# Chingford Express rebuild -- progress updates.



## xo18thfa (Jan 2, 2008)

“Chingford Express” is a Gauge 1 LBSC design that appeared in “Model Engineer” January 1944. The plan set came from M.A.P. and is still available from plan suppliers in the U.K. LBSC’s original is a 0-6-0 tank engine with a single, double acting, D valve cylinder between the frames. The motor has a 1/2" bore and 3/4" stroke. Drivers are 1-7/16” diameter. The boiler is a “Smithies” type. 

I built the Chingford Express in 2005 mostly from LBSC’s plans. Mine has two major deviations. First is the boiler, which is G1MRA “Project 0-6-0” style with a semi wetside firebox, single flue with cross tubes. My version has a tender that carries a bird feeder style alcohol tank. 

Chingford never got finished. It needs paint and some more detailing. But its been run very hard over the last seven years. It’s a great design. Very long run times. Reasonable slow speed performance. Good hauling capability even with the single cylinder. Here’s the Chingford as it went into the shop last week.



















Now it’s time for a rebuild. One nagging problem is the wheel quartering. I tried to fix the drivers with grub screws into the ends of the axles. It worked, but not very well. The wheels come out of quartering from time to time. Fixing the quartering is the main effort of the rebuild. Also change over from alcohol to gas firing. Convert to a tank engine as the original design, and a few other experiments.

LBSC specifies that the drivers get pressed onto the axles, with axles in the frames. I’ve done that before, it’s difficult. You get only one shot at it. If the wheel goes on wrong, you are in trouble. Instead I plan to “loctite” the drivers in a jig and transfer to the frame.

First up are new frames. They are cut from 16 gauge hot rolled plate. Chain drill, hacksaw and file to shape. Bolt the frames together to drill all the holes “in situ”. Here’s the new frames compare to the old ones.










The notches on the bottom edge are for drop in wheel bearings. 

Re-use/modify original parts as much as possible.










New wheel bearings are brass. Use a parting tool on the lathe to cut grooves to fit notches in the frames.










Secure the wheel bearings in the frame with a keeper strip bolted on the inside of the frames. 










The keepers prevent the wheelsets from falling out when you pick up the engine. They serve no other purpose. The bearings ride in the notches in the frames.

Cut some axle blanks, put the frames back together and see how axles turn. Everything is smooth and free.










Close up of the keepers in the frames










Next time we will get on the axles, crankshaft and quartering jig.


----------



## Nutz-n-Bolts (Aug 12, 2010)

Looks like another fun build or... rebuild. As usual, the workmanship is already looking first rate.


----------



## deWintonDave (Jan 5, 2008)

Posted By xo18thfa on 14 Jun 2012 08:08 PM 
Also change over from alcohol to gas firing. Convert to a tank engine as the original design, and a few other experiments.


Good work Bob! I'm a bit concerned that you are going over to the dark side - gas firing








Best wishes,
Dave.


----------



## Phippsburg Eric (Jan 10, 2008)

I have thought to use similar "keepers" for bearings but was concerned about getting in to insert and tighten the screws with the wheels in the way. How will you address this?


----------



## David Leech (Dec 9, 2008)

Eric, 
That is why they invented spoked wheels, so you can squeeze the screws between the spokes, isn't it? 
Mind you, you need to make sure that you place the keeper holes are where the spaces between the spokes are large enough for the screw heads to pass! 
All the best, 
David Leech, Delta, Canada


----------



## xo18thfa (Jan 2, 2008)

Thanks guys. I am hoping to get this rebuild done in time for the big steam up in Sacramento next month. Should make it.

Eric: The keepers screws are 0 x 80. To avoid the problem you mentioned I tapped the frames 0 x 80 and tightened the screws in from the outside. The round heads are less then the projection of the wheel bearing. Drivers should clear them easily. During final assembly, only have to deal with the nuts holding the keeper bars. Hopefully there is enough room inside to do that.







If not,









Dave: Not to worry. This engine will as complicated as alcohol, but less likely to burn up somebody's track. I still drool over your deWinton. "Someday project" for sure!!


