Feasibility of fabricating part of a universal joint?

[Ttrees]

I'd just simply use the arc welder for that, presuming it can be disassembled?
Tom

 

[sploo]

It's 19mm (3/4") OD, and about 65mm (2.5") long; so pretty small.

I've not been able to coax any of the pins out of the central section on this one, but it can be "coaxed" apart.

 

[chaoticbob]

It looks to be 3/4" OD, with a 5/8" bore. I'm thinking I could drill and (likely shoddily) mill out enough from a piece of 3/4" steel rod to make a replacement for the damaged end. However, would mild steel (e.g. EN1A or EN3B) be strong enough? I can get some EN8, but would that be feasible to machine with HSS drills and cutters? (yes - I am a noob metalworker)

I may be missing something sploo, but if it were me I'd machine a replacement from solid bar - not too difficult as you have a mill? Why do you think your effort would be shoddy? EN1A or EN3B should be fine, EN8 probably overkill for this application as there is no need to harden. I'm willing to bet a small sum that the original has lasted 40 years without being made from fancy steel. All will machine with HSS cutters.
Rob

 

[sploo]

I have some solid bar of the right diameter. I don't have a mill (or metalworking skill)

I've got a couple of ideas of how to make a replacement part (including cheating and doing the milling work - slowly - on my CNC router).

I have found a couple of local fabrication places though, so I do plan to contact them to see if they could weld a bit onto the existing damaged part.

 

[novocaine]

You could make that by hand with a pillar drill and a hand saw in an hour or so (ok maybe 3). 2 cross drilled holes one for the joint pin and one to form the bottom of the tangs (3 as you'll want the roll pin too), cut down to form the tangs, maybe file out the bottom, no reason to not just leave it round though, give it a bit of shape on the ends then drill the centre bore. you could drill the centre bore first if you want but I'd do it last.

 

[sploo]

It had crossed my mind that a bit of careful drilling (drill press and lathe) and a bit of hacking with a metal saw and files would probably produce something that'd work.

I do now have a small metal lathe, and I have a cheap compound slide that I may be able to mount to the lathe's slide - in order to give me vertical travel, so I'd have a poor man's mill.

Many ways to skin a cat; just need time and talent...

 

[heimlaga]

I rekon it would be possible to cut of the old ear below the hole and then weld a new piece of flat bar in place. Then grind and file it to shape. Then heat it to red hot and bend it open just enough to let the central piece slid in. Then heat it again and slid the central piece in place and carefully hammer or press it together.

Another way would be to turn a new fork and then rough out the "milled" slot with angle grinder and file it to size.

I have repaired worse things than that.

My welder in a 200 ampere three phase rectifyer type DC stick welder. Made by Unitor in Norway in the 1960-ies.
I rekon the welder itself has to be one of the very few machines I own which have never required any welding on it. I have fabricated some new copper parts for it but that is another story.