pic: Delrin Poly Cord Pulleys

[Garret]

Doesn't the hollow round belting flatten out when installed? Have you had trouble with the little connectors coming out?

In 2011 when we used 1/4" belting for our claw we had no problems with the connectors, however this year with the 3/16" belting it seemed as if we were always losing at least 1 belt because a connector came undone. I would attribute this to more likely too much tension on the belts but nevertheless something to be aware of.

[Mk.32]

Originally Posted by Garret

In 2011 when we used 1/4" belting for our claw we had no problems with the connectors, however this year with the 3/16" belting it seemed as if we were always losing at least 1 belt because a connector came undone. I would attribute this to more likely too much tension on the belts but nevertheless something to be aware of.

We also used 1/4 hollow tube and had no issues with connectors.

[Mk.32]

So my worst fears as been confirmed, the .6 ID of these pulleys make them to flexible. Under the load of 4 cords there is about an 1/8 of an inch of deflection which makes them very stiff to turn. We are switching to 6061-T6 and with an ID of .66.

[artdutra04]

Originally Posted by Mk.32

So my worst fears as been confirmed, the .6 ID of these pulleys make them to flexible. Under the load of 4 cords there is about an 1/8 of an inch of deflection which makes them very stiff to turn. We are switching to 6061-T6 and with an ID of .66.

If you can, go with a much larger OD and use round hollow tube for the roller material.

1.5" diameter x 0.040" to 0.063" wall thickness aluminum tube works great for polycord rollers.

[R.C.]

Originally Posted by artdutra04

If you can, go with a much larger OD and use round hollow tube for the roller material.

1.5" diameter x 0.040" to 0.063" wall thickness aluminum tube works great for polycord rollers.

Agreed, in the 1.5" range you can find very nice rubber tubing to slide over the Tube to act as grip as well!

Such as McMaster: http://www.mcmaster.com/#87235K34 (comes in black btw )

We used 1.25 OD X .060 wall. It allowed us to press in a FR8 Bearings. So we drove one roller and made the rest dead/pressed in bearings.

-RC

[AdamHeard]

Originally Posted by artdutra04

If you can, go with a much larger OD and use round hollow tube for the roller material.

1.5" diameter x 0.040" to 0.063" wall thickness aluminum tube works great for polycord rollers.

Yup. We loved it.

If you can drop down to 1.25" 1/16" wall the bores can accept an FR8 bearing too, very convenient.

[JesseK]

If you want to avoid grooves altogether, a plate of finger guides may work. See the bottom-left of this photo:
http://www.chiefdelphi.com/media/photos/37572

[BlacksmithWoods]

Nice, these look great! I wish I had those. I had to bang those out made out of wood on our homemade lathe. http://www.chiefdelphi.com/forums/sh...Homemade+Lathe