Prints come out twice too high

[sanne 0]

So. I've managed to put my Ultimaker together and am printing some test objects now.

Am using the default settings - RepG v.0026. Skeinforge35, profile Ultimaker failsafe.

All my prints come out quite nice but twice too high. Yoda looks like conehead. 20mm cube twice too high as well. Something with my Z-axis? layer heights?

Any ideas would be much appreciated.

Thanks, Sanne.

[Daid 306]

Most likely cause is a jumper problem. The steppers can be put in different modes, and the Z stepper needs a different mode then the other steppers, see the jumpers on this picture:

http://wiki.ultimaker.com/File:El1.5.4-PCB.jpg

 

[sanne 0]

I've checked, but the jumpers for the Z stepper motor are positioned correctly like in the picture.

I've started scaling all my .stl files down in the z-axis via a 3D application but it's not even exactly 50%. None of my models is printing in the right height. Could it be something skeinforge-related? Should I be posting it in that forum perhaps?

Any ideas?

[joergen 2]

I've checked, but the jumpers for the Z stepper motor are positioned correctly like in the picture.

I've started scaling all my .stl files down in the z-axis via a 3D application but it's not even exactly 50%. None of my models is printing in the right height. Could it be something skeinforge-related? Should I be posting it in that forum perhaps?

Any ideas?

if you open the control panel in repG, and move the table by 50mm down... how much does it move in reality?

[sanne 0]

great thought. i've checked, and when i move it down 50 mm it actually moves down 97 mm!

that must be it. but how to fix it?

i've checked the jumpers and am now fiddling with the pod meter of the Z stepper. no improvement until now...

[Daid 306]

Double the distance is not really possible if you have low or high current in the pod meter of the stepper. (You'll get missed steps or overheating if the pot is wrong)

Still, I remain at my previous statement. The jumper. Maybe a bad soldering on the jumper, maybe a bad contact of the jumper or a bad trace. Or a bad step driver. Try swapping the Z and X drivers to see what happens?

[joergen 2]

I've checked, but the jumpers for the Z stepper motor are positioned correctly like in the picture.

I've started scaling all my .stl files down in the z-axis via a 3D application but it's not even exactly 50%. None of my models is printing in the right height. Could it be something skeinforge-related? Should I be posting it in that forum perhaps?

Any ideas?

I would definitely check first if you are actually running 1/8 steps on the Z, and if there aren't any electrical problems with the pins and the jumper, as Daid suggested. if you have ruled that out, and you are 100% sure there is no electrical problem, check your firmware settings and/or use the current marlin.

once you connect marlin to repG, you should see a status line reporting the basic settings, and one of them is the Z-steps/mm:

#define DEFAULT_AXIS_STEPS_PER_UNIT {78.7402,78.7402,200*8/3,865.888}

200*8/3 (200 steps per rev * 8 (1/8 steps) / 3mm (per rev) = 533.333

if your UM reporting something else, upload a newer firmware, i.e. https://github.com/ErikZalm/Marlin and see if the control panel Z movement is still 97mm instead of 50mm

[sanne 0]

UPDATE

We've taken a CLOSE look at the jumpers and the MS1 left pin is missing and looks like it has been broken off.

I have some pics but can't post them here.

Guess i have to contact Ultimaker and get a new board..?

[Daid 306]

That's one option. It's clearly one of the defective electronics I would say. (seems like the last batch had some quality issues, because you're not the only one with problems)

Another option is, if you feel comfortable doing that, is to solder the 2 pins of the MS1 jumper together on the bottom of the board with a blob of solder. It would save you a lot of shipping time.

Soldering works because all it needs is an electrical connection, it won't need to carry a lot of current. Or you could replace the jumper header. It all depends on if you are comfortable with a soldering iron (and have access to a good one)

If you do solder on the board, it's recommended to remove the step drivers and Arduino before you solder. Just to make sure you don't kill those.

As extra bonus you'll also save 1 good electronic board on the Ultimaker team, so they can ship out 1 extra kit, making 1 extra person happy ;-)