Skelestruder with a Mosquito hotend and MMU2S  

RE: Skelestruder with a Mosquito hotend and MMU2S

Sounds like you just need some practice at nozzle changes... If you're having issues with a v6 I'm not sure a different hotend is going to be much more help. Basic change principles should be the same regardless of hotend type.

FWIW I'm running an MMU2S on a skelestruder with a stock hotend. You *will* need to compile your own firmware as the gears->nozzle distance is 10mm shorter and I expect you'll have load/unload problems if you do not.

RE: Skelestruder with a Mosquito hotend and MMU2S

Hello,

I agree some practice changing nozzles certainly would not hurt. The problem I have (at least I think my problem) is the heater block loosening from the heat break. I was thinking because of design differences I wouldn't have that problem using the Mosquito. Still, I do admit that's a lot of money to spend for the convenience of not learning to change a nozzle the right way. I mean it still only takes about 10 min to disassemble the skelestruder, retighten the hotend and have everything put back together. In all honesty, I might be just looking for an excuse to try out the mosquito 🙂

One of the voices is telling me "Just get the mosquito, If it all doesn't workout then just buy another printer to go with it" - lol.

For the firmware, I have already re-compiled with these changes listed in the skelestruder supplemental. Although I was not smart enough to figure out how to apply the patch automagically, I was able to go through using it as a guide to make the changes manually. Would these be the only changes I need or is there something more once the MMU comes into play? I do have my MMU built, I just haven't hooked it up yet.

Thanks for taking time to reply.

RE: Skelestruder with a Mosquito hotend and MMU2S

Yes, you'll need to edit load/unload changes in mmu.cpp where it does its "load a bit, then unload a little less" to check the load after filament has reached the gears. Otherwise it will unload too far and fail because the filament is no longer between the gears and the filament sensor reads 0.

RE: Skelestruder with a Mosquito hotend and MMU2S

So mosquito aside for now I figured I should slow down and at least hook up my MMU2 and see where I'm at before I consider adding another variable to the mix. I was playing around before I saw your reply. 

I have not made any changes (yet) to mmu.cpp but still seems I'm switching filament ok. Am I just getting lucky here?

I am using the MK3/MMU2 S profile in Prusa Slicer. Under Printer Settings >> Single extruder MM - I have only changed the filament parking position to 75. I'm not even sure that even has anything to do with changing filament though. To this point, I have not really needed to mess with many settings in Slic3r so these things are still very new to me.

I did actually make it through the first (more than 10 filament changes) MMU print I tried with zero intervention on my part!

I realize this still very short print so likely just beginners luck

RE: Skelestruder with a Mosquito hotend and MMU2S

Maybe it doesn't make a difference, I don't know. But it made sense to do so after seeing similar tweaks for e.g. the BMG.

Your video doesn't show the right section though, it cuts off before/right during the part in question, and you also appear to not be running an IR sensor setup... ? Or at least, not one that attaches to the bondtech gears itself like the MMU2S idler door. That will definitely play into things.

RE: Skelestruder with a Mosquito hotend and MMU2S

I'll get another video if it will help. (That one I just already had to post with my hairlock "make" on thingiverse)

For the sensor you are correct, I'm still using the old one that came with my MK3 (NON-S). To be clear, I had purchased my printer alone before the S model was introduced. I purchased my MMU separately as the MMU2S upgrade. I had already switch to the skelestruder which I am not aware will yet support the new IR sensor. I've had pretty good luck with the other sensor so I just stuck with it. I didn't hook up my MMU right away because it took awhile for me to figure out the MMU itself (and MMU firmware) was the same for both the "S" and NON-S model. My current understanding is that the "S" changes only deal with the new sensor, extruder body and obviously the firmware for the printer itself.

