# Motion and Centrifugal Forces

#### Huusoku

##### New member

New member, first post I am using SW2010.

My question: Do I need to do anything special to my assembly in order for SW to consider centrifugal forces?

I have a rotating disk with two face-mounted pegs near its edge spaced 180-degrees apart. I then have two beams with one hole on the end of each beam that fits over each peg. I've added a rotary motor to the disk and set some arbitrary RPM, say 500. I give a material to everything, say 1020 Steel.

Using Motion Analysis, what happens is that when the motion begins, the arms immediately move inwards towards the center and then rotate back out -- and back around again, indefinitely. I could be wrong but I'm pretty sure they would move outward by centrifugal force and would eventually remain straight out forever (since it's a constant speed), not continue to rotate around and around and around forever.

I've done this with the pegs on the leading side of the arms (where the pegs are pulling the arms) and with them at the trailed side (where the pegs are pushing the arms), I've done really fast RPMs, I've added gravity, all no change

Am I going crazy or is there some setting I'm supposed to enable before SW will consider centrifugal forces?

Thank you very, very much in advance!
Huusoku

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#### Huusoku

##### New member
Here is a short video of what SW is doing. I really don't think this should happen. It continues on forever. I realize there is no air resistance or friction, but what happened to centrifugal forces, how to I enable them?

Thanks
Huusoku

#### Huusoku

##### New member
Ummmmmmm anyone? Helllllloooo?

#### Huusoku

##### New member
Okay, I modified my Concentric mates and selected the Analysis tab up top. I then defined some friction at the joints and now it is behaving like it should.

So that is what it was, I needed to add some friction.

Guess I didn't need to register to this forum since I figured it out on my own after 3 days.

Good bye

#### Huusoku

##### New member
Well, it looks like adding friction only overcomes the tendency for each arm to continue rotating. Not to my surprise, it doesn't do anything in terms of "activating" centrifugal force in Solidworks.

Does anyone know how to enable centrifugal forces in SW please?

Is this forum still active??

Huusoku