Need Help!- step/direction to +/- 10v (analog)converter

[krummigudna]

Hello everyone.

I am looking for plans and drawings to built
a step/direction to +/- 10v (analog) converter for controling
my 3phase spindle drive(VFD) with MACH3.

I was told that SKYKO had this but not any more.
So im thinking to build me one.

Can someone help me with this.

Thank you.

KRUMMI

[Al_The_Man]

I believe you want PWM to ±10vdc, last time I checked the spindle was controlled this way.
Al.

[RotarySMP]

At $38, is it worth doing it yourself?

http://homanndesigns.com/store/index...c602191e6fa87c

[H.O]

Hi,
The Skyko product you mentioned was for controling analog servo-amps with encoder feedback back to the Skyko card, ie for closed loop servomotion.

Mach3 can control a spindle either thru step and direction or low frequency PWM. The LM2907 is a frequency to voltage converter chip that can be used to convert the step-pulses to an analog voltage. I'm attaching a schematic of how I did mine a couple of years ago.

[jjobezo]

I have used boards from this site with good results. This controller includes a relay for reversing direction.

http://diycnc.co.uk/html/spindle_2.html

[johnmac]

www.cnc4pc.com may have what you are looking for.

John

[Torchhead]

Originally Posted by krummigudna Hello everyone. I am looking for plans and drawings to built a step/direction to +/- 10v (analog) converter for controling my 3phase spindle drive(VFD) with MACH3. I was told that SKYKO had this but not any more. So im thinking to build me one. Can someone help me with this. Thank you. KRUMMI

You migth want to check your VFD specs again. Most use 0 to +10VDC (unipolar) for 0 to max RPM. I have not seen one (VFD) that uses negative voltage for speed control. + & - 10 are used in older servo drives to do both speed (velocity) and direction with one signal. The Skyko was made for that usage but the demand is low for analog only servo drives running from S & D. There are alot of spindle speed 0-10VDC solutions. Try to determine what you need and if it needs to be isolated. Some VFD's internal electronics are not isolated from the AC lines and can really mess up anything connected back to the PC logic side. Lots of noise in VFD's too...another good reason for isolation.

TOM Caudle
www.CandCNC.com

[krummigudna]

Hello everyone.

Tom, you are right this is controled like you pointed out.
There is a diffrent signal for changeing direction.
Just a shortcircuit in my head.

Thank you for your time and effort to help me.

Krummi

[krummigudna]

Originally Posted by Al_The_Man I believe you want PWM to ±10vdc, last time I checked the spindle was controlled this way. Al.

You are right Al it can be controlled this way (and maybe it is a better way).
According to the MACH 3 turn manual it can also be controled with step/direction.
I have not tried it so i dont know if it works.
Do you think PWM is a better way ?

Thank you for your time and effort to help me.

Krummi

[krummigudna]

Originally Posted by jjobezo I have used boards from this site with good results. This controller includes a relay for reversing direction. http://diycnc.co.uk/html/spindle_2.html

Good tip jjobezo
but i am not sure the British want anything to do with ICELANDERS right now

..............hahahahaha


Thank you for your time and effort to help me.

Krummi

[krummigudna]

Originally Posted by H.O Hi, The Skyko product you mentioned was for controling analog servo-amps with encoder feedback back to the Skyko card, ie for closed loop servomotion. Mach3 can control a spindle either thru step and direction or low frequency PWM. The LM2907 is a frequency to voltage converter chip that can be used to convert the step-pulses to an analog voltage. I'm attaching a schematic of how I did mine a couple of years ago.

Your answer and drawings were very helpful H.O

Thank you for your time and effort to help me.

Krummi

[krummigudna]

Originally Posted by RotarySMP At $38, is it worth doing it yourself? http://homanndesigns.com/store/index...c602191e6fa87c

Good point, but im the (built everything myself type)
......hahahahaha....

Thank you for your time and effort to help me.

Krummi