stringing after MM upgrade
Hi all,
I got my MK2S kit early this week and enjoyed building it. The print quality is as good as the Ultimaker 2 that I have at work (I'm a Mech Eng) and I was really impressed with the dragon off the SD card.
I was going to wait a month or so, but I decided to fit the Multi Material Upgrade the next day. 🙂 Now, running the same filament, with the same temperatures and the same file off the SD card, the dragon looks all stringy...
* I don't think its the Bowden tubes since the UM2 has them a doesn't have this problem.
* It is a different hot end, so it could be linked to that. Temperature reading different?
* The firmware is in beta, so maybe the settings are just different?
* I am using the same file off the SD card. Are there settings in the gcode that are adjusted depending on printer, e.g., retraction distance?
Any suggestions would be much appreciated.
Thanks
Carl
Re: stringing after MM upgrade
Carl
It is to do with the Bowden tubes, along with the filament elasticity, and viscosity. You need greater retraction values. The single filament GCodes have around 0.8mm retraction but this setup now needs somewhere in the region of 2 to 5 mm (4 is the standard I think).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: stringing after MM upgrade
Thanks Peter,
I'll try that tonight and see whether it improves things. 🙂
Cheers
Carl
Re: stringing after MM upgrade
You need to slice with the correct settings. Single extruder mode is in the normal MK2 Slic3r. Sample g-codes form the SD card cannot be used.
Re: stringing after MM upgrade
Thanks guys,
Everything appears to be working fine now, not a hint of stringing. 😀 In fact, the quality looks excellent so far.
I set the retraction to 4mm and generated new gcode as suggested.
It's 11pm here, so we'll see what happens overnight.
Thanks again.
Re: stringing after MM upgrade
I've spent an inordinate amount of time experimenting and studying retracts for many years. I know the E3D V"n" hot end inside and out. (Search for "hackney" on this E3D blog. I wrote Some musing on retracts to provide some background on what retracts are all about and to raise awareness on how certain materials (in particular, PLA) respond). Even with a very sloppy Bowden system (i.e. a long 700mm x 2mm ID tube) retracts over 3mm can be problematic with certain geometries and slicing profiles. I strongly advocate keeping retracts under 2mm for an E3D V6 hot end. The Bowdens on the MM kit are very short and should not require anywhere near that if you follow my recommendations on retract / advance speeds too.
At 4mm, you are playing with fire in my experience - especially with a system like the MM kit that relies on a balancing act of filament melt properties, retracts, and extrusion. I'm just getting started slicing MM objects today now that I have my MM installed and running. I'll certainly report my progress. In the meantime, I'd play it safe and reduce that retract to 2mm and reduce your retract/advance rate to 25mm/s (unless you are using KISS or Cura - they both support different retract & advance rates).
cheers,
Michael
Re: stringing after MM upgrade
I'd play it safe and reduce that retract to 2mm and reduce your retract/advance rate to 25mm/s (unless you are using KISS or Cura - they both support different retract & advance rates).
No, sorry, KISS does not anymore have different rates for retraction suck and prime.. And even with the new KISS Preload, I need 2mm or more retraction to prevent stringing.
I have spent the last 2 days getting the latest "Preload" sorted for my PLA and it turns out that the ideal retraction (for seams) is 1.33mm, but that also creates string between model parts.
I will however, have a look at your notes; I am sure there will be a lot to learn there.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: stringing after MM upgrade
Good Morning,
Unfortunately my print failed at 98% while I was watching it. The nozzle clipped the wing tip, went "twang" and then it started printing in mid-air. Anyway, not a problem. These things happen. I'll try again.
More importantly, the print from the MM mod now looks great with no stringing at all...
For a printer kit built on Wednesday, upgraded to Multi Material on Thursday, the print quality is excellent. I still have a bit of tuning to do, but I'm very happy with it so far.
Again, thanks for the help. 🙂
Re: stringing after MM upgrade
Is that a single filament print? Looks clean. I'm interested in the color and brand of filament too. I have a but if a filament fetish and always on the prowl for new stuff.
Re: stringing after MM upgrade
Hi Michael,
The filament is Prusa silver PLA that came with the printer. http://shop.prusa3d.com/en/filament/46-silver-pla-filament-1kg.html
It's a single filament print on the MK2S-MM. I want to make sure I can do good single colour prints before moving on to multicoloured.
I'm printing a replacement dragon now and that also look brilliant quality...
I'm definitely impressed with the machine. It'll mostly be printing boring mechanical parts to check fit and form prior to tooling rather than dragons though. 🙂
Thanks
Carl
Re: stringing after MM upgrade
What are all of your retraction settings? I'm having the same problem, but haven't been able to get rid of stringing by adjusting retraction settings.
Re: stringing after MM upgrade
I finally got around to installing my MMU 1.0 on my MK2. For a couple of years I have had flawless prints, especially with PLA, but after the upgrade I am unable to prevent stringing and bulging at the corners. It was certainly worse using previous version of Slic3r and older generated gcode without considerations for MMU. At this point I am using the latest versions of the firmware and Slic3r which have the retraction set at 4mm by default with the preconfigured printer settings. Using the latest Slic3r in combination with preconfigured Linear Advance settings have improved the results significantly but it's still not the same quality as before. Stringing and slight bulging on the corners are what i'm seeing.
Anyone know what may need to be changed to eliminate the stringing and bulging?