Alignment jig for driveshaft welding

[BreeStephany]

I am in the process of fabricating a slider shaft for a friend's derby car and would like some suggestions on making an alignment jig to make SURE that nothing falls out of square or out of alignment while I am welding it up.

My plan is to turn the drive shaft yokes / ends in a lathe to true the shaft end of the faces up, from which I will be welding on 3/8" plate steel and then will be welding the 3/16" thick slider shaft to the plate.

I know its a derby car, but I want to try to keep it as balanced as possible so that it doesn't destroy the tailpiece on the transmission.

Any ideas on a jig would be greatly appreciated.

I have a few ideas in mind, but also recognize that there are likely others on here with much more experience than me when it comes to making driveshaft and would love any input.

 

[csp]

I worked in a shop that built driveshafts (among other things) in college and we just welded them in the lathe. Then used heat/quench to remove runout after everything had cooled. None of them were ever balanced and we never had one come back for vibrations.

 

[2oolhound]

Further to what csp said, I used to get a lot of drive shafts lengthened or shortened in the 70's. The machinist had a 20' long lathe. He never used a jig, just cut the tubes, fitted the ends and likely indicated the ends before tack welding them in place. I know he was always concerned about the balance but I don't remember how he checked that. I just remember he didn't use a jig.

If you are attaching a female spline shaft to a yoke, that's a little different.

 

[vettex2]

is that legal in derby cars?

 

[gearhead1]

Vettex2, Yes, legal, depends on the rules of the promoter. Here in NC Joker rules will allow, but Stoney Roberts (TN) and J&M (NY) typically do not.

Bree, as long as you make a good effort to keep everything aligned/square it will be fine. There's so much vibration on the dirt track, then you start running over stuff that's come off of cars, it doesn't have to be as good as a street car going 70mph down the highway.

I don't run sliders in my derby cars so I haven't built one. I do make my own driveshafts (shorten/lengthen). I take a grinder and carefully grind the weld off of the driveshaft yoke closest to the rear diff. Out comes the yoke, which the part in the driveshaft is about 1.5" long and at a close tolerance, so it basically squares itself. I cut the driveshaft tube off with a chop saw, then put the yoke in, smack with a deadblow. Then I measure my yoke to yoke distance to ensure I've got the right distance before I weld. I've never felt a vibration and never had one come loose. I've broke the yoke itself in a derby, but never the weld.

Some of my friends use a portaband to cut the tube and isn't always a straight cut. When they put the yoke in, you'll see one area where the tube fits nice to the yoke flange and areas where it does not due to the non-straight cut. It doesn't matter because the 1.5" part of the yoke in the tube pilots it on center. I've driven their cars and haven't felt any vibrations or any adverse affect that I can tell.

 

[gearhead1]

The reason to run a slider is that when the rear or the car bends up, the driveshaft doesn't just come out of the transmission. Also, you can use a slider for several different vehicles since you can change the length.

I don't like the $600 price tag.

Bree, please post pics, I'm curious to see how you did it!

 

[why worry]

I have used a pipe vise and a tubing cutter then laid in a piece of angle iron to weld up with pretty good success.
Dave

 

[vettex2]

The reason to run a slider is that when the rear or the car bends up, the driveshaft doesn't just come out of the transmission. Also, you can use a slider for several different vehicles since you can change the length.

I don't like the $600 price tag.

Bree, please post pics, I'm curious to see how you did it!

Never needed one
we just duct taped the hell out of the u-joints
one year we took a shot to the rear by a 64 Imperial. Our rear bumper was straight up and for the next heat we cut a hole in it to let our driver see.

We learned to heat and weaken the back of the car before inspection about 1' in so it would ball up instead of bending up. It beats cutting and banging and works better and looks invisible after painting
after the second heat we'd do it again and it would ball up into a battering ram
We also did the same to the leaf springs (I assume you use a leaf spring car)
We got it down to a science. After that we went looking for Imperials to hit even if we didn't have one of our own to use

 

[BreeStephany]

I like the idea of the tubing cutter to square up the old yoke and will definitely do that. My plan for keeping reasonable alignment while welding is to make a small piece of metal that will fit tight inside of of the tube, then to a drill bit equal to the size of the pilot bit of my hole saw to drill a hole dead center through it, which I will use to keep alignment across the face, and then all I have to worry about is the shaft being square, which I can do with a tight fitting pipe through the yoke and a square.

I will definitely take pictures along the way and will be sure to post everything when I'm done.

 

[drivesitfar]

BREE: this is all new to me, but i'll never learn unless i start paying attention to these threads. also wanted to wish you the best of luck in your project.

wish i had something to add besides support, but maybe i'll see something that i might be able to comment on as you post up pictures.

good luck

 

[gearhead1]

https://www.workshopaddict.com/forum/metalworking-projects/6247-how-build-driveshaft.html

 

[Provincial]

My experince with pipe and tubing cutters (with a cutting wheel) is that they crimp down the area where they cut, reducing the ID of the tubing in that area. I prefer an abrasive cutoff saw or a good horizontal band saw for this sort of thing.

One could mark the cut with the pipe cutter by scoring the OD of the tube, then use a hand held grinder with a cutoff wheel. Cut just proud of the mark and use an angle grinder to trim down to the mark.

 

[Nor'Easter]

The machinist I have build my shafts has a dedicated lathe to indicate ends on the tube. It's also used as a rotator, so the shaft gets welded while being held in the lathe.

Then balanced on a driveshaft machine.

 

[BreeStephany]

I made a little progress on the driveshaft last night. I turned the old yoke end and then welded on a 3-1/8" round x 1/4" thick piece of plate onto each drive yoke and then welded the drive shaft on to each yoke.

Waiting for it warm up and adding a coat or two of orange high solids enamel.

 

[BreeStephany]

I got the last of coats of paint on it, as per my friend's request. Now to see how it holds up to abuse.

 

[gnpenning]

You will have to let us know how many races you help them win.

Love the color.