Oh, the BMG clones are wonderful! Watch my videos on the cheaper versions, as there is some minor mods you might (or might not) have to do for some of them, but once you do, they're ultra reliable. (The two mods are using a 2mm drill bit to open up the filament path and using a washer/PTFE/Printed spacer to prevent the gears from getting out of alignment.) Check out the videos of the Sunlu and the Ender 5... they're both upgraded to the BMG... and in all honesty, the only better extruder I've seen is the E3D Hemera, which is 10x the price. Bill

I might add, you don't need to switch to that extruder, as this end gcode will only unload the last used color, which will still be the active one.

I'm on the road right now (at Rapid in Detroit) but I'll post the code I have when I get back Thursday night. Basically, it'll be the first bit of code that the gcode generator does right up until the "Load Filament" comment in the auto generated gcode... just paste that to the start of your end gcode and you'll be ok. Bill

Hmmm... you can always use my direct as well... wjsteele @ hotmail . com (no spaces.) Not sure why you'd get an error like that on the first one... just to make sure, it's bill @ 3dchameleon.com with no spaces... you can also use info @ 3Dchameleon.com and it'll also come to me.

That part doesn't look correct to me. I think the alignment is off, as the bearing is before the gear (from the right to the left looking at your picture... they should be even.) Also, I see there is a missing screw and the stepper motor appears to be shifted in the red part... as it's not actually inside the round opening evenly.

1) Yes... attached is a simple graphic. Basically, the top outside is #1, the one just under it is #2... inside top is #3 and inside bottom is #4. 2) 1" is fine... it will load and then unload after the first use... note the position it is placing the filament for future loads. 3) You're good... you don't need to set anything other than the 4 extruders (and copy the settings from the first one to the other three, then past in the gcode. Optionally, you can turn on the purge block in the Print Settings tab. 4) Not sure what the pause was... we don't ever pause the print in our code. Now, to get to the root of your problem... I'm guessing that you don't actually have the button at the proper location indicated by the gcode generator. If it's not turning on the red light on the switch, then it's not hitting it... secondly, if it's not hitting it for the proper time, then it will also not function correctly. Since there is no connection between the electronics of the printer and the electronics of the 3D Chameleon, the button is the only interface... and having the timing correct is critical for sending the proper commands. Timing isn't just about how long the button is pressed for, but also the distance and speed the printer is moving when it tries to engage the button. If they're too fast, then the button press will be shorter than needed... likewise, if they're too slow, it'll be longer. Make sure you can press the button and advance the colors manually before each print... if not, simply power cycle the unit to reset it. Any videos you can send me will also help me diagnose it for you... just send them to my email... bill @ 3dChameleon.com.

Oh, one last thing on the extruder side... check to see that the 3D Chameleon B part hasn't broken... if so, here's a replacement part for it: https://www.thingiverse.com/thing:5181728

Ok... it sounds like you have two different issues. 1) The extruder won't load. 2) Tip shaping. With #1, make sure your extruder can easily be manually loaded first... if that can't happen, then the 3D Chameleon can't load it, either. By doing that, you should not have to touch the extruder at all when loading... simply present the filament into the input of the extruder, and drive the motor... if it loads there, then the problem might be in the timing. With the timing, especially with geared steppers, it's important to match the speed that the 3D Chameleon is pushing the filament with the speed that the extruder is running. 25mm/s is the feed rate of the 3D Chameleon... and the extruder must be running at that feed rate before the filament touches the gears, so they can grip the filament. The default feed rate we have in the gcode generator is for a stock extruder, so you might have to adjust that speed. Also, make sure the filament is actually hitting the gears and not stopping too early. On #2, make sure you have the 1.8mm ID PTFE tube in the area where the filament can cool... that's the most important feature of tip shaping to prevent it from growing too fat and jamming. Now, with that said, not all filament swells... only PLA really does that. Experiment with different types and brands of filament... we've had huge success with Jessie PLA as well as Prusament PLA and PETG. The idea is that the filament should be allowed to cool below the glass transition point before it's removed from that 1.8 tube so that once it's extracted, it can't grow and become larger than any of the rest of the system, which is nominally 1.85mm ID.

