# Decauville 2.75t



## Kovacjr (Jan 2, 2008)

For at least a year I have been designing a 2.75t version in 7/8ths, the smallest model they made. Being I had a set of RH Darjeeling cylinders I wanted to use those but with some difficulties. Of course the cylinders are larger so I had to stretch the front of the frame and raise it to clear the chest too. With that its a very short wheelbase and the front driver is smack up to the cylinder. Actually had to cut down the crank bolt to clear. Its a small step but a large one with live steam to get a operating chassis. The buffers are complete and I will move onto the deck plate and some other troubles I've come up to with the valve gear being wider than the buffers. Have a few thoughts so will see what looks the best. 

For the most part I used the Roundhouse Cylinders, expansion link and eccentric but made the rest of the rods as they are much smaller. Its built on my 18" wheels with a metal bushing for dual gauge should I want and also all new frames as its about 7" long. The boiler will be a huge 2.125" OD but 4" long

Fun part is building with real rivets.

A video of the chassis here 
https://www.facebook.com/jay.kovac.1/videos/10154178853958963/


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## RP3 (Jan 5, 2008)

Jay, can you put that video somewhere else so those of us who don't do Facebook can watch it?

Thanks,

Ross Schlabach


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## Kovacjr (Jan 2, 2008)

https://youtu.be/EZSMyHdQWdk


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## Kovacjr (Jan 2, 2008)

Some boiler progress today with my torch regulator here from warranty replacement. Its alot of boiler for only 4inch length. Internal throttle and dry pipe. One last bush to add them make some plugs and pressure test.


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## Kovacjr (Jan 2, 2008)

Spent part of the last day of 2016 doing the boiler mounts and boiler wrapper. Put a front smokebox ring to support the front of the wrapper and also mount the front plate. Cut out the front plate and finished off the door and latch. Its all non operational as the burner can be lit underneath or from the stack. Also removes with 2 screws.


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## Kovacjr (Jan 2, 2008)

Pressure tested to 120 and retested with the glass installed to 40 to check for leaks. Need to replace the rod in the glass with SS but all I had was tool steel in 1/16" or brass. Need to design and make a burner now.


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## Kovacjr (Jan 2, 2008)

Light progress today. Made the gas valve and lubricator. Need to design the burner and make that next. Then I can plumb and mount the gas valve. Gas tank will mount between the frames and be hidden. The gas valve is based on my fine spindles and is a really scale stand.


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## Chris Scott (Jan 2, 2008)

Jason;

What's the difference between Accucraft's Decauville Type 1 and your Decauville 2.75t ?

PS: 
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## Kovacjr (Jan 2, 2008)

Not sure Chris, I did add a Youtube link a couple posts later.

The difference on the 2 locos are not huge but mostly cosmetic. It is 1/4ton smaller in power but only a difference of a foot or so in length. Body design us similar but very different being the early 2.75t were outsourced by Decauville to Couilet. Like the larger one few exist today. One recently rebuilt in the UK and one runs in AU. 

Burner sorted. Its a shorter version of the RH drilled. Mike McCormack has been making them like this for a few years for Accucraft replacememts and are very good output. Very happy how this one came out except fpr that 3rd hole is off center. Hah


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## Kovacjr (Jan 2, 2008)

....


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## Chris Scott (Jan 2, 2008)

Kovacjr said:


> Not sure Chris, I did add a Youtube link a couple posts later.
> 
> The difference on the 2 locos are not huge but mostly cosmetic. It is 1/4ton smaller in power but only a difference of a foot or so in length. Body design us similar but very different being the early 2.75t were outsourced by Decauville to Couilet. Like the larger one few exist today. One recently rebuilt in the UK and one runs in AU.
> 
> Burner sorted. Its a shorter version of the RH drilled. Mike McCormack has been making them like this for a few years for Accucraft replacememts and are very good output. Very happy how this one came out except fpr that 3rd hole is off center. Hah


Thanks for the info.

What diameter are the holes? 

Are the RH burner holes the same diameter?
.


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## Kovacjr (Jan 2, 2008)

The holes at both the same. Drilled with a #0 center drill. .050" The few that have a larger looking hole are where the drill went into the chamfer on the point. Not actually a larger hole. Should of set the stop for the quill.


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## Chris Scott (Jan 2, 2008)

Kovacjr said:


> The holes at both the same. Drilled with a #0 center drill. .050" The few that have a larger looking hole are where the drill went into the chamfer on the point. Not actually a larger hole. Should of set the stop for the quill.


