[SOLVED] prusa i3 travel steps per unit distance way off

Hey guys, I'm pretty much a complete beginner in the 3d printing world and have been looking everywhere for some answers, but I have been struggling with the same thing for about a week. I bought a prusa i3 pro kit from makerfront. I also used the firmware that they supplied from here
I have it using an arduino mega with Ramps 1.4

I assumed that they would have all the configs setup and stuff. Anyways, when the DEFAULT_AXIS_STEPS_PER_UNIT is set to 80 for the X and Y, it would either not move at all and the motors whine or it would fly across the rail and try to keep going. I have tried pronterface(in windows) and am currently using mattercontrol(in archlinux) to control the printer. I noticed that when I pressed the 10 mm button, it would travel over 100mm; and i couldn't even press the 100mm button without hitting the edge and just grinding. So i adjusted using a formula i found online for calibration, which ended up being (10 / distance moved) * (old_steps) which gave me 5. When i use 5 instead of 80, the distance is correct, but the belts vibrate like hell, and i have yet to see anyone come up with those numbers. Are those numbers reasonable?

Also the Z axis refuses to move very well.I messed with the little current adjuster on the stepper driver, but it seems like one is moving faster than the other, if at all, and it's completely inconsistent. The motors also just whine when I try to do 0.1 or over. Any ideas? do you think it's the hardware? the config?

So naturally this thing refuses to home. I have tested all the endstops and they work.

Edited 1 time(s). Last edit at 12/24/2016 02:24AM by monkeycoder.

If you do the basic maths for stepper rotation, toothed pulleys and belt type you probably do get 80 steps/mm its a very common value

I would suspect you have totally failed to install micro stepping jumpers (3 jumpers under each pololu module)
Without these everything would move 16 * the expected distance, and be very jerky and loud.

Thank you for your reply! Yeah, micro stepping jumpers don't really sound familiar at all lol. Are these the same as using the A4988 stepper divers?

The stepper driver modules (pololu or what ever your using) are configurable

Under each module is 3 jumpers (add 1 to the m labels, different sources for images)



You set the micro stepping according to the following.



Most people set all axis to 1/16th micro stepping

Edited 2 time(s). Last edit at 12/24/2016 02:06AM by Dust.

OHHHHHH MY GOD DUDE!!!! I have been messing with this thing and the firmware for 5 days straight....It was totally not in the manual I was following, and i was just looking around and found pieces that look like jumpers after you sent those pics hahahah. I can't believe this LMAO. Thank you so much haha, i feel so stupid. You're a life saver