xo18thfa (Jan 2, 2008)

Joe, John: Thanks for the kind words.

I want to extend comment on the test procedure. There are only two ways to satisfactorily test a boiler. One is the pump method and the other is with a candle. Compressed air is not a good method, stay away from it. The pump method is most common and is the best method. The candle method has been around a long time, but using a pump is the way to go.


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## HMeinhold (Jan 2, 2008)

Bob,

If you do a lot of (boiler) silver soldering, consider buying a air acetylene outfit (not oxy-acetylene!). Our last boilers (some repairs and Bill Allens Uintah/Quadruplex/Heisler) were all built using the propane torch for heating up and the air acetylene torch for local heat. The nice thing about this combination is that the air acetylene is not as aggressive as the oxy-acetylene (burning of holes) but locally hot enough to melt the solder nicely without affecting the rest of the boiler. 
I am looking forward to more posts about this charming little critter.
Regards


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## xo18thfa (Jan 2, 2008)

Hi Henner: I might consider that. My wife is pretty good with a torch. She could handle the preheat work.

vr Bob


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## xo18thfa (Jan 2, 2008)

Only thing left to do on the boiler weldment is paint and some decorative brass bands. Here it is:












The brass bands are 0.014 x .125 strip from the hobby shop. Cut a 5' length and bend small loops on each end with a needle nose pliers. Polish to high shine, bend around the boiler barrel and secure with steel lacing wire. Looks nice.












Do the firebox next. It is a straight forward plate work job made from 4 sheets of 20 gauge or 22 gauge steel or brass secured with two brass angle gussets in each corner. Steel is probably a better material since it takes paint better. Here is the firebox assembled.












And here are the drawings


Firebox Back 
Firebox front 

Firebox Sides 

The firebox eventually gets attached to the frame with four brass angle tabs. Drill the angle tabs to match the firebox and frame. Here's the angle tabs on the firebox. 












Don't mount the firebox to the frame quite yet. It will be easier to install the burner assembly with the firebox off the frame.


Next up is the bunker. The only functional purpose of the bunker is to hide the fuel tank and fuel valve. Perhaps put a decorative load in the bunker later. Bend the bunker shell from 20 gauge or 22 gauge steel or brass. Here's an ortho projection drawing


Bunker drawing


As an alternative to bending, make the bunker in three sheets and use angle gussets as with the fire box.


Cut a profile on the edge of the bunker sides to remove sharp corners.












Soft solder a continuous length of 18 gauge copper wire around the edge of the bunker top. Form the wire to go up the side and curve around the profile to the back of the bunker. Use a very small torch and small bits of solder to tack the wire in place.












Bend the wire around the back of the bunker and continue to solder.












Bend the wire to the front, around the profile and back down. Snip off excess wire. Go back over the entire job with a torch and extra flux to get the solder flowed out smoothly. The process is not hard to do. Forceps come in handy to hold the wire in place as the solder cools. 


Bend some grabs from 1/16" brass rod. Drill the bunker sides and solder the grabs in place. Add some short lengths of 1/4" brass angle to attach the bunker to the footplate.












Don't install the bunker yet either. We'll do the fuel tank and plumbing first.


Clean up the platework and paint is your favorite color. Set everything on and have a look.












Looking good. Next time we'll get on the burner.


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## snowshoe (Jan 2, 2008)

That is really neat. Great work so far.


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## xo18thfa (Jan 2, 2008)

This installment is pretty dull. In fact you can skip all this and buy the parts from PM Research or another fitting suppliers and save the headaches. In fact, the next couple installments are the fuel system. If you can find a burner and tank from a Ruby or similar engine, then you can use it and take a break for a while. 


Today we are going to do nuts and cone union joints in preparation for steam and gas line plumbing. Five nuts are required. Two for the steam line, two for the gas line and one for a packing gland on the gas valve. Four cones are needed for the steam and gas lines. Here is the drawing for the nuts and cones.


