prusa mendel

I'm on the beggining of my fun with 3d Printing, (i've ordered plastic parts for prusa) and im going through desing, and I'm a bit puzzled why there are 2 stepper motors, for the z axis, and not just one with a belt driving both screws from one motor?
not sure if that was already considered at all? one motor is not strong enough?


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HE3r0

I remember reading a thread on this before. I'm pretty sure it was tried or at least after a long discussion it was concluded that the cost of the extra belts, parts, etc plus the loss of motor power and extra time you need to spend setting it up (it would be a good bit more complicated) really negated any money that was saved.

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-Richard

[tynan.me]

Yep, rptynan is correct - it turns out just to be simpler/cheaper/easier. The original mendel used one motor, but you get a lot of problems like needing extra bearings, finding some way to tension the belts (not as easy as the x/y belts as the belts need to loop continuously around the sprockets so you need an idler pulley. You also get much more consistent backlash - with a belt you get different backlash depending on what way you are turning the motors, but with two motors you get exactly the same backlash from the two z-nuts. Motors are cheap anyway.