A 3" Boiler build

[gimbal]

Hi Guys,

Thought you might be interested in some of my doings with regard to a boiler I am building for my recently completed steam engine (details at http://www.gimbal.com.au/post/Project-Mine-Engine-Completed.aspx).

Here is a pic of all the bits:

Here is the current progress - the bottom fire-tube plate and fire-tube have been soldered together and all the bushes have been soldered into the top fire-tube plate:

More details at www.gimbal.com.au

Cheers,

Pat

 

[steamer]

I really like the engine....that's the Coombs engine?..

The boiler work would seem excellent....nice solder job! :bow:

Welcome!

Dave

 

[GWRdriver]

Pat,
Very nice, neat, clean. Well done so far.

 

[cfellows]

Very nice work, Pat. A couple of questions if I might... What kind of solder did you use and how did you form the boiler ends?

Thx...
Chuck

 

[Orrin]

If here were here to see it, Elmer Verburg would be proud of you. You did a great job on the Mine Engine.

The boiler is looking great! Thank you for posting your pictures.

Did you do the design? If not, where did it come from?

Keep up the good work!

Best regards,

Orrin

 

[gimbal]

Very nice work, Pat. A couple of questions if I might... What kind of solder did you use and how did you form the boiler ends?

Thx...
Chuck

Hi Chuck - I used 45% silver solder and to form the plates I used a pair of aluminium formers pictured below.

I put much more detail on the forming process in a blog entry.

Cheers,

Pat

 

[gimbal]

If here were here to see it, Elmer Verburg would be proud of you. You did a great job on the Mine Engine.

The boiler is looking great! Thank you for posting your pictures.

Did you do the design? If not, where did it come from?

Keep up the good work!

Best regards,

Orrin

Hi Orrin,

The design is a variation on one I have used before, but is based on the numerous designs for single fire-tube vertical boilers that appear in Engineering in Miniature, Model Engineer and in K.N. Harris' book. I will post the drawings I have when I successfully finish it.

Cheers,

Pat

 

[NickG]

Nice boiler pat. It's nice to see not everyone has been put off making boilers with all the health and safety stuff and nice to see proper methods being employed.

Nick :bow:

 

[gimbal]

Here is some more progress - Here is a shot of the boiler sitting in the hearth after having the bottom tube plate soldered to the shell. The two lower bushings have been soldered in as well. The whole assembly was upside down for this operation and you can see how gravity assisted the distribution of extra silver solder. Better too much than not enough I suppose...

Here is the whole assembly with the top tub plate soldered on still at black heat.

Hydro testing next!

As always more detail at www.gimbal.com.au.

 

[zeeprogrammer]

It's great to see another boiler thread.
The more detail the better.
Looks great!

 

[gimbal]

Hi Guys,

Another update:

Last heat left a small problem - a gap between the shell and top plate. Annoying, but easily fixed.

With that fixed we are now ready for hydro testing. Here is the set up; a couple of hours at the lathe gives me a bunch of blanking plugs (where did I put the ones I used last time??). These and the judicious application of teflon tape gives me a good seal. I fill the boiler to the top and put the last plug in. Two strokes of the pump and I am up to over twice working pressure (30 psi).

Now to start on fittings....

 

[Deanofid]

This is looking really nice!

Dean

 

[JimN]

Realy nice boiler and the engine is super nice. I have looked at yours many times since I have started the same engine, just the base so far.

 

[gimbal]

The boiler I am making requires a safety valve to bleed excess pressure from the boiler during operation. I am using the same design as the last boiler I made. It consists of a body and a bridge, both made from bronze and a stainless steel pintle that uses a spring to hold a stainless ball against a seat in the body. A pair of stainless rods hold the bridge above the body.

A picture tells a thousand words so here is the finished article:

The body and bridge were both turned on the lathe and then shaped using the CNC mill. Here is a video of this process on the body.

[ame]http://www.youtube.com/watch?v=nvoiqc38bTk[/ame]

As always more at http://www.gimbal.com.au/post/Boiler-Fittings-Steam-Saftey-Valve.aspx.

 

[gimbal]

More progress...The Boiler Steam outlet.

The steam outlet is a fitting at the top of the boiler that provides a threaded attachment for the main steam line. It is made of brass; of which we start with a small block on the mill drilling the passages out.

After a bit of lathe work:

Eventually we end up with this:

More detail at http://www.gimbal.com.au/post/Boiler-Fittings-Steam-Outlet.aspx.

 

[NickG]

Pat, nice fittings there. Nice to see them being made from solid. most are silver soldered.

Nick

 

[gimbal]

Fitting Lock Nuts.

The lock nuts allow the boiler fittings to be positioned with more control. They are designed to lock against the boiler bushing. They are made out of 3/8" hex brass stock, and are a bit of an exercise in small scale production lathe work.

Here are the finished nuts:

More at http://www.gimbal.com.au/post/Boiler-Fittings-Lock-Nuts.aspx.

 

[doubletop]

Dunno how I missed this it looks a bit like the one I've done. I see the posts finished in Jan did it ever get finiished?

 

[gimbal]

Still working on it - my day job has been madness for some time, and I've been a bit side tracked. I will get back to this soon (otherwise I will go mad) I promise!

 

[doubletop]

We'll keep pressing you for progress to help you maintain your sanity