When you say it gradually becomes weaker... can you describe what you're seeing? The motor should stay on and locked to provide tension. Also, have you tried any of the other extruders? For example, set it to T2 and print with it. (I guess I should answer your first question, too: no, it doesn't need to all be loaded.) Lastly, the reverse drive code has been updated for 2.4.x... have you downloaded the most recent version? Prusa did change their code to and renamed their temporary files with a .pp extension in them, but I updated it a few weeks ago to handle that case.

Ok... there are a few things of note in your comments... ones that are quite easy to remedy, and I have some ideas for the others. 1) Timing of the button presses. If you press it for longer than 5.5 seconds and it's going 'silent', in reality, it's being pressed for 7+ seconds. The 7 second press causes it to "forward" all commands to a second Mk2 unit. It will only cancel that mode with an 8 second press. The solution is to shorten your button presses by 1/2 of a second to ensure you don't go over that limit. The time that the gcode has is the actual time "on the button", but if your unit is triggering the button a little earlier, then the time it takes to press the button and then back away from it can also add to that total time. Shortening that press time will take care of that. Also, make sure you're trigger point is exactly .1 or .2 mm prior to the actual distance you enter into the gcode generator. If it's more than that, remember, it takes 1 second to go over 25mm... which means it can take an additional 125ms for .1 mm of travel... time two = .25 seconds just for .1mm of travel both ways... if your button press is actually .5mm late, than you're adding an additional 5 x .25 = 1.25 seconds to long. (If you simply shorten the time on the button, then you don't have to worry about these calculations... it's the total time that is important... where you subtract it doesn't matter, if that makes sense.) 2) You can't use relays to switch the motors with modern electronics. The Mk1 version of the 3D Chameleon used exactly that method, which fails with modern TMC devices due to their "break detection" circuit which causes the stepper motor drivers to shut down. They won't restart until you recycle the power, which is not an option with these electronics. Also, Creality machines (in particular) and their derivatives, tie all the enable pins on the X, Y and E stepper motor drivers together, so it makes even software resets impossible. 3) Our Mk3 already is design complete and includes the extruder built in. (Similar to the current model where it's actually installed in the extruder replacement scenario.) If you'd like, we can send you the replacement plastic parts to make your Mk2 an Mk3 (or, technically, what we're calling the Mk2+) which should give you a much stronger drive. (It's has about 3x the grip on the filament of the old design... and is tunable.) 4) The inconsistent drive... with the Mk3, we improved the grip strength by about 3x over the Mk2, which should easily over power any friction points in the PTFE or the Y adapter. Mind you, the Y adapter is 1.85mm ID on the inside... so if your filament is larger than that, it will get stuck there. Relaxing the compression on the Y adapter by 1/2 turn is the correct path there... however, if you're using Capricorn tube in the hot end, be aware that Cap tubes are 1.95 ID +- .05... so you mileage may vary on if it'll fit or not. Our 1.8mm ID tube in the hot end should constrict it to smaller than the Y adapter. Cap tubes above the Y adapter should be just fine as well as between the Y adapter and the extruder. 5) Tip shaping... with the Mk3 parts, the drive system should be significantly stronger so the tip shaping is much less of a concern. Stringing is the only real concern. With a smaller 1.8mm ID tube in the hot end, and the stronger grip on the filament, you should see far fewer issues like these. Bill

Can you adjust the tension on that extruder? This reminds me of the old Chep (Chuck Hellebyuck) video where he had issues with flexible filaments. He found and printed an upgrade that had a piece of PTFE tube in it to help guide it better... perhaps that will work. Here it is: https://www.thingiverse.com/thing:2144277

Also, note, that if you're using this with a direct drive, you need to make sure you have the post processor installed. Here's the procedure for it here: https://www.youtube.com/watch?v=4mpSn5O6pAQ

