Proper way to indicate features on Sheet Metal (comaptible with Drawings)

n_schoemaeker

Hi all,

I'm trying to make a very simple part in Sheet Metal. This is basically a U-Shape part, with two slots on the vertical parts to slide something inside.

The issue I have is that Sheet Metal behaves curiously: we are very limited in what we can do before we "Finish Sheet Metal", but then everything which is done after cannot be made visible on blueprints (on the flat pattern).

I'm wondering if this is OnShape being still immature on Sheet Metal, or me badly using it

I've made a document in which I'm demonstrating what I'm trying to achieve: https://cad.onshape.com/documents/44537e7cfefd049c6b5038e8/w/8833def07fd24a5068c53274/e/03be1a7a7e9695268581d611

So the blue part on the left "Target Part (standard Extrude)" is what I'm trying to achieve: a simple U-bend with two slots.

On the right, in gray is the Sheet Metal part I have. I have started from a simple three segments U on a sketch "SM Master Sketch" .I have then started a Sheet Metal part and set the desired bend radius etc. It gives me a trivial U-bend shape.

But then when I try to cut out a slot on the sides, I can't "partially" cut it, no matter to depth (dimension 0.8 in sketch "Slots") I set, it cuts the entire thickness of teh sheet metal, and thus create three parts. You can visualize this by unchecking the Configuration "With Finish SM" which will suppress the "Finish Sheet Metal model 1" feature.

The only way I found was to finish the sheet model, and then the part behaves like a standard part (so check back the Configuration checkbox).

It would be okay with me, expect than when I create the Drawing for this part and insert the flat pattern for my sheet metla supplier, every modifications made after " Finish sheet metal model 1" do not modify the flat pattern (as advertise by the feature). But in this case, the slots must clearly be made with a CNC on the flat sheet beforte making any bends, so it is my understanding that they should appear on the flat pattern.

Basically, the way this will be manufacturer is: take a flat sheet of aluminum, create the two slots with a CNC, then bend the sides. Done.

By the way I have a similar issue with another part where I must have countersunk holes on the part. If we don't use "Finish sheet metal model 1", then the holes are just circular cuts but aren't countersunk, if we do use "Finish sheet metal mode 1l", the holes are countersunk, but I can't have them on the flat pattern, and again: it's a case when they clearly must be done before doing any sheet metal bending.

So what's the proper way to making such a part? I absolutely need to have Drawings reflecting this because otherwise I can't have the part manufactured. Is OnShape's Sheet Metal features still too early in development? Am I doing something wrong? I'm clearly not an expert in Sheet Metal, but those parts are simple enough that I don't think I'm making bad assumptions in the way they are going to be manufactured

I hope it's clear enough.

Thanks for your time and your answers!

Cheers, have all a good day.

lana

Onshape sheet metal does not support partial depth cut.  You can use sketch in flat ( see Sketch 2 here:  https://cad.onshape.com/documents/cf2665bd91c643031fe6d4b6/w/57ea2ad191fc3f4fe7d8713c/e/294a0747fa8d5f685c1a735d) to draw the slots and then show the sketch in the drawing view.

n_schoemaeker

Thanks for your answer @lana , and sorry for the delay. I went to holidays then forgot about this until I needed it again!

Okay so it's not just me: OnShape does not support this, all right. Too bad

It's the same for countersunk holes, too I suppose?

Okay for the sketch in flat, I saw your example and indeed that would allow some representation on blueprint, but since the cut is not actually made, it means I can't specify it in the blueprints (through a section view for instance). And maybe more importantly: the cut is not actually made in the 3D model either, so if I had to slide it in an electronics board for instance (as it's my case), I can't actually do it

I think I'll make a feature request because that's very handicapping for me. It means I have to make two configuration on the part, one for the 3D model and part of the blueprints and one for the sheet metal:/

Anyway, thanks for answering me on this!