Nut and Cone Drawing


First up are the nuts. All of the plumbing threads on Titus are 1/4" x 40 TPI. So that's the only odd tap and die you will need. Three taps are usually required to make plumbing nuts since the tapped hole is blind. The first tap is a taper tap, then followed by a plug tap and finally a bottoming tap. Three tap sets are very expensive, but there is a way around that. This method uses two pieces silver soldered together. The nut ends up much shorter then usual since it will have thread all the way to the bottom. Chuck some 5/16" hex brass in the 3-jaw. Drill deeply with either #2 or 7/32".












Tap fully 3/8" deep to ensure a full depth thread.












Lightly chamfer the end of the hex rod with a file. Part off a little over 5/32" length of the tapped hex rod.












The next step involves a threaded stub mandrel. To make the mandrel requires a threading die holder for the lathe. The die holder serves the same function as the tap handle. It holds the die in axis on the lathe to accurately cut male threads. Die holders are commercially available or make your own. I made this die holder years ago from a one inch hex head bolt.












Dies we use come in two diameters, 1" and 13/16". You will need an insert for smaller dies or two separate die holders. Here's the die holder in the lathe tailstock ready to use. The die is 1/4" x 40, 13/16" dia.












To make the threaded stub mandrel, chuck some 3/8" or 5/16" hex brass rod and turn down to 1/4" diameter for about 3/8" length. Use the die holder to chase threads on the turn stub.













***********It was at this point I figured out how to use this new camera to take close up photos. Hope these are better.***********



Parting off the hex stock will leave a burr which is difficult to remove. Chuck the stub mandrel in the lathe and screw on the threaded hex nut. Cinch it up with a lock nut matching the mandrel. Face the nut to its final length of 5/32" to remove the part off burr.












Next cut some flat brass stock well over sized of the nut. This will be the backer piece of the nut.












Silver solder the nut to the backer. Put the nut assembly on the mandrel and begin finish turning.












Drill the nut assembly first. Titus needs five nuts total. Drill three with #30 for a 1/8" tube/rod and the other two with #40 for 3/32" tube.












Turn the nut backer to 0.360" diameter which is the overall width of 5/16" hex.












Face the nut backer to 1/32" thickness. That finishes the nut.












Now for the cone. The cone eventually get silver soldered to the tubing, so the are much shorter the a regular compression cone. Set the compound rest on the lathe to 45 degrees and insert a wide parting tool bit in the tool holder. With the parting tool, turn some 1/4 brass stock down to 0.213" diameter.












Plunge the parting tool in a 45 degrees and advance the carriage to form the cone. The root of the cone is 1/8" diameter.












Drill the cone according to the drawing. Use the parting toll to part the finished cone off the stock.












Nuts and cones are done. 












I know this a prolix installment. Making nuts and cones is a tedious job at best. But, of all the tasks in fabricating live steamers, this is a good technique to learn. It's the plumbing that holds the project back. Doing your own plumbing means you can hide that butt-ugly Ruby fuel tank and clean up the cab mess. There are a lot more options in kitbashing a steamer if you can do the plumbing.


Next time we will do the fuel tank. That won't be so bad.


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## cocobear1313 (Apr 27, 2012)

That was really useful! Thanks. A much better way than what I was doing. 

Dave Johnson


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## xo18thfa (Jan 2, 2008)

Thanks Dave. Hope the nuts and cones work out for you.

Fabrication of the fuel tank goes almost the same as the boiler. Turning of bushings, silver soldering and testing the tanks are mostly the same. The only differences are the endplates go inside the barrel and the addition of 2 longitudinal stays. Here's the drawings for the fuel tank and bushings.


Fuel Tank Drawing

Fuels Tank Bushings


The fuel tank barrel is a 3" length of 1-1/4 "L" wall copper plumbing pipe. The bushings are turned from brass or bronze. Here are the parts.












Unlike the boiler, the endplates of the fuel tank go inside the barrel. Rough cut two disks of 1/16" thick copper plate. Drill a pair of #36 holes 5/8' apart and centered on the disk. Cut a 2" x 2" block of 3/4" thick hardwood, either oak or maple. Drill a pair of #36 holes top match the copper disks.