----------



## xo18thfa (Jan 2, 2008)

The Chingford Express drivers had a 5/32” diameter hole for the axle. Since the quartering method is with loctite, I decided to bore out the axle holes to 7/32”. This increases the surface area for the loctite by 40%. Boring out the drivers will then require new axles and crank. 

Chuck the drivers on a little spigot held in the 4-jaw chuck. Use a good dial test indicator to perfectly center the axle. Carefully drill and ream to 7/32”










Start on a new crank axle by clamping some web stock directly to the mill table and drilling holes for the wrist pins and a fixing spacer.










Couple years ago I made a “DRO” for the mill/drill using 1” travel dial indicators. What a lifesaver. Very accurate and no more worries about backlash in the lead screws. 










Here are all the pieces










Fit together and get ready for silver soldering.










Silver solder it all together.










Saw out the center. Turn and file to clean it all up.










A lot of people condemn silver soldered cranks, claiming they warp. I’ve done several of these and never had that problem. Machine all the parts with the proper clearances for the solder, and heat the entire assembly. They come out just fine.

Now it’s time to quarter the wheels. Since loctite is the method, we will need a jig to hold the axle and drivers while the loctite sets.










This jig mimics the engine frame. The plates are set much closer together then the engine frame so wet loctite won’t foul the bearings. The two posts are stops for the crank pins.

Here is a wheel set in the jig with the crank pins hard against the stop.










And on the other side










“Quartering” means setting the crankpins 90 degrees to each other. The quarter can be off a degree or two, but they must be identical. If the wheel sets do not have identical quarter, they will not turn.

Loctite one driver to an axle and let it cure. That way you only have to concentrate on one joint while the wheel set is in the jig. All done.










I use Loctite #680. It does a good job. 680 takes only 2 or 3 minutes to grab. After it grabs, carefully clean off any wet loctite squeeze out with a Q-tip and lacquer thinner. Do not let the squeeze out harden or it will never come off. Also ensure the bearings and axles are cleaned off. Don’t glue the bearings to the axles.

Some times it’s better to be lucky then good. The wheel sets dropped right in, the old siderods went straight on and everything rolled super smooth.










Everything appears to clear between the frames. The existing motor should drop right in.










The main effort of this rebuild is done – getting the quartering right. Chingford could go back together right now, but there are still a few other things to do. Next time we will paint the chassis (ugh!) and get into the motor unit.


----------



## HMeinhold (Jan 2, 2008)

Bob,
nice work as usual







. Did you use drill rod for your crank axle? Some people claim this material gets brittle during silver soldering. Can you elaborate on that?
Regards


----------



## Larry Green (Jan 2, 2008)

Your quartering jig design is going to be the basis of one I have to make. I have a Regner chassis kit which is just about at that point now. 

Larry


----------



## Phippsburg Eric (Jan 10, 2008)

Drill rod, being a high carbon steel is "hardened" by heating it to red hot then quenching it by dunking it into water. when hard it is also brittle thus tools are "tempered" by heating them again to a lower temperature. 

If the axle is heated to red hot (which it is to silver solder it) and allowed to cool too quickly it could become hardened and thus be brittle. if it is allowed to cool "slowly" it should be fine. I am not sure how slowly it must cool to be fine, I think just air cooling it is enough.


----------



## Steve Shyvers (Jan 2, 2008)

Henner, 

I've annealed drill rod by heating it to red hot and then air cooling it. Then I turned it on the lathe and filed it to shape with metal files. I saw no evidence of brittleness. Could the reported brittleness have actually been a consequence of stresses induced by the silver soldering? I have no idea how or why that would occur, but will toss the idea out there. 

Steve


----------



## Grimm (Oct 5, 2009)

Very cool locomotive Bob! 

I'm thinking that the people who complain that it's too brittle dunked their cranks into water right after soldering it. Unless it was an air-hardening alloy? If you are really worried about it you can dunk the crank into ashes, vermiculite or even sand so it will cool off slowly and not harden. I suppose you could temper it in the oven, but it might be a bit more tricky. 

Jason


----------



## xo18thfa (Jan 2, 2008)

Thanks again guys. The new axles are cold rolled steel, free machining, 12L14 alloy. It is very easy to cut and silver solder. The old axles were 12L14 too and they wore fine. 12L14 has a slightly rough finish. A little work in the lathe with 400 grit paper and oil polishes them up. Drill rod usually comes with a ground finish, so very smooth and polished. I just have a lot of 12L14, so that’s what got used.

