47 minutes ago, conny_g said:Extrudr Green-Tec White.
Temperature resistance of 110-120 °C and print temp at only 170-230, this stuff seems magic.
47 minutes ago, conny_g said:Extrudr Green-Tec White.
Temperature resistance of 110-120 °C and print temp at only 170-230, this stuff seems magic.
2 hours ago, yyh1002 said:Temperature resistance of 110-120 °C and print temp at only 170-230, this stuff seems magic.
Just been looking at it myself, sounds fantastic. I printed my parts in Biofila PLAtec but the finish wasn't as nice as I'd have hoped.
@foehnsturm
I assembled two heads now - redid the previous one to improve force / accuracy (magnets were not it completely straight) and made a new one for the second printer - and there is no gap between head and coupling for me.
It seem that the 3D model of the coupling changed, it's now 0.25mm thicker than the old one. Compared my old coupling with the new one with a caliper.
I don't think that's an issue (the magnets seem to still touch and have enough force), but just to let you know and to check if this known and/or if it was intended.
Hmm, there still should be a small gap (but it should work anyway). Will have to measure the step/stl.
Up to my recent experience with the corexy magnet tool changer parts it's quite easy to insert the magnets deeper than intended with a little more force applied. The bottom of the pockets in the print head actually isn't that strong (printed by bridging).
35 minutes ago, foehnsturm said:Hmm, there still should be a small gap (but it should work anyway). Will have to measure the step/stl.
Up to my recent experience with the corexy magnet tool changer parts it's quite easy to insert the magnets deeper than intended with a little more force applied. The bottom of the pockets in the print head actually isn't that strong (printed by bridging).
I used quite some force as I wanted to make absolutely sure to not have the magnets twisted again as last time.... :-)
The head was sticking "ok", but not strong in the first setup due to that. And I have the suspicion that this caused inaccuracies in the print of some 0.1-0.2mm.
1 hour ago, foehnsturm said:Hmm, there still should be a small gap (but it should work anyway). Will have to measure the step/stl.
Up to my recent experience with the corexy magnet tool changer parts it's quite easy to insert the magnets deeper than intended with a little more force applied. The bottom of the pockets in the print head actually isn't that strong (printed by bridging).
Hi foehnsturm,
I had the same issue as conny_g. I measured the step file and found the total depth for magnets in the coupling and head is bigger than 6mm.
Looking at the assembly instruction, it feels like the photos used 6x4mm magnets instead of the 6x3mm in BOM.
I therefore modified the model and made the holes 1mm shallower.
I stand corrected.
Updated git files for head and coupling. Holes in the head now 2 mm deep and coupling plate 3.75 mm thick to achieve a 0.25 mm gap
I find this ironic, I posted that I had printed these parts out and there was no Gap (conn g) implied my prints were under extruded? and low and behold the STL files are wrong. I botched my print head to make the gap, exactly because there was no gap, and have shelved my conversion, because I knew the files were suspect. I am grossly disappointed.
13 minutes ago, bob-hepple said:I find this ironic, I posted that I had printed these parts out and there was no Gap (conn g) implied my prints were under extruded? and low and behold the STL files are wrong. I botched my print head to make the gap, exactly because there was no gap, and have shelved my conversion, because I knew the files were suspect. I am grossly disappointed.
I think in most cases the head still works as designed, if the magnets touch or are very near (0.1-0.3mm) so their force is maximal.
I am using the new head without gap currently and I cannot find any issues with it so far.
3 hours ago, bob-hepple said:I find this ironic, I posted that I had printed these parts out and there was no Gap (conn g) implied my prints were under extruded? and low and behold the STL files are wrong. I botched my print head to make the gap, exactly because there was no gap, and have shelved my conversion, because I knew the files were suspect. I am grossly disappointed.
Well again, apologies for that.
Files were correct until I found out that the aligning square pockets might wear out after some time and therefore made them deeper but obviously without adjusting the overall depth of the coupling. You were right but some 100 people did the Mark2 without reporting issues. So I didn't invest enough time for investigations (there's still a daytime job for making a living from )
On 26.1.2018 at 8:04 PM, foehnsturm said:.... but some 100 people did the Mark2 .....
Do you have a register of the users? I remember you once planned to do a world map where how many built Mark2...?
On 18/08/2017 at 1:06 AM, tinkergnome said:There's no special reason (at least not that i'm aware of). AFAIK this are the standard formulas that Cura uses, if acceleration or jerk control is enabled. You can disable it in Cura, if you want. Mark2 works with the standard values of the printer as well.
What's the reason of your question? Did you noticed any serious drawbacks related to these values?
I found the super slow acceleration setting would create round corners.
In the photo below, both of the cubes were printed with extruder 2. The left grey cube is printed with default acceleration and jerk settings in the Mark2 profile, and the right white cube is printed with disabled acceleration and jerk control.
The over extrusion around the corners is quite obvious in the case of low acceleration.
I suspect the reason is that low acceleration setting would make actual print speed very different from the constant feedrate. Resulting in over extrusion at places where the head is slowing down or accelerating, and under extrustion at where there it reaches target speed.