With some 4 x 40 machine screws, bolt the copper disks to the wood block and center the assembly in the 4 jaw chuck. Turn the disks to a close fit inside the fuel tank barrel.












Hard wood works great as a backer plate for turning disks. After turning the endplates to fit, open out the #36 holes to #30 for the longitudinal stays. The stays are 1/8" dia brass or copper rod 3" long.

Silver solder the tank together. Do the endplates with stays first, then the bushings. Just like the boiler.












The fuel tank is a pressure vessel, just like the boiler. It requires a pressure test. The fuel we use is a mixture of 70% butane and 30% propane. The pressure inside the fuel tank is a function of temperature. The higher the temperature, the higher the pressure. "The Engineering Toolbox" has a chart showing the temperature and pressures of various butane-propane mixes. According to the data a 70/30 mix at 110F reaches 93 PSI. Since 110F is about the hottest it gets here in Las Vegas, I'll test the fuel tank to twice that amount. 200 PSI is a good round figure.


Here is the chart from the "The Engineering Toolbox"


Butane/Propane Pressure Data


My little home made hand pump won't go to 200 PSI. So I will borrow the boiler test pump from our local 7.5" gauge live steam club.












This is a Wheeler Rex hydrostatic test pump capable of 1000 PSI. We put a 400 PSI gauge on it since our annual boiler re-tests only require about 185-200 PSI.

Here's the set up. 












The pump connects to a garden hose. Fill the fuel tank with water and purge air out of the pump hose. Our city water pressure on the hose bibs is 90 PSI. About 1/2 stroke on the pump and it's at 200 PSI.












No leaks. Fuel tank is ready for service. 


I put a pressure gauge on the fuel tank of my LBSC "Chingford Express" to see what pressures really are. 65 PSI is the highest I've seen. That would make with a 90F or so summer day. Usually it's around 45 PSI with the burner off, and about 25 PSI with the burner on. I think testing our fuel tanks to 200 PSI is sufficient. 


If you make a fuel tank and have no way to test it, send it to me and I will put it on the club's pump for you.


Next time we will do the gas control valve.


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## xo18thfa (Jan 2, 2008)

The gas valve for the fuel tank is something you could cannibalize off an old engine or purchase commercially. However, these are easy to make and you can knock one out in a couple hours time. This gas valve came around by trial and error. It works very well. I have this valve on "Nina", "Chip" and the "Chingford Express".


Here are the drawings.


Gas Valve Drawing


Fabricate the valve body first. Chuck 1/4" diameter brass rod in the 3 jaw and run a 1/4 x 40 die for 3/16" length.












Go to the drill press and drill a 5/32 hole thru the center of the round bar 7/16" from the end.












Cut off the valve body from the stock. Face to 7/8" length and run a die over the other end for 3/16" length. Next is the "T" nipple. Turn 1/4" diameter brass rod down to 5/32" for a length of 5/16". With the stock still in the 3 jaw, run a 1/4 x 40 die over it for a good 1/4" length.












Part off the "T" nipple and face the threaded end so the thread is 3/16 long. Spot drill with #30 to a depth of 1/16". Then drill with #57 an additional 1/16".












Here are the two pieces that make up the valve body












Silver solder the valve body together and clean it up in the citric acid bath.












To machine the valve body, make a little spigot chuck. Chuck a 1" or so length of 3/8" brass hex. Drill and tap for 1/4 x 40. Tap a good 1/4" depth. Screw the valve body into the spigot and cinch up a jam nut.












Drill #30 to a depth of 1/4". Drill #43 an additional 1/4". Tap with 4 x 40. Lastly, drill #57 the rest of the way thru. After running the tap, ensure chips are cleaned out before drilling the #57. 












Finish the valve body by drilling thru the "T" nipple with #57












The gas valve stem is made from 1/8" diameter stainless steel rod. Set the lathe compound rest to 5 degrees to turn a 10 degree included cone on the end of the rod. Turn the taper for a length of 1/8". The cone does not come to a point. The tip is flat and just slightly under 0.043" which matches the #57 drill in the valve body.