Conversion: 0.050" = 1.27mm


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## Kovacjr (Jan 2, 2008)

Got the gas tank fabricated, laid out and built. Had to drill all the clearance and mounting holes on the floor. All drilled and just about fit and needed minor filing. Very happy with the concealed look. Tomorrow need to make the jet holder. Then I can get the last pipe plumbed and mount the burner.


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## Kovacjr (Jan 2, 2008)

Chris Scott said:


> Conversion: 0.050" = 1.27mm


Curious why you would convert it to metric? Roundhouse hole is not metric?


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## Chris Scott (Jan 2, 2008)

Kovacjr said:


> Curious why you would convert it to metric? Roundhouse hole is not metric?


I don't know how to convert to Cubits. (or Plott’s Cubit ( http://venturebeat.com/2017/01/04/plotts-cubit-makes-it-easy-to-measure-spaces-for-creative-projects/ ) or The CUBIT Geometry and Mesh Generation Toolkit ( https://cubit.sandia.gov/ )

Metric is the language of STEM.

Metric makes it easier to calculate the Bernoulli effect, gas and air flow (hence consumption), air mixture, flame size, heat output and wind shear in the flue. 

Notwithstanding Roundhouse and the English proud expression of national identity or a stubborn refusal to engage with the neighbours (aka Europe), England officially converted to Metric in 2009 (the effects of Brexit tbd.)

Only 3 countries still use the English system; U.S., Liberia, and Myanmar.

Metric is the only way to compare RH to other poker burners.

Because I attended the University of Colorado in Boulder, Colorado in the 70's.


(Above not in any rational order. And obviously I have a very low tolerance for temptation.)


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## TonyW (Jul 5, 2009)

Ah yes. we do metric so well that my local lumber yard sells 2 x 4 by the metre, and a container of milk purchased today in a major grocery store is clearly labelled 6 pints (because that is what it holds) and 3.408 litres with equal emphasis.


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## Kovacjr (Jan 2, 2008)

Chris, currently RH is the only drilled burner. Spoke in depth to Bing about changing them but that had not progressed. Milton in the UK used to make replacement Accucraft drilled ones. Nonlonger available as he has closed up shop some years ago. My friend Mike has been offering them in recent years. One recent was for a Accuxraft H8 for Stapleton. Runs like a champ now! Maintains 60psi no problem. No mesh no tent just the burner. I will make one for some of my DRGW locos to get them to steam better. I still uave issues with one burner on my K28. Even with no superheater in the burner end and a new return flue arrangement.


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## Steve Ciambrone (Feb 25, 2014)

I guess if the British government has converted to metric the English modelers did not get the memo. It is interesting to see both English and Metric dimensions on drawings I see from England. Not criticizing just find it amusing at times.
In the USA it is interesting to see different trades use English dimensions in either decimal or fractional values.

Steve


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## Westport (Nov 28, 2009)

Kovacjr said:


> Chris, currently RH is the only drilled burner. Spoke in depth to Bing about changing them but that had not progressed. Milton in the UK used to make replacement Accucraft drilled ones. Nonlonger available as he has closed up shop some years ago. My friend Mike has been offering them in recent years. One recent was for a Accuxraft H8 for Stapleton. Runs like a champ now! Maintains 60psi no problem. No mesh no tent just the burner. I will make one for some of my DRGW locos to get them to steam better. I still uave issues with one burner on my K28. Even with no superheater in the burner end and a new return flue arrangement.


Jason, there is a UK supplier that takes your Accucraft burner sent to him and provides a Bullet poker with holes versus the toast rake style poker. It will then send the new burner back to you; or if you send them the engine (at great mailing expense from NA) they will fit it for an extra cost. The ad was in two UK magazines, 16 mil and Garden Rail that l received this last week. Cost about 35 pounds for the burner. I only saw the advertisement so not aware of how good it is.
website is www.barleypitworks.com.
Myron


.


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## Pete Thornton (Jan 2, 2008)

Kovacjr said:


> Chris, currently RH is the only drilled burner. . . .


Jason, how about those "Barley Pit Works Bullet Burners"currently advertised on the FB GR Trading Group?











Maybe you could get Matt to supply some for us in the US ?


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## mocrownsteam (Jan 7, 2008)

Pete,

Barley Pit Works has nothing on us Yanks. I have been doing the same service through the Train Department for about a year now. Let us know what you need. Turnaround is about 3 weeks after receipt of your old burner.

Mike McCormack
mocrownsteam
Hudson, Massachusetts


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## Chris Scott (Jan 2, 2008)

Kovacjr said:


> Chris, currently RH is the only drilled burner.


Regner poker burners have holes; long and short models.

My earlier reply was not addressing solely burners with holes.


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