Roller hitting gripper nuts

I have an 8x12 Challenge Gordon. Beautiful press, came to me with 3 brand new rollers but only two sets of trucks. A machinest friend here created two new trucks for me today matching the ones on the press, so I popped in my 3rd roller (lower one in the photo) but when I turn the press the roller knocks into the nut holding the gripper bars in place. I am wondering if I just need to have shorter nuts to hold the gripper bars in place. The press runs very well with the 2 rollers, but I would like to use the 3rd if possible. Thank you for any advice you can provide. (And Yes, I know I need to clean my rollers-forgot to put the cover cloth on after my last run and the dust bunnies took over!)

image: RollerNutIssue.jpg


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Go to a good, well stocked hardware store with one of your nuts and ask for a jam nut of the same thread count. A jam nut is usually half as tall as a regular nut. But beware… the bolt/screw holding the gripper on the gripper bar may be long enough to hit the roller despite the jam nut installation. The solution could very well be a shorter bolt with a jam nut.


Hi Tom, Thank you. The screw shaft on the bolt does not come all the way to the end of the nut, event when tightened to the limit, so this is my answer I think! I will ask for two JAM NUTS tomorrow.

There’s a lot to be said for having a small tool box at hand; a hacksaw and file would have you printing in mere moments. :o)

Are you able to turn the bolt around so that the nut is on the inside/back of the gripper assembly?


the bolt is probably “milled” to fit into a slot and not turn. the new way is for the nut to be milled and come up from underneath with a low head “milled off” bolt from above.
if you are still having probs,,,,, (the above jam nut suggestion is a valid one), email me with slot width and depth. i can get you set up with something that will work.

Hi Everyone
Thank you so much for the help. this is a photo of the nut and bolt, there are two identical. The threaded part of the bolt does not come all the way up through the nut when it is tightened to hold the gripper bar in place. It has not been an issue to date as I have never had the 3rd roller on until last night.I am off to the hardware store shortly to check on the jam nut situation. Thanks again for the rapid response. Oh yes, I have a hacksaw, and the thought had come to mind, but I got to looking at the bolt. I think it is original to the press and the nuts are not. They seem newer.

image: BoltNutGrip.jpg


The rectangular feature underneath the head of the bolt fits directly into the slot that holds the gripper bar.

Hi Everyone
Well thank you for all the help! I am now in good order. The jam nuts did the trick!! The other nuts wer almost a full 1/16th higher than the thread of the nut when screwed in tightly. With the jam nuts, the screws go past the nut by just a wee hair, and where near the rollers.

I have never printed with all three rollers and am looking forward to the experience.

Thanks again for all the help!