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jbmachine
11-28-2010, 09:57 PM
I am upgrading an existing import mill that had a very old and dead centroid control / stepper system ( all electronics came in a box ) / 3 axis ball screw / manual variable head and nmtb 30 taper

for motors - home shop cnc 850oz
for encoders AMT102 or 103 encoders
whale3 drives
square d limit switches for table
micro limit switches for z azis
good power supply 70v dc 24w
caned cnc ubob builders pack
rogers cnc encoder board
mach3

and if i can find a 3hp vfd and driver so mach can control the spindle

any thing i missed or thoughts
thanks

macona
11-29-2010, 12:18 AM
I would skip all that and do what others are doing, get a set of used brushless motors and drives. You will be way ahead of the game in the long run. Better performance and no tuning.

You are looking at about $300 a drive/motor with the DC brushed motors. With the others its about $400 a motor/drive set.

These are the guys that usually have the sets, nothing right now though.

http://shop.ebay.com/fa-parts/m.html

jbmachine
11-29-2010, 12:56 AM
That's sounds good
any overseas vendors that may have any in stock - no tuning so will i need a special break out board

macona
11-29-2010, 01:15 AM
Nope. The drive sets usually come with them as well. The drives take a standard step/dir input.

The drives tune themselves as you use them.

jbmachine
11-30-2010, 01:31 AM
http://www.dmm-tech.com/Pricing.html

what about these they are ac servos ?

macona
11-30-2010, 01:01 PM
They are AC servos but I think 400W is borderline. It would be fine for a Quill but for the axes I dont know.

KiloBravo
11-30-2010, 01:37 PM
I almost bought the 900Watt package for a Bridgeport rebuild. I was on CNCzone and only a couple people have them and not for a Bridgeport.
They seem to be happy with them.

I just don't know about the 48Volts, that seems low. Also, it seems strange that all the power supplies go thru the breakout board and not direct to the motors. That's a lot of amps going thru a circuit board.

One guy on CNC MacTech54 highly recommends them but I think he has a connection to the seller. If I could have found a few satisfied buyers or someone who used those to convert a Bridgeport I probably would have bought the 900 Watt 4-axis kit. The price is very reasonable, just to many unknowns for me.

My $0.02 for what it's worth.

P.S. JBMachine I sent you a Private Message

KiloBravo
11-30-2010, 01:59 PM
I would skip all that and do what others are doing, get a set of used brushless motors and drives. You will be way ahead of the game in the long run. Better performance and no tuning.

You are looking at about $300 a drive/motor with the DC brushed motors. With the others its about $400 a motor/drive set.

These are the guys that usually have the sets, nothing right now though.

http://shop.ebay.com/fa-parts/m.html

I have been watching that guy for a while. He has not had a new set in about two months. They have a website fa-parts.com but it is in Korean. I think they decomission old machines and that's where they get the used drives from. If he posts a new set the price is great and free shipping from Korea is awesome.

KiloBravo
11-30-2010, 02:06 PM
and if i can find a 3hp vfd and driver so mach can control the spindle


These guys seem to have the best prices for VFDs.

http://www.factorymation.com/

As far as I know Mach3 can turn the spindle on and off, but it sends a PWM signal to control the speed. The Teco drives need a 0V to 10V DC signal to set the spindle speed. I read you can use a simple Resistor/Capacitor filter to convert the PWM to a proportional DC signal.
I am buying one of these
TECO MA7200 AC Drive, 2 HP, 230V 1 / 3 PH Input, 230V 3 PH Output
TECO FM50 AC Drive, 2 HP, 230V 1 / 3 PH Input, 230V 3 PH Output

I'll post the circuit when I figure it out. Anybody have a circuit handy for this or does anybody sell a breakout board for it ?

djc
11-30-2010, 03:43 PM
...The Teco drives need a 0V to 10V DC signal to set the spindle speed... Anybody have a circuit handy for this or does anybody sell a breakout board for it ?

The canonical solution is one of Peter Homann's Digispeed units, but CNC4PC sell similar, as do DIYCNC.

macona
11-30-2010, 04:31 PM
These guys seem to have the best prices for VFDs.

http://www.factorymation.com/

As far as I know Mach3 can turn the spindle on and off, but it sends a PWM signal to control the speed. The Teco drives need a 0V to 10V DC signal to set the spindle speed. I read you can use a simple Resistor/Capacitor filter to convert the PWM to a proportional DC signal.
I am buying one of these
TECO MA7200 AC Drive, 2 HP, 230V 1 / 3 PH Input, 230V 3 PH Output
TECO FM50 AC Drive, 2 HP, 230V 1 / 3 PH Input, 230V 3 PH Output

I'll post the circuit when I figure it out. Anybody have a circuit handy for this or does anybody sell a breakout board for it ?

Dont cheap out on a VFD. Get a sensorless vector drive. It will have a lot more power in the low end.

KiloBravo
11-30-2010, 04:38 PM
I don't want to steal the thread but I am a bit confused. I thought Mach3 controlled the spindle by PWM. The boards I looked out were to convert step and direction to analog 0V ~ 10V.

Don't you need to convert the width of the "pulse" to an analog voltage not the "frequency" of the pulse :confused:

macona
11-30-2010, 05:30 PM
Mach has a couple different ways to control the spindle. Generic off/on, pwm, and step/dir. They are all selectable in the setup pages. I use the homann boards in my mill and sherline lathe. The hercus uses a servo drive with a step/dir inputs so the spindle is driven like that.