Build Your Own SLA/SLS

Hey guys,

after i've calibrated my dlp printer, i made a testprint.

Everything is fine, but the z-axis is wrong. I mean, i printed a yoda model and it became a conehead yoda. It looks funny, but ...

I use a 1.8° stepper with an 8 mm spindle. I calculated the steps per mm like this: 200(steps) x 16(1/16) = 3200 / 1.25 (8x1,25 spindle) = 2560.

So what's wrong? I don't know where to change any z-axis values.

regards!

I've checked my firmware and CW.

I don't know why, but it looks like as if the z-axis is doubled in it's size.

Please help me before i'll lose all of my hair

What electronics are you using to control the Z? It sounds like your running the wrong micro stepping for your firmware settings.
If your using a RAMPS1.4 or similar board you must have all the jumpers installed under the step driver to run 1/16. If you don't your not getting the right steps.
If your using other electronics be sure to double check your dip switches or jumpers so you are running 1/16 stepping.

Clinton

When I was setting my steps for my Z axis I calculated a number and tried that but it was not correct. I ended up taking a micrometer and placing it on a stand which attaches to the printer and measures the actual Z axis distance. With this I was able to very accurately setup my Z steps. I ended up with a step number with 1 decimal place to get it just perfect. I was using a 0.0005" micrometer. I also checked to make sure the Z returned to the exact same spot after several up and down movements with the micrometer.

I suggest getting one to properly calibrate your machine.

You might be able to do the same with a Digital caliper if you can find a way to measure the Z travel with it. I used that as well with good results but I had to be very careful how I held it.

It sounds like your machine is way off. I would check your microstepping and do some more changes to the steps to get the travel closer to what its supposed to be and then calibrate using accurate measuring tools.

Are you using RAMPS? if so edit your configuration.h file to set the proper steps/unit

The most hipster calculator ever may be able to help you:

-S

Hey,

i'm using a ramps 1.4 Board and all jumpers are installed. I've checked the stepper data sheet....

If i use the manual control and move the z axis 1 mm up, it goes 1mm up, but not when i'm printing.

It makes me crazy....

Are you making a top-down or bottom up printer? It looks like the ZAxis is moving in the negative direction first, which would indicate a top-down. Here' a snippet for some of my gcode:
;<Slice> 1
;<Delay> 3000
;<Slice> Blank
;********** Lift Sequence ********
G1 X3.5 Z3.5 F125.0
G1 X-3.5 Z-3.425 F250.0
;<Delay> 500

As you can see, it lifts the Z axis by 3.5mm, then back down -3.425 for a layer height of .075mm. If you've got a bottom up printer, change it to bottom-up in the slice profile configuration.

I've got a top down printer.

So it seems to be correct, doesn't it?