If I was to use a servo in a RepRap,

3D Printing
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1

If I was to use a servo in a RepRap, what are good requirements for ease-of-sourcing? I was told this HS-422 servo is very popular and easy to find http://www.hitecrcd.com/products/servos/analog/standard-sport/hs-422.html
Any others to look at?

2

You’d be treading into relatively new territor. I don’t think I’ve seen any repraps using servos. You’d need support in firmware to manage that.

3

Servos can’t move 1 degree at a time. You would need to move the servo 10 degrees ahead and then 9 degrees back. The cheap ones (PWM based) can’t return their position. So you print would get out of alignment after a few position changes.

4

The HS-422s don’t have enough torque and would need to be modified to be full rotation. The servos you would need are 2-way serial controlled robotics servos and they start around $170 each and go up from there. That route would be much more pricy then stepper motors.

5

I’m not using servos for linear motion. It’s a specific mechanism. I was just curious about sourcing for open source. I want to choose the most commodity, and easy to find servo.

6

The HS-422 is one of the most popular and available Hitec servos. Comparable servos that may be easier to source would be the Futaba S3003 or GWS S03N.
http://www.servodatabase.com/servos/all

7

@James_MacGowan brilliant. thanks!

8

Also have a look at http://www.servocity.com

9

If you want a servo that is cheap, has a lot of torque and durable, have a look at the MG996 from towerpro or a clone from towardpro. They are quite good. Not very fast though.

They are for sale on ebay and any other hobby/RC like shop.

10

Thanks everyone! I will definitely be sharing my progress once I have something working.