Cutting wire with motor

Projects
1

Hey

So I’m trying to develop an object that will cut copper cabling using motors and something like a hook blade or utility knife blade. It needs to be portable so the concern is battery sizing. The electronic aspect I’m not that worried about right now as I think that will be the easiest of my two main issues (plan is to use a Uno controlling it, not powering it). Right now the focus is on something like Cat-5 to cut. Most of the motors available on CE within the battery pack range they also offer may not have enough torque however someone may have more understanding on this.

2

Hi Jake, If you want a low power solution, I would recommend getting a motor with a gearbox attached, such as this one:
https://core-electronics.com.au/metal-dc-geared-motor-w-encoder-6v-100rpm-6-5kg-cm.html

I would also use 2 18650 batteries to provide power: https://core-electronics.com.au/polymer-lithium-ion-battery-18650-cell-2600mah-solder-tab.html

And a DRV8838 motor driver: https://core-electronics.com.au/drv8838-single-brushed-dc-motor-driver-carrier.html

Hope this helps!

2 Likes
3

Is the H bridge required even when operating only in one direction?

Also what if I opted for a setup that included this motor? https://core-electronics.com.au/metal-dc-geared-motor-12v-50rpm-50kg-cm.html

What would you recommend for a battery? Multiple connected together?

4

If you only ever want to run your motor one way you can just use a single MOSFET. You only need an H-Bridge if you need your motor reversible.

As for power, yep. Run any of a 3s Lipo pack (11.1v nominal), a 6 cell lead acid, or a 10s NiMH pack. Lipos will give you the best energy density but are probably the most expensive. Lead acid will give plenty of punch but for the mass won’t give much run time - mechanically and electrically very durable though. NiMHs are a good balance, but suffer loss of capacity if not fully discharged before being recharged.