[irxplod]

hi too all (group)

i have a Lathe machine that i want creat a 2Axis CNC Base on this machine and UHU Servo driver(developped by Stefan http://www.gertronik.de/cncecke/servo.zip) ,

here there is a Video that there are a 2axis cnc lathe, (shortpawn_WM9_256Kbps_download_NTSC_ConstrainedVBR .wmv - 4shared.com - file sharing - download movie file)

My Question : if i use the uhu contorller with servo motors can i give this Speed from my X and Y axis ?

and in the new industrial CNC machines the DC Servo Motors Are popular or another ? ( for Spindle is too ? )

thanx

[H.O]

Hi,
The speed you'll be able to run the motor at is a function of the resolution of the encoder and the step rate that your controller (Mach3, EMC2 etc) is capable of outputting.

If you have a 500 line encoder on the motor it takes 2000 step pulses to turn one revolution. If your controller can output 45000 pulses / second your max speed would be 45000/2000*60=1320rpm.

If you then couple that that motor to a leadscrew thru a 2:1 belt reduction the top speed of the screw is 660rpm and if the screw has a pitch of 5mm you'll get 3300mm/min.

The smallest increment of movement (resolution) would be 5/2/2000=0.00125mm.

Want more speed? Increase the pulse frequency, reduce the encoder resolution (or use the step multiplier in the UHU), reduce the reduction ratio between motor and screw or increase the screw pitch. All of the above, except increasing the pulse frequency, has the drawback of also reducing the resolution of the machine.

I'd say most machines today uses brushless motors (AC servos or brushless DC) for both axis and spindles. Brushed DC motors are "old technology" but works just fine. What voltage and current ratings does your servo motors have?

/Henrik.

[irxplod]

thanx my friend , i create Uhu Driver but i dont Choice a Motor for my late.
You thought this driver is good for a brushless DC motor ? and what kind of motors (mark, Voltage and ampers) are beter for this usage ?

Thanks for Your Time mr Henrik

[H.O]

Hi,
No, you can not run a brushless motor with an UHU based drive. The UHU based drives are meant to drive permanent magnet brushed DC motors (PMDC).

As for voltage and current etc it's impossible for anyone to say when only you know what type of drive you've built and how big the machine you intend to run is. A small Sherline lathe will likely work with some 24V 50W and then it goes up from there.

[irxplod]

oh its bad (
but is there a open Controller board such as uhu for AC or dc Brushless servo motors?

[H.O]

Hi,
Not that I know of but that doesn't mean none exists...let me know if you find one.

For a low(ish) cost brushless servo drive have a look at the VSD-E from GraniteDevices and the systems avaliable from DMM-tech.com

[irxplod]

no just for mony , My nationality is iran and now my country is in USA and world chopping block for our MISTAKE government. we Can't buy any thing from frogien countris
HOWEVER thanx for your help my friend , i search and i Hope too find that ,

good time