Author Topic: CONWAY 0-4-0 3 1/2" GAUGE LOCO  (Read 46034 times)

Offline scc

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #510 on: July 08, 2018, 08:15:54 PM »
I like it a lot :popcorn:

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #511 on: July 08, 2018, 09:16:30 PM »
Hi

Thanks Nick and SCC :ThumbsUp:

We also need a blast nozzle and blower  ::)



This took a bit of studying to figure out how it works and how to make it so I'll give a little more detail.

Starting with a bit of phospher bronze bar, face and machine a 1/8" deep pocket and part off and finish to 7/16" as per the plan



Looking at the part it just didn't look right  :thinking:. After some more studying of the plans it finally dawned on me that there is an error on the drawing. Good old Martin errors has struck again  :cussing: :Mad:

The dimension showing the total height of 11/16" is wrong. It should be 13/16".

Start again and make the part the correct size



Using the same bar make the cap







Silver solder the two parts together





This makes an internal circular chamber

To cut the internal taper and tapping size hole for the 1/2" x 32 tpi I made a cutter. Starting with some silver steel turn the taper, the tap size and the 3/16" spigot to 1/8" long



Transfer to the mill and machine away exactly half the diameter







Heat to cherry red and quench in clean water. I didn't bother to temper it.

The part is mounted in the lathe and drilled through 3/16" followed by the custom made cutter









The cutter is advanced slowly until the 3/16" spigot just protrudes and is flush with the face of the part

Followed by the 1/2" x 32 tap



Now comes the 4 little jets. And they are small. Too small for my eyes  :hellno:

I have one of these little CO baby lathes. Too be honest they are in my opinion not that good for general work but where they do score points is the 3800 rpm they are capable of. So I dragged it out and donned some magnifying glasses.

The jets are made from some 5/32" brass hex. Turn down and thread. I have used M3. Drill the larger hole. Cut off and make another 3.



Chuck a bit of scrap brass, face and drill and tap M3. Each jet can be screwed in and with a hand ground cutter turned to profile.





With the tiniest of drills, which I could barely see, drill the jets



The body must be drilled and tapped M3 at an angle of 2. I have a rotary table that tilts





Back in the mill to drill and tap 1/4" x 40 and silver solder in a bit of threaded brass that is centre drilled to form the cone







A few shots of the finished part







Cheers

Rich






« Last Edit: July 08, 2018, 10:26:07 PM by Firebird »

Offline Kim

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #512 on: July 09, 2018, 12:49:46 AM »
Wow!  That's a lot of little work there!
Kim

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #513 on: July 11, 2018, 10:03:52 PM »
Hi

Thanks Kim  :ThumbsUp:

Cheers

Rich

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #514 on: July 15, 2018, 08:39:17 AM »
Hi

Next is the exhaust T and pipes

Starting with a block of bronze drill and tap 1/2" x 32







Mark the sides and set at an angle of 30





Drill with a 5/16" slot cutter









Drill and tap M3







Make the flanges





There are a couple of photos to follow when I get them uploaded. Use.com is off line at the moment

Cheers

Rich



Offline scc

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #515 on: July 15, 2018, 09:42:38 AM »
Nice work :cheers:    Terry

Offline Firebird

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Re: CONWAY 0-4-0 3 1/2" GAUGE LOCO
« Reply #516 on: July 15, 2018, 04:55:49 PM »
Hi

Thanks Terry  :ThumbsUp:



A couple of lengths of 3/8" brass tube threaded 3/8" x 40. Slightly over long at the moment. When I get the cylinders mounted I will be able to get the correct length and silver solder them to the flanges



Cheers

Rich