tangent constraint/Cam problem

[NTM]

Hi guys.

I have off an on problems with the tangent constraint. We design cams for our machines and I export the cam profile out of autocad into my machine assembly (iam). I constrain the cam follower to the cam face with a tangent constraint.

I can sometimes rotate the cam around and see everything move, checking overlaps and timing, it's GREAT. But sometimes it will just "stall" and give me a constrain error, RIGHT AFTER it just ran flawlessly. Or it will move super slow.

This happens to other people here too. Any thoughts why this is happening.

[NTM]

Any ideas at all.


Bueller... Bueller.. Bueller

[Anonymous]

NTM,

Good luck with this we have the same problem.
1.) When it seems to work in one direction reverse it and error.
2.) Drive it, works both directions. Drive again and cam jumps to other side of slot. Or errors.
3.) Drive it to a distance or angle great works. Now shorten drive increment and error.

We are probably doing it wrong but it seems we have tried every sugestion in this group with mixed results. Search group for yourself and it may help.

Also there is a tool from sdotson to drive along spline path.
http://www.sdotson.com/vba.asp

[Anonymous]

I use the contact solver for running my follower around the cam. It works great.