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Is there a method by which an angular limit to the 3 rotations in a Ball Mate can be achieved?
StephenG
Member Posts: 367 ✭✭✭
The Ball Mate doesn't allow a range of min/max angles for the 3 degrees of rotational freedom.
Trying to restrict angular movement to reflect a hard interference limit in an mechanism.
Trying to restrict angular movement to reflect a hard interference limit in an mechanism.
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mahir
Member, Developers Posts: 1,291 ✭✭✭✭✭
I can't think of any way to do this directly with just mates. But one workaround is to use an invisible dummy part. This part can be anything that has a flat surface you can use for orienting it. In my example I used an L shape just to illustrate the mates better. Next, add these 4 mates.- Ball mate #1 between the "joystick" part and ground MC.
- Ball mate #2 between the dummy part and the joystick, but not at the pivot point.
- Parallel mate #1 between the dummy part and the ground MC from ball mate #1
- Parallel mate #2 to orient the dummy part and constrain rotation
https://cad.onshape.com/documents/57acdfaae4b005c413ed9b6f/w/3fd585a46d3af1b3ba413c53/e/c8f982e2ff311457b1c60bd0
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Answers
- Ball mate #1 between the "joystick" part and ground MC.
- Ball mate #2 between the dummy part and the joystick, but not at the pivot point.
- Parallel mate #1 between the dummy part and the ground MC from ball mate #1
- Parallel mate #2 to orient the dummy part and constrain rotation
The rotational limits can be implemented via X/Y min/max in parallel mate #1. It will function sort of like a universal joint.https://cad.onshape.com/documents/57acdfaae4b005c413ed9b6f/w/3fd585a46d3af1b3ba413c53/e/c8f982e2ff311457b1c60bd0
However I only needed 1 parallel mate to achieve the desired effect.
Note: I used a surface as a the dummy part.
(Comment: Shame the Ball mate doesn't have a rudimentary way to limit the amount of rotation about the rotational 3 DOF.)