Next, turn the 1/8" rod down to 0.112" diameter for a length of 1/4". Run a 4 x 40 die over the turned down section.












Cut the stem to length and silver solder a knob on the end. The stem can be as long as you would like, but the 1/8" shanks needs to be a clear 3/8" long. Make two jam nuts in the same manner as the union nuts. Here are the parts ready to assemble.












The stem is packed using an o-ring and a union nut. Used one of the jam nuts against the packing to prevent it from coming loose with repeated use.


The o-ring packing is thin wall buna or viton with 1/8" or 3mm inside diameter. Time tested graphite yard will work for packing too. The packing is not exposed to much pressure from the gas. There is no pressure against it at all when the valve is off. 


Assemble the valve. While you are at it, make a few for future use.












Next time we will do the burner pot.


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## deWintonDave (Jan 5, 2008)

Excellent project Bob. I liked how you tested your boiler, I did similar by placing the whole job on the woodburner until the pressure came up to 86 psi - full pressure on my gauge, and it wasn't too hot to handle. 

I agree with your rationale on the gas tank test pressure. Again, I could only test to 86 PSI, and got some flak over it. But this equates to a butane gas temp 60 deg C, and the tank stays cold with gas draw off as it is remotely carried in a wagon.

Best wishes,
Dave.


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## xo18thfa (Jan 2, 2008)

Today we are going to start on the butane gas burner assembly. Here's a picture of the complete burner assembly, with part names, ready to install. 

//http://1stclass.mylargescale.com/xo18thfa/Titus/Burner%20Final.jpg

Next up is the gas jet. The gas jet is a 2 x 56 brass model hex bolt 1/8" long and a commercially available wrist watch bushing as the gas orifice. The bushings are the “KWM German Made” type available from the TimeSavers Company in Scottsdale, Arizona (www.timesavers.com). Use bushing size L-56 (part number 11356). The idea for the gas jet is to press a wrist watch bushing into the 2 x 56 brass model hex bolt and install in the jet body.

Here’s the dimensions of the wrist watch bushing.










To make a jet, start with a jig to hold the model hex bolt. Cut a 1 1/2" or so length of 1/4" brass rod and face both ends clean. Drill # 42 hole 1/16” deep. Then drill and tap 2 x 56 about 1/4" deep. Screw in 1/8” 2 x 56 model hex bolt. The #42 spot drill ensures the bolt rests flat on the head.










Chuck the assembly in the 3 jaw. Lightly center drill and then drill thru the brass bolt with #58 drill. Follow up with a clean sharp #56 drill. Number 56 drill provides a very nice press fit for the 1.2mm diameter watch bushing.










Finish the bolt drilling with a very small chamfer to break the sharp corner left by the drill. Just twist a countersink bit with your fingers.

Now chuck the hex bolt and fixture in the drill press. Place a watch bushing on the drill press table with the flat face down. Lower the drill chuck, aligning the watch bushing with the hole in the hex bolt. Use a needle or long pin to move the watch bushing around. When aligned, press the watch bushing home.










The little chamfer, it helps align the watch bushing and prevents getting hung up on the hole edge.

Fabricate jet bodies that will accept the 2 x 56 jet and connection to the fuel tank. Here's the drawing for the jet body.

http://1stclass.mylargescale.com/xo18thfa/Titus/Burner%20jet%20Body%20Drawing%202.jpg

The jet body is from 1/4" hex brass. Turn to 1/4" dia for a length of 3/16". Die this end with 1/4 x 40. Drill with #30 to 1/16" depth.










Make a female spigot to accept the 1/4 x 40 thread on the jet body. Turn, die, tap and drill according to the drawing.










The 0.209" dimension shown on the drawing is somewhat critical. This places the very tip of the jet centered on the air mixing holes. Here is the jet body and jet ready for the burner.










That's it for now. Next time we'll finish the burner assembly.


