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Cam design software

bill_danielsbill_daniels Member Posts: 277 ✭✭✭
"Cam" is one of many English words which has lost usefulness because of overuse and misuse.  Is it a CAMera, (as in Cat-CAM) Computer Aided Manufacturing or that mechanical thing that makes the valves in your car engine go up and down?  Google doesn't have a clue - which makes it very difficult to find specialized applications to aid in precision mechanical cam design.

I need to design an axial ("barrel") cam which uses two cam followers running on either side of a sinuous "rib".  That's the inverse of one cam follower running in a sinuous groove.  If a barrel cam is to run quietly while carrying a heavy load at speed, the curves must be very precise which requires specialized cam design software - software which deals with things like acceleration.  Oh, it would be nice if it a free trial was available.

Anyone have suggestions?

Answers

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    konstantin_shiriazdanovkonstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    edited May 2017
    I have seen an app for cam design in autodesk inventor few years ago. what is the law of motion between driving and driven elements of your cam mechanism? i think one can always generate some closed curve based on motion law with featurescript. like i did for this transmission
    https://www.youtube.com/watch?v=hf8vh8ee9hc

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    michael3424michael3424 Member Posts: 678 ✭✭✭✭
    This turned up on a Google search for "cam follower design software":

    https://www.psmotion.com/

    It looked like there might have been a few other relevant hits as well.
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    bill_danielsbill_daniels Member Posts: 277 ✭✭✭
    michael3424 - thanks, your search term is much better than mine.

    The motion I seek in the driven component is not complicated - just a symmetrical linear reciprocating motion with as short a turn-around at the reversal points as can be reasonably achieved with decent cam follower service life.  The cam follower traverse distance is about 175 mm. I'm thinking the cam diameter would be ~300 mm.

    The only complicating issues are that the driven mass is 45 kg and the cycle frequency can be as much as 2 Hz so the design has to be really strong to handle the inertial loads plus a varying bias load of up to 160 kg-F.  I've thought about using spring bump-stops to assist with the turn-around.

    Self-reversing screws and linear actuators can't handle the mass and speed.  Plan B is to use a large AC linear motor instead of a cam but I think that would be a more expensive solution.
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    bill_danielsbill_daniels Member Posts: 277 ✭✭✭
    I think I have been able to sketch the cam shape I want in 2D.  But, I don't have a way to wrap this onto the surface of a cylinder. https://cad.onshape.com/documents/b861f747663a033235f6b8f2/w/93ca587d59ac20b262daef73/e/bb08c0d644b45ded44fa5792
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    konstantin_shiriazdanovkonstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    edited May 2017
    that how far i could do something similar in OS untill sweep by composite curve failed
    https://cad.onshape.com/documents/6fd6d0b7eb9062b9bf951127/w/2fe6b629d78d2788d63f646d/e/1b19abcfd8d6927a6746d1ed

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    Jake_RosenfeldJake_Rosenfeld Moderator, Onshape Employees, Developers Posts: 1,646
    @konstantin_shiriazdanov

    Would you mind filing a support request (? menu > Feedback) for that broken sweep? I checked it out and it seems like a bug.
    Jake Rosenfeld - Modeling Team
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    bill_danielsbill_daniels Member Posts: 277 ✭✭✭
    konstantin, great effort. 

    However, sweeping a rectangle along a path won't exactly do it.  While the axial thickness is constant, the rib section is thicker in the reversal area as measured normal to the rib surface.  This section is essentially a nested pair of parabolas each with a different curvature - the inside of the curve is wider than the outside.
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