Z-axis moves only half the distance (solved)

my prusa is now working good (sang. 1.3, sprinter, repG)
but it sucked at printing more than 3 layers.
i used the .5mm thin wall cube, and no mather how high i set the layers, it always hits the previous layer.
so now i figured out that when i move 10mm in replicatorG (or anything else) the X and Y move 10mm, but the Z-axis just moves 5mm

is there something i'm overlooking? and is there a easy fix?

it's frustrating cause everything now seems to work perfect.
the thin wall test cube comes out nice, but is only 5mm high (and it should be double that i think)

Edited 1 time(s). Last edit at 11/05/2011 11:10AM by possenier.

Hi Possenier,
There are three things that I can think of that will cause it.

1) Firmware - your microsetting for Z doesn't match your hardware microsetting. If you are using 1/16th microstepping then make sure the Z steps match this.
[calculator.josefprusa.cz] <-- second formula will calculate the correct Z steps.
2) You do not have your hardware matching your firmware microstepping (You need to make sure you are using all the jumpers on the Z driver to enable 1/16th microstepping)
3) A bad solder joint on the jumper pins (I experienced this myself - my X axis was twice as long as it should have been)

Seeing as your prints are half the correct size I would guess that you have calculated Z steps for 1/8 microstepping when you really want it at 1/16 - so use the calculator link above.

Hope that helps.

i doubled the Z steps in the reprap.xml file in the replicator G machine folder
if i ask info for my machine i now see what i changed, but when i move 10mm it stays the same.
this makes me think that i need to change it somewhere else to.

the Sanguinololu i uses has all jumpers installed (so all on 1/16th)
i assume if one was missing, or bad soldered, it would make the Z-axis move twice the distance, and not half.

The steps_per_mm setting is in firmware. I don't think the values you can for those set in rewrap.xml are evaluated.

ok then,
is there a way i can download the sprinter firmware back from my board, since i didn't flashed it on there myself?
i've got arduino and a basic sprinter here, but i'm afraid that if i flash that on it, i will lose all the settings that are correct now (and i can't see)

(to put it simple, i'm afraid to flash sprinter to it, as i think stuff will explode)

Possenier, unfortunately not!

Your arduino will not explode your mind might - e_steps_mm is quite cumbersome but the rest is very straight forward.

The calculator I linked will provide all the steps_mm, the volumetric calculator at the bottom will give you the e_steps_mm (which needs to be right! its the most important part).

There's a good guide here:
[www.mendel-parts.com]
OhmEye's post - under Dimension (the rest is worth a read also)

Post back if you have problems

so, it didn't explode, and that's a good thing
and Z now moves 10mm when i ask it to, and that's a even better thing.

but (why does there always has to be a but?)
the extruder now thinks it's a formule 1 car.
when testing in replicatorG on the thin wall cube, it only made a strong squeaky noise,
and in redsnapper i put it on reverse, and it tried to launch the filament.

F.Y.I.:
in sprinter i have this:
// X, Y, Z, E steps per unit - Metric Prusa Mendel with Wade extruder:
float axis_steps_per_unit[] = {80, 80, 3200/1.25,700};

what i think is correct

and in skeingforce/repG i have speed set at 30mm/s (as it was before, and printed good)

Possenier, you have not done the most important step yet, calibrating e_Steps_mm. 700 as a generalised figure is okay but it is dependant on your extruder.

What extruder do you have? If it's not geared than 700 is a very large number for e_Steps_mm (for example).

Mark your filament at 20mm increments from the extruder (or anywhere it is easy to repeat measurements). In RepG tell it to extrude, lets say 20mm for now. Measure how much it pulls.

[calculator.josefprusa.cz]

Use the calculator:
Extrude button clicked times (1)
Extruded length per click in host (20)
Actual e_steps_per_mm (700)
Marked length on filament in mm (Measurement)

This will output a new e_Steps_mm for you to put in your firmware (And replace 700).
Now test again, and use the calculator (make sure you change the Actual e_steps_mm field to reflect the previous ouput.)
Repeat until it is bang on and increase the extruded length to 100mm (change the calculator extruded length to 100 also). Do that until it is also bang on.

If your extruder motor is just buzzing when you click extrude in RepG, then you need to make sure you lower the extruder speed, if that doesn't help, lower e_Steps_mm to 50 and work up from there - also ast a low extrude speed.

i did the calculations a few times, and with how it turned i had to put it to 41.66667
i did that, and its printing the thin wall cube good.

But since most people have that number set between 700 and 2400 it looks as if something is completely wrong
since i have it on 41 (i use a wade extruder)

Since you have wades I would agree it is too low, and really the higher the number the better.
I guess that the extruder has no microstepping on. Have you checked the extruder driver, as long as the motor has enough torque (about 50Ncm) then 1/16th microstepping is preferred.

41*16 = 656. It seems to me that your extruder is on full steps and therefore none of the jumpers are enabled. Bad soldering?

i've started the whole thing again, i now used M92 E50 code in redsnapper,
and after doing it 3 times i came to the conclusion the number of my printer is 548
if i send G1 E10 F60 now, it extrudes exact 1cm at a speed that is good.

I then set up the skeinforge 40 exact as OhmEye's post
i printed, and the extruder started to run of again way to fast.

i then said a few fuck you's to it. (didn't help, but i felt better)

i then went in to my Gcode, and saw that for the thin wall object it had +E20 something value's, what had to be wrong,
since that would mean it needs over 20mm to print a single extruded line.

i went over the Skeinforge settings again, and then found the "add export suffix" was on
i looked at my folder where i put my gcode's and found the new one there.

so what happened? no matter how many renders and changes i did, replicatorG kept loading a old previous one, with the extruder speed way to fast or to long.

so i open the new one in replicatorG and printed the thin wall cube perfect without even turning on my heated bed.

I'm happy again.

(PS: i said sorry to my printer for telling it to go fuck off, so we are all good now)

the good thing about this whole thing is i now can flash my sanguinololu, i can edit sprinter, can calculate steps per mm and understand both replicatorG and skeinforge a lot better.

it also so learned me this was one of the typical computer problems: General error ==> change user.

thanks everyone who helped me.