controlling spindle speed

[R.thayer]

I would like to know how I can control the spindle speed with emc2. I have a spectalight turning center that has been retrofitted with new stepper motors and controller. The spindle has a pm motor and a speed controller on it right now that needs a positive 10 volts to control speed. How can I get this from a pc? Also it has a encoder on it and I would like to use this to thread with. How? Anyone doing this? Please give me ideas. Thank you and hope to hear from you very soon.

[acondit]

Look at this thread particularly, message 28. Peter Homann talks about using his digispeed-xl to control a 0-10v dc speed control circuit. http://www.cnczone.com/forums/showth...461#post238461

[phomann]

Originally Posted by acondit Look at this thread particularly, message 28. Peter Homann talks about using his digispeed-xl to control a 0-10v dc speed control circuit. http://www.cnczone.com/forums/showth...461#post238461

Thanks Alan, that message just about sums it up.

If there are any question regarding the DigiSpeed range, I'm happy to help.

Cheers,

Peter.

[R.thayer]

What kind of signal do I need from the pc to vary this voltage coming from your product? I know that it depends on my software package but if I can understand what the interface is looking for then I can pick my software. This machine as a pot that has a swithc built in so you can select computer spindle control or manual using the pot. Thank you for your help and hope to hear from you soon.

Anthony Thayer

[phomann]

Originally Posted by R.thayer What kind of signal do I need from the pc to vary this voltage coming from your product? I know that it depends on my software package but if I can understand what the interface is looking for then I can pick my software. This machine as a pot that has a swithc built in so you can select computer spindle control or manual using the pot. Thank you for your help and hope to hear from you soon. Anthony Thayer

Hi Anthony,

The DigiSpeed can accept one of the following inputs;



1. PWM signal. This input is a low frequency (10Hz - 50Hz) PWM signal where the duty cycle represents the % of maximum motor speed. for example, if your max speed is 2000 rpm, then a 25% duty cycle will result in the DigiSpeed producing an isolated 2.5V analog voltage which equates to a spindle speed of 500rpm.

2. Step/Dir mode. This is a bit of a strange one designed for TurboCNC. The interface is a step/dir one similar to a stepper motor. There are 1024 steps from 0 to 100% of maximum speed. To increase the speed, the direction line is set to +. to decrease the speed the direction line is set to -. so to get 50% speed, the dir line is set to + and 512 steps are issued. Then to set the speed to 25%, the dir line is set to -, and 256 steps are issued.

3. 0-5V signal. The DigiSpeed-GX can also accept a 0-5V signal that is translated into an isolated 0-10V signal.



The diferrent input modes are described in the manuals found at;

http://homanndesigns.com/store/index...&products_id=2

http://homanndesigns.com/store/index...products_id=21


What software are you planning to use. I assumed that it would be EMC. If you are open to other software, have a look at Mach3. It is very powerful and will do threading with a 1ppr encoder.

Cheers,

Peter.