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Is there a break in the motors?

Hi,

I am wondering if the motors got a break, or how do they overcome gravity/stay standstill when powers off? What is the holding torque?

Regards,
Run

Gear ratio - the transition over comes the weight effectively locking when there is no power.

Thank you

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What was the main reason of using this type of motor instead of a NEMA stepper motor, like Farmbot?

Run

The internal break with the worm gear mechanism is needed to hold position, but also the cost/performance of closed loop system is much higher than stepper motor systems like farm bot uses.

The main reason was the internal break right?

Personally I just much prefer closed loop systems :grin: I think they are a more elegant solution.

I think you could build a machine using a stepper motor on a gear box something like this:

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I think for a machine like maslow that doesn’t have a built-in homing system and it being terribly vital to know the exact length of each chain, a close loop system is preferred. I think things are more forgiving in a system where each motor controls a specific axis. I have a small desktop cnc to mill small intricate parts and am always running the bed up against its limits (without end stops) and it loses its locations. It’s simple enough to just readjust on those machines… If something like that happened on a maslow, you’d have to go through the process of resetting the chains.

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even on a single motor-per-axis machine, the inability to know when you have
skipped a step is a significant limiting factor.

Also, the DC motor/encoders that we are using are FAR cheaper than stepper with
similar amounts of torque, even leving out the self-locking mechanism that the
gearboxes provide.

higher-end CNC machines use servos (i.e. closed loop), not steppers

David Lang

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Thanks for the info!

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