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## Captain Dan (Feb 7, 2008)

Completed Burner Assembly actual location of picture

http://1stclass.mylargescale.com/xo18thfa/Titus/Burner%20Final.jpg


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## bille1906 (May 2, 2009)

Bob
Beautiful work
For some reason, I have missed this build till now. like the way you used the 2-56 screw for the jet holder. 
I have had trouble with the #56 bit making the fit too tight so I have been using a 1.2 mm but I didn't chamfer the hole so I will try that next time.
I assume the plastic sprocket would have been ok for the wheels but the pinion sprocket was your concern and you decided to do both while you were at it ???


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## xo18thfa (Jan 2, 2008)

bille1906 said:


> Bob
> Beautiful work
> For some reason, I have missed this build till now. like the way you used the 2-56 screw for the jet holder.
> I have had trouble with the #56 bit making the fit too tight so I have been using a 1.2 mm but I didn't chamfer the hole so I will try that next time.
> I assume the plastic sprocket would have been ok for the wheels but the pinion sprocket was your concern and you decided to do both while you were at it ???


Hi Bill: You have to chamfer the 2 x 56 bolt a little bit or the bearing is a dickens to get it. A plastic pinion might work too. Don't think the engine unit will get too hot. 

See you in Sac. Bob


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## xo18thfa (Jan 2, 2008)

Made a lot of progress on Titus lately, but am way behind on the paperwork. Should have a couple more updates in the next week or so. Today we are going to finish the burner and install it in the fire box. There is no particular order in doing the parts, so just go from back to front.

The mixing tube is a straight turning and threading job. Here is the drawing










The front end of the mixing tube is rather long and may be over extended. Support the end of the mixing tube with a live center in the tailstock of the lathe.










And the mixing tube all done.










Next is the burner head. This burner head is a shortened version of a Ruby burner. It is a brass tube with a series of six slots. Here is the drawing










Start with a length of 3/8" diameter round brass rod. Drill a 5/16" hole 1-1/8 deep. Now machine the burner slots. It is possible to saw the slots by hand with a fine jeweler's saw, but it's more precise done on the lathe. To machine the slots, use a 0.020" thick, fine tooth slitting saw mounted on a mandrel. Here's my saw on a shop-made mandrel.










Clamp the brass tube stock in the quick change tool post on the lathe and the saw mandrel in the lathe chuck. Advance the stock into the saw blade to a depth of .156". Make six slots at .187" intervals.










Silver solder a cap on the end of the burner head and finish in the lathe.










The riser tube is 5/32" diameter brass hobby shop tube. Cut and square up a 5/8" length and silver solder to the burner head. It is a good idea to wrap a piece of insulating blanket or sheet metal around the end of the burner head. The insulation will protect the burner head during the second soldering step.










Now silver solder the burner head to the mixing tube. Again, use some insulation on the entire burner head.










The burner assembly is done and ready to install. There is a slight modification to the firebox. The plan calls for a 3/16" hole for the burner, enlarge it to 1/4". Install the burner and tighten the jam nuts.










The placement of the burner in the firebox looks counter intuitive. You would think the burner head should be parallel the boiler. It turns out that flame pattern fans out perpendicular to the burner head, so this placement is correct. The 0.15mm jet orifice is just right. The flame is a clean blue color and very quiet. You can open the gas valve all the way and not blow out the burner. That burner gets stinking hot and boils water in a hurry.

The burner system for Titus is a lot of fiddly work. It also involves a lot of trial and error. There are 4 failed attempts in the junk drawer. If you can get burner parts from a scrapped loco, you can save a lot of work. Another possibility is alcohol fuel. The original "Maguffin" is alcohol fired with a simple fuel tank between the frames and gravity feed to the wick pots. A birdfeeder drip system will work too. Maybe, in the future, I'll change out the gas for alcohol.

Next time we'll do a bunch of assembly and gas line plumbing.


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## xo18thfa (Jan 2, 2008)

Finally get to put some things together and make Titus look more like a real locomotive. First assemble the boiler to the firebox using some short lengths of 1/2" aluminum angle. Install the burner assembly into the firebox using the jam nuts to center the burner on the boiler.










