Author Topic: DSCAD MAX v25 exported stl file is mirrored in 3D printer software  (Read 1152 times)

BlankMan

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I exported a drawing as a stereolithography file. When I go to print it on my 3D Printer if flips/mirrors/reverses the left and right sides along the Z axis.

I kind of doubt itís the printer software or printer because if it were either of those thereíd be a lot of people complaining and that is not happening.

Does DesignCAD 3D MAX not follow some industry norm and have the +/- opposite on the X Axis or something??

This CorrectLSBracket image shows how it should look.



This BackwardsLSBracket image shows what it looks like when the stl file is opened in the 3D Printerís software. Note the left and right sides are switched and thatís how it prints.

Newbie? Not.
Been using DesignCAD 3D since ~1990
Still have version 4 floppies...

JJG

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #1 on: November 22, 2015, 10:28:19 AM »
Does DesignCAD 3D MAX not follow some industry norm and have the +/- opposite on the X Axis or something??
The answer is "Yes" : Designcad is not using "right hand system of coordinate" as default, but "left" one.
Also, Z Axis is in the opposite direction.
 ;)
(note that you can assign "right hand system of coordinate" in Option, Tag "General" / Coordinate system area)

BlankMan

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #2 on: November 22, 2015, 04:42:54 PM »
Does DesignCAD 3D MAX not follow some industry norm and have the +/- opposite on the X Axis or something??
The answer is "Yes" : Designcad is not using "right hand system of coordinate" as default, but "left" one.
Also, Z Axis is in the opposite direction.
 ;)
(note that you can assign "right hand system of coordinate" in Option, Tag "General" / Coordinate system area)
Thanks that was it. Changed it to "right hand" then as you mentioned the Z axis was reversed so even though an stl export now matched in the printer software the part was still wrong.

Luckily I draw most of my stuff via BasicCAD so I had to go reverse everything on the Z axis now all is good.

Is left hand popular? Are they used 50/50? I never gave the coordinate system any thought because the drawings appeared correct. But to find out it reverses things for 3D printers, would it be the same for CNC then?

Is DesignCAD the odd man out or is it a crap shoot and only matters when CAM becomes involved?
Newbie? Not.
Been using DesignCAD 3D since ~1990
Still have version 4 floppies...

magic

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #3 on: November 22, 2015, 07:39:21 PM »
Hi BlankMan,

But to find out it reverses things for 3D printers, would it be the same for CNC then?

No, at least not with ContourCAM.
It's a kind of magic!




samdavo

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #4 on: November 23, 2015, 03:43:16 PM »
(note that you can assign "right hand system of coordinate" in Option, Tag "General" / Coordinate system area)
...
Thanks that was it. Changed it to "right hand" then as you mentioned the Z axis was reversed so even though an stl export now matched in the printer software the part was still wrong.

Luckily I draw most of my stuff via BasicCAD so I had to go reverse everything on the Z axis now all is good.

Is left hand popular? Are they used 50/50? I never gave the coordinate system any thought because the drawings appeared correct. But to find out it reverses things for 3D printers, would it be the same for CNC then?

Is DesignCAD the odd man out or is it a crap shoot and only matters when CAM becomes involved?
Couple of points from the peanut gallery.  First, I am guessing that most people use the LH system  :-
Yes DCAD uses a sort of Left Hand System - in that the Z axis is into the page.   BUT, in case you are a purist :) , (mathematical) rotations are a mixture of Right Hand and Left Hand, in that :-
a) a positive rotation about Z goes from X towards Y  (left hand rotation)
b) a positive rotation about X goes from Z towards Y  (right hand rotation)
c) a positive rotation about Y goes from X towards Z  (right hand rotation)

These rotations however look anticlockwise when viewed in Front (or 2D), Right Side or Top respectively, which is "convenient" if not technically perfect.  One reason it is convenient, imo, (looking at your block), is that you can still see the XY plane after you extrude into the page (just imo).  I have no idea if this affects CAM of printing (?)

If you draw a cone pointing out from the page in LHS, and change Options/General to RHS, then the cone is unchanged.

Now if you check the rotations, you find that rotations are "correct" even to a purist. 

a) a positive rotation about Z goes from X towards Y  (right hand rotation)
b) a positive rotation about X goes from Y towards Z  (right hand rotation)
c) a positive rotation about Y goes from Z towards X  (right hand rotation)
(2 cents).
« Last Edit: November 24, 2015, 07:57:00 PM by samdavo »

samdavo

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #5 on: November 23, 2015, 03:49:02 PM »
By the way, in case you ever want to check those axes, you can use this macro (written by prl).  After starting the macro, simply set two points, one at the centre of the set of axes, and one giving the length of the axes.

DrollTroll

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #6 on: November 23, 2015, 04:13:07 PM »
If you drew in LH coordinates in DesignCAD, just temporarily switch the drawing to RH coordinates before exporting to STL. Then switch back.
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Dr PR

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #7 on: November 23, 2015, 11:15:03 PM »
DT,

It would be a good idea to make the LH to RH chage automatically - and temporarily - when doing an STL export. At least ask the user.

