A small boiler

[firebird]

Hi Sandy

As it happens I only used the PTFE rolled up and under the washer and not wound around the threads so I am safe there. I have started to make the injector one way valve pretty much as per your drawing. I'm going to use a 3/16 stainless steel ball as I have some of those in stock. If I can't get it to seal well enough I can change it for nitrile later.

Cheers

Rich

 

[Circlip]

When you're trying to get a ball seated make a "Staking" punch, a piece of rod the same diameter as the bore of the valve body, 5/16" in your case, with a centring dimple to locate the ball and only give a LIGHT tap to seat the ball. Then take that ball and throw it away and use a new one and screw the bits together. Many people erroniously think that you need to smash seven shades of s**t out of them to seat them.If it doesn't seat first time you need to recut the seat and try again.
Regards Ian.

 

[firebird]

Hi

I have just finished the injector valve and had to do as you suggested Ian to get the ball to seal. I may look into getting some nitrile balls in stock, I can see that the softer material would seal easier.

I made it pretty much as per Sandy's drawing so I don't thnk any further drawings from me will be necassary.

The body being cross drilled.

The threaded boss trial fitted

Then silver soldered in place.

All the parts.

Assembled

Fitted into the boiler.

Theres a bit of video to follow later.

Cheers

Rich

 

[firebird]

Hi

Heres the video of testing the injector.



Cheers

Rich

 

[SandyC]

;D

Hi Rich,

Excellent job and I am pleased the drawing was of use to you.

Couple of things : -

1/ I hope you made allowance for the THICK copper washer when you made the top plug..... i.e added the thickness of the washer when cutting the threaded section to correct length to achieve the 1/32" (0.031") ball lift dimension.
If not,it could lift too far and possibly slip sideways and block, or partially block, the inlet when pumping.

The other down side of to much lift is: -
The pressure can get under the ball and hold it open rather than force it closed.

If this does pose a problem then drill the No 2 bore a little deeper(say 1/16" (0.0625") or 3/32" (0.0938")) and make a new plug with a short 1/8" dia extension below the threaded section to adjust the ball lift. The length of the extension will be the same as the extra depth +/- any lift adjustment.

2/ Not being picky but........ now you are a fully fledged member of the LIVE STEAM CLUB...... I feel, as I am sure others do, that it is always better to get used to using the correct terminology, if only to avoid confussion, so please don't take my comment as any sort of critiscism........

this device should always be referred to as 'A Non-Return Valve', 'A Clack Valve' or a 'One way Valve', NEVER as an Injector or Injector Valve....... I know what you mean, as do several others on the board, as we have been following your progress. However, if you were perhaps talking to someone outside the board community (who may not know the history) then it is almost certain they could/would get the wrong idea of what you were describing/referring to.

An INJECTOR is a very specific piece of kit/device, which may or may not require a non-return valve. (Most do)

It does the same job as your pump, however, it uses steam pressure to force water into the boiler.
MOST locomotives and/or Traction engines (model or otherwise) use these devices in addition to/or in conjunction with a manual handpump system. (The latter is generally a Backup system in such cases)

NO you don't want to get into INJECTORS at this stage.... VERY tricky devices ;D ;D ;D ;D ;D

I look forward to seing the boiler fitted into it's outer casing.

Keep up the good work.

Best Regards.

Sandy ;D ;D

 

[firebird]

Hi Sandy

Yes i did allow for the thickness of the copper washer, In fact I had to knock up a mandril to turn some washers of the correct size, I didn't bother to show that cos I didn't think it would be nec.

I agree things should be called by their proper name to save confusion, one way valve, one way valve, one way valve, one way valve, one way valve, I think i've got that one now.

Cheers

Rich

PS

The sound of steam is absolutely wonderful

 

[Circlip]

Clack valve, Clack valve, Clack valve, and don't be a spoilsport Sandy, I'm itching to see him getting into injectors :big:

 

[SandyC]

??? ??? ??? ???

But then he'd have to call them non-return valve, non-return valve, non-return valve, clack valve, clack valve, one way valve, one way valve injector valves. :-\ :-\ :-\ :-X :-X : :

So about these INJECTORS......... first you need.....................

;D ;D ;D ;D

Fun Here ain't it.

Sandy

 

[firebird]

Hi

I have started to make the casing for the boiler, from 3mm ally sheet. I printed out patterns and stuck them to the ally sheet with spray glue.

Cut them out on the band saw, heres the front and back. After squaring up the edges and sizing in the mill the hole was bored in the lathe and the opening for the burner cut out.

The two sides having air holes drilled after squaring up and sizing.

I am thinking of soldering the parts together. I bought some ally solder at a steam fair a couple of years ago but have never got round to trying it. A bit of practice on some of the scrap off cuts first I think. The guy who was demonstrating it made it look very easy ;D ;D We'll see :big: :big:

Cheers

Rich

 

[SandyC]

;D ;D ;D

Hi Rich,
So pleased you chose to continue posting your progress.

It looks good so far and I am pleased to see you have made plenty of provision for air entry along the lower sides.
Having said that, it might pay you to think about adding some means of closing off, or partially closing, some of them should you need to reduce the air flow in order to balance the flow of hot gasses.
perhaps some rotating baffle plates, for example, on every other hole.

How are you thinking of mounting/securing the pressure vessel?...presumably you are going to make use of the threaded sections on the stays in some way at one end..... if so, then how are you going to support/fix the other end? and what do you plan for top covers/heat/combustion gas exhaust (funnel) etc?

