Quantity of parts or sub-assemblies in the assembly in drawings

jan_kvapil507

Hello. I am new to the onshape and I have a problem I can't figure out. I need in my drawings the quantity of the part from assembly and possibly a list of subassemblies.

For example. I have part P-001 which is used 2 times in sub-assembly SA-001 and 1 time in sub-assembly SA-002. SA-001 is used 3 times and SA-002 is used 4 times in the main assembly. When I am creating a drawing for P-001 I need to have a table or a list or at least a note that the total quantity is 10 (2x in SA-001 times 3 in the main assembly plus 1 time in SA-002 times 4 in the main assembly). Also, a table containing which sub-assemblies contain the part would be great but not necessary. The same thing for the drawings of the sub-assemblies, I need a quantity of how many times it is used in the main assembly, i.e. for SA-001 is quantity 3, and for SA-002 is quantity 4.

I understand that I can set the quantity by hand but I would rather not because it is prone to mistakes, especially for bigger jobs. The last one I did had 179 unique parts and over 600 instances and during revisions, we repeatedly switched parts.

Does anyone know a way to do it? Maybe a featurescript? I feel I am missing something simple and apologize if it is a rudimentary question. Thanks

nick_papageorge073

I believe you can also hide rows on the BOM table. I know you can split the table into multiple tables as well. That might also work. But your solution is probably quicker. 

nick_papageorge073

Are you looking for a "where used" of individual parts? Or are you looking for a BOM table on a top level asm drawing? If the latter, it's very simple. Insert the top level asm in a 2D drawing. Add a BOM table. Select "flattened" on the BOM table insertion dialog box. That will add up all of the same PN across all the sub-asm's. Add item callout balloons if you like.

jan_kvapil507

Hello, unfortunately, no. I didn't find a way to add anything from the "where used" to the 2d drawings. BOM I use regularly for assemblies but I cannot use it for part drawings.

To elaborate on the example above. After finishing the model I prepare 2d drawings for every individual part separately and send them to fabricators or contractors for fabrication. They need to know the quantity of that particular part to fabricate. We never send assemblies to them, that's the company's IP. For now, I write the quantity manually, so I'll look into the BOM of the main assembly and write the number on the part drawing.

I am looking for a way to automate this because in big projects we can have hundreds of parts and almost every time there will be revisions. The obvious way would be to add just one row from the main assembly BOM that contains only the part's information, but I didn't find a way to do that in Onshape. But really any way that would write the quantity on the drawing and update it with the main assembly would be a huge help for me.

jan_kvapil507

Unfortunately, no. I am using BOM regularly, but I am talking just about part drawings. We are sending 2d drawings of the specific parts to fabricators or contractors and they need to know the quantity of only that part. Something like adding just one specific row of the BOM that contains information only about the part, but so far I was able to add only the whole table.

nick_papageorge073

I’m not in purchasing but I’ve never heard of writing on a drawing the qty for a vendor to make. That’s part of the purchase order. That does not even scale for example, if you want more of the “top level asm” for the next order. You’d have to update each individual part drawing to update the qty written on it, and then send all new drawings to each vendor. 

PeteYodis

I agree with @nick_papageorge073 Putting process information on drawings is not a good idea and leads to changes of drawings just for process change sake, not for material design requirement changes.  It's best to control process information separately from a drawing.  

jan_kvapil507

Hello, thank you for your answers. We are happy with this system. Putting all the information in one file has significantly lowered mistakes and errors. I'll give you another example. When the part is ready, we send a driver for it. If he needs to check 2 different files during a pick-up, the probability of a mistake is double. Also, we are fabricating more than half of the parts in our workshop, same thing. Or when the Quality/compliance supervisor is checking the products before expediting. That's only a few that I can think of right now.

Nonetheless, thanks to suggestions from @nick_papageorge073 I was able to devise a solution. I added the main assembly BOM to the part drawing but put it outside of the drawing's borders. After that, I just used a comment bubble with a leader. It is exported without the table but the quantity is still there. So problem solved 

nick_papageorge073

I believe you can also hide rows on the BOM table. I know you can split the table into multiple tables as well. That might also work. But your solution is probably quicker. 

jan_kvapil507

That is very interesting. I wasn't able to do this. Do you know how? Or link? Thanks

nick_papageorge073

I couldn't find if/how to hide a row. But here is how to split the table, if it helps you.