Stump the Chump: How Can I make My Cam Follower “Roll” on the Cam Surface?
This is the second installment of our new Stump the Chump blog series here at SOLIDWORKS. In this series we will delve into common SOLIDWORKS questions and/or problems that our users have on a day-by-day basis and will present various ways in which they can solve them. While we have a large team of seasoned CAD users at SOLIDWORKS available to answer user questions, we also have the most passionate and best CAD community in the world. So in this blog series, we are going to share advice, tips and suggestions from actual users.
We are scouring the SOLIDWORKS User Forums for questions and/or problems that we feel are probably pretty common among our users. If after reading this Stump the Chump post, you have an alternative answer or simply have an additional question, please feel free to add it to the comment section below.
So without further ado, here is the question:
Question: How can I make my cam follower “roll” on a cam surface?
User answer: I tried some things out, and I don’t think that it is possible using ONLY mates. I tried a combination of cam and RACK AND PINION mates, and it works, but only on the straight areas of the cam, if there are any. But once the cam follower went around a corner, the rolling ceased and sliding started.
SOLIDWORKS Expert Weigh-in: Yes, it is possible to make the cam follower roll on the cam surface. I created a video and attached the models showing two ways to approach this solution.
There are two ways to accomplish this. If you want to make something that looks good in a design review or video, you can accomplish it with a Gear Mate, and set the ratio to be close to the average diameter of cam. This will make the follower appear to roll on the surface of the cam. This works well visually, but if you are looking for the angular velocity of the cam follower, you will need to use SOLIDWORKS Motion, and choose a Motion Analysis study as opposed to an Animation study.
Since the Cam Mate does not account for friction as does some of the basic mates, you will want to use curve contact to define the contact and set the coefficient of friction between the cam and follower to be 1, or very sticky. Apply a motor to the cam, and gravity so that the follower does not fly off the cam, and run the motion study. This will give you the precise angular velocity of the follower if that is the information that you are looking for.
Thank you to John Bryjak for the question and to Dan Pihlaja for providing solutions in the SOLIDWORKS User Forum. If you have a question that you would like to pose to the greater SOLIDWORKS user community or to provide tips and tricks to your peers, our User Forums are a great resource. Access the SOLIDWORKS User Forums here.
Barb Schmitz