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Message No. 18798, Started by john2005 on 05/25/07
Hi everyone,

I would like to ask if anyone could please help me with the following problem.

I have a small conjugate dual-roller rib or blade cam that has an inner and outer cam-follower roller working on a corresponding inner and outer cam curve. The cam curve is basically a curved "rib" with a roller on each side of the rib. The rollers oscillate about a swing arm in response to cam oscillation.

The force of the small 3/16" OD rollers is pinching the cam rib and causing drag on the manually oscillated cam. The system also has roller noise that must be reduced as much as possible. The system is very sensitive to any friction between the cam & roller, or any drag or noise in the system.  

I've tried to polish the cam, and add lube, but there is still too much friction. I could also try to polish the rollers.  

Is there any type of hard coating I can apply to the cam and/or rollers that will help significantly ? Any type of special lube I could use ?  

The maximum Hertz contact stress is probably around 180,000 PSI. Right now, the cam is made from hardened 4140 and the roller is hardened A2 Tool Steel.

Is there any type of non-metallic roller that I could use ?

I would appreciate any suggestions for alternate materials, coatings, lubes, or anything else I might try.

Thanks for your help.
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Follow-up Messages (14)
John,My background is in the automotive performance aftermarket since the l...
No. 18836, Posted by larrycoyle on 06/06/07, 21:34 PST.
Regarding figure 2 at the link in my previous post, the very inner curve is...
No. 18834, Posted by john2005 on 06/06/07, 18:10 PST.
After checking into this further, I think that this might be a case where t...
No. 18833, Posted by john2005 on 06/06/07, 17:24 PST.
Hello John,Yes, you can email me information at: dynamic_systems@chart...
No. 18827, Posted by mdg_cam on 06/04/07, 06:47 PST.
Thanks for the additional feedback gerdb, John
No. 18821, Posted by john2005 on 06/02/07, 10:35 PST.
you don't have to pay for parts that are not to tolerance and you are alrea...
No. 18819, Posted by gerdb on 06/02/07, 04:24 PST.
Hi everyone, Thanks for the additional feedback. Actually, this is a ...
No. 18817, Posted by john2005 on 06/01/07, 19:39 PST.
i would make the roller from a 3/16 dowel pin and grind the ends down ...
No. 18816, Posted by gerdb on 06/01/07, 16:56 PST.
Hello John,Despite my best efforts I have not been able to insert a referen...
No. 18814, Posted by mdg_cam on 06/01/07, 11:19 PST.
Hi Mdg_cam, Thanks for your message. Actually, the preload is a sprin...
No. 18812, Posted by john2005 on 05/31/07, 20:57 PST.
Hello John I’ve read your posts & I have a few comments that...
No. 18806, Posted by mdg_cam on 05/29/07, 08:21 PST.
John: Several points to be made:-1.     flame hardening...
No. 18804, Posted by metal5192 on 05/28/07, 09:35 PST.
Hi Metal5192, Thanks for your reply. The parts were supposed to be fl...
No. 18801, Posted by john2005 on 05/27/07, 13:06 PST.
John:There are many surface antifriction treatments available for both mate...
No. 18800, Posted by Metal5192 on 05/27/07, 09:38 PST.
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