Best Of

Hi @steve_shubin

thank you for sharing that document and your solution.

In my sketch, there were no constraints between those two points marked by your red arrow and the 35mm construction circle. However, assuming you meant that I should remove the 2 points that the red arrows were pointing to, I did that and still got the same error. I'll post the screenshots in my next message.

I do appreciate you looking into this issue I am having, however, that is not the point of my post. @andrew_kleinert described it well in his now missing post above. These errors keep happening and it's difficult to figure out if it's me or if it's OnShape. The lack of feedback about errors makes troubleshooting them time consuming because you aren't given any clues to narrow down your search for a solution. You then face the decision of either starting again (often quicker than troubleshooting) or starting again and spending even more time to write a bug report.

You know the saying that one should learn from their mistakes? That isn't possible with these types of errors. Not in a practical sense anyway.

Without access to your document, I am GUESSING this MIGHT be where the problem is.

But it is a big guess at this point. Looks like things might possibly be fighting with each other at each of these points.

I believe there are points coincident to the 35mm diameter construction circle where the red arrows are pointing to that should be removed and this would possibly free up the problem you are having.

Notice that in my sketch at the link above, I did not have any such coincident points, and as such, this is why I was able to make the 4 chamfers at the same time.

Any constraints where the RED ARROWS are pointing to in the post/picture above should be removed.

If you want to make that 35mm construction circle coincident to the vertical line, the constraint should be placed where the GREEN ARROW is pointing to below.

Here Onshape is able to chamfer one edge but fails to chamfer another edge that is identical to the first. Not only is the failure to chamfer illogical, the error message gives the user nothing. As a user, you are left to figure out whether it's your sketch, whether it's a bug, or maybe you clicked the wrong entity? In short, your troubleshooting options are all options. You get zero clues that might narrow down your search for the solution.

Except, there is no error. That 4th edge is able to be chamfered, without alteration. Just do it in a separate operation. When you figure this out, especially after you went searching for why the error occurred in the first place, then you have just wasted your time.

I draw a sketch that is symmetrical. The circles are symmetrical by definition. The edges in the upper half of the sketch are mirrored from the lower half. Therefore the shape I extrude should is symmetrical.

When I go to chamfer the extruded shape, I can chamfer the 3 edges. But not the 4th. Except, I can chamfer the 4th, just as long as I do it in a separate operation, proving that the chamfer tool here in this example does not work consistently. [edit: add "Or, instead of 2 separate operations, just pick 5 edges and that 4th edge, that could not be chamfered before, is now chamfered."]This type of illogical inconsistency is frustrating, makes me second guess myself and wastes users time.

Please Onshape, get rid of these types of errors. They occur regularly for me and turn simple tasks into frustrating wild goose chases often resulting in solutions like this one (which don't always work), or the redoing of work.

The Sketch:

The Shape:

Chamfer tool can do 3 edges:

But it can't do 4 edges and can't tell me why it can't do 4 edges:

Expect it can do that 4th edge: