vladson

Yuhu! I actually managed to find out where my problem was! It was pt100 with 4k7 setup. Somehow it showed big error and temperature of the bed was around 2°C. And actually firmware is blocking heating without any message. After I heated the bed a little (with a lighter) it started the circuit! Thanks a lot for your help @zoev89! Can you tell me which circuit do you use now to control and power HB?

Well I found this marlin build guide, I definitely should give it a try.

Oh, I see, I did exactly as you explained. When the heated bed is "powered" from the controller, the drain is still in closed state. No connection to the ground, the led is turned off and the voltage is zero. It is either dead output of my Arduino Mega, or strange behavior of the firmware or some hardware problem of the UMO board (shield) itself. While connection to the +19V from terminal is ok. Does anyone knows how to build marlin to use second extruder heater's terminal as heated bed's one? I decide to use https://www.youmagine.com/designs/ultimaker-heated-bed-mosfet-relay-hack-v2 by Jonny Bischof. And after a while I also plan to switch to powering the whole setup with single psu. Which 24 -> 19 V stepdown regulutor do you use?

Thanks, @zoev89! I use dedicated 300W 24V industrial PSU for my HB, so my intentions are to use UMO board heated bed connections only to control MOSFET key. I assembled a test circuit with 10kOhm resistor and a diod, but i used both heated bed connections (as V+ and GND), should I use 19V direct from the power inlet of UMO board to check if 19V is available on the socket? After all, diod on the UMO board near the HB connector is always off too.

@Labern, sorry for that, of course I forgot to) I have ultimaker original.

Hello everyone! I recently managed to get self sourced heated bed that is nearly identical to HBK, except the converter board (it is absent). Also i assembled a mosfet key to operate a heated bed's power, but didn't connected it. First I tried to turn bed heating on, without actual power connection, and it turned out, that output voltage was around 0 and corresponding led was also turned off, while ulticontroller was showing target temperature. I tried a couple of firmwares, and default one, and built using https://bultimaker.bulles.eu/ - all of them showed no errors but no power was present on heated bed terminal. Is it dead electronics or am I missing something? How can I configure marlin to use second extruder's output for heated bed? Thanks in advance!

Thanks. Jonny, gr5! Hour of tinkering yesterday revealed, that thanks god, nothing unfixable happend: indeed cartridge heater is not so good, and I had to add some insulation. Thermocouple was burnt only near the amplifier terminal, resulting in 1cm shorter wire. And amplifier itself still works properly. Printhead either wasn't damaged. So I fell in panic too early)))

Hi! I encountered very interesting issue. This how it all began: I started a rather long print and after an hour left it printing. When I returned, the print was just a half complete, but the controller reported it to be finished. I found out that small gear has fallen off the feeder stepper and that caused no extrusion. On the print table there where several drops of overheated PLA, but the PEEK itself seems to remain functional except darker color and small amount of leakage. Here the interesting began: I powered the machine and immediately smoke appeared from the printhead. Origin of the smoke was one of the thermocouple wires – it was completely burnt. Voltage between amplifier ground and thermocouple turned out to be 19V - proper evidence of heater short circuit to the block. My thoughts are that after extrusion loss some overheat was present which resulted of insulation damage thus resulting in short circuit to the block. Does anybody encountered something similar? Is MOSFET conducting ground or +?

Yes, a bit of standard machine oil worked perfectly! Hope it'll work till I'll find new shafts. There is another issue occurred, but I'll start new thread for it.

Thanks to all! It turned out, that getting good shafts is indeed big problem: being impatient as I am, I managed to buy a long one 8mm rod from local reseller, but it was also bent a little (less than chinese ones but still tangible). After cutting with Dremel (oh! 2 hours and a ton of dust) and installation, I've been able to get my first print done! It was marvelous! I was very surprised to see my Um printing just after building completion. Unfortunately, my happiness disappeared pretty soon: I could not help, but noticed, excessive friction in the gantry on the thick 8mm rods. On the one shaft friction is not linear, it is periodic (like sinusoidal alongside with rotation of the shaft), on the other it is quite linear, but it is was so big, that sometimes stepper could'n turn the shaft, which resulted in shift of the printhead location. So, now I'm here, where I started: need more precise rods (no way to get Misumi rods alas) from local precision shafts factory, and any possibility to get rid of sliding blocks friction. Is it a good idea to add some grease? or should I use reamer to slightly treat my sliding blocks bushings?

Thanks! The error is on both thin and thick rods. Today I managed to measure actual error with mirror and caliper. It seems that axes have only one point of binding (in the middle). For the thick ones (8mm) the error from the plane is 1 or 1.1 mm. For the thin ones (6mm) it is 0.4 and 0.5 mm. So it is not so enormous but still unacceptable. I'll try to straighten them carefully, maybe it'll work. JonnyBischof are you experimenting with direct X-Y drive? What sizes of thick rods do you use? As I can see They should be apprx 1.5 cm longer, are they? Thanks again. Trying to find local source of rods with quality control.

Hi all! I'm in process of building self-sourced Ultimaker Original and already sourced all the parts needed and built the frame and some of other stuff. And now I encountered issues with rods, which I ordered from Aliexpress. All the X and Y shafts are not straight: they have curve from 1 to 3 mm. As gantry alignment is one of the most important things for good print quality, can anybody recommend anything on rods straightening or is big issue at all (suppose yes). Thanks in advance!