johan

Hi, I just finnished the 5th print on my Ultimaker, and I get some z-wobble at the last 50mm of a 150mm print. An easy way to remove this, is to let the z nut move in x and y, and just have a snug fit in z. This allows a small wobble in the z-spindel, without making the build platform wobble. On some Reprap Prusas they even leave the z-steppers untightened. It is better to let the spindle wobble freely, than to try to get everything straight! :-) Johan

I had a 1 hour 40minutes session with Siert at Ultimaker today. In the end, we found out that the problem was a shortsircuit were the steel tube is shrinked to the thermocouple wire. By cutting of the steel tube, removing the insulation at the ends and twisting them and then insulate witk Kapton tape, we solved the problem! Finally! It's 6 months since I ordered the Ultimaker! Now I am happy calibrating, and only minutes from my first print! Johan

I have the same problem. I have got replacements for all the parts... Motherboard, cables thermocouple etc and still got the same problem. I have found out that everything is ok as long as the TC is out of the heaterblock. The themp readings are what they should be. When I touch the heaterblock with the TC temp-reading falls, and Minthemp is triggered. I am going to have a Skype meeting with UM on monday, and I hope we will be able to sort it out. I ordered my Ultimaker in october, and still no printing.... :-( Johan

This looks like a good solution. Will adjusting the preasure from the second gear influence the performance of the gear? This will mean that the center distance will change? I have printed the parts an made some tests. It workt well with a Feedrate of 250mm/s but started to fail at 300mm/s. To me it seems to be a problem that comes with the fast reversal at this speed. When it returns to the position from before the reversal, it has to push the filament at fast speed against the buildt up preassure in the Bowden tube. On my printer (Reprap Prusa derivat. My Ultimaker is still not up and running... :-( ) I got a Makerbot MK6+ hotend, wich uses a stainless steel nozzle and a inner tube made of PTFE. The filament is not in contact with the heater core: the inner tube is going all the way down into the nozzle. I wonder if the inner tube insulate to much, so that the filament isn't melting fast enough and actually block the nozzle at high speeds. When I monitor the hotend themperature during fast infill, I can se it drop 5-7 degrees. The Mk6+ got a 40W cartridge heater wich is the same as the default Ultimaker cartridge heater. I have got 2 J-head nozzles laying around so I think I will try one of those, before I make further changes to the driving mechanism. Johan

Hi, I have made some progress with the new exstruderdesign, and have started to print the parts parts on my Makerbot. I will test the extruder on my Reprap first, and if it works fine, I will adapt it to my Ultimaker. ( I still have my Mintemp trigger problem on the UM... :cry: som shortsircuit with the TC) Here are some screenshots new extruder: Stretchlet Ultimaker original 100x.g.zip Stretchlet Ultimaker2 100x.gcode.zip

Hi, I have had the same idea, and I have made a counterweight system on the x-axis of my Prusa printer. I can't say if it helps, because I need to solve problems with the feeding mechanism before I can test at high speeds. It's also possible that acceleration have reduced the effect of vibrations so much already, that the counterweight is out of date... The moving mass on my printer is about 160 grams, and I got a Bowden extruder as the Ultimaker. Johan

I have thought of something similar, but at the moment I think that it will be a more simple solution with to steppers, almost like the to steppers on the z-axis on the Prusa versus Sells. I want the posibillity to adjust the pressure on the filament. I think it would be more complicated to achive this with one stepper, and pinions to drive the second drivegear. Now I can just print out some parts ( and wait for the the new stepper) and assemble and test! :-)

I have a Makerbot TOM, wish I have upgraded with the MK6 + exstruder. It has a big hi-torque Nema 17 steppermotor, wich drives the drivegear directly. On my Prusa verson it skips steps because I have to push the Delrin plunger so hard against the filament to avoid slipping. With the filament between to drivegears, and to hi-torque steppers, I hope to push the filament without to much truble. Another thing I have observed when printing at a feedrate of 150mm/s with my Prusaverson, is that the themperature is going down 8-10 degrees when printing layers with 100% fill. I have a 40W cartridge heater in the hotend, wich I think is the same as the standard Ultimaker? The nozzle is made of stainless steel, so maybe it can't transmit the heat fast enough? Johan

