While making parts for the Model T...
I use a grinder and a drill (1/2" Jacobs Chuck), each with a cut off wheel to start the process of fabrication. Of course, they both have their own cutting disc sizes with external and internal diameters such that the two are not interchangeable across devices. There is a growing pile of spent grinder cut off wheels with 7/8" arbor that I wish would fit the 3/8" arbor for the drill. Purchasing a special arbor seems expensive and I do not own a lathe, though I did watch my dad build a wood cutting lathe fifty years ago, I will not be making one anytime soon. So, lets make a cheap arbor/mandrel but read the instructions first (ya, right).
- The Challenge
about (four) inches of 1/2" welded steel tubing
(one) 3/8 x 5" hex bolt UNC, not fully threaded
(one) 3/8" UNC nut
(two) 7/16" fender washers
(one) 5/16" fender washer
Second, preparing the shank:
Test the fitment of the bolt inside of the 1/2" tube, it probably won't be snug.
Run the nut on the screw back and forth before the next step.
Cut off the head of the 3/8" bolt and you can take 1/2" of shank with it.
Cut the 1/2" tube to the length of (the smooth part of the bolt) plus (two threads) plus (1/8").
Run the nut down on the screw and place the tube over the other end all the way to the nut.
There should be 1/8" more tube than bolt. Fill that end with weld. Remove the nut.
Grind the outside welded end of the tube smooth and round again to 1/2" diameter.
- The Parts
With a round file, enlarge the "A" 5/16" fender washer's I.D. so that it can fit down on the 3/8" screw.
With same said file, enlarge one 7/16" fender washer "B" to fit very tight on the 1/2" tube, threaded end.
The second 7/16" fender washer "C" should just slide down the 1/2" tube, snug fit is good.
With your favorite tool, cut inside notches in the "C" washer for plug welds. I used a Dremmel but a triangle file would work.
Making the 7/8" receiver:
Place only the "B" on the 1/2" tube, threaded end.
Mount smooth end into your drill.
Setup your $20 drill bit sharpener, AKA bench grinder.
Power up both devices with them turning in opposite directions.
Grind down the washer until a 7/8" cut off wheel just fits on the washer.
Lightly clean up the sides, keeping the round washer square, no bevel.
- The Business End
Mount the "A" washer and nut down on the threads, tight.
Place the "C" washer, flat side toward the "B" washer.
Place in a vise and hold the business end together with your ground clamp.
Plug weld and rotate away.
If the nut is wide, square cut about 1/16" of it off along with the excess screw thread.
Grind it square.
Remove the nut and the "A" washer.
Finally:
Using your favorite ball peen hammer and least favorite socket, cup the "A" washer".
Mount a cut off wheel.
Place the "A" washer on (you know which way).
Put the nut on reverse, flat side down.
Mount in drill to make it easier to tighten down.
The fun part...make a test cut.
- The End Result
Lightly touch up the end of the thread.
Temporarily tack up the "B" washer before you grind it down to 7/8".
Sleeve/shim the 3/8" bolt in the 1/2" before welding together.
Drill 1/8" holes all the way through the sides on both ends of the tube for plug welds of the 3/8" bolt.