Steper Motor vs Servo Motor

[fernandosantos]

Hello,

I am about to buy a CNC table machine to work with acrylic´s, but I have a serious issue...some say that for a 1500x1000 mm (working area) servo motors are to much others say that is the best option.

Can you help me with your opinions, what i will do better?

Buying with servo motors or Steper Motors?

Thank You

Fernando Santos

[Al_The_Man]

Just depends who you talk to, .
Most use steppers for the ease of fitting and less cost, I personally prefer servo's, whatever the size, there is no really particular deterrent to using servo's however small the system is, apart from the cost issue previously mentioned.
Servo's possibly require slightly more tuning.
They have an advantage of much higher rpm while retaining torque throughout the total rpm range.
Al.

[samu]

stepper lost a lot of torque at high speed but are much less expensive(motor itself and the drive too) Evrething depend at which speed you want to run and how much you want to spend on your machine. For an industrial use 10 hour per day servo must be considered but for hobby work i think it is overkill

[fernandosantos]

Thank you for your opinion,

Now, other issue...

I have to decide about this two machines:

1- 1500x1000 (working area)
Servo Motors
High rigid aluminium structure
Made in Portugal (www.pronum.pt) with European components.
High precision on Z axe
Transmission: Rack/Rack (150 mm belt diameter)
Price: $ 13 300




2- 1300x1300 (working area)
Stepper Motor
Steel Structure
Made in China High precision on Z axe
Transmission: Rack/Rack (165 mm belt diameter)
Price: $ 10 750
"http://www.youtube.com/watch?v=G2xlWZygUsQ"]YouTube- SISTEMA DE FRESADO TEC-CAM 500 - GRABADO EN METACRILATO


What machine will you choose if you have to work 8 hours per day.

Thanks
Fernando

[Benonymous]

Another factor you may want to consider is whether you're buying DC servos or AC servos. AC servos and their associated controllers will be more expensive but AC servos do not have brushes and commutators to wear out.

Brushes can also generate electromagnetic noise.

Anyway, I chose AC servos over DC servos for the lack of brushes.

I guess for a machine that is not running constantly it may not be a big factor but if the machine is going to get commercial use for hours a day, you don't want to be fussed with changing brushes.

[lunchtrayrider]

if those are ac servos probably the one from Portugal would be my vote.