Hi all,
My Printer:
'Official' Prusa i3
Mini-Rambo
E3D V6 hotend
Running Octoprint on a Pi
You've solved many of my problems without me having to start a topic but I need a little advice with my latest issue. I bought a Prusa i3 about 3 weeks ago and have upgraded the heated bed to aluminium. I've been getting better and better prints out of it and I've learnt loads with every issue I run into. But last night...
Halfway through printing, my Y axis went crazy; it had no idea where it was and was making a very loud vibrating noise (much, much louder than skipping teeth) and my aluminium bed was making a hell of noise; presumably vibrating against the Prusa Y carriage mount or the subsequent linear bearings. The noise persists when jogging around manually so I assumed I had a catastrophic mechanical issue. I unhooked the belt under the plate and pushed the carriage by hand: almost perfect, just a tiny left to right twisting motion across the X axis.
So then I assumed it was the stepper. I dismounted it ready to take it down for a like for like replacement. But when I turned it by hand it felt fine, like every other stepper I've had. No mechanical issues at least. So, just as a last gasp check, I swapped the steppers for the X and Y and lo and behold, the strange noise and awful jerky movement was now across the X axis.
So, I'm now convinced the following are fine:
* Y and X railings/mechanics
* Both stepper motors
* No belt teeth damage
I thought that since I'd been tinkering in the Marlin config, I'd reflash it with the default load-out supplied with my printer. I didn't expect this to work since I've never touched the stepper current digi-pots and sure enough, it changed nothing.I did up the current limits with M907 but it just whines more when holding.
So now I can add the Marlin firmware to the list of things I know not to be the issue.
That only leaves my Mini-Rambo, no? The X and Y ref test points seemed to be shared so can't be useful in debugging, what can I do since the Allegro chips are tiny surface mount jobs?
Has anyone seen something similar before? The driver obviously isn;t broken altogether as it does attempt the drive in the right directions, but something is clearly very wrong and it MUST be the chips unless I'm going mad. Which is possible...
I can make a video of it in 'action' but will have to wait until tomorrow for my neighbours' sake.
John
My Printer:
'Official' Prusa i3
Mini-Rambo
E3D V6 hotend
Running Octoprint on a Pi
You've solved many of my problems without me having to start a topic but I need a little advice with my latest issue. I bought a Prusa i3 about 3 weeks ago and have upgraded the heated bed to aluminium. I've been getting better and better prints out of it and I've learnt loads with every issue I run into. But last night...
Halfway through printing, my Y axis went crazy; it had no idea where it was and was making a very loud vibrating noise (much, much louder than skipping teeth) and my aluminium bed was making a hell of noise; presumably vibrating against the Prusa Y carriage mount or the subsequent linear bearings. The noise persists when jogging around manually so I assumed I had a catastrophic mechanical issue. I unhooked the belt under the plate and pushed the carriage by hand: almost perfect, just a tiny left to right twisting motion across the X axis.
So then I assumed it was the stepper. I dismounted it ready to take it down for a like for like replacement. But when I turned it by hand it felt fine, like every other stepper I've had. No mechanical issues at least. So, just as a last gasp check, I swapped the steppers for the X and Y and lo and behold, the strange noise and awful jerky movement was now across the X axis.
So, I'm now convinced the following are fine:
* Y and X railings/mechanics
* Both stepper motors
* No belt teeth damage
I thought that since I'd been tinkering in the Marlin config, I'd reflash it with the default load-out supplied with my printer. I didn't expect this to work since I've never touched the stepper current digi-pots and sure enough, it changed nothing.I did up the current limits with M907 but it just whines more when holding.
So now I can add the Marlin firmware to the list of things I know not to be the issue.
That only leaves my Mini-Rambo, no? The X and Y ref test points seemed to be shared so can't be useful in debugging, what can I do since the Allegro chips are tiny surface mount jobs?
Has anyone seen something similar before? The driver obviously isn;t broken altogether as it does attempt the drive in the right directions, but something is clearly very wrong and it MUST be the chips unless I'm going mad. Which is possible...
I can make a video of it in 'action' but will have to wait until tomorrow for my neighbours' sake.
John