Odd Inconsistent Z level on Rostock
Posted: Thu Mar 13, 2014 10:49 pm
Hello!
First, some background:
The machine I am working with is part of equipment used in a makerspace. As such, it gets used by a bunch of people. While we usually try to train our members before turning them loose on a piece of equipment, it doesn't always work out the way we want, and of course some members take better care of the equipment than others.
Anyway, I got back to this machine after a few month's absence and found it in poor shape, so I fixed it up a bit. It had lost a screw which was supposed to hold one of the towers in place, so I found an appropriate replacement and replaced it. Also, one of the cheapskates had become loose and was wobbling during during printing, so I tightened it down. Last, the mount plate for the EZ-struder had become destroyed. I used our in-house laser cutter and the files from github to cut a new one out of acrylic. I also had to clear a jam of something that looked suspiciously non-plastic from the hot end, and in the process man-handled the hot end into breaking the thermistor. I therefore ordered a new thermistor and replaced it. I mention all this maintenance work in case something stands out to you as a problem area to check on.
Naturally, with all this work needing to be done, the machine was pretty far out of calibration as well. I went in and adjusted the individual tower heights via screw, as well as the z-travel in EEPROM. However, I'm getting a weird change in the z-axis when making moves.
The following is more or less what I did and the odd issue I am seeeing.
g1 f5000 z2 x100 y-50
press z down 1mm twice. I'm satisfied with the height here.
Move the head slowly to z0 x-100 y50, basically diagonal away from the arm. This moves (to my eye) perfectly level. This may be my best calibration ever, or so I think.
move the head back to z0 x100 y-50. The head slowly dips over time until it is obviously too low.
I can home the machine and repeat this issue without fail. The first time it comes down from home it is in the perfect position. After movement it is too low.
Anyone have any advice?
First, some background:
The machine I am working with is part of equipment used in a makerspace. As such, it gets used by a bunch of people. While we usually try to train our members before turning them loose on a piece of equipment, it doesn't always work out the way we want, and of course some members take better care of the equipment than others.
Anyway, I got back to this machine after a few month's absence and found it in poor shape, so I fixed it up a bit. It had lost a screw which was supposed to hold one of the towers in place, so I found an appropriate replacement and replaced it. Also, one of the cheapskates had become loose and was wobbling during during printing, so I tightened it down. Last, the mount plate for the EZ-struder had become destroyed. I used our in-house laser cutter and the files from github to cut a new one out of acrylic. I also had to clear a jam of something that looked suspiciously non-plastic from the hot end, and in the process man-handled the hot end into breaking the thermistor. I therefore ordered a new thermistor and replaced it. I mention all this maintenance work in case something stands out to you as a problem area to check on.
Naturally, with all this work needing to be done, the machine was pretty far out of calibration as well. I went in and adjusted the individual tower heights via screw, as well as the z-travel in EEPROM. However, I'm getting a weird change in the z-axis when making moves.
The following is more or less what I did and the odd issue I am seeeing.
g1 f5000 z2 x100 y-50
press z down 1mm twice. I'm satisfied with the height here.
Move the head slowly to z0 x-100 y50, basically diagonal away from the arm. This moves (to my eye) perfectly level. This may be my best calibration ever, or so I think.
move the head back to z0 x100 y-50. The head slowly dips over time until it is obviously too low.
I can home the machine and repeat this issue without fail. The first time it comes down from home it is in the perfect position. After movement it is too low.
Anyone have any advice?