Friday, November 15, 2019

Stepper Motors For Hot Wire CNC Foam Cutters

When we cut foam with a hot wire foam cutting machine it’s not actually being cut but melted.  Its referred to as cutting by radiance.  So the load on the steppers motors is virtually nothing from the hot wire if its temperature and feed rate are correct.  Nearly all of the load comes from the weight of the moving parts of the machine.

Nema Size 17 Stepper Motor Bipolar 45Ncm (64oz.in) 2A 42x40mm 4 Wires w/ 1m Cable & Connector for DIY 3D Printer CNC Rob

So NEMA17’s should be fine if your machine is not too heavy, something around 50-80 oz/in should be OK.  Vortec RC uses NEMA17 on their kit. www.vortex-rc.com/product/4-axis-diy-hot-wire-cnc-for-rc-hobbyists-aeromodellers-and-designers/
FoamLinx offer several machines but these are not really aimed at hobbyist, costing several thousand dollars. However, we can see they are using NEMA23 rated at 220oz/in on their small machine.



My current CNC foam cutter uses NEMA23 motor 175oz/in rated at 2.8 Amps. The moving parts on my build weigh a little over 11KG or 25 lbs, so it’s a bit on the heavy side. It’s made from 3/4″ (18mm) High-Density FIbreBoad(HDF) which is very strong and stable but quite heavy. So I decided to use the bigger stepper motors with the recommended 24 Volt power supply.

My updated design for 2019 which will use 12mm MDF and features several changes and improvements. It reduces weight considerably and allows the use of NEMA17 steppers. Keep checking back for the updated design should be out soon.

http://www.apsense.com/article/whats-the-difference-among-4wire6wire8wire-step-motor.html
https://www.techsite.io/p/1278002




No comments:

Post a Comment

Torque vs Speed Characteristics of Steping Motor

The Speed-Torque graph indicates the characteristic relationship between the speed and torque when the stepping motor is driven. The torq...