Hello Michael.

I am very new to cad programming but I really like MoI as it was reccommended by a professional jewellery cad programmer. I am having trouble with chamfer etc. On selecting a ring shape (circle and sweep) only one side will chamfer no matter what I do. I have tried selecting whole piece, no success, after that tried turning the piece, edges on their own, even mirror and copy. Every time chamfer occurs on just one edge of the ring, repeatedly. Could you tell me why this is happening and how I can get round it please. Thanks.

Hi Barbara,

I'm not Michael but welcome to the forum and the world of cad design.

Usually for us to help you out with your problem it'll be better if you posted the model or part of that's giving you the problem, in that way the guy's here can analyse the model and guide you through the best way to fix it, with words alone it's quite difficult to give you an answer.

Cheers
~Danny~

Hi barb, welcome! And yes like Danny mentions if you can please post the 3DM model file as a file attachment here that really helps a lot in analyzing your problem, there are a lot of potential problems that can prevent filleting and chamfering from working well and it's really hard to know which particular thing you might be running into without seeing your actual model file.

Thanks,
- Michael

Hello again. Thanks Michael. I can only get half the ring chamfered.
I have tried other rings but no luck with any filleting on more than one side, inside or out .
Barbara

Hi Barbara,

Suggest a fresh start with a new rectangle, revolve about the z axis.

There is something wrong with the bottom of halfchamfer.

Did a boolean diff, with a plane, and discarded bottom slice, and chamfer now works on the smaller ring.

hi there

that's got something to do with the bottom seam (may be michael will hop in with an explanation, i really can't remember) ..so a workaround would be

1 separate the object into faces
2 rotate the bottom surface just a bit
3 join to make solid
4 select edges ( are a bit cluttered now)
5 chamfer

but to be honest..just rebuild the ring like bemfarmer suggested.







~ marco

Hi Barb -

I make rings all the time in MoI. I like to create a closed profile of the ring using the 2D drawing tools, then sweep that profile around a circle. This allows a precise definition of chamfers and rounded edges without using fillet or chamfer after the fact. Click on attachment image.

Ed

Hi Barbara - try using the Revolve command for building these kinds of circular type forms - Revolve will make much more precise and also lighter weight geometry for these kinds of things and that should avoid various problems.

It looks like in your case here you probably used Sweep along a circular path instead of Revolve? Sweep has a problem on some closed curves where it can make a surface that is not quite all the way smooth at the closure point, it can have something like a 1 or 2 degree deviation from being smooth right there. That kind of small shallow deviation then is something that fillet and chamfer don't like to deal with very well since fillet and chamfer surfaces do not meet up exactly at sharp juncture points and have to be extended and trimmed and also corner patches put in, all of that is difficult to handle for very shallow angle juncture points.

I am planning on tuning up Sweep for these cases to make a totally smooth surface result, but it's unfortunately not an easy fix, it's a problem in the geometry library.

But in the meantime if you use Revolve for this type of thing instead it should work better.

- Michael

Thanks so much for all the help. I will try everything out. Busy making real rings at the moment.

Just a side note, you can make that chamfer work by deleting that bottom face, then select the enitre object and hit the construct-planar command. FYI.