E step setting on Sanguinololu - newbie

Hi,

I have completed the build of my Prusa Mendel LM8uu Rep Rap with the usual one step forward two steps back, nearly there!

Anyway I'm trying to calibrate and level and just checked my extruder feed. When I ask for 100mm it gives me 113.33mm, how do I up-date the settings? I'm assuming it's in the Sfact settings somewhere?

I'm using a Sanguinololu 1.3 and a Gregs Extruder with 3mm filament and a 0.50 nozzle, and Pronterface.

Thanks Guys

Ray

It is actually a setting in your firmware.
For example, I'm using Sprinter on my gen6 board and I use Arduino to change the setting. For Sprinter it is on the tab Configuration.h and the line titled float.
The default was:
float axis_steps_per_unit[] = {1600/50.8, 1600/50.8, 1280,((PACKING_DENSITY*EXTRUDER_MTR_STPS*EXTRUDER_GEAR_RATIO*(1/MICROSTEPPING_RATIO))/(PI*BOLT_DIAMETER))}
I changed it to:
float axis_steps_per_unit[] = {31.604, 40.44, 1295, 408.278}

But everyone will have a different setting since people use different parts and there are variations. You need to know if you have stepper motors or DC. If you have a prusa, I assume you have stepper motors. Be aware that the default settings in skeinforge/sfact are for DC motors. You'll most likely need to change the feedrate and flowrate. I suggest setting both to 20 to start with. ( on the Speed tab of Skeinforge/Sfact)

For how to calculate what to change it to see [www.youtube.com]

When you move on to calibrate the other settings go here: [www.thingiverse.com]

Some good videos: [www.youtube.com]

Hi Grog,
Thanks for that

Cheers

Ray

Hi Grog,

I'm using Nema 17 stepper motors, 1,8 degrees/step. I've been through the Forums and worked through Trffid Hunters calibration guide, but just can't see where I enter an values I calculate?

Thanks.

If you're using sprinter firmware, open it in Arduino. I believe Sprinter doesn't play well with Arduino 1.0. I have v0023
If you need to download it go here: [github.com]

Once you have it open in Arduino click on the Configuration.h tab. Scroll down a bit to the line that starts with 'float'. I recommend copying the line and pasting right below. Then commenting out the original line ( type // at the beginning) just in case you want to revert back.
The settings are in this order: x, y, z, e (for extruder). I changed the formula to an exact number so I could have a better idea where it was and what direction it was going. A higher number meant it extruded more.

Oh yea, and how to get it to the board. After you save the file in Arduino, you need to upload to the board. The printer has to be disconnected in Pronterface before Arduino lets you upload.
You also need to tell Arduino what kind of board you have and what com port it is on.