Nozzle off center...by a lot?

[DLS3141]

OK, so first off, I tried searching for this in the forums with no success. My apologies if this has been answered elsewhere or a thousand other times or is other wise a "stupid" question. I'm still pretty new to this.

So, I've finally got my Rostock Max set up and moving after 18 or so months of intermittent work on it. (Long story or stories...) Anyway, I bought this right when the LCD and the Orion were new to the Rostock MAX. As I've been messing about with heating it and making it move about, I've noticed that while calibrating the Z height works, when I bring the nozzle down to the bed, the nozzle is off center by 2-3 cm. I'm pretty sure it's the same way when I send the hot end to to the top as I don't see it moving horizontally. Any suggestions?


I did update the RAMBo firmware, but otherwise it's original. I don't think my problem is firmware related.

[guanu]

if its that far off center, it should be directly toward or away from one particular tower... I'd suggest take the pulley off that motor and count the teeth, we did have a time back about when you are talking where we had a problem with pulleys that were marked as 20 teeth, but were actually 18 teeth... thats the only time I've seen where it would be way off center.

[DLS3141]

Well, you were correct in that it was a problem with the pulley. I noticed that offset of the nozzle was directly opposite the Z tower. So I relaxed the belt tension and popped the belt off of the drive pulley. It was immediately obvious that something was wrong with the pulley, I could see that the plastic had split axially and that the plastic pulley had shifted axially toward the end of the stepper shaft. When I removed the pulley, it was clear that the inner hub had come loose from the toothed pulley after cracking. I'm not sure why that would have happened, but I guess I need some new pulleys.

Any ideas?

http://picpaste.com/QbHHoDZW.jpg

[Earthbound]

The newer all metal ones are nice for that reason.

$4 each from http://www.reprapdiscount.com/home/44-gt2-pulley.html

but I'd suggest doing all 3 to prevent future issues. In which case might be worth the buying the 3-pack for $20 from SeeMe's shop since you won't have to wait so long to get them. Same pulley.

[jmpreuss]

Well, you were correct in that it was a problem with the pulley. I noticed that offset of the nozzle was directly opposite the Z tower. So I relaxed the belt tension and popped the belt off of the drive pulley. It was immediately obvious that something was wrong with the pulley, I could see that the plastic had split axially and that the plastic pulley had shifted axially toward the end of the stepper shaft. When I removed the pulley, it was clear that the inner hub had come loose from the toothed pulley after cracking. I'm not sure why that would have happened, but I guess I need some new pulleys.

Any ideas?

http://picpaste.com/QbHHoDZW.jpg

Contact seemecnc, this is a know problem (I had the same thing on my machine about the same age as yours) and there is a decent chance they will replace free of charge.

[DLS3141]

I chatted with them this AM, but since it's more than a year old, it was a no-go on a replacement because it's been over a year. That's OK. I ordered the replacement pulleys and the new spring loaded cold end. They've already shipped. Now I just have to wait for the mailman...