Phil
DesignCAD user since 1987

JJG

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #8 on: November 24, 2015, 11:03:04 AM »
Dr PR,

it would be even easier to work in RH as default, as all the other CADs.
On my side, at the begining I have work with DC (in 3D, also year 2002), it had been very long and unnatural to take this habit of LH, because at school, in maths as well as in technologie, all is learned with RH system.
With time I got done gradually, but again, it was not natural.
If DesignCad is criticizable on one point, it is that one.

For the rest, as a user of Missler TopSolid since I changed of employer, I can certify that the ease, simplicity and friendliness of use and work in DesignCad remains unsurpassed. And for a 75x lower price !!!
(Moreover, the logic sometimes funny (to not to say "stupid"), as well as the heaviness of using of 3D-parametric software irritates me almost every day)

samdavo

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #9 on: November 24, 2015, 01:50:51 PM »
Further comments from the peanut gallery - but on the subject of Presentations by

a) exporting to Sketchup, and
b) planning ahead and choosing the colours of axes in DCAD as X=red, Y=green, and Z=blue  (trivial, but helps to keep track of what's going on)

I enclose the final results when you export (obviously using DCAD V25) with
1.  Y and Z untransposed / unchanged  (in the export Setup options)
2.  Y and Z transposed (ditto)
obviously screensnaps from Sketchup ( and PS this is the free version, SketchUp Make - and this export capability is a major feature of V25 imo)

As prl once described (and I hope I'm not misquoting him), the choice of axes colours is intended to match Sketchup, i.e.
blue = z (up) = sky
red = X (to right)
green = Y (into page)= grass 

PS He invented this system BEFORE V25 gave you the option of transposing Y and Z.
PS You might have to look carefully to see the axes colours - these are just the normal SketchUp axes.
cheers
« Last Edit: November 25, 2015, 12:23:51 AM by samdavo »

js

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #10 on: May 16, 2017, 06:46:16 PM »
I want to work in the right hand system. I can change the default DC system to right hand in options>general.

But.. I cannot save that seletion as a default. I save the drawing with RH system selected and set as default. When I reopen the drawing the coordinate system is LH.

Can I find an initialization file somewhere that I can edit to force RH on startup? Can i use a macro to run on startup that would change LH default to RH?

thanks
js 

Dempsey

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #11 on: May 16, 2017, 08:53:01 PM »
js,

Go to Options --> Options --> General Tab
Then check the Right-Hand coordinate system --> click Apply and click Safe as Default --> exit program
After that it should be okay.

Alternatively look for the DC_General.ini file and set:
CoordSystem=1

I have my DesignCAD installed for multi users that means that the programs/DLLs are in Program directories, while the "user" type data like .ini files are in user directories.

If you installed for one user then everything is in one place, but if that is in the Program directory then you may not have enough privileges to save .ini files. A solution is to install DesignCAD in a separate directory outside the Program directories.

« Last Edit: May 16, 2017, 09:00:07 PM by Dempsey »
Dempsey

js

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #12 on: May 18, 2017, 07:17:52 AM »
Thanks Dempsy.
I did change the coordinate system to RH in a drawing and tried to save as default. When I reopened the drawing the coordinate system was LH.
I ran a basic macro to set SYS(110)=1 (RH coordinates) and SYS(22) =1 Save parameters with drawing
That procedure seemed to set the default to RH. I am not sure why this procedure worked and "set as default" did not.
 [edit this procedure did not work when I shut DC down completely - file locations and coord sys were not saved as a default. I will look at the .ini file]

As far as my installation... it is all screwed up. I have an executable in program files>IMSI>DesignCad..2016. While,sample macros, textures, materials are in a folder under my user name.

thanks again for the response. I might try a reinstall if I could figure out why i did what i did on the original install. js
« Last Edit: May 18, 2017, 08:06:12 AM by js »

Pearco

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #13 on: May 18, 2017, 08:43:46 AM »
Js;

When you start Dcad, the program reads the work space settings to start with. Open the work space config under files then edit work space settings. At the bottom of the dialog there is a setting for right or left hand. Select the one you want, close it out and be sure to save it as your current work space. Then go out of Dcad and restart the program so that it reads it before starting. Now you should be ready to go.
Jim
User since ProDesign 1.5

js

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Re: DSCAD MAX v25 exported stl file is mirrored in 3D printer software
« Reply #14 on: May 18, 2017, 02:09:07 PM »
Pearco.
When I tried to save the workspace settings file, I was denied access to the program files directory. The program offered to save the workspace config in my user directory. I accepted. Apparently the .dws file must be in the directory with the executable (program files).

when I gave myself permission to access the program files directory I could save the .dws and it seems to be working.

I've done enough to garbage this topic on coordinate systems. With help, I have a RH system now. Thanks Dempsy and Pearco.