Barrel Cam modeling

[sbmathias]

I'm trying to make up what I know as a barrel cam. This is a cylinder with a groove around it, but the groove moves longitudinally as it goes around. You can see what I've got so far at

http://home.surewest.net/mathias/posts/panel_cam_2.jpg

I've circled, in a very rough way, those two areas that need improvement. At the right-hand area, there's a step at the transition between the vertical slot and the spiral part. At the left-hand area, the transition is sharp, not at all what you get if you use an end mill to create this.

I'd like to figure out how to make this better. It seems like there should be a way to model this much as you'd make it - take a cylinder (cutter) and move it along a path on the surface of the part. However, I'm not even sure you can create a path sketch on the surface of the cylinder.

All suggestions welcomed.

 

[mncad]

sbmathias,

There is not a good way to create it. I submitted an Enhancement Request many times for what you are asking (move a cutter along a path, just like many CAM softwares) to create a cut, but it has been done yet (SW2006 anyhow). I usually try to use Multi Bodies to create this. Looks like you may try a face fillet for the sharp corner, but based on my past experience I don't know that it will work either.

mncad

 

[CorBlimeyLimey]

Swept solid thread559-138062
Barrel Cam thread559-74659


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[Heckler]

Here is a sample model. I think this will get you started in the right direction

http://www.mooload.com/new/file.php...902628/Cylindrical+Harmonic+Cam-Worked.SLDPRT

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 5.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
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Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

 

[dude29341]

Try creating a flat pattern of your cam path on a plane tangent to your cylinder/cam equal to the length of your cylinder circumference and then “WRAP” it around your cylinder. Next create a sketch on another plane perpendicular to the previous tangent plane with the cam track profile then do a revolved cut following the previous WRAPped pattern.

 

[Timelord]

sbmathias,

Do you need a real accurate track, or can you get by with a good picture? Solidworks cannot do an exact representation of a track of this sort due to the lack of ability to sweep a solid. If a real good picture is all you need, dud29341 suggested the best way. A good check of your representation is to build a quick assembly of the cam and a follower, mate the follower tangent to the side of the track and rotate the cam. When the simulation hangs up, run an interference check and look at the size of the small moon shaped interferences.

Timelord

 

[Jamaz17]

I agree with dude29341, I tired to do this a few months ago, using the wrap feature was as close as I could get it to the true barrel cam profile. It's not exact but i think as close as SW can get at this point.