Home› Using Onshape

Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.

First time visiting? Here are some places to start:
  1. Looking for a certain topic? Check out the categories filter or use Search (upper right).
  2. Need support? Ask a question to our Community Support category.
  3. Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
  4. Be respectful, on topic and if you see a problem, Flag it.

If you would like to contact our Community Manager personally, feel free to send a private message or an email.

Trying to figure out animation with an engine block.

ede_N_ede_N_ Member Posts: 13 EDU
in Using Onshape
I'm working on a project thats independent from outside of my intro to engineering class and im trying to figure out how to animate the crankshaft and piston correctly as it gets stuck at 288 degrees for some reason and I can't quite figure it out, the link is below. Thanks!

https://cad.onshape.com/documents/a7db7002771dafcfc6ee1e89/w/438796e7a338ae7de57d6502/e/4cf21d2e2d4f6615598a04e6?renderMode=0&uiState=6458eabc0c21642abeaa0fa8

Comments

  • glen_dewsburyglen_dewsbury Member Posts: 782 ✭✭✭✭
    You have an unnecessary limit placed in the piston sub assembly that is stopping the rotation. After getting the main assembly to function there is still something odd in the animation. I think it has to do with parts themselves pushing limits.
    https://cad.onshape.com/documents/3000ed37d8e6a69f73507375/w/89ed91d79275e606415657cf/e/f1365b40e7b39c3f601fa71c
  • ede_N_ede_N_ Member Posts: 13 EDU
    If you could define the "unnecessary limit" that would be awesome, I appreciate the help. Yeah it seems that some of the parts have issues with size and length and ive been trying to figure it out 
  • ede_N_ede_N_ Member Posts: 13 EDU
    also specifically why cylindrical mates if I may ask, just curious!
  • eric_pestyeric_pesty Member Posts: 1,885 PRO
    Looks like you figured it out!
    It's best practice to avoid "over constraining" things, so for example if you have a mate that stops sliding in the z direction at one of a connecting rod, using a revolute at the other end is easier to "solve" than if it's another revolute that also locks the z motion even they can both be true at the same time.
  • glen_dewsburyglen_dewsbury Member Posts: 782 ✭✭✭✭
    @ede_N_
    The unnecessary limit was angles on a revolute mate that stopped the rotation of everything in your main assembly. Noted from piston assembly. If the connecting rod hits the piston then review design.
    Use the simplest mate available at any given time. A cylindrical mate will let the piston moved up and down in the cylinder without restrictions. It will not create locks up with other mates like the revolute used in your connecting rod to crank. If the piston does not meet requirements (IE it moves past the top of the block) then your design needs updating not limits to restrict movement. Using a slider is more complex but not needed for limits in this case.
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. Sign in or register to get started.

Sign In

Categories

Vanilla Forums