I just want to say that this was ment to be a posible solution to the filament drive problems at high speed printing, not seeking for advice for my Prusa-verson... . I think pushing filament between to drivegears, will mean much better grip on the filament. I hope this will result in less grinding and deformation and much more predictible amount of extruded filament. Johan

Just normal indoor climate in my flat. Before I insert the TC into the heaterblock, it measures 22-23 degrees. And since it's winter the air is dry.... The strange thing, is that the same thing happend with the first TC. ( I did not test to remove it from the heateblock) If I use needle-nosed plier an hold the steel tube on the TC gently, the themp reading drops down to 15 degrees, and rises to normal, when i let go. When I do the same with a plastic tweezers the themp stays at 22degrees. I now tried to remove thr heater cartridge from the block, and then insert the TC again. Now it works! I pulled it out again, and tuch the cartridge, and the Mintemp triggers! The machine is only powered over the usb. I guess this means I got a gnd problem somewhere... Could anyone give me a hint where to look? Johan

While trying to get the Mintemp trigger fixed on my Ultimaker, I am doing tests on my new Prusa style Mendel. It has a Bowden extruder and a build envelop of 300 x 300 x 260mm (at the moment) I am using a Makerbot Mk6 hotend, and the MK6 Stepstruder. When testprinting with a feedrate of 150mm/s, it seem to get the same problem as you get with the Ultimaker: to little filament extruded. The MK6 has a Delrin plunger, to push the filament against the drive gear. I have to tighten it very much, to avoid slipping, and when I am tightening to much, it misses steps. I was planing to use a Wades extruder with a ballbearing instead of the Delrin plunger, but then I came up with another idea I am going to test: the dobble Makerbot MK6. This means having to steppermotors with drive gears on each side of the filament. I have just started moddeling, but here are some pictures to show the idea: http://dl.dropbox.com/u/55953222/My%20P ... Mendel.JPG http://dl.dropbox.com/u/55953222/Dobble ... %20MK6.JPG http://dl.dropbox.com/u/55953222/Dobble ... K6%202.JPG Any thoughts? Johan

The UIltimaker is placed on a wooden table, so that couldn't be the reason. It is when I insert to the heaterblock that the temp is falling, and at last triggers the mintemp. If I insert it and watch the themp drop, and then pull it out again before it reach 5 degrees, it rises to normal roomtemp at once.... It insn't happening if I just touch the outer surface of the heaterblock.... Johan

No. The Mintemp is trigggered when I insert the TC in the heaterblock. When I insert it the themp starts to drop. If I wiggle it it goes up and down. I think the same thing happend with the original TC and TCpcb. It was ok when the bot lay on its side, but triggered when I turned it to upright position. I have a Makerbot TOM, and in the assembly wiki, they point out that the TC should be wrapped with kapton tape for insulation before attached to the heatblock.... Johan

Hi, I have had an issue with the MINtemp triggered at my new Ultimaker. After a lot of testing, I contacted the Ultimaker Support team, and today I recived replacement TC and TC pcb. I conected the pcb and the TC it, but didn't insert the TC into the heaterblock. It worked perfect! I meassured the themperature for some time, and it was at 23 degrees. So I assembled the printhead and inserted the TC in the heaterblock and locked it with the screw. After that, I conected the printer to Pronterface again but.... :cry: MINtemp was triggered again.... So I moved the TC out of the heaterblock again, and voilà: perfect meassurements.... So I guess that I get a short sircuit when the steeltube is inserted in the heaterblock. Have anyone else had this problem, and is ther a fix for it? Johan