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.

Options

Split parting line draft help

nick_papageorge073nick_papageorge073 Member, csevp Posts: 711 PRO
Hello, I'm trying to make this exact parting line split (draft exaggerated for clarity). I can make it without issue by splitting the part, drafting each resultant part independently, then boolean union the two back into one part. What I can't figure out is how to do it using the "parting line" option within the draft command. I read the help on that to split the face, and I was unsuccessful with even the split. Would someone be so kind to do it in this document so I can see what you did? Thanks greatly.

https://cad.onshape.com/documents/00ef86a3465d95f1b358b19e/w/b752dc491a31ef71ed32990d/e/ba76bbfe8f1632f72b7bd716?renderMode=0&uiState=643a02690d72e778f044f1a9





Best Answer

  • Options
    S1monS1mon Member Posts: 2,492 PRO
    edited April 2023 Answer ✓
    That will leave a steep shut off. It's possible, but it will reduce tool life. The initial DFM feedback may not have caught this detail, but often when they get into the detailed work on the tool (and there's a PO) then you might get challenged on things like this.

    I would recommend doing something more like this (P/L in red):


    At the very least, you want the shutoff surface to be 5 degrees, but you have room for a gentle ramp which is better for shutoff. Depending on how you want to do it, you can make the parting line have no mismatch, but it will make the nominally flat surfaces need to warp a little.

Answers

  • Options
    eric_pestyeric_pesty Member Posts: 1,607 PRO
    You can use "split face" to save yourself from having to boolean back afterwards. The only thing is that you have to uncheck "tangent propagation" to only draft one side.
    The issue with the "parting line" option when using two sides is that every edge you pick has to have two faces to draft. In you example you have several edges that only have one "side" to draft.
    Here's an example where the split line is higher up so that every edges has two faces to draft:

    https://cad.onshape.com/documents/1999d7ea6b53f445e3424de2/w/cb3b4a2a9c5b62df6e253f55/e/8cf017727ba5662130a1120a?renderMode=0&uiState=643a17710db2af427b1a15e7


  • Options
    nick_papageorge073nick_papageorge073 Member, csevp Posts: 711 PRO
    Thanks for the help @eric_pesty. I played around with it more, and I had forgotten I needed the PL to follow the tangent of the rounds, which I didn't have in the fake example part on my first post. Here is my real production part. No complaints from the toolmaker yet:) I did end up splitting the whole part (not face), and then unioning it back together. I'll try splitting the face on the next one. Thanks again.


  • Options
    S1monS1mon Member Posts: 2,492 PRO
    edited April 2023 Answer ✓
    That will leave a steep shut off. It's possible, but it will reduce tool life. The initial DFM feedback may not have caught this detail, but often when they get into the detailed work on the tool (and there's a PO) then you might get challenged on things like this.

    I would recommend doing something more like this (P/L in red):


    At the very least, you want the shutoff surface to be 5 degrees, but you have room for a gentle ramp which is better for shutoff. Depending on how you want to do it, you can make the parting line have no mismatch, but it will make the nominally flat surfaces need to warp a little.
  • Options
    nick_papageorge073nick_papageorge073 Member, csevp Posts: 711 PRO
    I like that! Its been about 10 years since I did a molded part and I'm rusty. I knew the 5 deg shutoff rule but I was having a brain fart on this. Its such a simple part and I just couldn't visualize the tooling well. Ive used the 5 deg shutoff a lot when making bypassing steel "holes" on the vertical face of a part. Just didn't make the connection with this simple shape.

    Anyway, I know how to change it now if the toolmaker requests it. thanks.

    And yes, I know the "actual" toolmakers cutting the steel don't even look at any parts until the PO is signed. ha ha.
Sign In or Register to comment.