Mirror without copy?

[NormandC]

I'm actually guilty for this.

I did that essentially because I kept running into it again and again: after finishing one body, I would make a new one, while the old one was selected. Result was unpleasant enough for me to put this nonsense block in the code. I also couldn't come up with any reason why one would base a body on another body, but now it's clear there is a good reason.

Thanks for coming forward.

I understand your reasoning. This is basically a usability issue, and it's not something easy to decide on. You're "screwed" one way or the other.

I could give you quite a few more reasons why you would want a Body based on another. I'll just give you two here.

Have you happened to check out the PartDesign Bearingholder Tutorial I & II that Jan Rheinlaender wrote 5 years ago when he first programmed the PartDesign changes? For the past year I've been trying to update it because much was changed when his code was salvaged and expanded by you guys. I also wanted it to be more friendly to less experienced users, and introduce them to a more robust modelling work flow using datum planes.

The first tutorial shows how to model a die-cast bearing holder. Die casting being an imprecise process, the holder is modelled bigger for the casting, then there is some machining done on it. Jan made all features inside a single Body, but I just realized that if this was something I needed made for the company I work for, then I'd need to create two separate parts. One is the die-cast part, and the other is the die-cast part after the machining. So two parts, two drawings.

So a better way in this case would be to end the first Body right up to the "Machining starts here", then create a second Body based on the first to add the feature of the final machined part. This way it would be easier to get separate drawings in TechDraw for each Body. Now that I'm thinking about it, I may very well change the tutorial to propose this method.

Second use case is similar. Almost 10 years ago I was working freelance and designed a complex plastic enclosure. The manufacturing process was injection molding. There were a lot of features to get the basic shape, the details (holes, ribs, mounting bosses...) and finally the filleting. If I recall correctly, there were more than 400 features in total. After about 100-150 features the model was taking forever to recompute after edits, so I used a trick I read from a Solidworks expert: basically what we are talking about here, a Body based on a Body (but in this case, they were separate files). I actually had 3 levels: a first Body defining the outer shape; a second Body based on the first for detailing; and a third Body based on the second with all the fillets added.

[NormandC]

What about a Mirror with an option to sever those links on demand.

The request is rather unusual, I don't know why one would want that. Seems, macro territory.

I've used that too in my line of work... Sometimes you just need to break the history tree and start from a "dumb" solid.

That's how PartDesign mirror works.

Please elaborate, because IMO that's not how it works. For one thing PartDesign mirrors features inside a Body, and we are talking about mirroring a whole body; second, it always remains associative. If you were talking about Part Mirror, then it too always remains associative.

---

I'm not happy with how we have to jump through hoops for these features - and we still have not mentioned scaling. Another thing that I dislike is that a Base feature is always linked to an original solid. I wish I could discard that solid and unclutter the tree. The perfect example for this is an imported STEP part I want to modify. There is no feature history, so why should I need to keep the dumb shape in the tree linked to the PartDesign Body?

This will definitely require some thought. ickby mentioned in the past that the ShapeBinder feature could be expanded to convert the linked shape into a base feature. Maybe that's the solution.

Just as food for thought, here are two screenshots I took today from our old version of commercial CAD software we use. The "Part Copy" tool combines functionality between PartDesign's base feature and ShapeBinder and it throws scaling and mirroring into the mix. Oh, and it also accepts a different coordinate system for placement inside the body. A "Design Body" is a solid, a "Construction Body" is basically a ShapeBinder. When copying as construction body, I can either select the solid ("design") body in that linked part, or a construction body inside it.

[OldDraftsman]

Hi All, has there been any movement on this issue? I am again in need of a Mirrored copy that I can remove some stuff not needed on the mirror-copy.

Currently I have been using Cura Slicer to mirror the parts which it does nicely and instantly, but on this latest object there are a couple of pads on the original that are getting in the way for the copy. There is about 2 hours work in the original, so I really do not want to have to repeat almost all of that just to not include two lumps.

Dare I say it, but if the naming convention (or whatever it is preventing deleting earlier Sketches within a Body) was not as touchy as it is, I could just copy the Body and remove those pads and Sketches.

I have struggled with the Clone in Draft WB, but still cannot get it to see things my way.

[chrisb]

You can use Part->Mirror and add or remove things from that mirror. If you don't succeed you can upload your file and explain in detail what you want to achieve.

[NormandC]

You can use Part->Mirror and add or remove things from that mirror.

As previously mentioned, OldDraftsman prefers the PartDesign work flow - using a Part Mirror will oust the result from PD and require creating a new Body from it.