Circle Tangent & Coincident with Spline Issues

ewan_griffith

I am trying to create a dynamic equation driven gear from the tutorial below, and at about 14:40 he tries to connect 2 circles to a pair of symmetrical (mirrored) splines by making them coincident at 2 points and also tangent to the splines themselves. In his video in which he is using Solidworks, the two circles are the same size and the stated affects are true, but when I do it one is much bigger than the other, and the smaller of those is not actually tangential to the spline. If anyone could help me out I would greatly appreciate it! Link for document : (Gear Template)

https://www.youtube.com/watch?v=3ixCxjDkmV0

Matt_Shields

The link to your document appears to be broken.

ewan_griffith

Apologies for the late reply, I'll try to put the link in here again and see if it works:
https://cad.onshape.com/documents/6b41dffdc140db873e6cd493/w/cbe624c2de24210f6f5671c2/e/337ae20a949b1c2f608528a8?renderMode=0&uiState=6924856d3ee3af74ac823fcd

Matt_Shields

That is bizarre. I assume you have a constraint somewhere that is throwing things off. I tried the tutorial and my circles appear to be the same size.

https://cad.onshape.com/documents/8599b97967bf83834614d764/w/37f28f6d0a15921bdd09c854/e/858bac6e6e28b88fb97fe1d7

Matt_Shields

Actually, I think I figured out that you need to fully define your splines first. That way, adding coincident and tangent constraints to the circles doesn't modify your splines.

Updated doc:
https://cad.onshape.com/documents/8599b97967bf83834614d764/w/12aa4f6b6edd21d9623566fd/e/858bac6e6e28b88fb97fe1d7

ewan_griffith

Thank you so much! I can see yours is fully defined but I can't figure out why mine isn't defining, do you have any idea? Thank you for the solution regardless!

Matt_Shields

A spline is defined if the end handles are defined (length and angle) and the spline points are defined (x, y, z).