Larry: The quartering jig worked like a champ. It’s the way to go.

Before getting to the motor, the frame and drivers got painted.

Here’s the motor unit as it came out of the frame during tear down.










This motor is straight from LBSC’s plan. It’s a great little pack. All I did was disassemble, clean up and replace the piston O-ring and glands. After all these years, the piston ring still looked new and absolutely steam tight. The motor goes back in without significant change. The only thing I plan to do is re-work the lubricator. It does, however, need a new timing set-up.

There are two main tasks in timing the engine. First is setting the advance angle on the eccentric. Second is setting valve location when the piston is at top-dead-center. Mr K.N. Harris wrote a very fine book on model steam engines “Model Stationary and Marine Steam Engines”. Mr Harris completely explains how valves work in model engines. It’s a great book. You can download a PDF file of it from:

http://www.fastonline.org/CD3WD_40/JF/424/19-423.pdf

The advance angle on Chingford is 25 degrees. You can set the advance angle by eye, or do some math and modify the quartering jig with two stops. I used the quartering jig to set the eccentric










Setting the valve location on this engine is difficult. The valve is on the side of the motor block, all between the frames. You basically have to take one of the frame sides off and juggle everything as you set the valve. Really cumbersome – no pictures. Just did it and it got back together.



















Did a one-hour air test. Everything runs smooth and with good power.



Next time we will get started on burner parts.


----------



## xo18thfa (Jan 2, 2008)

Before getting started on the burner, it may be a good idea to fit a footplate and mock up the boiler. LBSC never really describes the footplate on any of his designs. I guess you are just supposed to know what they are. So this footplate started out as a slab of 20 gauge steel plate covering the whole deck.










Then cut out a large slot for the boiler firebox, mount the smoke box and solder on the side valance plates and steps.










The burner is a regular poker style burner that will sit low in the firebox, just above the rear axle. A few years ago I came across some half finished burner parts that I think are after market parts for a Ruby. So I am going to give them a try. 










The parts on the right are the jet body and flange for the flue. I won’t use them, just the burner tube.

The burner parts and gas plumbing come from the “Nina” build. That system works very well. The gas jet itself is a brass wristwatch bearing with a 0.20mm bore, pressed into a 2 x 56 brass hex head bolt. All of that is described in detail in the “Nina” build log at:

Nina Build 

Here is the burner, ready to mount on the firebox.










And installed in the rear firebox plate.










Finish the boiler mock up.










Next time is the fuel tank and gas line plumbing. Maybe putts on the cab too.


----------



## xo18thfa (Jan 2, 2008)

After long deliberation, some preliminary mock up and measurement I have changed my mind. The Chingford Express will have a fuel car rather then on-board fuel. There are several reasons for the change. The Chingford Express is a narrow engine to start with and my boiler is wider then LBSC called for. There is very little room on the sides. The fuel tanks would be in close proximity to the boiler and have very small capacity. There is no room in the coal bunker area, the boiler is longer and sits well back in the cab. My Chingford ran for 25 to 30 minutes on the huge alcohol tank in the tender. So to take advantage of the long run time, I decided to go with a fuel car.

The new butane tank is fairly big. 1-1/2” diameter copper pipe, 4-1/2” long. The endplates are 1/8” thick copper disks with three longitudinal stays. About 7 cubic inches capacity. The intake pipe to the gas valve runs well up into a fairly large dome. So there should be enough accumulation space for gas vapor. An experiment on this rig is the addition of a 100 PSI pressure gauge. Find out, once and for all, what’s going on inside the fuel tank.

Here are the parts.










And all soldered up ready for a car.










My original Chingford had a water column gauge with blow down. I never used it or even looked at it. So it’s gone. The bottom end is plugged; the top end is a new outlet for the pressure gauge.










The pressure gauge is a huge, ugly, plastic case thing from McMaster-Carr. They work great and are only $9.92 It still fits inside the cab, kind of.