I thought I read somewhere the MK3S extruder is something like 8mm shorter than the MK3 extruder and I thought the skelestruder was 10mm shorter than the MK3. So in other words, basically a 2mm difference between the skelestruder and the MK3S extruder? Also, in my first MMU test prints I was using the MK3 (NON-S) profiles in slicer but having problems with the purge block, not the actual models themselves. I read a few times this could be cause by the wrong printer profile being selected so I tried the MK3/MMU2S Slicer profiles and seemed to get my purge block looking better. The firmware I compiled was based on the MK3 firmware, not the "S" firmware. If I'm correct about the extruder heights, I think it makes sense the MK3S slicer profiles could be a closer starting point for the skelestruder? Please correct me if I'm wrong. I do still have sooo much to learn

RE: Skelestruder with a Mosquito hotend and MMU2S

There's beta support for the IR sensor here:

https://www.thingiverse.com/thing:2845416

Slicer profiles don't have anything to do with this particular area; it's handled in the firmware as part of the MMU load sequence, during the T-code, not discrete sliced gcode.

RE: Skelestruder with a Mosquito hotend and MMU2S

as i understand the MMU2S firmware, it feeds filament to the extruder till the IR sensor triggers due to the filament spreading the moving  bondtech gears. at that point the MMU2S disengages from feeding and lets the extruder take over. with the MMU2S it just feeds a preset ( in the MMU2S firmware) amount of filament at high speed and then switches to low speed feeding till the IR sensor triggers .

I haven't looked at the MK3/MMU2 ( non-S) firmware but i think this whole sequence is the main difference. I know the BNBSX extruder specifically has a redesign if the sensor system to decouple the sensor adjustment from the idler door that allows the sensor to be adjusted without disassembling the extruder or dismounting the sensor  ( there is a adjustment 3mm screw in the door that pushes on the new sensor flag arm and allows the relative door to flag position the change easily)

RE: Skelestruder with a Mosquito hotend and MMU2S

Thanks guys.

In case there is a difference in MMU filament loading at the firmware level, I'm going to get those beta IR sensor parts printed and get my printer on the "S" firmware before moving on.

I was looking at the BNBSX extruder as an option but being fairly new to all this, I still enjoy to watch my printer. I know these are both great extruder options but the skelestruder just has a better view when your watching it print 

RE: Skelestruder with a Mosquito hotend and MMU2S

Ditto. I'm also partial to it because it can be lighter and print a bit faster than stock. 

RE: Skelestruder with a Mosquito hotend and MMU2S

OK   I looked at the MM-Control-01 firmware - there is only 1 version but it behaves differently on the mk3 amd mk3s

on both it will feed a "calibrated " length of filament to the extruder, on the mk3 you HAVE to do the calibration to let the MMU know the distance from the Finda to the bondtech. On the MK3s the calibration is optional and not in the manual. the mk3s printer firmware sends an "A" to the MMU when the IR sensor is tripped and the MMU stops feeding and releases the filament from the idler. 

for reference the printer to MMU command are 

"Tx" Switch to filament x ( 0-5)

"Lx" Load filament x (0-5)

"Mx" Motor mode x ( 0= Normal, 1=Stealth)

"Ux" Unload filament (x ignored)

"X0" Reset MMU 

"P0" Read Finda state

"Sx" get MMU status ( 0= return OK, 1 = firmware version, 2=firmware build#, 3=get Drive Error )

"Fx y" set Filament x type to y ( x=0-5, y=0-2) [Not Used in Code]

"C0" Continue filament load [after T command]

"Ex" Eject Filament x (0-5)

"R0" recover after Eject

"W0" wait for user click

"Kx" Cut filament x (0-5)

RE: Skelestruder with a Mosquito hotend and MMU2S

It's the mmu.cpp in the main firmware. You don't need to edit mm-control. 

RE: Skelestruder with a Mosquito hotend and MMU2S

the only MMU outputs are "start" and "Ok" with the P and S commands prepending the OK with a number

RE: Skelestruder with a Mosquito hotend and MMU2S

Thanks again guys. I have my IR sensor parts printed but I'm going to busy with work for the next few days. I'll have to wait until next week before I have more time to get things swapped out.

I'm not admitting to a complete lack of self-control but with some unexpected over-time this weekend I took it as a sign that I should just order the mosquito as well. Although at this point, I still plan to get things running with the V6 before I switch hotends.

RE: Skelestruder with a Mosquito hotend and MMU2S

Good plan. Throwing more variables in the mix on something that already doesn't work is just setting yourself up for a world of hurt 😉