Assemble the firebox to the frame using 0 x 80 machine screws.










Install the gas filler valve to the fuel tank. This filler valve comes from Roundhouse. They come with a small rubber O-ring which is pretty much worthless as a seal. Remove the ring and use teflon tape instead. Fabricate a special driver tool to install the filler valve. This tool is a spare metric nut driver with the sides ground down to fit the filler valve.










I installed the foot plate prematurely, and, of course, it was already painted. It had to come off in order to install the bunker and fuel tank. Drill a 3/8" hole centered and in front of the fuel tank. This hole is for the gas line to the burner. Drill and bolt down the fuel tank and bunker. Install the gas valve on the fuel tank with some teflon tape and a jam nut. Re-install the foot plate, bunker and fuel tank assembly.










Use a length of bailing wire to make a gas line pattern. Then make the gas line to match. Use 3/32" OD thin wall copper tube from the hobby shop.










Silver solder the fuel line cones to the fuel line.










Install the fuel line. Snug it up tight.










And to the burner underneath. 










Now test for gas leaks. Fill a squirt bottle with soapy water. Soapy water is a good leak detector. The best test method would be to fill the tank with air, but I did not have a way to do that. So, take the engine outdoors and put some butane fuel in the tank. Crack open the fuel valve and squirt every joint and packing with soapy water. If there is a leak, you will clearly see it. Bubbles form from even the smallest leak. Tighten up all the weepers and check it again. Make sure all the leaks are tightened. 

Put some water in the boiler. The boiler holds 175cc. Fill it to the top and withdraw about 40cc. Light the fire. She'll boil cold water in about 3 minutes.

Next time we will do a safety valve.


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## xo18thfa (Jan 2, 2008)

Titus does not really need a safety valve. Since it does not have a throttle or other steam shut off, the engine itself acts as a safety valve. Pressure in the boiler will lift the engine cylinder off the port face and relieve excess pressure. 

However, since safety valves are not difficult to make, it's a good policy to do one. Here are all the parts ready to assemble.










And here is the drawing










Start with the valve body. Chuck a length of 7/16" or 1/2" hex brass, turn down and run a 5/16 x 40 die for a length of 3/16".










Drill 5/32" thru and tap with 3/16 x 40 to a depth of 1/8"










Drill, tap 5/16 x 40 and face cleanly a length of brass bar stock. Any size will do. This is a spigot for the rest of the work on the valve body.










Tighten the valve body into the spigot.










Turn the upper portion of the valve body. Tap with 3/16 x 40 to 1/4" depth










Fabricate the valve bonnet from 3/16 square brass. Hex stock will work too. Use a split collet from 3/8" brass round to hold the square in the 3 jaw chuck. The rest of the bonnet is turning, die and drilling to the plan.










The seat screws into the bottom end of the valve body and provides a steam tight seal for the check ball. The seat is a straight forward job. Set the compound rest to 15 degrees to turn the edge for the check ball.










In most safety valves the ball seat and valve body are one part. The edge for the ball valve is cut with a specially made "D" cutter bit. I've never had much luck with "D" bits. They seem to chatter and leave a bad edge. So I make the parts separate and assemble. 

Here are the parts again. The spring is about 1/2" long and very light. In fact, this spring is from a Gauge 1 sized Kadee coupler. The spring must be rustless, so use stainless steel, brass or bronze. The check ball is stainless steel. They are extremely hard and perfectly spherical. 










Prior to assembly, drop the check ball into the valve body. Insert a 5/32" diameter rod and give it a tap with a hammer. This deforms the seat edge to accept the check ball. 










How hard do you tap it? I don't know. If you can suck on the end of the seat and the seal is a perfect vacuum, you got it. It might take a couple of seats for practice to get it right. 

