Pulley teeth count and precision

General Discussion
1

Basic Information:

Printer Model: CTC A13
MCU / Printerboard: SKR2
klippy.log

Hello,

I’m thinking about new belts and pulleys.

I have a cheap Ender 3 clone. The original pulleys have a teeth count of 20.

Reducing the teeth count to 16, will it make any difference in precision? Did anyone tried this?

I was searching the www, but without success.

Kind regards, hcet14

2

Yes, it changes the resolution.

You can calculate it here:

http://web.bluecomtech.com/Prusaprinters%20Calculator/www.prusaprinters.org/calculator/index.html#stepspermmbelt

1 Like
3

Thanks for the calculator link.

So, you think it would make sense to reduce the teeth count?

4

As long the pulleys are a good quality and sit snug on the stepper motor axes: Yes.

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5

The Ender 3 clones already have pretty good resolution on the x and y axes, so I don’t think that the extra 20% resolution will make much visible difference. Having said that though, I don’t think it will hurt, and I’m all for tinkering for tinkering’s sake, so I say go for it :slight_smile: Let us know how it goes!

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6

You have to consider the complete impact of 20 → 16

  • Precision +20%
  • Torque -20% (means your motor needs to work less)
  • Speed -20% (means your motor needs to rotate 20% faster for the same printing speed)

In addition there are additional effects that are harder to quantify, like the quality how the belt is guided (should be better with a larger diameter pulley) etc.

Likely a bit of a philosophical question. Since you can increase the resolution with microstepping and / or 0.9° stepper, I’d rather stick to 20 teeth pulley.

1 Like