The lubricator is also an experiment. It is a pressurized lubricator based on the G1MRA “Project 0-6-0” design. Steam from turret in the cab goes to the bottom of the lubricator tank, forcing oil out the top. As with the G1MRA, this lubricator will be in the cab with a feed line going forward to the valve crest. Here it is:










The boiler now sits a smidgen higher then before, so the cab needed a little off the top to fit better. The lubricator sits in the back right corner inside the bunker. 










The old BP tar wagons will look just right behind the Chingford.

Next time we will work on the cab, side tanks and bunker. Get the footplate off and drill for all that. Paint maybe (yuck).


----------



## Steve Shyvers (Jan 2, 2008)

Bob, 

I am surprised that you haven't figured out how to replace the pressure gauge's plastic housing with a brass housing! 

Steve


----------



## David Leech (Dec 9, 2008)

Bob, 
I know that you know this already, but in case others don't: 
"The lubricator is also an experiment. It is a pressurized lubricator based on the G1MRA “Project 0-6-0” design. Steam from turret in the cab goes to the bottom of the lubricator tank, forcing oil out the top. As with the G1MRA, this lubricator will be in the cab with a feed line going forward to the valve crest." 
The lubricator on the project is in the cab, a long way from the connection with the cylinders, so when first steaming up, it is relatively cold. 
So, to get the oil moving in the right direction, the lubricator is MOMENTARILY pressurised by a very quick 'open and close' of the extra valve on the turret. 
Do NOT leave it open, or all the oil will very quickly disappear. 
Once pressurised, the displacement lubricator will work quite fine. 
All the best, 
David Leech, Delta, Canada


----------



## steveciambrone (Jan 2, 2008)

What keeps the steam in the bottom of the lubricator separate from the oil? Is there an internal piston? What is the benefit? 

Steve


----------



## David Leech (Dec 9, 2008)

Steve, 
A displacement lubricator work on the wonderful principle, that oil floats on water. 
Steam enters the lubricator down a tube whenever the throttle is opened. 
The steam condenses into water and 'sinks' to the bottom of the lubricator, and the oils floats up. 
Since the oil has nowhere to go, it goes back down the tube that the steam in coming up, having been 'displaced'. (Don't ask me how - it just does!) 
It of course then finds it's way into the cylinders. 
The main 'trick' is to have the diameter of the tube just right, so only the correct amount of oil is able to pass down to the cylinders. 
All the best, 
David Leech, Delta, Canada


----------



## steveciambrone (Jan 2, 2008)

David, 
Thanks for your description of a displacement lubricator. I do not see how what is described as pressurizing the bottom of the lubricator, makes any difference, since I know the steam will condense quickly and no pressure will be maintained in the lubricator. If the pressure is quickly lost then it just works like any other displacement lubricator, if it is already full then it will start flowing oil on its own. 

Steve


----------



## David Leech (Dec 9, 2008)

Steve, 
The difference is the need to get the oil movement started due to the distance between the cylinders and the lubricator. 
Without adding the pressure to start the displacement, I would imagine that lubrication may or may not get going for quite a while. 
Another thing that need testing to find the answer! 
All the best, 
David Leech, Delta, Canada


----------



## xo18thfa (Jan 2, 2008)

Hi Steve: Bob = lazy. Brass case is one of those "roundtoit" things.

Displacement lubricators are functioning whenever the throttle is open. Oil is always flowing. The pressured lubricator is "oil on demand" Open the oil valve and pressure pushes the oil forward. The steam going to the lubricator will condense quickly. So going into the bottom of the oil tank puts the water where it will end up anyway and makes the lubricator more responsive (I would think). This is the first try for me.

IMO displacement lubricators blow most of the oil out in the first few turns of the wheels. There is a lot of oil coming out with the water as the cylinders warm up. After a little run, the exhaust feels dry. Another experiment someday is to use a fine needle valve in an attempt to control the flow.