With the Prusa mini motor set up as the extruder, pressing the button won't drive it... use the Prusa Mini's menu to move the filament instead. Also, you can't use the Auto generated gcode, as that is expecting the button to control the extruder, but since it's hooked up to the stock motor, the normal gcode commands are needed for it. Here is the tool change gcode I use for mine: ; - 3D Chameleon Tool{next_extruder} - ;begin switch from extruder {previous_extruder} to extruder #{next_extruder} M117 Unloading Tool [previous_extruder] M82 ; turn absolute distances for the extruder {if previous_extruder>-1} ; unload extruder {previous_extruder} G92 E0 G0 X90 Y177 F5000 ; cool (and size) in 1.8mm tube G0 E-50 F7800 ; quickly retract the filament to shape it G0 E-80 F600; slowly allow it to cool G0 E1 F7800 ; blob elimination ; back to tip size G0 E-50 F7800 ; quickly retract the filament to shape it G0 E-80 F600; slowly allow it to cool G0 E1 F7800 ; blob elimination G0 E-10 F7800 ; quickly retract the filament to shape it G0 E1 F7800 ; quickly ram the filament to shape it G0 E-10 F7800 ; quickly retract the filament to shape it G0 E1 F7800 ; quickly ram the filament to shape it ; back to 1.8 constriction G0 E-50 F7800 ; quickly retract the filament to shape it G0 E-80 F100; slowly allow it to cool ; forging in Y adapter (adjust for extruder) G0 E-170 F7800 ; quickly retract the filament to shape it G0 E-110 F7800 ; quickly ram the filament to shape it G0 E-170 F7800 ; quickly retract the filament to shape it G0 E-110 F7800 ; quickly ram the filament to shape it ; retract it back out of the Y adapter G92 E0 G0 E-80 F7800; quickly retract it back out G92 E0 G0 E-50 F7800; quickly retract it back out {endif} ; load extruder #{next_extruder} M117 Loading Tool T{next_extruder} ; always reset to extruder 0 G0 Y177 F2000 ; holding pattern 1mm short G0 Y180 F500 ; press the button G4 P800 ; dwell for 1.1 seconds G0 Y177 ; back off the button G4 S3 wait for it to happen ; press the button for each extruder (1,2,3) {if next_extruder>0} G0 Y177 F2000 ; holding pattern 1mm short G0 Y180 F500 ; press the button G4 P100 ; dwell for .2 seconds G0 Y177 ; back off the button G4 P700 ; wait for it to happen {endif} {if next_extruder>1} G0 Y177 F2000 ; holding pattern 1mm short G0 Y180 F500 ; press the button G4 P100 ; dwell for .2 seconds G0 Y177 ; back off the button G4 P700 ; wait for it to happen {endif} {if next_extruder>2} G0 Y177 F2000 ; holding pattern 1mm short G0 Y180 F500 ; press the button G4 P100 ; dwell for .2 seconds G0 Y177 ; back off the button G4 P700 ; wait for it to happen {endif} ; - 3DC Process Tool {next_extruder} - ; reload filament into extruder G92 E0 G0 E100 F7800 G92 E0 G0 E100 F7800 G92 E0 G0 E55 F7800 G92 E0 M83 ; turn relative distances for the extruder M117 3D Chameleon Tool T{next_extruder}

Can you send me your gcode file that you're testing with? Just email it directly to me at Bill@3dChameleon.com.

Yep, that's by design. The 3.5 and 5.5 second presses don't tell it to load or unload, rather, they tell the motor to turn clockwise or counterclockwise. Since T2 and T3 are on the opposite side of the drive gear, they're naturally backwards from T0 and T1. Our GCode Generator automatically takes that into account and will reverse them for T2 and T3.

Nice! Thanks for posting this!

I might add, if you continue to see this error, simply add the G92 E0 line to the layer change gcode. Apparently that's a change in 2.4, as it doesn't have that requirement in 2.3.

Let's correct the base problem first. What extruder are you using? Please send me any details and questions you have... I'm sure somewhere on here we have the answers.

Well, that's not good... we'll send out a replacement right away. Bill