KISSlicer Can't Handle Dual Extruders Correctly?

[inventabuild]

I have two stls, one a flat rectangular board, the other is letters that are to be printed on top of the board (see pic 1). The board and letters were sketched and extruded in Autodesk Inventor with the letters sketched on top of the board. I open the two files together to superimpose the letters ontop of the board just like they were created in Inventor and assign Extruder 1 to the board and Extruder 2 to the letters. KISSlicer adds layers of letters that are not there and assigns them to Extruder 1 (see pic 2) even though all the letters are assigned to Extruder 2 and the letters that I assign to Extruder 2 are printed on top of the erroneous letters that KISSlicer erroneously assigned to Extruder 1. It appears KISSlicer is getting confused here.

As a double check, if I open the two stls separately so they appear side by side then assign the board to Extruder 1 and the letters to Extruder 2, then KISSlicer will will correctly print the board using Extruder 1 without adding layers of letters to the board and it will correctly print the letters w/ only Extruder 2, so it prints the stls correctly when they are opened separately (see pic 3), but not when they are opened together for a dual extruder print.

The board and letters are each 1 mm high. Interesingly, when I open the two stls together so the letters are superimposed on the board, KISSlicer gives me a height of 4 mm which double what the height s/ be and it is because it is erroneously adding layers of letters and further still it is assigning those erroneous letters to Extruder 1. If I open the two stls separately so they are side by side then KISSlicer gives me the correct height of 1 mm for each stl.

Is this a bug in KISSlicer?

As an aside I tried to upload stls to this post, but the forum will not accept them. Why won't this forum accept stl's and where's the best place to post them so I can link to them?

Pic 1 - Letters On Top Of Board

stl Letters On Top Of Board.jpg (55.77 KiB) Viewed 3646 times

Pic 2 - Layers Of Letters Erroneously Added By KISSlicer

stl Erroneous Letters Added By KISSlicer.jpg (56.82 KiB) Viewed 3646 times

Pic 3 - KISSlicer Handles stls Side By Side

stls Side By Side.jpg (45.15 KiB) Viewed 3646 times

[Davide Ardizzoia]

KS multiextruder capability is one of the reason I am preferring it over other slicers.
IMHO Inventor is messing something with your STL export.
I am using Solidworks, and never had any issue with multiple objects export into STL files.
Also, just download from thingiverse any multiple-body STL (i.e.: "traffic cone") and you will see that KS is handling them without any issue.

Best Regards
Davide Ardizzoia

[inventabuild]

Well KISSlicer proved smarter than me. It turns out I was thinning the board down from 3mm to 1mm for a test print to save time just to see how the letters came out...and I forgot to re-save the letters that are sketched to the board surface which now had its height reduced. So KISSlicer, seeing space between the top surface of the board and the letters, filled the space between the board and the letters with a loft of sorts, that is it used the board mesh to create letters that joined up w/ the letters in the letter's mesh. Hope that makes sense.

Davide, thanks, believe me I was all over Solidworks because I heard it is the flagship CAD package, but the trial period was too short, combined with the expense being a little too much and I ended up starting out w/ Inventor. So far Inventor is doing a great job for my applications, but I'm far from an expert modeler. At some point in the future I wouldn't might giving Solidworks a shot once I'm a little higher on the learning curve.

[inventabuild]

...as a side note Jonathan said at one time in the recent past that he does not own a dual extruder 3d printer. I thought it would be nice to take up a collection from KISSlicer fans and buy him one, maybe it would help him write / debug code for duallies, but it would also be a nice gesture for all the great and hard work he has done and done it better than all the others I know of.

[duaneh]

A couple of things here - 1st - I would be happy to contribute to the dual (or more) head fund - set something up.
For doing lettering like that described above, I use one file, and just begin a new sketch on top of the base layer, and then do the letters on that. You will, however, have one problem with Kisslicer if you do that - because all the parts of the file are contiguous, it will just assign everything to one extruder and not allow you the option to split it up. To resolve this, you can offset the 2nd layer by some very small amount (I typically use .05mm), so that it does not touch the base layer. Then you will have a separate mesh for the base layer and each individual letter.
You can also embed the lettering into the base using a similar technique - make a second sketch on top of the base and put the lettering on it. Then do an extrude cut into the base the depth you want the letters to be. Third, do a 3rd sketch and copy the letters from the 2nd sketch, offsetting them inward by .05. (remove the copied letters once you've done the offset so all you have are the smaller letters). Finally, extrude this layer backwards into the base, to a depth equal to the extrude cut minus .05 so the extrusion doesn't actually touch the base layer.
The printer will fill in the .05 (or whatever you choose) with no problem, but Kisslicer will treat each letter as a separate mesh and allow you to assign each mesh individually (via All Models -> Show Extruder Map Window).