Moving part origin to different point?

Here's the place for discussion related to CAM/CNC and the development of the Path module.
Forum rules
Be nice to others! Respect the FreeCAD code of conduct!
User avatar
ex-Gooserider
Posts: 27
Joined: Sat Jun 10, 2017 3:51 am

Moving part origin to different point?

Post by ex-Gooserider »

Quick Summary:

Restarting to learn FC, most of my prior CAD experience is in LibreCAD, which I like, but I need a tool that can generate CNC machining paths, as hand writing G-code is PAINFUL! :(

I've just completed my first part, and am not happy with where the origin ended up. I'm used to putting my part zero on the top-rear-upper corner of the part surface, to match how it will go into the mill vice and make it easier to set the part zero's.

I got the X-Y zero right in the first sketch, but when I padded it to make the body (mostly following the steps in https://youtu.be/uh5aN_Di8J0 if that matters) the Z axis zero ended up on the BOTTOM corner, not the TOP where I wanted it.... It appears the pad extruded the sketch up on the Z-axis, when I would have wanted it to extrude down.

Does this matter for generating the G-code in the Path workbench, and how can I fix it? Is there a way to set things up so it doesn't happen again on future parts?

I may not be using the right words, but didn't find anything that looked relevant when searching the docs, wiki and forum.

Requested info -

Code: Select all

OS: Manjaro Linux (KDE/plasma)
Word size of FreeCAD: 64-bit
Version: 0.20.2.29603 (Git)
Build type: Release
Branch: makepkg
Hash: 930dd9a76203a3260b1e6256c70c1c3cad8c5cb8
Python 3.11.3, Qt 5.15.9, Coin 4.0.1, Vtk 9.2.6, OCC 7.6.3
Locale: English/United States (en_US)
Installed mods: 
  * Help 1.0.3
bot-plate-2.FCStd
part file
(29.38 KiB) Downloaded 84 times
Linux User, FSF Member
"Inmate" at Artisans Asylum, Allston, MA, USA
Primarily use FC for CNC machining w/ some 3D printing, etc.
edwilliams16
Veteran
Posts: 3106
Joined: Thu Sep 24, 2020 10:31 pm
Location: Hawaii
Contact:

Re: Moving part origin to different point?

Post by edwilliams16 »

Check the reversed option on the Pad and it will go the opposite way.
GeneFC
Veteran
Posts: 5373
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Moving part origin to different point?

Post by GeneFC »

ex-Gooserider wrote: Thu Jun 08, 2023 12:48 am
There is a lot of flexibility built into the Path Job setup that allows placing the origin exactly where it is wanted.

It is probably best if the original model is placed correctly, but it is very easy to offset the z-position in the Path WB.

See the "Setup" tab in Job Edit.

Gene
jbraun
Posts: 252
Joined: Fri Sep 18, 2020 5:41 pm

Re: Moving part origin to different point?

Post by jbraun »

Your question is answered but here's something for future reference anyway.
Link to video -> https://youtu.be/g55hiFvq5Ns
(I tried to embed but failed)
Relevant section from 5:30 to 6:50.
btw: near the 6:50 mark Sliptonic turns off the part model and turns on the model 'inside' the job. That surely confuses a few people the first time they use Path :)
For English help on youtube check out Joko Engineering or Mango Jelly Solutions.
Look for recent videos, this software is updated at a rapid pace.
User avatar
ex-Gooserider
Posts: 27
Joined: Sat Jun 10, 2017 3:51 am

Re: Moving part origin to different point?

Post by ex-Gooserider »

Thanks, I've been starting to try to figure out the Path workbench, mostly using this video https://youtu.be/9aqmyJ2Fue4 and have figured out the origin issue I think... The video was listed in the Path bench description in the wiki.

What is stopping me right now is the tool step - I get the box shown at about 0:40 in the above video, except that it doesn't have the "Tool" box at the bottom. At about 0:45 he hits that box and expands it into a box that lets you define the tool type and size, etc... I've been totally unable so far to figure out how to define the tools that I want to use, nothing in that first box is clickable outside the parameters, and I can't find anything in the menus that seems to let me do it.

I found the button that toggles the tool selector, but it doesn't seem to have a way to add a tool... I don't seem to have the button that opens the library editor, which seems like it ought to do the right thing?

I'm sure it will seem easy once I figure it out, but right now I'm stumped!

ex-Goosrider
Linux User, FSF Member
"Inmate" at Artisans Asylum, Allston, MA, USA
Primarily use FC for CNC machining w/ some 3D printing, etc.
GeneFC
Veteran
Posts: 5373
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Moving part origin to different point?

Post by GeneFC »

ex-Gooserider wrote: Fri Jun 09, 2023 5:06 am What is stopping me right now is the tool step
The tool library was completely rewritten a couple of years ago. I believe that video is using the old library.

