Z Axis not moving (Resolved)

I'm not exactly sure what is happening. If my z axis is stopping moving or if it just isn't moving enough while printing.

I'm using Skeinforge 31, 5d firmware, printing with ABS

It seems to be printing the 3 layers of the raft fine. After the first layer of the object, 40mm cube, it seems that my Z axis isn't working any more. As it is printing the layers, it is just plowing the plasic that is just layed down.

I'm new to this, so I may just not have a setting correct.

Thanks

Edited 1 time(s). Last edit at 11/18/2010 07:34AM by bbriggstkd.

It also seem to stop moving filiment at about the 3rd or 4th layer. On the layer where it starts to .20 infill about, no plastic is actually coming out.

I think that the heater may be turning off. The light on the board is still on but it may be cooling off too much. When I run it from the RepStrapper host software, I sometimes have to cycle the "Switch heat on" button to get it to turn back on.

If you have the z-axis speed too high then this will happen.
Make sure that Limit is set to 1 mm/sec in Skeinforge.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I have tried dropping my z axis speec to 1 mm/sec and even 0.5 mm/sec. I just seems to stop moving in the Z axis after the first few layers are printed. I can hear the stepper motor chirp and the lights flash on the stepper driver but the axis doesn't move.

It moves up just fine while it is printing the raft and the first couple layers of the object. I've tried changing the layer thickness but that doesn't seem to make any difference.

Once I stop the print, I can move the Z axis up using the interactive controls in RepStrapper so it doesn't seem to be binding.

I've attached the gcode if that helps anyone.

Could it be the tension of my Z belt? Too tight or too loose?

What electronics do you have?

The gcode is correct.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I had to disable acceleration in the firmware because it was trying to do the z move quickly because it was decelerating from a fast x-y move. After I did that I think I saw a post somewhere saying you could do something with a homing code in skeinforge to somehow separate the xy moves from the z moves. I never pursued it because it works fine for me without acceleration. Sorry for the vagueness of the post, but it may help you direct your searches to find a solution for your problem.

I have TechZone electronics

So you have two problems:

1. The heater appears to turn off.
2. The Z-axis does not move (or not enough).

BOTH of these can be caused by bad gcode.

I took another look at your gcode file and you are definitely moving the z-axis too fast (F240 where it should be F60).

The temperature commands also look funny:

M104 S200
M109 S210
M104 S245.0
M104 S230.0

Are you generating the gcode each time after making changes?

Hint: Take a look at the Z-axis nut on the bearing when it changes the height. If you are using 8mm threaded rod then that is 1.25 mm / revolution. With 6 faces that means that for a layer height of 0.45 mm this would mean it must move 1/3 rotation or 2 faces. Since your feed rate is too high it is either moving much less or not at all.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Does the z axis move easily at that spot when turned by hand?

Buback
I can turn the Z axis by hand with no problem. I've greased it too so it would be smoother. If I use the RepSnapper host software in interactive mode, I can move the Z axis with not problem. No strange noises, binding or anything that I can detect.

rhmorrison
I do regenerate the code every time after making changes.

I actually mounted a flag On one of the Z axis rods to be able to see the movement easily. I have 5/16 threaded rod instead of 8mm. What I find is a little off is that where the gcode has F240 is where I think it is printing the raft and that Z movement is working. A few layers up it looks like the speed drops to F41 or something like that, this is the part where it is not moving enough. I can see the flag on my Z axis move but it is no where near 1/3 of a turn. That is about where it is on the raft though.

I still suggest turning off acceleration in the firmware. That solved it for me.
Here is the post I found that suggested it: [projects.pelrun.net]
Also this forum post describes a more elegant solution than turning acceleration off: [forums.reprap.org]

Edited 1 time(s). Last edit at 11/17/2010 04:21PM by Greg Frost.

Success! I tried both of these options. The homing setting in Skeinforge only gave me limited success. If I had tried some more setting I might have gotten it to work but it was still trying to move the Z axis too fast after a fast X or Y movement.

Turning off acceleration in the firmware is what worked for me!!! I got my first successful print. Now I have to continue to dial in setting but I'll be printing things off the Thingiverse shortly.

Thank you all for your help!

Brian