thetastysnail

I can answer my own question now. the answer is sort of. the motor will operate and you can print stuff. I had to leave the cover off, which leads me to think it may get hotter than normal, but the temps seem ok compared to the x axis motor. also this motor only just clears the build platform. but the biggest problem what that i kept getting axis slip. It wasn't slipping on the pulleys, i tightened them up a lot. but it would become misaligned on the y axis, usually later on in the print. I tried lowering the current in the options and this seems to have cured it. So i conclude the bigger motor was causing the stepper driver to overheat and cut out periodically. I will be putting a heatsink on it later and putting the current back up, so we'll see how this helps. I'm still gonna get the correct motor for it as soon as poss.

Hi, hope someone can help with hopefully a simple question. On my UM2 the y axis stepper motor became notchy and stiff, so i bought a new one to replace it. to cut a long story short, i managed to get the wrong one. I bought a sy42sth47-1684a instead of a sy42sth38-1684a the main difference is that it's longer by a few mm so i cant fit the shroud back on. the key specs of degrees per step seem ok, and it's more powerful. so can i do any harm in fitting this as a short term measure. i intend to get the correct motor asap, but i have a big job to finish right now cheers Rob

Seeing as i got a private question asking about this problem, i thought i would complete my description of how i fixed it. firstly i got one of these temp sensors http://www.ebay.co.uk/itm/Pt100-222-Thin-Film-RTD-Sensing-Element-Class-A-Platinum-Temperature-Detector-/321161934491?ssPageName=ADME:L:OC:GB:3160 a Pt100-222-Thin-Film-RTD i think they are easy to find from many places. i then scratched a small square of coating off the bottom of the heated plate near the connectors. I glued the sensor on with some thermal epoxy compound. it was stuff i got for glueing heatsinks onto computer components. I soldered the wires to the connectors (dont think it matters which way round) i then desoldered and removed the old sensor. making sure there is no solder bridge across the pads. since then everything has worked perfectly. see my pics for clarification

Well in the end it was the thermocouple on the bed that had failed. I replaced the thermocouple and everything works fine now. Later today i will upload a couple of pics to show what i did and also what thermocouple i used for the benefit of others who want to do the same fix (it's pretty easy) everything is working fine now, temps rock steady and confirmed with external temp probe. I suggest anyone with a bed that won't heat up to try this before getting a new bed (check for loose connections first)

ok i completely removed my heated bed and put it into a room heated to about 60C (actually a paint spray booth on it's bake cycle) at room temp the temp sensor measures about 108 ohm. at 60C it measures about 190 ohm. This tallies with what i was experiencing with the bed in operation. ie things go weird at about 60C I was measuring the resistance directly on the sensor. but i got the same reading if i measured on the connectors also. Given that i have already ordered a new bed from ultimaker what should i do about this one. I could try getting a new thermistor, and soldering it on. And should i have had to pay for a new bed given that this one is clearly faulty and the printer is 3 months old. Rob

i read that the solder joints on early printers could be bad, but i dont think mine is an early printer (bought in april). I had a really good look at the solder joints and they seemed ok. I might take out the heated bed completely and seeing if there is any other place i can identify problems on it. I am in the UK and i have already ordered a new heated bed. Had to phone them to get it done though cos it was taking ages by email.

Hi people. Ive had my UM2 for about 3 months now. done a lot of ABS prints on it, but around a week ago i had a couple of prints warp badly on it. then the next print i did i got a temp bed error on the display and the machine locked up. had to turn it off for a while then it came back on ok. tried another print and the same thing happened. so after a week or so of emailing back and forth with ultimaker, (and a few phone calls) they are sending me a new heated bed. In the process of diagnosing the problems i took a vid of what happens when i try to gradually heat up the bed, manually. thought you might be interested to see it, and maybe some of you experts can give your opinion on what is happening. for those that don't want to watch the vid, it shows that everything is ok until i set the temp to 60C then the recorded temp shoots up.