----------



## David Leech (Dec 9, 2008)

Bob, 
If all the oil is coming out after the first few turns of the wheels, then I think that there is a design problem. 
As I suggested, the real problem is the diameter of the tube and or 'hole' in the lubricator. 
All my locos oil just right, the only exception was the Accucraft Royal Hudson which when new, had no restriction for the oil and it went as soon as the throttle was opened. 
Now with a .038" hole, it is just right. 
The cylinders due to there mass of metal will condense more steam than the lubricator which is thin metal, so you will get condensed WATER out, but there should not really be any additional oil. 
What diameter tubing, and/or restriction, do you have? 
All the best, 
David Leech, Delta, Canada


----------



## xo18thfa (Jan 2, 2008)

Hi David. I wish to revise and extend. It's commercially made engines that blow oil. Mine do fairly well. 0.040 is a little big. 0.031 work well.


----------



## David Leech (Dec 9, 2008)

Sorry, Bob, I'm not too sure that I agree with such a 'general' statement. 
ALL of my Aster locos use just the correct amount of oil, and have since new. 
As I said, my one Accucraft needed fixing. 
I have no other manufacturers, so can't comment on any others. 
Did you want to name names???? 
All the best, 
David Leech, Delta, Canada


----------



## xo18thfa (Jan 2, 2008)

Next step was getting all the platework done. I thought about making a new cab, but this one looks good. So, recycle it. The rest of the platework includes the sidetanks and bunker across the back. They are made up from 20 gauges steel and soft soldered together










Certainly a different look then before.



















Now for a fuel car. Try to make it look like a small tanker car, based on the BP Tar Wagon.










One of the BP Tar Wagons took a bad fall and was heavily damaged. It became the donor for the fuel car.



















Turned out nice.

The first operational fill of the fuel tank took place at 86F degrees in the shop. The fuel was 30% propane and 70% butane camping fuel. The pressure was 65 PSI, which is very consistent with the results I got from my pressure experiment last year.

Next was a burner test, a complete failure. The burner would not light at all. “Putzing” with it revealed it was getting way too much air. I plugged 3 of 4 air holes and it ran better, but not the way it should. I cut nine slots of 0.020” width in place of the holes in the original burner. Ran very well. Very nice, soft flame. Looked just like an alcohol flame. Settled on a gas jet of 0.30mm. The first burner now heavily modified, served as a pattern for a new burner.










After painting everything, time to reassemble. Boiler first.










The new, pressurized lubricator.










The cab will be crowded with piping.










Time for a steam test. Got it all ready and clamped it on the bench. Filled the lubricator about 3/4 full. Put on the Aster suction fan and gave it a light. All went well. Got up to 10 PSI, opened the blower and took the fan off. Got up to 40 PSI and opened the throttle. The boiler was way too full of water so it started out wet and jerky. Once the water level settled down Chingford ran great. It settled at 55 PSI and ran for about 20 minutes.

The fuel car gets rather cold and holds at about 35 PSI. Once up to pressure, the burner runs at a trickle

The new lubricator seems to work well. I gave it a good shot at the start and a little squirt every 3-4 minutes or so. There was a little oil left after the run, it used about half a tank. I think a good squirt at the start and another half way thru should be good. Just have to experiment.

Here’s the steam bench test:



Monday I’ll take it down to Clark Lord’s for a test spin. Knock on wood it will run fine. Then get the platework installed and finish up.


----------



## xo18thfa (Jan 2, 2008)

Well, today was the big day. The first field-test on the track. Sunday I did a few little fixes and ran another bench test. All went well. So, I put all the cab work on and went down to Clark’s for a test run.

All done and ready to go. Someday, it might get some jazzy pinstripe work.



















Chingford ran the best ever on the track. So smooth, powerful, nice speed. No annoying ticks, knocks, quirks it used to have.

It was 102F at 0800 this morning, so the fuel tank was at 80 PSI. Took about 5 minutes to reach 50 PSI on the boiler clock. Got in two good runs, about 20 minutes each before the heat drove us off.

Andy took some HD videos on his new whiz bang cell phone thingy.





So, we are off to the steam up in Sacramento next week. See you guys there.

Thanks for taking a look at the rebuild project and thanks for the kind words along the way.

Vr Bob


----------



## steveciambrone (Jan 2, 2008)

What was your fuel tank pressure after 5 or 10 minutes of running? 
Thanks 
Steve


----------



## xo18thfa (Jan 2, 2008)

A little over 40. It appears the gas pressure drops by half after running a while. Then it drops to 10 when there is about 2 minutes left.


----------

