Issue printing with T1 on a multi-extruder printer

I have finally gotten my self-designed multi-extruder printer back to the point where I can actually print with it.

What I did first was to print a 10x10x10 cube with each extruder separately. I simply sliced the stl file without saying anything about multiple extruders. As expected, there were no T commands in the G Code. When I printed it with T0, it came out perfect.

Next was to try tool 1. I manually switched by entering the T1 command, and then tried to print the same G Code file. I also had to manually heat up tool 1 since the G Code was written with T0 in mind. I printed perfectly again, except that it was 52 millimeters to the left of center - which
is my T1 offset. The T1 offset is specified in firmware (Marlin) only - Slic3r does not know anything about it.

Thinking this might not be a real-life scenario, I edited the G Code, changed all the Hot End temperature statements to work with T1 and added a T1 statement at the beginning. It still printed 52 millimeters to the left.

Is there something I'm not understanding about working with multiple extruders?

Thanks

Even more to the point - what's a good multiple extruder tool chain? Any chain that has "notepad" or "textedit" in the middle of it is likely to get real old real fast....

Actually I was subsequently able to print, somewhat successfully, a two color object. Here is my procedure:

I created an object in openscad, and then I created an openscad object in the same file that was the "subset" of the original object I wanted in the second color.

I differenced the two objects and saved that as one stl file, and then I intersected the objects and saved that as the second stl file.

Next I went into slic3r, and chose the merge option from the main menu. I picked the two stl files and saved the amf.xml file. Then I brought that xml file into slic3r's plater and sliced it. Then I printed it.

A couple things of note:

1) slic3r did nothing for retraction when a tool was made inactive. I thought I had it set to do 10mm of retraction in this case, but it wasn't apparent that was happening. I had a lot of oozing and had to baby sit the print to pick the ooze off of the inactive extruder.
2) slic3r did nothing for temperatures. There was an M104/109/140/190 in there from my start code, but nothing else. There weren't even any commands in there to deal with the temperature of tool 1 at all. Not only do I want to see the initial temperature get set, I'd like to see the standby tool go into a lower temperature until it's needed again.

I have to investigate this further. I know slic3r lets you put in tool change g code, I just don't know if it will let me do the following:

1. retract current tool - say 10 millimeters
2. lower temp on the current tool
3. switch to the new tool
4. increase temp on the newly current tool to the operating temp
5. extrude the previously retracted distance

The problem I see is that I want to do things both before and after the actual tool change. I assume slic3r gives your code control at one of these two points (which one I'm not sure), but not at both.

Edited 2 time(s). Last edit at 12/16/2013 12:03AM by jbernardis.

I suspect that dual (or multiple) extruders are a little exercised feature in Slic3r. I'm not to surprised that you would find issues....

I agree with the retract and cool approach. You would also need a heat up / wait / feed on the other end of that process. The ideal case would be to have an option to move someplace you don't care about when you did the tool change. You might not want to do it all the time, but it could come in handy.

If you had any sort of change in the gcode between tools, (I'm pretty sure you do) you could write some sort of post processor (Python or what ever) to add the extra code in there. Not quite notepad, but still not as slick as one would hope.

Edited 1 time(s). Last edit at 12/16/2013 06:31PM by uncle_bob.

You need to home with T0 selected both times, then switch to T1 or stay with T0. If you home with T0 selected one time, then home with T1 selected the next time, you will see an offset equal to your extruder offset.

Also: Cura support for dual extruders is pretty good. Make sure you have all your settings correct (dual extrusion retract set fairly high, etc.) then import an STL file for each extruder. Right-click on the model that you want to use the first extruder to use, then select dual-extrusion merge. Voila, you now have dual-extruder g-code.

KISSlicer does a very good job with dual-extrusion as well, including options to cool the unused extruder to a keep-warm temperature to reduce oozing. It does cost money though, and isn't open-source.

Edited 1 time(s). Last edit at 12/16/2013 06:54PM by NewPerfection.

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I downloaded cura and it looks OK. I'll try it over the next few days. I'd really like to stick with slic3r though because I have a fair amount of time and effort invested in developing my own host software and I like a slicer that can be integrated with it. If it pans out, though, I'll use cura independent of the host program and import the gcode until these issues are addressed by slic3r (or should I say if they are addressed)

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NewPerfection
You need to home with T0 selected both times, then switch to T1 or stay with T0. If you home with T0 selected one time, then home with T1 selected the next time, you will see an offset equal to your extruder offset.

