Best way to have multiple, identical features in a model

øyvind_kaurstad

Being a CAD novice, I've got a question regarding modelling.

The other day I was drawing a circuit board (PCB) holder for two sandwiched circuit boards. The curcuit boards are connected with one connector, and sits in different heights.

Now, the holder is simple. It's a base plate with vertical standoffs at the hole posistions for the PCBs, and the standoffs have different heights (since there are two PCBs). The standoffs have a diameter that is larger than the PCB holes, and at the top of the standoffs I wanted to have snap-in mechanism. However, in the first iteration I just had a small cylindrical peg that would just keep the PCB in place sideways.

Now comes the question: This snap-in mechanism would be identical for all of the standoffs, and it would be tedious to re-draw it at each standoff. Creating the snap-in as a separate part therefore seems logical, but what is the correct way to copy and align this part to each standoff? Mate connectors?

3dcad

@øyvind_kaurstad Did you try creating part in new studio and derive it to your main studio and move in place using mate connectors as I suggested in the beginning?

I have done many parametric models with this workflow and I don't see any reason why it wouldn't work in your case too.

noa

øyvind_kaurstad if you want to keep all the parts in the same Part Studio and use Mate Connectors, you can with Transform. First add mate connectors everywhere that you would like to copy the part to, as well as on the part you'd like to copy. Then, use the Transform feature: switch from "Translate by line" to "Translate by mate connectors" and check the box "Copy part." You'll have to repeat this for each copy but this should work.

3dcad

You can create it as subassembly and mating is easy but if you wan't to stay in part studio you can use derive + transform with mate connectors. 

øyvind_kaurstad

In my case I have no need for an assembly, because you can't export from an assembly to an STL for printing.

Derived seems to be for use between different part studios. In this case, I could of course create a separate part studio for my snap-in part, but somehow that seems a bit weird.

jakeramsley

If you have already made the part, you can use transform + copy part option to create duplicates of it.

øyvind_kaurstad

I get that multiple copies of the part is the way to go, my question was more how to position the copies. It does get tedious if they will be in different planes and positions, which is why I thought of mate connectors. In this case, the mates are just used to fix multiple part copies to one main part, and not for any motion purposes in an assembly. The end result is just one solid part. I see no other way of referencing two parts to each other. A translate by xyz is fixed, so if the target area for the copy is changed, then one has to readjust the translation values.

Are there any major downsides to use mate connectors like I've outlined above?

billy2

I was thinking a derived part.

I offer this up because no one else has, it's probably how I would attempt your challenge. 

daniel_chow

The problem I have with extruding multiple parts / multipart as I understand it from THIS onshape cantilever tutorial is that you would still need to draw the entities in a sketch before you extrude them. Although the tutorial shows you several tips on using the mirror and equal commands to make it easier, you still have to draw them. 

I think I have the same question on my model that 'm trying to build. I'm looking for a way to COPY sketch entities from one sketch into a different sketch on a different plane, then be able to snap those entities into place. 

Here is the thread I started that i think is related to your question. 

øyvind_kaurstad

In my case, I could also of course copy a sketch and the extrude that, but that's cumbersome. It wouldn't be just one sketch either, since what I want is a part/subcomponent that I want to have multiple entities of, and I want to edit just one to change all of them.

Creating this as a separate part then makes sense, but I also want to attach it to some other features on my main part. If I translate copies by x/y/z, my part will break if I then need to resize or move the feature that the copied part is attached to.

daniel_chow

That makes sense, well I haven't experiments with this feature much but you CAN copy a part. Simply right click the part on the bottom left corner of your parts assembly and COPY. It'll ask you to transform your part, how you want to offset, transform it ... I haven't experimented with this feature too much, I just know it exists. 

It sounds like you want to to the same thing as me. Copy entities from one sketch into another and modify it to add it to an existing part. 



My questions on this method are does it copy the sketches too? I don't think so as it would have to copy all the steps to create the copied part. Can you move it around, snap it in place to a point on a sketch or a face / edge of another part? I don't think so but it appears you can transform it around. 

So the three methods of creating duplicate parts discussed so far:

1. Multi-part extrusions as described in this OS tutorial,
   But you would have to redraw the sketch then extrude them all at once as described in the tutorial. Not sure this would work with complex sketches. The tutorial shows multipart extrusions on spacer pins, a relatively simple sketch to multi-extrude together. 
   
   
2. Copy entities from one sketch into another
   I believe this allows you to not just modify the sketch, but copy parts of the entities you want and modify it. I wanted to copy a sketch, modify it and extrude / add it to another part. By copying part of a prior sketch I hope to save some time and not have to redraw everything from scratch. My question is posted to this  thread 
   
   
3. Duplicate a part
   As described in this post. 
   

Anyone else? 

3dcad

@øyvind_kaurstad Did you try creating part in new studio and derive it to your main studio and move in place using mate connectors as I suggested in the beginning?

I have done many parametric models with this workflow and I don't see any reason why it wouldn't work in your case too.

noa

øyvind_kaurstad if you want to keep all the parts in the same Part Studio and use Mate Connectors, you can with Transform. First add mate connectors everywhere that you would like to copy the part to, as well as on the part you'd like to copy. Then, use the Transform feature: switch from "Translate by line" to "Translate by mate connectors" and check the box "Copy part." You'll have to repeat this for each copy but this should work.