Newbie- DC Servomotor question

[cnc2]

Hi every body on the forum !

I have a four brushed dc servomotor, the manufacturer told me it's a 290 W "useful" (i'm not sure at the translation 'cause it was in french) it's rated 42Vdc & 8.5 Amp & 1075 rpm, and he said 2.58 Nm of torque computed from the power in Watt through the formula P=T*omega, omega=(2pi*(rpm))/60.

My questions are:

1) what is the torque that is computed through that formula, the continuous torque or continuous stall torque or peak torque ?

2) Is the shaft spinning at 1075 rpm with 2.58 Nm of torque ?

3) Is the peak torque 2.58 Nm or it's much higher than this ?

4) Is it possible to increase its speed safely, and how ?

5) Is this servomotor enough for a cnc metal milling machine, does it need a speed increasing ?

Thanks !
cnc2

[mmjpotter]

cnc2

1- the rated value is usually quoted as continuous stall torque
2- Yes. 100w corresponds approximately to 1Nm at 1000rpm
3- Peak torque will be higher but cannot be mainatained for more than a
few seconds
4- To increase the speed you will need more voltage but it is not
reccommended to input more than the rated value (i.e 42 volts) as this
will cause the motor to over-heat.
5- These are more than adequate motors for must small workshop machines.
1000rpm coupled via a 1:1 toothed belt drive to a 5mm(0.2in) pitch
ballscrew will give you 5000mm(200ins)per minute traverse speed. I think
this would outrun most stepper/mach3 sytems.

MJP

[cnc2]

Originally Posted by mmjpotter cnc2 1- the rated value is usually quoted as continuous stall torque 2- Yes. 100w corresponds approximately to 1Nm at 1000rpm 3- Peak torque will be higher but cannot be mainatained for more than a few seconds 4- To increase the speed you will need more voltage but it is not reccommended to input more than the rated value (i.e 42 volts) as this will cause the motor to over-heat. 5- These are more than adequate motors for must small workshop machines. 1000rpm coupled via a 1:1 toothed belt drive to a 5mm(0.2in) pitch ballscrew will give you 5000mm(200ins)per minute traverse speed. I think this would outrun most stepper/mach3 sytems. MJP

Thanks a lot man for these precise & convincing answers, but

what you mean when saying "small workshop mashines" do you assume they can mill steel with these motors & 1:1 drive, will the torque be enough for that purpose ?

Thanks !

cnc2.

[cnc2]

Hi every body on the forum !

I got a matsushi'ta DC motor with tach on it, it's a 20vdc geared motor & ther's no current spec it's a GMX-7MP008A. I already posted the pics here post#1:

http://www.cnczone.com/forums/showthread.php?t=54079

My questions:

1) How to know its rated current (Amp) ?

2) It's near impossible to stop it by hand because it's geared and spins at 475rpm with 20vdc, is it suitable for a metal milling machine ?

Thanks !

cnc2.

[cnc2]

:UP:

[cnctechno]

hello ,
I have two servo brush motor model EG&G ME-3515-131E and do not know
the voltage and current amp for these motors and can I use 320 geckodrive to
drive them and what power supply should I use.

I am very stuck, I need help. thank you

[Al_The_Man]

Look on the CMC site http://www.cmccontrols.com/ if you cannot find them, I have the spec sheet for them somewhere.
Al.