a different way to do cross rods!!?

Tools, shop setup, jigs...
Jon B
Posts: 3
Joined: Sun Mar 04, 2012 10:23 pm
Location: New York, NY
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Re: a different way to do cross rods!!?

Post by Jon B »

Thanks for that tip, Will. (I don't have a lathe.)

The drilled end of the 3/8" square bar seems plenty robust to me. I like that it avoids having an aluminum pin. I have a prejudice against aluminum bearing surfaces. The one in the photo has a brass pin in one end - to facilitate tapping screw holes into the cross rod for the knee lever cradle - and a steel dowel pin in the other. Both 1/4". They fit tight enough to require light hammering, but I epoxied them also. The rod mounts in nylon bearings.

I centered the hole just by measuring carefully. It seems to me that the concentricity is not actually all that critical. I did take a lot of care to clamp the rod perpendicular to the drill press table. My hunch is that the error is in the same ball park as the error I'd get with a lathing or annular milling process (if done in an urban tenement apartment like the one I work in). If I were doing a bunch of these, maybe I'd devise a jig that would better insure that the second hole drilled was in line with the hole at the other end (which is what's critical).

Re: hollow mills: I have a number of counterbores that act as annular mills if you leave the centering pin out. I don't have one large enough for a 1/4" pin. But maybe people shopping for hollow mills/annular cutters might want to check out counterbores too?

Jon
Per Berner
Posts: 7
Joined: Tue Jul 16, 2013 2:55 am
Location: Sweden

Re: a different way to do cross rods!!?

Post by Per Berner »

Why not just tap a hole and add a 3/16" thread allen head screw on each end? They could easily be polished to function as bearing surfaces.
maxi19
Posts: 365
Joined: Mon Oct 22, 2012 12:55 pm
Location: Milton Keynes, England

Re: a different way to do cross rods!!?

Post by maxi19 »

A good idea Per.

Ron Mc
Rick Dillon
Posts: 51
Joined: Sat Sep 14, 2013 11:01 am

Re: a different way to do cross rods!!?

Post by Rick Dillon »

I have been racking my brain on how to round my square cross shaft ends on my new build, I,m sure glad I stumbled cross this posting from Wayne, I have plenty of stainless steel allen headed screws to tap in the ends. Thanks Wayne for sharing your thoughts. Rick
sojen
Posts: 11
Joined: Fri Jul 10, 2015 12:36 pm

Re: a different way to do cross rods!!?

Post by sojen »

Kline turned his cross shafts down to 1/8",,,smaller diameter = less friction. Being that short, into a bushing = plenty strong enough. JMO
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