A little experiment I am trying.

[Flateric]

400 steps per rev, 0.9 degree, double shaft double damped nema 17 Sanyo Denki stepper motors.

So the motor has twice the step accuracy, prior to microstepping and a shaft mounted damper designed by Sanyo Denki stepper motors for this specific stepper. The second damper is supposed to decrease settle time and allow for faster more precise movements. Still has the vibration damper also. We will see, it may be a complete waste of time, but it may not. I will use the optimal steps per mm calculator by Prusa from....

http://calculator.josefprusa.cz/old/#PrintSetup

Many good tid bits there for you guys to look at.

Here's my calculation....

Steps per mm = ((360°/Motor step size°) * (1/Driver microstepping))/(Belt pitch * Tooth count) or

Which is in my case 213.6 steps per mm. With my 15 tooth metal pulley (400 steps per rev)

160 steps per mm. With my 20 tooth plastic pulley (400 steps per rev)

Compared to

80 steps per mm. With the stock steppers (200 steps per rev) and plastic pulley. Or even 40 steps per mm if running a Rambo 1.0 in 1/8 step mode.

[img]http://i.imgur.com/kWvSGnY.jpg[/img]
A shot of the backside of the stepper and the second damper.

[JohnStack]

I'm wondering if you might not need a fan for these with those steps...good luck! Might be an excellent mod!

[kbob]

Eric, I have not read the Repetier source, but Marlin only generates accurate step timings up to 10 KHz. Above that speed, it does steps in gangs of 2 or 4. I have to think Repetier is similar.

At 213 microsteps/mm, 10 KHz is 50 mm/sec (carriage speed). So 400 step motors are good for spatial resolution, but only at low speeds. At medium speeds, they'll actually be worse.