It will be interesting to see if the ALI solder you have actually works.... I bought some a few years back (ALUSOL if I recall correctly) and found it to be very unsatisfactory.... the problem I found was that no matter how well I cleaned/prepared the joint areas, the surfaces oxidised again (a matter of seconds on some grades of Ali) before I could get the job done; leading to a poor adhesion and solder flow. This even occurred if a coat of the special flux was applied immediately after cleaning each section. :'( :'(

This was, as I say, some years ago so perhaps the latest types have improved capability.
Now if I want Ali joined without screws (a very very rare requirement) I get it TIG welded.

Looking forward to the next instalment.

Best regards.

Sandy.

 

[firebird]

Hi Sandy

Sorry for the delay in answering. I intend to have the boiler stick out through the hole in the back plate by say 1/8 of an inch and fix it to another plate inside the boiler housing using the threaded part of the stays. The top cover will be made from the same ally plate. I will make some baffles to adjust/close off the holes in the sides although I haven't decided yet as to how I will do that. A chimney will be fitted to the front end of the casing. I have some boiler insulation material to line the inside. I hope to get some shop time this weekend.

Cheers

Rich

 

[Divided He ad]

Hi Rich,

I was just catching up on your thread.... Haven't read much of anything for a few weeks!! Well I spotted this....

the hole was bored in the lathe

And couldn't help but wonder how? I am sure it is obvious to most (face plate or something similar) But I just think it is such an odd shape it would be nice to know if you have any pic's of that process in piccy storage? Or a little description?
I would have been trying all sorts of stuff to get a hole in there.... Don't know if I would have used or been able to think of using my lathe.... Odd what you don't think you can do on your machines ehh?!

It is looking mighty fine by the way ;D I assume you are very proud of it so far.... I know I would be 8)


Ralph.

 

[firebird]

Hi Ralph

Yes I am quite pleased with the way things are going so far. Ive had a lot of help from the guys here but I'm getting there, slowly but surely. Unfortunately I have no photos of the hole being bored. I usually photograph everything, the camera is at my side always but for some reason I missed this bit. It's straightforward to do though. After marking out I drilled a small hole (1/8) in the centre of the hole to be bored. A sacrificial piece of MDF was fitted to the lathe face plate then the ally plate clamped onto the MDF using the tail stock centre in the 1/8 hole to centre the ally plate. The 1/8 hole was then drill out to 1/2 inch. Finally using a boring bar the hole was opened out to 3 inch and then bit by bit until the boiler would fit through the hole with a little clearance.

Cheers

Rich

 

[Bernd]

Very well done Rich. Another member learns how to use a face plate. To bad you didn't take any pictures. It sure would have been interesting to see that procedure. I've used it several times myself.

For doing a hole that large what you did works the best. I'm sure some are thinking "hole saw", but when that sucker grabs hold of the work............look out.

Can't wait to see that boiler finished.

Regards,
Bernd

 

[Divided He ad]

Thanks for the reply Rich.

The explanation is more than adequate. I have logged it for future reference and am quite happy with the idea ;D

Ain't it nice when you get a bit of help and encouragement from those who know?!


Ralph.

 

[max corrigan]

Rich i sat and went through your little boiler build over the course of two nights and found it brilliantly constructed and with the help from your pix and video narratives superb it was like reading a good book that you don't want to end! got try it myself one day! i felt i just had to add my two penn orth
keep up the good work it inspires us all
Regards Max...........

 

[firebird]

Hi Max

A pat on the back is always welcome. Thanks for the encouragement.

Cheers

Rich

 

[firebird]

Hi

I managed a few hours in the shop today so I got some more work done on the boiler housing. I have made the baffles which will open and close the air holes along the bottom. Bit of a b***s up here. The air holes I drilled out 3/8. There is supposed to be a 3/8 gap between each hole. I carefully worked it all out, used the DRO on the mill to drill them all out but sadly the gap between adjacent hole isn't 3/8 its more like 5/16.???? So I had to drill the holes in the baffle to 5/16. Its not a major problem I'm just annoyed with myself for getting a simple bit of working out wrong. Anyway on with job. 2 strips of 3mm ally 5/8 inch wide ( yes I know imperial and metric together) were cut and machined to size and left over long for now. Then the two pieces clamped together in the mill and drilled the 5/16 holes.

The back plate mounted in the mill having two slots cut to accept the baffle.

The othe end of the baffle will be supported by a machined ally saddle.

First mill the slot 5/8 wide and 3mm deep.

Then cut off two pieces in the bandsaw.

Trial fitting to make sure they slide freely.

The baffle in the open position.

And then closed.

I intend to ally weld all the boiler case together so I spent the last half hour having a practice go at it. Two pieces of 3mm ally were clamped together and placed in the brazing hearth. You can see in the photo the ally welding rod, an old screwdriver and a cigarette lighter. The process is straightforward enough. Heat the ally. Put the rod into flame and melt of a small piece of the rod. With the screwdriver scratch along the joint and work the weld in. For my first attempt it worked really well. The two pieces have ben welded to form a really strong joint.

Cheers

Rich

 

[Paolo]

Hi Rich
Please... where did you found that magic rod? I'm interested on welding ally..
Thanks
Paolo

 

[firebird]

Hi Paolo

Go over to the tips and tricks section and look at the topic 'ALLY WELDING' where you will find I have posted the spec sheet. The guy I bought it from was Sweidish I think. If you GOOGLE it I'm sure you could find a local supplier.

Cheers

Rich