SoliForum - 3D Printing Community — How to Set EEPROMS for Pulley Setups

Re: How to Set EEPROMS for Pulley Setups

2014-03-27T10:58:31Z

Here is how I look at it:

There are 16 mmicrosteps per motor step.

There are 200 motor steps per revolution of the output shaft of the motor, or 3200 microsteps per rev.

There are 20 teeth per rev of stepper pulley, or you can say there are 3200/20 = 160 microsteps / tooth.

There are 25 teeth per revolution on the leadscrew pulley, or 160*25 = 4000 microsteps / revolution of leadscrew.

If you leadscrew has a 2mm/revolution pitch, then it takes 4000/2= 2000 microsteps per mm of movement of leadscrew.

Re: How to Set EEPROMS for Pulley Setups

2014-03-26T12:00:39Z

Very cool. Quick Question on your formula, is that Teeth on both pulleys I'm dividing by, or the steps per mm of each pulley that I'm dividing by?

EDIT: I found this while scrolling through the forum. Is this possibly relevant to your formula?

Steps per mm = (((360/Motor step angle) * (1/Driver microstepping))/((Leadscrew pitch)*(Leadscrew pulley teeth count / Motor pulley teeth count))

Steps per mm = ((200)*(16))/2.117)*(25/20))
= (3200/2.117)*(1.25))
= (1511.5729806329711856400566839868)*(1.25)
= 1889.4662257912139820500708549835

Does that seem correct.

Re: How to Set EEPROMS for Pulley Setups

2014-03-26T10:55:11Z

Assuming 1.8 degree stepper motor (200 steps/rev) and 1/16 microsteppeing:

[(200 steps)*(mm/rev of leadscrew)*(microstepping of driver)] / [(teeth of stepper pulley)*(teeth of leadscrew pulley)]

[(200)*(25)*(16)] / [(20)*(mm/rev of leadscrew)]

will give you steps/mm

Re: How to Set EEPROMS for Pulley Setups

2014-03-25T15:05:56Z

I understand what your asking and without knowing the pitch of your lead screw it is impossible to answer. Even then your only going to get close and you'll still need to measure. If you have the components you could just set up a simple test platform.

Re: How to Set EEPROMS for Pulley Setups

2014-03-25T14:58:04Z

That's what I figured, I just want to verify how I would get the approximate correctly

Re: How to Set EEPROMS for Pulley Setups

2014-03-25T14:37:48Z

I would think that calculating it out will get you close. Ultimately you will want to measure actual travel of each axis to get any kind of precision.

How to Set EEPROMS for Pulley Setups

2014-03-25T13:47:18Z

Sorry if this is in the wrong section. I'm upgrading one of my current 3d printers to an aluminum extruded frame one (a Utilimatker kind of design). I'm going to use pulley's to drive 3 lead screws for my Z axis and was trying to figure out how you figure out the EEPROMS settings for this. The drive pulley on the Stepper motor will have 20 teeth and the pulley on the lead screws will have 25 teeth. this gives me a Gear Ratio of 1.26:1 (one full rotation of the 20 tooth pulley will rotate the other pulleys only 79.3% around.

My question is since I know how to figure out what the steps/mm should be for one of the gears, do I find the Stepper motor pulley (20 teeth) and just add 20.7% to that in order to have it transfer the proper distance to the Pulley on the Lead Screw. Or do I need to find the steps/mm for the lead screw pulley (25 teeth) and add 20.7% to it instead? It would be nice if the pulley's were the same in diameter but unfortunately when you have a 10mm lead screw and a 5mm stepper motor shaft, the pulleys won't have the same diameter. I don't have a lot of experience with pulleys so getting this information now would be beneficial in the long run for me.