Z-Axis not working!!!!

I'm having issues with the z-axis being very unstable and randomly not working. I've had the printer for about a week now and the issue hasn't gone away. I ended up getting two days of flawless printing but now the problem has come back and I can't get the Z-axis to work again. I have the R1 model with self-leveling and followed all the steps in setting up the printer.

When I first turned on the printer I usually home all axis separately using Matter Control. The X and Y axis always work but when I try to home the Z-axis, nothing happens (sometimes the z-axis will home correctly but soon after it will stop working, usually through the probing stage or within the first couple of layers in a print). When I press the home Z button it sounds like the machine is 'thinking' but there is no movement in the Z direction. I can hear this humming noise for the same time it would usually take to make the maneuver. I am still able to adjust the X and Y axis manually using the + and - buttons but no matter what I do I can't get the Z working.

I messaged Jerry and he said that I may have accidentally updated the firmware so he gave me instruction to re-flash the firmware. I downloaded the latest Arduino Software (I used 1.0.5-r2 for Windows) and followed the instructions for flashing the Arduino with the auto level files provided by Jerry. I then re-installed MC although the Z-Axis still wouldn't work.

I decided to check all the connections into the board underneath and they all seemed to be in correctly. When I flipped the printer back over the z-axis began to work again. I homed all the axis and tried to do a print but the z-axis stopped working again as the printer started to probe the bed. I haven't been able to get it working since. Any help would be much appreciated.

 

Are you certain your switches are activated on the auto level points?

 

I'm fairly certain they are activated as they seem to work on the times that the z-axis is moving...for instance when homing the z axis, they will detect the hot end hitting the heatbed and then adjust themselves back up. Not sure if you have some other way of testing this? My main issue seems to be that I can't get the z-axis motors moving....occasionally when they do move everything seems to work fine.

 

What happens when you run a test print?

 

I just turned it on and all axis seemed to be working. I homed all axis separately, heated the head bed and extruder and started a print. The printer started probing the bed like it should but the z-axis stopped working half way through (it continues probing the bed but there is no movement in the Z axis)....so I cancelled it. I had a better look at the auto level points and your right, the right hand switch may not be activating. There is movement in the switch when the hot end hits the bed but there may not be enough for it to activate like the left hand side does. Is there a way of fixing this?

 

Adjust your switch arms for the z axis until they're just barely activated. Ideally they should be in a position where they activate when pressed down on, but almost immediately deactivate when touching the bed.

 

I adjusted the right side switch as low as possible so that it is still activated and theoretically as soon as the hot end hit the bed it should be deactivated. However, when I try to home the z-axis, the left hand switch will always deactivate but the right won't. I put the left hand side switch as high as possible so that the switch is fully against the x-axis bracket (ie so that it would require more movement to deactivate the switch). Even when I do this the left will always deactivate before the right.

Once the hot end hits the bed I think the right hand side is able to bend down further due to the extra weight of the motor mounted on that side. Meaning that I need to get extra movement in the right hand side to compensate for this flex in the x-axis bar. Not sure how I can do this.

Is it right to assume that it is ideal for both switches to deactivate simultaneously?

 

Have you calibrated the levelness of your X axis?

 

Yeah, I home all axis then adjust the z-axis so that the hot end is just off the bed. I then manually slide the hot end from left to right and make sure that the gap is consistent.

As far as I can see it is quite level. Are both switches meant to deactivate simultaneously or does one just need to deactivate?

 

Just one is fine.

 

If only one switch has to deactivate for the printer to know it's at the bed, I thought I'd just put the right sensor all the way up so it is always activated as it doesn't ever deactivate anyways (I figured if the right side was somehow deactivating through prints this would stop it from happening).

Although, when I tried to test this theory, the z-axis stopped working again and I can't get it working anymore. When I try to home/move the z-axis it just makes a 'humming' noise but doesn't do anything. This makes me believe that the issue isn't with the z-axis switches.

 

What happens when you power cycle?

 

If your talking about turning off my computer and the printer then turning on everything again...nothing happens. The z-axis will continue making a humming noise when told to move (both x and y axis still work perfectly though).

 

Sounds potentially like a driver issue, pehaps it's amp rating is too high

start a technical support request here: http://www.robo3dprinter.com/pages/technical-support

Do you know much about probing circuit boards?

 

I've actually already started a technical support request, that's why Jerry gave me instructions to reflash the firmware. It's just been taking too long between responses so I decided to make a thread as I want the problem fixed asap.

I don't really know anything about probing circuit boards to be honest. Would it be possible that I may have a faulty RAMPS or Arduino board?

 

Unlikely. Chances are if there was a problem with those nothing would work. The issue, being isolated to the z axis, is most likely the stepper driver. There's a few things we can test.

The first thing is try swapping the stepper driver from the z axis to the x axis. See if this resolves the issue or if the problem moves to the x axis

http://reprap.org/wiki/File:PololuExample.JPG these are the stepper drivers

Getting them out can be a real challenge, but they do separate.

http://reprap.org/wiki/RAMPS_1.4 here's the wiki for the ramps 1.4

and here's the image for where the boards are: http://reprap.org/mediawiki/images/6/6d/Rampswire14.svg Green rectangles are the stepper drivers.

What I'm thinking is happening is when it does work it gets too hot and shuts off amperage. Which is why you're seeing the motors just suddenly die. This is hopefully just a faulty stepper driver, though it could be that the driver is pulling too many amps as well.

 

Are these stepper drivers meant to come off easily? Mine don't really wanna move....just don't want to break them

 

Not easily but they will come off.

 

I just swapped the z and x stepper drivers and it makes everything worse. All axis make a really bad sound when I try to adjust them. I had to pull the plug coz it sounded like something was going to break. I then plugged it in and it says 'Unable to connect' in MC.

Should I reflash the firmware????

 

are you sure it's in the correct orientation?