Cam drawing and strategy

[O.Tan]

Hi,

I got a project coming up which will likely use some cam mechanism, any idea what's the best practice to do this in F360? This includes both drawing and joints. 

[Mike.Zhang]

You mean you're trying to add cam into your project, the cam is talking about "Camera"?

If so, you can check my previous design here:

https://fusion360.autodesk.com/projects/robot-camera

Try to download the model, and analyze it.

Hope it helps.

[O.Tan]

Mechanical cam, not camera or machining CAM

 

[Mike.Zhang · Accepted solution]

Hi,

I just created a simple model to give you a instruction. Attached the model, and below is a demo video.

Currently Fusion 360 does not support the CAM Mechanical well, though we still can use Joint/Contact/Ground... to simply simulate it.

Anyway, we may add more related functions in future. Hope this helps you in current status.

https://screencast.autodesk.com/main/details/bfa962f3-018e-43e7-9e45-2d7ff1945d13

[Anonymous]

I did a sketch that demonstrates a cam lobe being driven by User Properties parameters table. Rather than drive the spokes of the wheel in the cam directly, I am driving an array of vertical lines, like a bar chart almost, and these lengths are copied to the spokes of the wheel via the equals constraint for each one, every 10 degrees. If you do this for a real cam, you will want to drive the lengths of each spoke directly perhaps, but I had problems simply defining the length of the line when it already existed at an angle, for the wheel spokes that define the cam shape. It wanted to dimension the length of the spokes relative to horizontal or vertical, rather than the simple length of the line at the angle it existed. Maybe there is a toggle for this, I have to look it up. When I figure that out, I can put the rectangluar "bar chart" in a different sketch and bind both the circular and rectangluar arrays to the User Parameters.

Also, I do not know what kind of line segment is best for connecting the spoke tips to form the outer contour. In this example I used splines, but these can ring and over/undershoot. Straight lines would give you flat sides, and I did not check out conic curve yet. Maybe some spline curve wizards can chime in on how to avoid these problems. This was more of a framework exercise than an attempt at a serious cam profiler, but maybe it goes in the right direction for folks who don't need super precision anyway. I also attached the Fusion 360 file below.