Assemble the safety and set it for 9 PSI. Since the engine will run at about 6 PSI, the safety won't have to lift all the time. Set the safety with steam pressure rather then air. Steam and air are not the same. Add about 120 ml water to the Titus boiler, install a 30 PSI pressure gauge and light the burner. At first the safety will weep a little. You will know when it lifts, it will spray water. Adjust the bonnet until the safety lifts reliably at 9 PSI. It will reseat at 8 PSI. 

If the thread on the valve body and bonnet are loose, use a center punch to stake the thread on the bonnet. That will keep it tight.

I made four safety valves total, tested and set each to lift at 9 PSI. After, I measured the overall length of each valve. If the safety gets disturbed, reset the bonnet to the overall length to maintain the 9 PSI lift.










Next time we will do the chimney, steam dome and finish off the top of the boiler.


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## Joe Johnson (Jan 2, 2008)

Thanks Bob. Too old and slow to start machining on that level, but I'm learning a lot.


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## xo18thfa (Jan 2, 2008)

The chimney for Titus purely decorative. The chimney is a two-piece turning that screws into the center bushing on the boiler. There are no drawings for the chimney. This is left as an exercise to the student. The upper part of the chimney is a 3 inch length of 1/2" diameter hobby shop brass tube. Turn and silver solder end rings on both ends. 










The chimney base starts as a 3/4" length of 1 inch diameter aluminum. Center drill and tap with 1/4 x 20. Turn and finish a decorative profile.










To make the cope cut on the base to fit the boiler shell, fabricate a angle plate from angle iron. Fabriacate a method to attach the angle plate to the compound rest on the lathe.










Assemble the chimney base to the angle plate with a 1/4 x 20 machine screw.










Make up a fly cutter bar from a long heavy bolt or a length of rod. Center drill both ends of the fly cutter bar.










The set screw opposite the cutting tool help to set a precise cutting circle. Set the cutting tool to exactly 1 inch radius from the bar center. One inch radius matches the 2 inch diameter of the boiler.










Mount the angle plate assembly to the compound rest. Install the fly cutter bar between centers. Take several light passes and in no time the cope cut is done.










The last step on the chimney base is to make a recess cut to accommodate the bushing on the boiler. Make a little spigot with a 1/4 x 20 machine screw.










Screw the chimney base on the spigot and use a 1/2" end mill to cut the recess.










Here are the chimney parts. After painting, fish a short machine screw down the chimney to attach it to the boiler.










The steam dome is not really a dome. It's just a take off point from the boiler. It's a straight forward turning and soldering job. Here are the parts.










It's easier to make the raiser section by drilling the 3/16" nipple cross hole first.










Thread the end 1/4 x 40 to match the bushing in the boiler. Drill 5/32" almost to the nipple hole. Don't break thru quite yet. 










Turn the nipple with 1/4 x 40 thread. Drill #30 and part off.










Silver solder the nipple and raiser. Make a jam nut to hold the steam dome in place. Assemble to the boiler.










Looks very nice.

The steam motor for Titus is done and has 4 hours of running on air. Today Titus got assembled and is ready for it's first full up run. Hopefully do that this weekend. Just have to do all the write-ups.

Next time we will get started on the steam motor.


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## bille1906 (May 2, 2009)

Bob
Looks Great
I assume we will see it running in Sacramento ???


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## xo18thfa (Jan 2, 2008)

bille1906 said:


> Bob
> Looks Great
> I assume we will see it running in Sacramento ???


Hi Bill: Yes. First steam test is Tuesday.


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## xo18thfa (Jan 2, 2008)

At the time of this writing, Titus is done and ready to run at the big Sacramento Steamup next week. Still getting caught up with the paperwork however. Today starts the steam motor unit. Titus is powered by a single acting, single cylinder oscillating steam motor. The bore is .437" and the stroke is .714". First up is the flywheel and crankshaft assemblies.

The flywheel is from 1.5" diameter round bar stock. Any metal, except aluminum will do. Here is the drawing.

http://1stclass.mylargescale.com/xo18thfa/Titus/Titus%20Engine/Flywheel.jpg

Chuck a 3/4" length of 1.5" dia stock in the three jaw chuck. Turn the front face of the flywheel. Drill thru 5/32".










