Advice on Assembly Structure or Methodology for Populating Instances in Large Quantities

Kyler_Walker

I am wondering if anyone has advice for a methodology of populating fasteners or other high quantity instances in high level assemblies without greatly slowing the performance of the assembly.  Once I have replicated hundreds of screws, washers, and t nuts in my top level assembly, adding new mates becomes very slow.  I like to include all of these fasteners in my assembly to have a complete BOM and know what I need to purchase, but the slow performance really is detrimental to my productivity.  Does anyone have a workflow or a method of structuring their assemblies to avoid the problem of assemblies slowing down when high quantities of instances are added?  I think I have heard something about keeping the number of mates per assembly under about 30, but I don't see how this is possible without creating extraneous subassemblies.  Any advice would be appreciated.  Thanks.

eric_pesty

I would make sure to use the replicate feature (or patterns) and avoid inserting too many fasteners separately.

If you are already doing this, you could create a configuration checkbox to toggle the suppression of the fasteners, this way you can have them suppressed most of the time and only turn them on when you need to export the BOM (or on a drawing).  A simple way to do this is to put all the "hardware" into a folder in you assembly and toggle the suppression of the folder. If you have complex subassemblies you could also create similarly "simplified" configurations in your subassemblies. 

Creating sub-assemblies wouldn't really help as all mates are solved at the top level in Onshape.

Another thing to look into would be to add "group mates" to your fasteners which I think "overrides" the other mate types so this might help (if you change something and need the positions to be re-calculated you just temporarily un-suppress the group mate, let it recalculate and unsuppress it again)..

Kyler_Walker

Thanks for the advice.  I use a lot of replicates, but I generally try to avoid patterns because they are less flexible.

I like the idea of suppressing and unsuppressing a folder.  I have been reluctant to use a checkbox configuration because it feels like it slows me down to add all those configurations.  Dragging and dropping into a folder is easy though.

This group mate techniques is intriguing.  You are suggesting that I position all my instances with fastened mates, group all of my instances, then suppress all but one of my red fastened mates?  I almost never use group mates because they are totally inflexible, but toggling back to fastened mates might solve this issue for me.

eric_pesty

What I wrote about the group doesn't make a lot of sense, I think I was thinking about it when talking about sub-assemblies: if you have a lot of mates in a sub-assembly (for example a bunch of fasteners), I think you can group them at the top level without causing an error in the sub- assembly mates, but I am not 100% sure. If you have to suppress all the individual mates after adding the group to prevent error it doesn't help as that's a lot of work especially since we can't put mates in folders (come on Onshape devs, we need this!) so this probably isn't helpful...

For all around performance it's hard to beat suppressing them when not needed... A folder controlled by a checkbox is very easy to manage as all you have to do is drag any fasteners (and replicate features) you add to the folder and they will toggle on and off with the rest. Even if you have to add configured folders to your sub-assemblies so everything suppresses at once it's really quick and easy to setup in Onshape.

Kyler_Walker

I didn't realize that I could configure the suppression of folders.  That really simplifies the turning off of large quantities of instances.  Thank you for alerting me to this.