If you look at the FreeCAD wiki there will be an explanation.

https://wiki.freecad.org/Path_Workbench

Also, I recommend the videos from sliptonic. Focus on the more recent ones from the past couple of years that show the new tool manager and library.

https://www.youtube.com/@sliptonic/videos

Gene
User avatar
ex-Gooserider
Posts: 27
Joined: Sat Jun 10, 2017 3:51 am

Re: Moving part origin to different point?

Post by ex-Gooserider »

Well the Wiki page shows the tool editor as one of the buttons in the dock, but it isn't there now... However the entry for the editor itself gave me the current ways to access it from either the selector or the menus. I think I've now figured out how to add a new tool. What I'd found confusing was the way it would asking you to select a shape file, and then an existing tool file. Not sure why but the first time I tried it, it wouldn't let me enter a new file name, but this time it did...

However I was also having problems with the initial part model, I kept getting errors in the report view "Recompute failed! Please check report view." :? (seems recursive, especially with no other info given) Searching the wiki w/ that string didn't find anything (I didn't try the forum)....

Repeatedly looking at all the different items showed the last sketch didn't seem lined up with the pad sketch, and I couldn't find a way to get the zero point of that sketch to match the zero point of the pad sketch :x I ended up deleting that sketch and going into the previous one and modifying it to put all the holes I was adding in that one, so that I now just have one sketch that I padded for the basic outline, and one with the holes I'm drilling....

Is it legitimate to have two feature sketches mapped to the same face of the pad?

ex-Gooserider
Linux User, FSF Member
"Inmate" at Artisans Asylum, Allston, MA, USA
Primarily use FC for CNC machining w/ some 3D printing, etc.
User avatar
Shalmeneser
Veteran
Posts: 9474
Joined: Wed Dec 23, 2020 12:04 am
Location: Fr

Re: Moving part origin to different point?

Post by Shalmeneser »

ex-Gooserider wrote: Thu Jun 08, 2023 12:48 am 1) I'm used to putting my part zero on the top-rear-upper corner of the part surface, to match how it will go into the mill vice and make it easier to set the part zero's.

2) I got the X-Y zero right in the first sketch, but when I padded it to make the body (mostly following the steps in https://youtu.be/uh5aN_Di8J0 if that matters) the Z axis zero ended up on the BOTTOM corner, not the TOP where I wanted it.... It appears the pad extruded the sketch up on the Z-axis, when I would have wanted it to extrude down.

3) Is it legitimate to have two feature sketches mapped to the same face of the pad?
1) There are different origins in a FC file :
* the global origin
* the origin for the body (dependant of the global origin)
* the origin for the sketch (dependant of the body origin)
You can change the origin of body and sketch with Attachment (Basic_Attachment_Tutorial)
You should find how to use each origin to help you in your job.
In your 1st file, the body is nearly symmetric and you should use this symmetry inside the body.
The small arc center should be at the origin of the body/sketch.

2) When you pad a sketch, this pad will be normal to the sketch. One time over two you will use 'reversed'.
btw, this video is bad.

3) You can reuse the same sketch as many time as you want.
But you should not sketch upon face : TNP.
User avatar
ex-Gooserider
Posts: 27
Joined: Sat Jun 10, 2017 3:51 am

Re: Moving part origin to different point?

Post by ex-Gooserider »

Still having problems, and the Report view gives me errors that aren't very helpful....

I *THINK* I have gotten the model cleaned up and done properly, it looks right, and I get no errors when I run the geometry check in the Part workbench - is there a better way to verify that the part is correct?

In the interest of keeping things simple, I'm attempting to create a path to drill the two 1/4" mounting holes that I'll be using to bolt the part to a jig plate for the rest of the jobs....

I think I have everything set, the model appears to show a path that matches what I want to do, and when I run the CAM Simulator I get a bit that moves to the right places - I don't see it do the actual drill down, but I don't know if it would?

But when I try to tell it to run the post process I get an error
Running the Python command 'Path_Post' failed:
Traceback (most recent call last):
File "/usr/lib/freecad/Mod/Path/PathScripts/PathPost.py", line 430, in Activated
PathLog.debug("about to postprocess job: {}".format(job.Name))
^^^^^^^^

'NoneType' object has no attribute 'Name'
But where is the missing name?

This is what I currently have for my model
bot-plate-2.FCStd
(46.42 KiB) Downloaded 21 times
ex-Gooserider
Linux User, FSF Member
"Inmate" at Artisans Asylum, Allston, MA, USA
Primarily use FC for CNC machining w/ some 3D printing, etc.
Bance
Veteran
Posts: 4186
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Moving part origin to different point?

Post by Bance »

Your file does not contain a Path (wb) Job.
Post Reply