3d Stuffmaker Mega Prusa problems

Yes, sometimes taking a break is the way to go.

OK, the :H results show that the firmware thinks the endstops are triggered. If the carriage was away from the endstops they should read :L, so yes you should change the switch on grnd, normally open to normally closed and recompile and upload the new firmware. Then check again to make sure they are reading :L when the carriage is in the middle, and change to :H when you activate each endstop in turn.

Hi

Thanks for the advice. The X and Y axis now work. YAAAAAAYYYYYYY.

Making those changes got them moving properly.

Now the problem is the Z axis. I can get absolutely no life out of that. It moves in not at all. This is where I am not sure if the stepper motors are damaged or if I damaged the ramps board again.

This is where I placed the z axis plug on the board and the smaller arrow is where I placed the nozzle connector when I put them on wrong. I have corrected the position now.



This is how the config.h file looks with the change.



Any thoughts.

Regards

Ian

Edited 1 time(s). Last edit at 07/11/2016 08:22AM by Templar66.

Hi

Now the display on the printer has gone blank of all things.

As I am controlling it through repetier, I suppose that isn't important but I don't understand why it all of a sudden stop working. It lights up but stays a blank blue colour.

Any thoughts on that.

Regards

Ian

That's a pain with the LCD - you seem to be having a remarkable run of bad luck. Not sure what to suggest other than checking the cables are fully plugged in. Does it do the same thing when running on just USB power and with the USB unplugged and just running on the printer psu?

For the Z axis, you could try plugging the Z motors into the X axis driver and see if you get any movement when you press the X controls in the host software. That will let you check if the motors are good or not. If the motors show signs of life, you could plug them back into the Z axis driver, and swap the stepper drivers between X & Z, so that you can check for a bad driver. If the driver is bad you'll need to order a replacement - might as well get a couple of spares at the same time.

If neither the motors or the driver is bad it might be a firmware problem, in which case you'd need to go over the Z axis settings - which pins are configured for the axis, what speed and acceleration values, how many steps/mm (and check that the jumpers are installed under the stepper driver for the micro-stepping setting). Trying to drive a stepper motor faster than it's capable of will often result in it not moving at all.

Hi

The screen doesn't display with just the usb and with the power plugged in, so I imagine that's for replacement. Later though.

I had a spare stepper driver that came with the ramps board so I changed that over last night. But that made no difference. I was going to get an electrician mate to test the stepper motors but just swapping the z and axis plugs over to see if there is any life sounds like a great idea.

I will give that a try.

Thanks.

And yes, I am having an extremely long run of bad luck.

Regards

Ian

Hi

Just a thought.

Your comment 'check that the jumpers are installed under the stepper driver for the micro-stepping setting', when I swapped the stepper driver over, I checked the jumpers with what was on the original ramps board. I had copied exactly what was on the old board replicated that on the new board. In this case it has three jumpers on three pins.

I assume that is what is normal. It seems to be the case with each of the Z,Y,X axis stepper driver jumpers.

Unless the repetier firmware requires that to be different?

Regards

Ian

I assume this is the relevant stepper driver that we are talking about?



Regards

Ian

Hi

I swapped over the z and y axis plugs and tested the motors. They moved, kinda.

They seemed to really struggle trying to lift the print head. Its as if there wasn't enough power getting to the Stepper motors.

I don't know if this suggests that the stepper motors may not be totally destroyed but are halfed in power.

I don't know how this then relates to sorting the z axis on the ramps board. Whether because the motors had life on a different set of pins and none on the original pins that this suggests a problem with the ramps board.

I definitely need some direction on this one.

Regards

Ian

OK, that sounds promising. Yes, all three jumpers in place is normal if you are using a4988 drivers, giving 1/16 micro-stepping (details [www.pololu.com]).

So when you connect the Z motors to the X axis we get movement (don't worry if it's not completely normal, we just want to see some signs of life). What happens when you swap the X and Z stepper drivers over. Does the X axis still work with the 'Z' driver?

Have you checked and adjusted the reference voltages on the stepper drivers? For A4988 drivers the reqiured voltage is the required current divided by 2.5. With two Z motors connected in parallel you will normally need to run the Z driver close to its upper limit. That limit will mostly depend on how well cooled the stepper driver is as they will tend to overheat above 1A. If you start with a voltage ref of 0.4V that should be enough to get things moving on the Z, and you can try small increases if necessary from there. If you have a thermometer to check the temperature of the stepper drivers and motors that can be useful.

Hi

It does sound promising.

Where do you change the voltage for the stepper drivers?

Regards

Ian

The voltage ref is controlled by the small silver trim pot on each stepper driver. It's fiddly because the full range only covers about 1/4 turn of the pot, so make very small adjustments. You can measure the voltage between the ground (-ve) power connector anywhere on the board (but ideally as close as possible to the driver) and the central part of the pot (where you put the screwdriver to adjust it). The easiest way is to use a metal screwdriver to adjust the pot with the meter probe clipped to the screw driver, but you have to be careful not to slip with the screw driver and short anything on the driver board.