# Deriving Parts Without Sketches

We have built about half of our game design challenge field in a part studio with the center of the field (edge of the half field) being the origin. We can then derive that half twice into another part studio and rotate one of the halfs 180 degrees around the origin and change some colors to get basically the full field.

One problem we have is that any planes and unused sketches in the half field part studio become visible when they are derived into the full field part studio. Also they don’t get rotated with the rest of the geometry. How can we avoid these issues?

If you’re doing a 180 degree rotation, there’s no point in doing a derive, since they’re the same part. If you’re just doing this for the colors, you can set a configuration on the parts to make them the color you want.

If the intent is that the parts are mirrored, then you can do feature mirrors that include a plane or similar.

If parts are identical other than color, I wouldn’t create duplicates.

Some relevant courses in the Onshape learning center if you go down the configurations path:
https://learn.onshape.com/learn/course/introduction-to-part-configurations/part-configurations/what-are-configurations

https://learn.onshape.com/learn/course/assembly-configurations/introduction-to-assembly-configurations/what-are-assembly-configurations

4 Likes

To add onto that, though, if you are set on using derive, I believe hiding the derive feature should hide those sketches without hiding the geometry.

3 Likes

Our field is rotationally symmetric like Infinite Recharge but not mirrored like 2014 or 2018. So a simple mirror operation does not work (at least I haven’t figured out how it would work).

Perfect! I thought hiding the derive would hide the geometry but you’re right that it doesn’t.

1 Like

In that case, a transform would probably be your best bet.

I did try a mirror and then a transform but I couldn’t figure out how to keep the half field from going upside down.

It looks like because we’re using 2 derives when new geometry is added to the half field it does not get auto-added to the selection of the rotation and only shows up on one side of the field. Is there a way to select the entire derived feature in the selection of the rotational transform so that future geometry is automatically added?

If there’s a better way to mirror instead of the 2 derived features, that would be great as long the problems in previous posts can be solved.

Whenever you’re selecting things in Onshape, you have the option of clicking a feature (such as a sketch or a derive) in the feature tree on the left of your screen, as opposed to manually selecting the geometry created by that feature. If you do so, the selection will point towards the things created by that feature, resulting in a much more robust reference that automatically adapts to changes in that feature. In your case, by clicking the derive in your feature tree when selecting your parts to revolve (as opposed to manually selecting the individual parts in the graphics window/parts list), you will make it so that the revolve always points to every part created by the derive, thereby creating a more robust reference that will automatically update to future changes.

Since your field is rotationally symmetric, you should be able to get the results you want with either a rotate transform set to copy parts or a circular pattern set to new. You shouldn’t really need more than one feature to accomplish what you’re trying to do, and having less features should be a lot better for performance since your part studio is presumably very large.

On the topic of performance, you can also get significantly better performance with derives by having your derive point to a version in your part studio instead of main. Your derive won’t automatically update anymore (you’ll have to manually create a version and update it), but the reduced regeneration times are often more than worth it. I hope this helps.

This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.