Also: Cura support for dual extruders is pretty good. Make sure you have all your settings correct (dual extrusion retract set fairly high, etc.) then import an STL file for each extruder. Right-click on the model that you want to use the first extruder to use, then select dual-extrusion merge. Voila, you now have dual-extruder g-code.

KISSlicer does a very good job with dual-extrusion as well, including options to cool the unused extruder to a keep-warm temperature to reduce oozing. It does cost money though, and isn't open-source.

Kiss is dead as far as everyone is concerned, there have been no updates from the developer and multiple people have tried to contact him with no response. I do have the paid version and it works great but I often face myself wanting to go elsewhere because Kiss can not bridge. The support works great but I get tired of having to dig support out of everything I print when I know most of it is easily done when bridging.

I want to say this again...Kiss DOES NOT bridge. In special situations it will "bridge" perimeters and the infill but it is not intentional.

For instance, try to print a j-head/groovemount recess vertical. You can place a tube that would in theory support the ceiling and allow you to print the hole for the filament to enter the j-head but if you do this in Kiss, it will attempt to do concentric perimeters floating in the air unless you make the support tube wide enough to enter the infill area and by that time the tube is so thick you have no chance of removing it.

I know that information isn't really relevent to this topic but thought I would add for anyone that finds this, Kiss is great but do not expect to do bridging with it. The support is extremely good but sometimes you just need a bridging ability.

I have tried to use Slic3r many times but the constant changes like the first solid layer overlap that was changed ( and screwed up) in one revision with no ability to change overlap because it was coded in really gets me. The same settings do not apply to all printers so why not make something like the overlap adjustable?

But in either one I have never seen much for the ability to choose colors per area of the same model so how is this done? I know both of them support using the second extruder for support I believe but beyond that I don't recall much.

jberndardis, I don't think you will be able to make that g-code automatic unless there is a command to find current extruder in use. I know Kiss has some properties that will pull information from the slicer and not force you to find it yourself but I don't know if slic3r has this.

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tjb1
Kiss is dead as far as everyone is concerned,

Yep. I'm kinda wishing I hadn't paid for it, although it is still a good program.

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tjb1
But in either one I have never seen much for the ability to choose colors per area of the same model so how is this done? I know both of them support using the second extruder for support I believe but beyond that I don't recall much.

The only way to do this is to create two separate models, one for each color. OpenSCAD's boolean operations are useful for this. Hopefully this will be improved with a better file format than STL.

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Quote
NewPerfection

Quote
tjb1
Kiss is dead as far as everyone is concerned,

Yep. I'm kinda wishing I hadn't paid for it, although it is still a good program.

Quote
tjb1
But in either one I have never seen much for the ability to choose colors per area of the same model so how is this done? I know both of them support using the second extruder for support I believe but beyond that I don't recall much.

The only way to do this is to create two separate models, one for each color. OpenSCAD's boolean operations are useful for this. Hopefully this will be improved with a better file format than STL.

So everyone doing these multicolor prints are just manually modifying extruder used at X layer? I had an idea for my next printer that I would pair ABS with that NinjaFlex to make some things like hinges and stuff but without knowing if they will bond I had come up with an idea that would constrain one inside the other but it would require printing both materials on the same layer. Maybe separate them by a very small amount and I guess that would work with Cura?

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tjb1
So everyone doing these multicolor prints are just manually modifying extruder used at X layer? I had an idea for my next printer that I would pair ABS with that NinjaFlex to make some things like hinges and stuff but without knowing if they will bond I had come up with an idea that would constrain one inside the other but it would require printing both materials on the same layer. Maybe separate them by a very small amount and I guess that would work with Cura?

You can have two colors/materials on the same layer. You just need a different model for each color/material. See for example: [www.thingiverse.com] Ideally, the clearance between different colors/materials is zero, so that they bond together.

Your idea with NinjaFlex and ABS would likely work, as long as they stick to each other somewhat.

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I am able to produce 2 color objects with both colors on the same layers, although I'm still working out the issues. The toolchain is the biggest issue right now, but I'm slowly getting all of the needed functionality into my host software.

The issues I am facing right now are 1) I cannot use slic3r 1.0 rc1 because I use Ubuntu, and the Linux package is missing the XML::sax package and so cannot parse the amf.XML files. 2) I finally integrated cura into my host program, but its a somewhat clumsy interface and I have run into files that it cannot properly slice.

I really like some of the features cura has for multi extruders. It seems to do a better job of temperature management, and you can optionally turn on 1) a wipe tower which is a cubical tower printer alongside the main object whose sole purpose is to wipe ooze of of the heads, and/or 2) an ooze shield which is a single width wall build around the object whose job is to catch the ooze as the heads go by.