Reverse the flywheel and grip by the inner recess. In my case the jaws on the three jaw chuck are too wide to fit the recess. I switched to the four jaw chuck. Since the four chuck is independent, you will have to pick the center hole with a test indicator.










This is a test indicator. It's an essential tool for the lathe and mill. This one is accurate to 0.0001"










Grip the flywheel at an angle in the mill vice. Drill and tap for a 6 x 32 set screw. 










The crankshaft is very straight forward. The shaft is 5/32" diameter stainless, 2-3/8" long. The crank disk is a 9/32" thickness of 3/4" steel round. The wrist pin is 1/8" stainless, 11/16" long. The throw of the crank is .357". Here are the parts.










Once in a while round bar stock comes slightly oversize. If this is the case, press the shaft and wrist pin into the crank disk with a machinist vise. In most cases however, round bar stock is slightly loose. Use Loctite #680 to assemble the crankshaft. Clean the crank parts and assemble with Loctite. After a few minutes, clean off the excess Loctite with lacquer thinner. Do not let excess Loctite harden, or you will never get it off.

Here's the flywheel and crank ready to go.










Next time is the engine frame.


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## BigRedOne (Dec 13, 2012)

In a case like the crank disk, do you need to - I think the word is chamfer - the holes or ends of the rods to get the assembly to go together?

Very cool how you're making all the components, and including all the pictures and instructions. Thanks!


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## xo18thfa (Jan 2, 2008)

Yes, chamfer the holes and ends of the rods. They get burrs sometimes that interfere with assembly. Also chamfer the corners of the flywheel. Edges like that can reach out and cut you.

We are at the National Summer Steam Up in Sacramento right now. Titus is running like a champ


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## bille1906 (May 2, 2009)

Bob had four of them pulling 32 cars in Sacramento. Quite a sight !


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## xo18thfa (Jan 2, 2008)

Titus made its debut run at the National Summer Steam-up in Sacramento in July. It ran great. Titus warms up in about 6 minutes and can tow 10-12 freight cars for about 30 minutes. Here's a couple of videos.












The only problem was the lubricator. The displacement oil we use is too thick for such low pressures and temperatures. The steam oil gummed up the engine and it would not turn. We abandoned the lubricator and used a drop of light oil on the portface before lighting up. I might try a different oil in the lubricator, but most likely it will come off. 

Back to the engine build. The engine frame is a soft assembly of brass. Here are the drawings for the frame

http://1stclass.mylargescale.com/xo18thfa/Titus/Titus%20Engine/Engine%20Drawing%201.jpg

http://1stclass.mylargescale.com/xo18thfa/Titus/Titus%20Engine/Engine%20Drawing%202.jpg

The main bearing is a straight turning and die job.










The steam manifold is silver soldered together










The engine standard is next. Remove some excess material from the center portion. The two tapped holes at the bottom are for attachment to the base plate.










And he reverse side of the standard.










The portface of the standard requires lapping before assembly. Tape a section of wet/dry sandpaper to a flat surface. Oil the paper and gently work the portface until smooth. Use a "figure 8" motion. Lap the portface to at least 600 grit, 1200 or finer is better.










The remaining frame pieces are sawed and filed from 1/8" thick brass. Tap 2 x 56 holes in the gussets to attach to the base plate.










Here is the engine framed assembled and ready for solder.










Soft solder the frame together. Saw out the center portion of the main bearing to fit the crankshaft and chain pinion.










Here is the engine frame with crankshaft and chain pinion.










Last step on the engine frame is to locate and drill the steam and exhaust ports. It is rather difficult to layout and drill these accurately. It's best to use a drilling jig.










Use the crankshaft and cylinder pivot to secure the jig. Drill the first hole, rotate to the opposite side to drill the other.










Next time we will get on the cylinder.


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## bille1906 (May 2, 2009)

Bob
I enjoyed your presentation at the NSS and thank you for your detailed photos here of how to build an oscillating engine.


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