hypothetical cnc machine with stepper motors

Thread Starter

vane

Joined Feb 28, 2007
189
supposing i was gonna' try to make a cnc machine with stepper motors would the circuitry be easy to make? thanks
 

Papabravo

Joined Feb 24, 2006
19,595
Probably not. Stepper motors have generally poor speed torque characteristics and are subject to electrical and mechanical resonances. They can require large standby current to hold their position. The biggest problem is that they are normally controlled open loop. Real CNC machines use DC electric servo motors with a supply of 300 VDC or larger and are controlled closed loop.

Still, if your burning to try then knock yourself out.
 

hgmjr

Joined Jan 28, 2005
9,027
The fact that you are asking for suggestions would indicate that you might benefit from experimenting with stepper motor design on a small scale as a means of familiarizing yourself with the different types of stepper motors and driver circuits. This will allow you to experience firsthand some of the characteristics of stepper motors and thereby be in a better position to judge their suitablity for use in implementing cnc machines.

hgmjr
 

kender

Joined Jan 17, 2007
264
It depends on the type of the machine. Did everyone just assume a mill?

Steppers are impractical, when you need to apply force and torque. Steppers are practical, when something needs to be postioned without a lot of force and acceleration. So, steppers would work for a laser cutter or CNC drill-press.
 

Thread Starter

vane

Joined Feb 28, 2007
189
i make rc planes and wondered if i could make a machine that cut out the parts acurately, really want is a two axis machine that i could attach tools to to draw, cut vinyl, cut wood etc, thanks
 

Thread Starter

vane

Joined Feb 28, 2007
189
ive been thinking about getting an old printer and instead of the ink pump i have a little tool that goes down and drills a hole, it may be good for a start.
 

Irving

Joined Jan 30, 2016
3,190
So much misinformation about steppers. Used correctly they are capable of significant torque. While I agree a closed loop servo is a better high-end solution, in many cases a stepper works as well... almost all CNC'd mills and lathes in the serious hobby and/or light industrial class of machines use steppers because they are a cost-effective and practical solution.

For them to maintain their position, a lot of standby current may be needed.
Somewhat true for a belt drive, not so for a non-back-drivable leadscrew. The table and quill drives on my mill and the carriage and cross-slide drives on both my lathes are all NEMA23 or NEMA42 steppers

anyone know where i can get good stepper controllers and stepper motors in the uk?
https://www.motioncontrolproducts.co.uk/
https://www.cnc4you.co.uk/
https://automotioncomponents.co.uk
https://www.robotshop.com/uk/
 

MaxHeadRoom

Joined Jul 18, 2013
26,286
An old thread revived!
Steppers are not traditionally used for Industrial applications, but many CNC DIY'ers use them successfully, see the CNCzone forum for examples.
 
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