refine shape option not there

[cue340]

Hi everyone
I have imported an STL I designed in sketchup, its a pretty basic adaptor plate. I was able to create shape from mesh and then successfully make solid. Next I wanted to refine shape my understanding is PART should be selected in the drop down which will make the option Part appear in the top menu and refine shape should be in that part menu. However its not there.

I uninstalled freecad today and downloaded a fresh copy and re-installed it.
version: 19
revision number: 24276(Git)
release date: 2021/03/11 19:48:53
OS: Windows 10 Version 2004
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24276 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: a88db11e0a908f6e38f92bfc5187b13ebe470438
Python version: 3.8.6+
Qt version: 5.15.1
Coin version: 4.0.1
OCC version: 7.5.0
Locale: English/Australia (en_AU)

I spent quite a bit of time going through all different menus, if you select openSCAD in the drop down there is a refine shape feature in the openSCAD menu but this just deletes the part completely
I also checked the forums but couldn't find anyone else with this issue.

I also tried to find a way to join two shapes together manually, the closest I found was make a union of several shapes, but I cant get this to do anything whatsoever. (More than likely this is for something completely different)

I thought simply deleting the extra lines would be simple, but all i can do is delete the entire part.

Maybe I just need to find an older version that will match the tutorials I was able to find.

Thanks
cue340

[jmaustpc]

G'day and welcome to FreeCAD.

I have imported an STL I designed in sketchup, its a pretty basic adaptor plate.

If you attach the file and/or a screen shot then we may be able to help more. I suspect you have a miss understanding about what Refine can do and/or have unrealistic expectations.

STL is a garbage format, in that it is a lossy format so can never be simple or automatic to convert it back into a proper CAD format. It can not describe curves, everything is approximated by triangles.

Refine is still in Part menu but under the copy sub menu...

Screenshot_20210422_104848.png (174.13 KiB) Viewed 4356 times

Maybe I just need to find an older version that will match the tutorials I was able to find.

That is usually a very bad idea in FreeCAD terms. Also note that anyone can write a tutorial, they will vary in quality and relevance, may have been only intended to show something specific, the biggest problem is just that they are simply out of date. FreeCAD 0.19 has something like 7 thousand bug fix and new feature updates just since the last version, 0.18. Slo tutorials can age quickly.

Don't forget to read the FreeCAD wiki, it is not perfect but does contain an enormous amount of useful information.

Jim

[cue340]

Hi Jim
Thanks for the info, very helpful.
I will remember to attach a screen shot next time.
I managed to use version 17 to "refine shape" yesterday while waiting for my post be approved.

It seems modifying this file I created in FreeCAD is impossible is this correct?
I cant seem to do anything with it whatsoever, cant move a line or add a line, nothing. All i want to do is extrude it 2mm

I understand I need to start designing in FreeCAD but I do have many designs I have already created where exact accuracy is not paramount.

I thought an import would fairly straight forward, but unfortunately I think it would have been quicker to learn to use FreeCAD and start the models from scratch.

[jmaustpc]

I managed to use version 17 to "refine shape" yesterday while waiting for my post be approved.

Generally it is a very bad idea to have obsolete FreeCAD versions on your system, unless you are an advanced user that understands the issues and consequences, but even then why bother?. It is impossible for 0.17 to open a file created in 0.19 reliably since the newer FreeCAD contains new things that 0.17 couldn't know what to do with. FreeCAD 0.19 will have no problems opening old 0.17 files since it is backwards compatible.

I thought an import would fairly straight forward, but unfortunately I think it would have been quicker to learn to use FreeCAD and start the models from scratch.

in many cases, yes definately, but it's not just about speed, its mostly about quality and details.

The problem is you have used a very limited format, STL. It is just a mesh of triangles. FreeCAD can import it, can convert to a simple non-parametric solid but that simple non-parametric solid will be made up from sometimes many thousands of triangular faces made from that triangular mesh. CAD format to STL looses all curves and colours etc. so it permanently looses that data so it is always by definition going to be impossible to go straight from STL to CAD format, because that data is just simply not there in an STL. Imagine some one gives you a colour photo, you fax it on an old fashioned black and white fax machine, how could that receiver of your fax ever get the colours back again? Of course they can't because the colour data is just not there in the fax copy. That data loss is similar to what happens when you go from any CAD file format to STL format.

I cant seem to do anything with it whatsoever, cant move a line or add a line, nothing. All i want to do is extrude it 2mm

It will be (if it is a valid solid) just a non-parametric simple solid so you can not just edit it by for example looking for Length parameter and just changing its value. It is one solid made up from component faces, edges and vertices. You generally can not just select a single edge and drag it expecting the solid to stretch or something, that is called direct modelling where as FreeCAD is a Parametric Modeller hence everything in FreeCAD is defined and adjusted via its parameters.

But what you can topically do is, if the solid is valid, add or cut things to it, in various ways. Most commonly by Booleans with other solids in Part WB or by sketches and solids in PartDesign Workbench. It is also possible to blow apart your solid into its component geometry, delete some faces for example then create a replacement for the deleted stuff, then re-combine it all together again, depending one exactly what your model looks like and what you want to acheive, but doing so it more of a hack for emergency use rather than a proper work flow.

Attach a file and tell me what you want to acheive and I will have a look and suggest something. But you must use FreeCAD 0.19 or newer as the 0.19 files will not reliably open in earlier FreeCAD versions. There are well over 7 thousand bug fix and new feature commits of code in FreeCAD 0.19 after 0.18, 0.18 was also many thousands of commits beyond 0.17. Trying to use 0.17 is like trying to drive a 1930's car.

I have to go do somethings on my farm now but I will be back in a few hours, if your file is private or something you could send me a private message or even send me something similar enough so you can understand the principle of what I end up showing you.

Don't forget that editing these STL models will be really a bit of a hack, to help get you out of your current situation, it is not a good or recommended normal work flow.

Jim

Jim

[cue340]

Hi Jim
Thank you so much for taking the time to go through all this, I really appreciate it. It makes perfect sense what you are saying, I did what you recommended and moved back to 19, I went through the steps I did on the previous model that had worked before, and the conversion was successful . Next I re-edited the version and I was having trouble with in Sketchup once again and was able to convert it this time!
I am not sure if I was doing something wrong over and over or there was an issue with the install on my laptop or maybe the stl had a glitch. Anyway I managed to get the file out and over to the CNC guys.

Going forward I will spend some time on FreeCAD every week to get familiar with it so I can design here instead of in Sketchup.

Again thank you for your time
Quinton

[papyblaise]

I have been looking in vain for this option since I switched to V20, I can no longer find it in "Preferance