Part built Allchin 1.5 inch

[derek blakeParticipant @derekblake72550]

Just one last question, if you wanted to use the valve casting I have but reduce the steam cavity how would YOU go about it?

Thank you in advance

[JasonBModerator @jasonb]

You could silver solder a piece of similar metal into the cavity.

Probably even be OK to use something like JB Weld to build up the edge and then that is easy to trim back to size, should take the temperature OK.

Another option would be to file off the lower half and then make a new piece with a suitable hole in it and then silver solder that back onto the top half. I've made a few valves that way.

[derek blakeParticipant @derekblake72550]

Right ok I'm with you, the steam cavity itself has an angled curve within is that critical and must match drawing? sorry for all the questions but trying to learn.

[JasonBModerator @jasonb]

Does not have to be shaped

[Anonymous]

Posted by derek blake on 31/01/2019 09:33:57:

……the steam cavity itself has an angled curve within is that critical and must match drawing?

I wouldn't think so. The cavity only controls the exhaust, steam inlet is controlled by the outside edges of the valve. In theory you might want a small radius on the internal corners of the cavity to reduce turbulence. But in models where efficiency is unimportant it's not necessary.

Andrew

[derek blakeParticipant @derekblake72550]

interesting, thanks very much guys its great to be able to learnt about these things.

I find that a joy to understand what I'm doing.

[derek blakeParticipant @derekblake72550]

Good morning all, hope everyone safe in this snow.

Many thanks again for the help with the slide valve issue, exhaust hole now drilled from centre port to base of cylinder.

Side hole I’ve not drilled yet as I’d like to have boiler and chimney together first to make sure all lines up, so the next two or three main stages are the regulator port in the top and the boring of the cylinder.

Unfortunately even with all the will in the world I cannot do these operations on my lathe as there is just no way to clamp cylinder to it.

It’s just too small and to be honest if I go off line I’ve ruined hours of work, with thanks to all on here I’m half way through the build more than I ever thought I would be and I’m proud I’ve got this far.

However I am going to have to ship out for these two three operations, bore cylinder, mill regulator port area and drill connecting steam ways from bore to valve face.

I’m not expecting anyone to be able to talk about machine shops on the forum but if anyone has used someone and can recommend there work please could you PM me, my original quote was £740+VAT im hoping that I’ve reduced that slightly now but doing the work I’ve done.

I’d love to get this cylinder finished, and if that means I hand over for some precision finishing that’s fine by me as I never thought I’d get this far, it’s the confidence and help of this forum that I’ve got this far.

Many thanks

Derek

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[derek blakeParticipant @derekblake72550]

Thank you Bill, that’s very kind

[derek blakeParticipant @derekblake72550]

Couldn’t resist seeing how it may all look, just stuck trunk guide on with some double sided tape, fingers crossed everything will line up.

[derek blakeParticipant @derekblake72550]

Evening all

Little bit of work done tonight, thought I’d have a go at the Pickering governor gives me practice at least on the lathe.

[derek blakeParticipant @derekblake72550]

[derek blakeParticipant @derekblake72550]

Poppy trying to grab my head while uploading pictures.

[Jeff DaymanParticipant @jeffdayman43397]

Poppy made a lovely job of those machined parts Derek! Well done.

Never been able to teach any of our shop pets to sweep up, let alone turning and milling.

[derek blakeParticipant @derekblake72550]

Thanks Jeff

[derek blakeParticipant @derekblake72550]

Hi guys

Quick question, I'm about to buy some bolts or studding for the cylinder block.

does it need to be stainless steel bolts and studding or is just steel OK, stainless seems a lot harder to find.

Thank you in advance

[JasonBModerator @jasonb]

As they go through into the boiler you want bronze or stainless

[derek blakeParticipant @derekblake72550]

Thank Jason, how about the ones holding steam chest/exhaust pipe on etc?

Thank you

[JasonBModerator @jasonb]

They can be steel.

[derek blakeParticipant @derekblake72550]

Thanks Jas, I had a look at your fowler album today at work.

Lovely work, if I can end up being half as good as that in the years to come I would be very happy.

[Paul KempParticipant @paulkemp46892]

Posted by derek blake on 06/02/2019 16:14:37:

Hi guys

Quick question, I'm about to buy some bolts or studding for the cylinder block.

does it need to be stainless steel bolts and studding or is just steel OK, stainless seems a lot harder to find.

Thank you in advance

Derek,

Strictly speaking theory says avoid stainless steel for boiler studs as stainless unless a particular grade is vulnerable to crevice corrosion which will be exacabated by chlorine in tap water if that's what you run on. Certainly a full size boiler inspector would 'have a baby' seeing stainless studs in a full size boiler. Normal recommendation for those is EN3B.

However in practice for your boiler being copper and considering the size, stainless would probably be accepted by club inspectors and I doubt failure through crevice corrosion is very likely. Best choice though for your application I would say is bronze.

Paul.

[Clive Brown 1Participant @clivebrown1]

IIRC, the Hughes' construction notes recommends 1/8" dia. PB threaded 5BA. Brass nuts are silver soldered onto the threaded rod to form dummy studs which can then be treated as hex. head bolts whilst having the correct appearance.

I suppose M3 could be substituted for 5BA.

clive

[derek blakeParticipant @derekblake72550]

Hi All

Yes you are correct about Hughes book, I have to say I don't really like the thought of permanent studs incase one snapped or the thread stripped during assembly.

I think home made studs with stainless would work, I think the 2 inch burrell engine kit you can buy from steam traction world uses stainless bolts/studs into copper boiler.

Regards,

Derek

[JasonBModerator @jasonb]

If you do go for stainless then you can use hex stock to make bolts but do them with a dome on the top of the head to look like a protruding stud.

[derek blakeParticipant @derekblake72550]

good idea, thanks Jason

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