Author Topic: CONWAY 0-4-0 3 1/2" GAUGE LOCO  (Read 98327 times)

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #60 on: January 28, 2017, 08:18:26 PM »
Hi

Thanks Jo, I figured that would be the one. Just to be doubly sure I have emailed the supplier I use and asked them to verify the type of 26TPI thread on the safety valves they supply.

The valve rod guides need to be turned from some phospher bronze over 3/4" diameter. I don't have any that big but it seems an awful waste to turn something that size down to 5/16" so I decided to have a go at fabricating some. The flange part is turned from brass and drilled 5/16"



Part off 2 pieces a little over 1/8"



Turn a piece of steel to 9/16" long and drill through with a 1/2" drill. Cut 2 lengths of 5/16" phospher bronze 1" long. Flux the 2 parts, stand them on the steel tube which ensures the correct length and silver solder





They can now be held in a 5/16" collet in the lathe and turned to size.



Thats it for now. I need to buy a 3/16" reamer to finish them off

Cheers

Rich

Offline zeeprogrammer

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #61 on: January 28, 2017, 11:20:03 PM »
I hope to follow along!

I enjoy seeing loco builds (which I say is an engine build). That's different from a loco forum where it's not just about the engine.
So I certainly think it's appropriate here. Particularly from a long-time member (and friend).

I have to say I've thought about you several times as I go through my remodeling and new workshop. I remember when I first joined (and first started machining) and saw some of your posts of your shop with a view outside. I said that's for me!
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #62 on: January 30, 2017, 05:15:05 PM »
Hi

Thanks Carl

My supplier has confirmed the safety valve 26TPI is BSB

Cheers

Rich

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #63 on: February 04, 2017, 08:03:32 PM »
Hi

The 3/16" reamer turned up so the valve rod guides have been drilled and reamed



Most of today I have been drilling and machining the frames, pretty much just follow the plans. I don't know if its common with other plans but Martin Evans seems to take measurements from strange places. Instead of all coming from one datum point they come from both ends, top or bottom edges, from a point half way along the frame, from the centre of the horn block cut outs  :headscratch:  :noidea: I found I had to go to one place first, then move from there to another place then from there :shrug: Anyway I got most of it done with only one tiny error.





I used a series of drills then a 25mm blacksmith drill to open out the cut outs



Followed by a 6mm cutter to cut out.



I had to  move the sub table along the bed and reclamp to machine the rear end



We, Julian and I, are  off to our railway club tomorrow to speak to the boiler inspector. We need to know exactly whats required before we start to cut up the expensive copper  :help:

Cheers

Rich

Whoops the photos are in the wrong order  :old:

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #64 on: February 05, 2017, 03:32:31 PM »
Hi

We went to our club today, Julian and I, and spoke to one of the boiler inspectors. He's happy with the materials we have purchased and happy for us to build our boilers as per the plans.

The only deviation from the plans for me is to fit 2 safety valves in the boiler instead of the one specified as per the suggestion from SandyC. The inspector was happy with this change.



Cheers

Rich

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #65 on: February 09, 2017, 09:55:00 PM »
Hi

Slight change of plan. Julian and I went to the AGM of our loco club tonight and afterwards the boiler inspector had a word and said after some thought he would be happier if I stick to the published plans and have the one safety valve in the original position inside the cab area so its back to plan A.

Cheers

Rich

Offline zeeprogrammer

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #66 on: February 09, 2017, 11:15:51 PM »
Hi Rich,

What is wrong with two safety valves?
Or why stick to published plans?

Thanks
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Jasonb

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #67 on: February 10, 2017, 07:39:17 AM »
The only reason I can thiok of is that putting them lower down on the barrel could see boiling water comming out on a full boiler where as having them at the highest point acts a bit like a steam dome so you are less likely to get water comming out just steam.

The shape of the Conway boiler with the top of the wrapper above the top level of the barrel in turn means that the the firebox crown is nearer to the top of the barrel. Drawing shows only 7/8" of which you loose at least 1/8" due to teh depth of the safety valve bushes.

Now as the top of the crown should always be covered in water that gives very little space between a crown with say 1/4" of water min over it and the bottom of the safetys. As a safety blows it will tend to suck boiling water up with it unless there is a decent space.  Think of boiling a kettle, if it has too much water in it then that starts to bubble out of teh spout if you let it boil over. This is why you often see the safety placed on a dome or in the case of traction engines it is placed ontop of the cylinder.
« Last Edit: February 10, 2017, 08:35:29 AM by Jasonb »

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #68 on: February 10, 2017, 09:00:37 PM »
Hi Carl and Jason

I'm sure he said something about the highest point now you mention it. It makes sense I suppose. At the end of the day I have to go with what he wants.

Cheers

Rich

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #69 on: February 10, 2017, 09:18:54 PM »
Hi

Just been reading the plans, one of my favourite reads at the moment and spotted another error on the axle feed pump.



The thread on the pump body at the piston end is 5/8" x 26. OK so far.
Now look at the gland nut, 5/32" x 26  :thinking: :disagree: :headscratch: :facepalm: :facepalm2: :ShakeHead:
I don't think those 2 parts will fit together do you  ::)

Cheers

Rich

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #70 on: February 11, 2017, 07:32:15 PM »
Hi

I have been working on the frames today. First though the front and rear buffers are starting to show signs of rust even though I have kept them in zip seal bags so I have zinc plated them.





Back to the frames. the opening for the cylinders is at an angle so the jig has to be turned.



A bit of drilling



Then machine out



Finally the frames are brought down to size by maching away the waste from the top edge



A little bit of file work



Then a fine sand and de-grease and spray with grey primer



There are just 4 holes that I haven't drilled yet and they are for the outside motion plates. The plates are mounted at an angle, the same as the cylinder, so I will drill them to suit the job.

Cheers

Rich


Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #71 on: February 12, 2017, 03:16:52 PM »
Hi

Found another error, well actually an omission. Looking through my stock to see what can go onto the to do list i came up with the outside motion plate.



A clear image of where it fits is here on the drawing by JULIUS



Unfortunately the 6 holes where it bolts to the frame are not shown on the plans and have not been drilled in the frames while they were in the jig in the mill



Cheers

Rich

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #72 on: February 12, 2017, 06:24:27 PM »
Hi

A start on assembling the frames. A couple of blocks of wood helping to hold things together



Cheers

Rich

Offline zeeprogrammer

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #73 on: February 12, 2017, 07:18:42 PM »
Looks fantastic Rich.  :ThumbsUp:

What was the size of that drill bit you used to drill two holes before making the slot.  :o
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #74 on: February 12, 2017, 07:35:06 PM »
Hi Carl

The rear slot  I used a 25mm and the front slot I used a 22mm from a set of blacksmiths drills I have. The plans call for 7/8" and 1" but the slot size is not critical.

Cheers

Rich