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.

Trouble dimensioning a part I'm working on

jesse_starrjesse_starr Member Posts: 15

Part link: https://cad.onshape.com/documents/c3f16c529c52cfdc8e2e6860/w/d3ae9f1a53716f7dae2d98a1/e/605a574b1da1bdb39aacb3a9?renderMode=0&uiState=66e5136215518861ceb1be19

I made this too small at the edge where the screw holes are and I can't figure out how to dimension it to adjust to the size I need. The side with the screw holes should be 70mm.

Can anyone help please?

Answers

  • Oliver_CouchOliver_Couch Member Posts: 161 PRO

    You need to edit the sketch and just change your 30mm dimension to 35mm. This is a basic tenet of parametric modelling.

    I'd strongly recommend working through some tutorials at learn.onshape.com before trying to dive into productive work. You'll get to your end result much faster if you take a step back and do some training.

  • jesse_starrjesse_starr Member Posts: 15

    thank you. I had tried to adjust that edge on the sketch but there’s something wrong with the sketch that won’t let me modify it. It says it is undefined and I can’t figure out why.

  • jesse_starrjesse_starr Member Posts: 15

    I have done a lot of the tutorials but some times I mess up a constraint when I'm trying to accomplish something and I can't figure it out…

    I tried dimensioning the lines but it changes the shape… Can you help me with what constraints/lack of constraints is causing this?

  • robert_scott_jr_robert_scott_jr_ Member Posts: 482 ✭✭✭

    Hello Jesse. An important point is that your sketch is floating on it's plane. Decide what point (vertex) of your sketch to be coincident to the origin. Start the sketch there or move it there early in the sketch. The line you are dimensioning to 35 mm needs a vertical constraint. The dimensions of 68.663 and 65 look good in the image you posted but will conflict with each other if you change another dimension; loose one of those (I suggest the 65). Correct those things and continue to dimension or constrain any blue elements until all are black and change the dimension you need to. - Scotty

  • rick_randallrick_randall Member Posts: 326 ✭✭✭
    edited September 16

    @jesse_starr

    I might mention a little technique to help with sketching - try to pick and grab (blue/under-defined) points or lines, and manually move them around to see if they behave the way you intended. If not, you need to add more constraints. Do not underestimate how important constraints are - they are about as important as dimensions. Do yourself a favor and take the time to learn how to use them (use the free"self paced courses" in the "learning center") It's also good practice to constrain the center-line to the origin along it's length somewhere, as Scotty suggests, because this gives you an anchor point to fully constrain the sketch later. We all were beginners at one point, keep at it, it does get easier with practice. I hope this helps

Sign In or Register to comment.