x axis not to drawn dimension

This forum is for general discussion about Cut3D
Post Reply
bentfab
Posts: 6
Joined: Mon Nov 27, 2017 4:11 pm
Model of CNC Machine: CNC Router Parts 5x10 kit

x axis not to drawn dimension

Post by bentfab »

Howdy. I've been using Cut 3D for a few years to make art, I use cnc to get me 90% there then do the rest by hand adding details and mods as I go. Over the weekend I was making some pieces much smaller than I normally do and realized that the actual part made by cnc was consistently about .1" smaller in the x axis than what I had drawn. The y and z dimensions were also a bit smaller, but only by a few hundredths, which is acceptable.

These 3D cut parts are supposed to match up with some 2D cut pieces which came out as drawn. I checked some older pieces I had made and they appeared to also be off about .1" on the x axis. But these are much bigger pieces and they don't have to fit anything so I never noticed.

I draw in Rhino 5 and export as a stl. I don't think it's my machine because 2D cuts are spot on. Have I inadvertently changed a setting in Cut3D, or never set it up correctly? Is this just the way it is and I need to stretch all my drawings by .1" x axis before I export?

Any help appreciated.

User avatar
Leo
Vectric Wizard
Posts: 4082
Joined: Sat Jul 14, 2007 3:02 am
Model of CNC Machine: 1300 x 1300 x 254 Chinese Made
Location: East Freetown, Ma.
Contact:

Re: x axis not to drawn dimension

Post by Leo »

Have you ever calibrated your machine for "steps per inch" on all three axis's?
Imagine the Possibilities of a Creative mind, combined with the functionality of CNC

bentfab
Posts: 6
Joined: Mon Nov 27, 2017 4:11 pm
Model of CNC Machine: CNC Router Parts 5x10 kit

Re: x axis not to drawn dimension

Post by bentfab »

If my machine was off wouldn't 2D cuts be off as well as 3D?

User avatar
adze_cnc
Vectric Wizard
Posts: 4325
Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008
Location: Vancouver, BC, Canada

Re: x axis not to drawn dimension

Post by adze_cnc »

Instead of exporting the model as an STL file could you export it as a Rhino version 4 file and try that instead?

You'll have to tell Rhino that yes, indeed, you want to use version 4 instead of 5. (Honestly McNeel, can you not trust that I know what I'm doing instead of forcing me to verify that I do want a 4.0 file?)

Steven

bentfab
Posts: 6
Joined: Mon Nov 27, 2017 4:11 pm
Model of CNC Machine: CNC Router Parts 5x10 kit

Re: x axis not to drawn dimension

Post by bentfab »

I'll give it a try next time.

bentfab
Posts: 6
Joined: Mon Nov 27, 2017 4:11 pm
Model of CNC Machine: CNC Router Parts 5x10 kit

Re: x axis not to drawn dimension

Post by bentfab »

Will rhino 4 export directly to Cut3D

User avatar
Leo
Vectric Wizard
Posts: 4082
Joined: Sat Jul 14, 2007 3:02 am
Model of CNC Machine: 1300 x 1300 x 254 Chinese Made
Location: East Freetown, Ma.
Contact:

Re: x axis not to drawn dimension

Post by Leo »

bentfab wrote:If my machine was off wouldn't 2D cuts be off as well as 3D?
Yes it would.
Imagine the Possibilities of a Creative mind, combined with the functionality of CNC

User avatar
adze_cnc
Vectric Wizard
Posts: 4325
Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008
Location: Vancouver, BC, Canada

Re: x axis not to drawn dimension

Post by adze_cnc »

bentfab wrote:Will rhino 4 export directly to Cut3D
My apologies. Rhino v4 files import fine into VCarve so I suspected Cut3D would also handle them. I was in error.

You could try exporting an OBJ file using NURBS curves rather than a polygon mesh. That I know works.

Steven

bentfab
Posts: 6
Joined: Mon Nov 27, 2017 4:11 pm
Model of CNC Machine: CNC Router Parts 5x10 kit

Re: x axis not to drawn dimension

Post by bentfab »

I just tried obj with nurbs, but it wont load in Cut3D

User avatar
adze_cnc
Vectric Wizard
Posts: 4325
Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008
Location: Vancouver, BC, Canada

Re: x axis not to drawn dimension

Post by adze_cnc »

OBJ with NURBS (using whatever defaults Rhino v5 uses) loads fine in my Cut3D v1.11. So I an at a loss. Since VCarve added 3D toolpaths I haven't needed Cut3D though.

My reasoning for wanting to try either Rhino v4 or OBJ with NURBS was to keep the surfaces as mathematical entities as long as possible and to avoid the polygon mesh of STL files. Rhino files import nicely into VCarve.

I also thought that perhaps in the export and the import of the STL file some unknown scaling was happening. I have received exported STL files from Solidworks that needed to be scaled by 2.5 to get them to actual size. I originally thought it was a mm vs inches problem but that would have meant scaling by 2.54. And the STL was in inches and supposedly exported at 1:1 scale. I never did figure that one out I just made it work.

bentfab
Posts: 6
Joined: Mon Nov 27, 2017 4:11 pm
Model of CNC Machine: CNC Router Parts 5x10 kit

Re: x axis not to drawn dimension

Post by bentfab »

Yeah, my thoughts were also that there was some sort of scaling issue when converting files.

I'm still using VCarve6.5, maybe it's time I updated. I've been hesitant to try because when I bought V carve I was working with a company that doesn't exist anymore, so that email doesn't exist, so I have no way to prove I bought it.

Thanks for your help.

Post Reply