Trouble with motion link of gears

[kenahoo]

I successfully created a motion link between the first two gears in my model, but I'm having trouble defining the second motion link.  Please see attached.

The first link is between gears with 8 & 83 teeth, so the ratio between rotations is 83:8, and that works fine.  However, when I put another 8-tooth gear rigidly on top of the 83-tooth gear and try to use it to drive a new 59-tooth gear, it seems to try to drive the *first* (8 tooth) gear again.  So something seems messed up in my understanding of how to create the rigid & revolute joints.

Any suggestions?

[laughingcreek]

which gears are you trying to connect with the motion link?  You can't connect gear 3 and 4 because it wold conflict with the other motion link. 

[kenahoo]

That's what I'm trying to understand - without the motion link, gear 4 is free to spin without any impact on any other gears, so why am I unable to link that spin with the spinning of gear 3?

[laughingcreek · Accepted solution]

gear 4 is jointed to the collar.  so the rotation of gear 4 is in reference to the collar.  the collar is rotating.  ie the reference location is rotating.

usually when doing this type of thing with gears, you joint to a stationary object, like a stationary shaft on the board.

[kenahoo]

Aha, I see - so it might indeed be rotating as instructed, but relative to a rotating member.  I'll have a go at changing things around tomorrow.  Thanks!

[davebYYPCU]

Works as expected if dragging gear 2 with the mouse, hide the plate and check it out, 

using animate model Rev19 slows it down. The problem was the collar joint, as Alex mentioned.

Gear 4 is joined to the plate sketch point.

Might help....