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MK2.5 upgrade Vs MK3 print quality

Posted: Sun Sep 24, 2017 12:53 pm
by WassimFilali
In short:

do the Trinamic micro steps improvement have an impact on print quality ? if yes, in which example and how much ?

Long version :
Question that around 30 000 MK2s owners will be asking sooner or later : What do I lose in print quality compared to an MK3 ?
So, here, we're in the case where an MK2S has been upgraded to an MK2.5 so some print quality improvements expected such as :
  • Bondtech two extruder gears => no slip or skip (can someone confirm this ?)
  • PINDA 2 with thermistor => better adjusted temperature, less wrap (can someone confirm this ?)
Now the real question of this topic is what do we lose that is not part of the 2.5 Kit ?
  • No 24 V, just 12 =< is there any material for which bed temperature cannot be achieved ?
  • octoprint RPi beeing embedded not outside => just better compact look
  • beeing more silent => can suffer but live with it
  • Trinamic micro steps => Does this have an impact on print quality ?
I shared a spreadsheet ... sp=sharing where anyone can comment for those who wants to make an exhaustive comparison :

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Sun Sep 24, 2017 1:32 pm
by MaxRink
The TMCs should have little to none effect on the print quality in the used implementation ( taken from ultimachines git repo).
It's still an 8 bit avr ( thus the interpolation feature is used, which is not as good as native 256 Microstepping and the 2130 has no integrated step generation like the 5130) so that is still the limit.
It might be slightly better than the Allegros, but not that much.

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Sun Sep 24, 2017 8:39 pm
by WassimFilali
Thanks for the info, that's interesting to know and quitening for all who just purchased an MK2S :)

If someone notice something having a significant impact on print quality (MK2.5 Vs MK3), please let us know ?

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Mon Sep 25, 2017 8:03 am
by ido
As an MK2S owner, this is indeed a question I was asking myself. Do I get the upgrade or do I try to sell my MK2S and get the MK3.

All the handy bits are included in the upgrade, so that's good, but indeed, what about print quality, that is all that counts in the end.
Nice overview upgrade vs mk3s, I am going to keep a close watch on this thread.

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Wed Sep 27, 2017 7:54 am
by ido
Still a good thread, but its not really alive I noticed. O fcourse this could also be because the printer is not available yet.
Perhaps you should also post this at the prusa forum

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Tue Oct 03, 2017 9:38 am
by 3dvs_ch
At first I'll upgrade to the 2.5, main reason for me to upgrade is the spring steel coated bed, huge plus for me.
But I might buy a MK3 too at some point.

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Tue Oct 03, 2017 11:12 am
by Vertigo
I dont expect any noticeable difference in print quality.
The bondtech extruder; im not entirely sure what the point is. Maybe when printing very fast? Maybe for some slippery materials, like nylon? I have no complaints about my MK2S extruder at least for PLA/ABS/PETg.

Pinda2 ought to solve the problem when you change bed temperatures. I do have this issue, between PLA and ABS temperatures, I need to adjust Live Z significantly. MK3 would be improve convenience here, no doubt.

I think the biggest improvement will be noise, to some extend, speed (not all that useful with a V6 hotend) and maybe the convenience of the heatbed. All in all, it sounds like decent improvement, but not enough for me to spend money upgrading my MK2S. Only exception being the pinda2 probe, I would like that, and it should be a pretty cheap upgrade.

Re: MK2.5 upgrade Vs MK3 print quality

Posted: Sun Jan 21, 2018 2:09 pm
by slippyr4
I think one of the driving reasons for going 24V was the trinamic drivers themselves; they are quieter with more voltage headroom over that required for the motors.

The temp sensor in the pinda probe is designed to compensate for the fact that the distance from the bed at which it triggers varies with temperature. I've no idea how good the compensation really is (i.e., how good a predictor of trigger distance is temperature) but personally, i make sure I preheat with the extruder >50mm above the bed and it seems pretty consistent to me.

On the facebook groups it seems like a lot of people are underimpressed with the bondtech gears; dual drive and an enclosed filament path should in theory make them great for flexibles but, anecdotally, there are a lot of people having a lot of trouble printing flex.