I need help picking a motor

Help & Support Robot Parts
1

Hello all,

I need some help. I’ve been trying to determine a motor for a project I am working on and I feel like my research is taking me in circles. To be clear I am not a ME, simply a hobbyist with with a passion for building things.

I am looking to find a DC or Stepper motor that is capable of pushing and pulling 10-20 lbs by way of power screw in a linear motion and is as small and compact as possible. 2-4 inches in overall length. Small is the key for this application.

My test model uses a DC motor currently but carries no load. My initial set of plans was to have the motor shaft directly connected to the drive shaft, (1/4 or 5/16 screw), but plans can be changed if the motor size is going to affect model overall length and gears can be added if needed to get the results I need.

Sorry for the vague description. If more info is needed to help determine please let me know and I will try and answer as best I can.

Cheers

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2

To confirm, is the weight being displaced horizontally or vertically (against gravity). If it’s horizontal, the motor will need to overcome static friction of the lead screw / bearing and inertia of the load in order to move. Ideally this would need to be calculated, but as you indicated, might be beyond what you’re prepared to do. As such, you can always choose a motor which is overkill. The first step is to decide if you want a DC motor or stepper. If you’re not sure of the differences:
robotshop.com/blog/en/how-to … ors-2-3703

Note that you’d likely need a geared DC motor for the torque needed, and they come in small sizes. If you need a specific maximum RPM, you’ll need to calculate that based on the lead screw you choose.