Six legged walker with strong joints!

Step 2 Get some pipes!

Now get some weldable steel pipe that has a slightly larger ID than your bolt's OD. Then get some brass tubing or pipe that will make up the difference. Make sure (DAMN SURE) that your pipe doesn't have welds internally, or else you are going to have to get more pipe. 

i got lucky with my top end, and have 3/8th bolts, with 13/32nd or 27/64th inch brass tube, and a 1/2 inch OD steel tube that fit really well. At this point of buying things, go around with your bolts, and just try different combinations to see if you can get lucky. If you don't get lucky... Well then.

I didn't get lucky with the main drive. I got the 1/2 inch bolts, I found some weldable steel pipe with supposedly 1/2 inch ID, (which was a good bit larger, around 1/8th or 3/16th larger), and then got some brass pipe with a 31/64 ID, and a large OD. Measure accurately with some calipers, chuck that brass on the lathe, and go to town.