Bed leveling wizard

[mihc 0]

Hey,

I just finished the assembly of my Ultimaker Original, downloaded Cura and opened the first run wizard. The problem occured at the step with the bed leveling. When the extrusion head moved to the front left corner it immediately said that the communication with the printer failed, and I couldn't restart the process untill the extrusion head cooled off.

I have no idea what to do next. Any ideas or suggestions?

Miha

 

[gr5 2,192]

Do you have an Ulticontroller? If so look for "mintemp" or "maxtemp" error on the UC. If not, I'm not sure how this error is shown.

It's okay to shove the head around when the servos have no power. Try moving the head more towards the middle. I'm guessing there is a loose wire somewhere connecting to the head. I know if you lose connection to the thermocouple you get one of the above errors and everything shuts down until you power cycle. So I am thinking it is that cable. Consider using the alternate cable (for if you have two extruders). It may be that your primary cable has a bad connection or that you didn't plug it all the way in.

 

[mihc 0]

gr5, I don't know if you're a wizzard, but you were right...I checked the wires on the head and one of thethermocouple wires was loose (I guess all the moving it back and forth loosened it a bit). The calibration process was able to proceed now without any cancelation but the next problem occured...when the head moved from the front left corner to the back left corner it ran smoothly. But when it wanted to go from back left to back right it got stuck after 4 cm, stopped, moved a little bit and stopped again so in the end it stopped in the middle of the bed surface so instead of a square it started to make a rectangle line out of PLA. It wasn't even a line because it got stuck on the X axis.

I guess the belts are to tight?

Miha

 

[gr5 2,192]

I guess the belts are to tight?

 

Much more likely one of your set screws (aka grub screws) in one of your pulleys isn't tight enough. You have to tighten the hell out of those things - almost to the point where you think the screwdriver is going to break.

Actually your UM should have come with a spare set of screws. The screws that come inside the pulleys are black and not as good. The spare set are pointier, shiny and work better. I still have the original black screws and I'm fine - my spare set is still ready just in case.

Make sure you get ALL 6 grub screws on the X axis. Especially the 2 on the short belt. The hardest one to get is the one on the motor - you will probably have to remove the motor to tighten that one.

Alternatively you can use a permanent marker to mark the shafts and pulleys so you can see with one is slipping.

 

[mihc 0]

I tightened them as hard as I could and tryed the calibration process again. It didn't change much, but now when the head travels from left to right and reverse in zigzags a bit, and travels only third of the way on the X axis. Only the Y and Y axis routes run smooth.

 

[mihc 0]

Hm I guess the zigzaging is now resolved. The test line around the bed ran smooth so I tryed to make a first print. This is what happened...

 

[gr5 2,192]

There are 6 (SIX!) per axis. I'm sure you tightened them plenty but I think you missed one or two pulleys.

It looks like only one axis is slipping. The most likely two are the ones on the short belt - including the motor. To get to that one is difficult - I think you have to take the motor out maybe - certainly you might have to remove the white metal corner cover that hides the stepper motors.

Try it again. There are 5 other things that can cause this but the other things don't do a sudden slip like this - this is 99% surely a slipping pulley still.

If you don't believe me try the permanent marker test I suggested.

 

[mihc 0]

I tok the bed out and the motors as well so I could tighten the pulleys even more (especially the ones on the shorter belts). After assembly and restarting the bed levelling again, during the homing process when the head moves to the front left corner it started to make and incredibly loud clacking sound, like something got stuck or as if the motor is trying to push the head against the wall.

 

[gr5 2,192]

Something wrong with the left limit switch. If the noise is the loud banging when the motor is trying to move farther left than it can then it should be fine. The stepper motor doesn't care and the belts and such can handle the stress. But it *does* sound horrible.

Turn off power and push the head to the left until you hear the limit switch click. If it doesn't click then something is not properly hitting the limit switch. Look at it carefully - perhaps you have to move the switch away from the corner by a mm or so and re-tighten the screws.

 

[mihc 0]

gr5 you officially became my idol right now. I'm making my first promising print and it looks really good (for a basic rectangle with fillets). I appreciate the help and more than useful advice you've given.

I'll post a pic when the print is finished.

 

[mihc 0]

Here it is. After some tweaking it looks pretty good for the first official print (except for that smudge on the upper right corner).

I have just one question. Is it normal for that blue PLA puddle to appear above the nozzle. Or isn't it tight enough?

 

[gr5 2,192]

Not normal. If it isn't leaking onto the print you can ignore it. If you print hot (240C to 250C) it will boil and bubble and turn brown and gunky and seal up the leak but this is dangerous as the same thing can happen inside the hot end and gunk that up also. If you are lucky it will eventually gum itself up. If it doesn't fix itself or if it starts dripping on your prints, you can heat the head to 180C (that's plenty hot!) disassemble and reassemble. It might be as easy as tightening the nozzle only but possibly you have to do more than that.

It's also okay to use teflon tape for those threads - you can get some for under $1 or 1 euro at any plumbing section of a hardware store. teflon melts around 327C so it is fine in a print head.

http://en.wikipedia.org/wiki/Thread_seal_tape

 

 

[mihc 0]

I dissasembled it, cleaned the threads, put teflon seal tape around the thread and tightened it but the same thing happened again, although the print came out really nice.

Any other advice?

 

[illuminarti 18]

When you assemble the head, start with the nozzle loose by about 1 turn. Screw the brass tube in from the other side of the aluminum block until it is tight against the end of the thread on the nozzle. Then assemble and install the hot end on the printer, and once everything is done, then tighten the nozzle some more if it needs it, so that the threads of the nozzle are tight against the end of the brass tube inside the block again.

If you don't do it that way, you can end up with the nozzle and tube not really tight against one another because the block will tend to rotate as its installed.

I used a high temp pipe joint compound on the threads of my nozzle and tube assembly - it's like PTFE plumbers tape, but as a paste in a tube.