I am thinking about having a certified welder I know make up a short pitman arm from a later longer one.
Thinking about cutting a piece out of the arm and welding the two ends together. I've seen early front axles made up by welding repro ends to a later middle section. Seems like it should work for pitman arms if the right technique were used. Has anyone tried this?
Just my humble opinion, but I would not trust my life to a welded Pitman Arm. I would find one or have a machinist make one.
While I am not going to recommend it, this has been done with the Model A pitman arm. When done in that case a lap joint is used. The ends are not just butt welded.
I have not done this, so this is an indirect response that doesn't answer your direct question. However, my opinion is this: Having a certified welder perform the job, perhaps followed by x-ray or ultrasonic testing to check for voids would be fine.
Your average neighborhood handi-man, not so much
Additionally, I believe the part was originally forged. A manufactured one could be cast which you would most certainly not want, and if made from raw stock would be cost prohibitive. From a manufacturing/machining standpoint, that is a deceptively complex part. Cost would go down substantially if multiple parts were made after programming was done for a multi-axis CNC, but I doubt that the market would support sales of those items. Doing it by hand on manual machines and finishing by hand would take quite a long time. To add to the issue, depending on the material used, there likely would be a heat-treating expense, though that would be the least of the $$ worries.
Here's a pretty good discussion on the subject, with lots of opinion:
since it's not wood and no glue is used, I don't see how a welded lap joint would be superior to a V'd weld. With a V, the entire structure would be made with fused/molten metal...with a lap joint, there will by design, be a void. I am not a certified welder, but that doesn't sound like the best method. Though we'll never know, it would nevertheless have been interesting to hear the original repairman's thoughts on why he did it that way.
For one it gives a lot more surface to weld then just a butt welded V'ed piece. There would still be V'ed out area along the joint. I was just relaying what was done with the A pitman arm when shortened in the past before the ones sold be Snyders. I will have to check Les's Model A repair books tomorrow to see if I can fine the info.
It's ugly but I don't go in for judging and only one person in 7 years has said anything about it.
I got the dimn for an early arm from Kim Dobbins, cut 2 arms with an overlap joint and found a thickwall piece of tube that fitted snugly round the arm. Having been advised by many people not to weld Mr Ford's vanadium steel I used a 2 pack industrial adhesive and 2 grubscrews (drilled & tapped into the pipe) just as security. It hasn't moved or broken yet.
Ratio has changed from 1 1/4 turns lock to lock to 1 3/4. I can now get the infamous 'over-centre' on full left-hand lock, but anyone who says they have experienced that at anything over slow parking speed must have been in the process of rolling the car! The wheels are almost parallel with the axle beam before it happens, it's not an issue.
Just my experience, you may disagree if you wish.
Those that know me know that I am not often "speechless",....but this is one of those rare times!
Jem could you provide the dimensions of the pitman arm you received from Kim?