Union Pacific Big Boy 4012 in 1.5"

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Joined: Sat Sep 14, 2013 11:54 pm
Location: Melbourne, Australia

Re: Union Pacific Big Boy 4012 in 1.5"

Post by DanSmo » Wed Jun 07, 2017 4:51 am

Asteamhead, thank you! By the way a pizza oven is a great idea! I'll have to get one specifically for doing the rest of the rims.

These last few weeks I decided to tackle one of the more repetitive tasks and get it out of the way. Springs.

After a lot of investigation I decided to cut them with an abrasive wheel and drill the holes. I considered punching and cropping but considering the time to make and/or source the tools I would have them done faster if I cut and drilled.

Using the angle grinder with a ultra thin cut off disc kept heat to a minimum and when the disc showed signs of glazing I swapped a fresh one on. I cut all the leaves about 0.5mm longer to allow for cleaning up and squaring off with a quick pass of a with a carbide end mill. The leaves were then dropped into aluminium drilling jigs I made and stack drilled with straight flute carbide drills. The clamps were made from box section and the rollers are 0.375" rod that was drilled in the lathe. I did deviate from the drawings however, which called for a 0.125" pin to pass through the roller and be riveted over at either end. I simply used an M4 button head cap screw and tapped one side of the clamp, any excess head height that causes interference will be ground down. It has the bonus of making spring packs more easily serviceable should they need attention for whatever reason.

As of now 2 engine truck, 10 main and 4 trailing truck springs are done. Just another 14 for the tender and the monotony is over!
2017-05-12 15.43.59s.jpg
Rolls of tempered 1095 material
2017-05-19 19.25.00s.jpg
Cut lengths organised in takeaway boxes
2017-05-27 18.32.28s.jpg
Aluminium drilling jigs
2017-05-27 18.36.49s.jpg
Clamps and rollers
2017-06-07 18.57.05s.jpg
Finished, assembled springs
I just don't understand pronouncing solder as "sodder"... where did the L go?

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Re: Union Pacific Big Boy 4012 in 1.5"

Post by boaterri » Wed Jun 07, 2017 9:03 am

Your wife's kitchen oven should be able to get to 250c (482f) just do a "mother may I" and make sure that there is no oil or other nastys to make smoke/odors.


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Re: Union Pacific Big Boy 4012 in 1.5"

Post by Asteamhead » Wed Jun 07, 2017 7:06 pm

Hello DanSmo,
Nice job on your springs! For my A, I did it almost the same way. perhaps some fotos my be of interest to you :D ?

Best regards Asteamhead
A 180 spring leaves cutted to coarse lengths by means of a sheer,red.jpg
By means of the tool all leaves for one spring are milled to the exact length
A spring clamped into a tool for welding,red.jpg
A quick small TIG-welding won't affect the spring material (1.4310)
A spring leaves  sorted by means of a tool for welding,red.jpg
Second look at the TIG-weld
A leave clamps welded,red.jpg
Clamps were pressed, then welded for a narrow fit
A spring welded and clamped to be drilled,red.jpg
Drills were made at slow rpm by means of a high quality Ti-Co8 drill ('Titex plus' )

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