Edited by yyh10028 hours ago, conny_g said:
Do you have a register of the users? I remember you once planned to do a world map where how many built Mark2...?
Unfortunately not, it's an estimate based on the approx number of Mark2 boards sold.
I wanted to do this map but it's hard to collect the data from most of the Mark2 users. I even suspect the majority isn't active forum posters.
Optimized Mark2 profile settings would be great!
There's a lot of settings which could be fine tuned, like different motion settings for head 1 and head 2 (almost twice the mass). And yes, the calculated Cura default settings became notoriously slow over the past two years.
7 hours ago, yyh1002 said:The over extrusion around the corners is quite obvious in the case of low acceleration.
In my experience this effect depends not so much on acceleration, but more on the (so-called) jerk.
I you want, try your test cube again with enabled acceleration control, but switch off jerk control or increase the (very low) wall jerks to values not lower than 10 (or 12) mm/s.
It could be interesting to compare the results.
BTW: what are your default settings for acceleration and jerk on the machine?
2 minutes ago, tinkergnome said:
In my experience this effect depends not so much on acceleration, but more on the (so-called) jerk.
I you want, try your test cube again with enabled acceleration control, but switch off jerk control or increase the (very low) wall jerks to values not lower than 10 (or 12) mm/s.
It could be interesting to compare the results.
BTW: what are your default settings for acceleration and jerk on the machine?
That makes more sense. I'll try it later.
I set the machine at 3000mm/s2 acceleration and 20m/s jerk on the menu.
I just wanted to say a big thank you to Foehnsturm, Tinkergnome and everyone else involved in the development of the Mark-2. This is a fantastic modification, managing to do 2 colour prints on a UM2 when Ultimaker had already given up on the idea!
I've now got my 2nd head working and after some painfully frustrating setup (my fault no-one elses!) I've managed to print a few sample pieces.
I think I need to dial in my 2nd extruder (orange material in following photos) as I seem to be suffering a lot of ooze. Printing with an ooze shield definitely helps, but I need to optimize the settings.
1st Print
2nd Print
3rd Print
Edited by ssloan
@foehnsturm
I think this might be interesting to include in the BOM of the Mark 2 upgrade:
I am about to upgrade a former UM2 as well and it is possible to reuse the old head for Mark 2, so you need to buy only 1 upgrade kit for a UM2, not 2.
12 hours ago, ssloan said:I think I need to dial in my 2nd extruder (orange material in following photos) as I seem to be suffering a lot of ooze. Printing with an ooze shield definitely helps, but I need to optimize the settings.
You could also use a prime tower instead of the ooze shield. I prefer that. Alternatively you optimize the tool change retract settings to perfection, I think @foehnsturm is a master in that. :-)
Good morning experts,
I am stuck with my Mark 2 conversion and need some help.
I had my Ultimaker original - very original, one of the very first - converted to be an UM2+.
This "UMO2+" is a very good printer and gives a lot of joy.
Next step was to convert to Mark 2.
Everything went fine with one problem remaining.
When I want to "adjust z" my print bed moves up and never stops. The print bed then crushes into the print head.
I do not know how to make the print bed stop near the nozzle.
Now, one suspicion I have:
Loading the Tinker firmware I initially made the mistake to load the extended version, but had that replaced twice with the correct firmware version "expansion-board".
I had the firmware replaced before I started to "adjust z".
It appears as if the Ultimaker still has the extended length in force, despite the change in firmware.
Maybe someone has experienced the same and/ or could offer advice .
Thank you very much.
42 minutes ago, garaha2012 said:It appears as if the Ultimaker still has the extended length in force, despite the change in firmware.
Yep, the setting stays there, once it is stored - at least until the next "factory reset".
Go to "Advanced -> Preferences -> Print area" and reduce the maximum z-value to a lower value (225mm is the default for an UM2+).
BTW: thank's for the picture - it looks great!
Edited by tinkergnome40 minutes ago, garaha2012 said:Good morning experts,
I am stuck with my Mark 2 conversion and need some help.
I had my Ultimaker original - very original, one of the very first - converted to be an UM2+.
This "UMO2+" is a very good printer and gives a lot of joy.
Next step was to convert to Mark 2.
Everything went fine with one problem remaining.
When I want to "adjust z" my print bed moves up and never stops. The print bed then crushes into the print head.
I do not know how to make the print bed stop near the nozzle.
Now, one suspicion I have:
Loading the Tinker firmware I initially made the mistake to load the extended version, but had that replaced twice with the correct firmware version "expansion-board".
I had the firmware replaced before I started to "adjust z".
It appears as if the Ultimaker still has the extended length in force, despite the change in firmware.
Maybe someone has experienced the same and/ or could offer advice .
Thank you very much.
Hi there,
there is nuthing to suspect, the new firmwares store some settings inside the eeprom, so i would recommend you first factory reset and install back the original um2+ latest firmware just check it out whether it functions normally, then again hit a factory reset and install the correct version as per your printer, once done try the setup again it will be a success, i realised this eeprom thing while doing my HT printer with @tinkergnome and @gr5, so good luck and hopefully please show us some impressive results.
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Extrudr Green-Tec White.
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