[motorhedmike]

I just bought a small cnc lathe, it's a D&D electronics mini turn 2. It looks like a pretty standard chucker- hydraulic chuck, 8 station turret, coolant.... After I gave it a quick once over I decided worst case I could always part it out and get my money back. It's super beefy and heavy, the tool turret looks just like the horizontal hardinge type. I thought at first I would try to remove as little of the electronics as possible and get a mach control running on it, but now that I look at it, the spindle and drive are DC, and the spindle and axis all have resolvers. I was wondering if a working 15hp Systrol SCR drive and 7.5hp Powertron DC motor have any value? If i could ditch the spindle and drive for a vfd, and replace the {freakin' huge} axis motors and drives with ac/ digital I would be back in more familiar territory.

[samco]

If you used linuxcnc.. (which has encoder threading) mesa has a resolver interface board

sam

[motorhedmike]

Hey, thanks, I'll have to check that out, I guess the other problem is the resolver feedback rack is in the control cab, which I'd like to get rid of, and the spindle drive inputs are way more involved than the GE ones I've had experience with. I guess I'm just trying to talk myself out of gutting this thing and starting over, but getting from new control to axis and spindle drives seems to be a lot mor complicated than it usually is.

[hanermo]

No idea on right approach - I use new ac brushless stuff, these days, but only experience upto 2.5 kW.
A new 7 kW import servo is approx 5k€.

Maybe the drive has an input for external 0-10 V control, or analog input ?
This would allow use as-is.

Cheap option is new or used 3 phase motor and vfd.
Maybe 500-1000$ for motor, similar for vfd.
So, for 1500-2000$ you have new kit, that will work as is from any 0-10 V output (any nr of boards).

I would not want any vfd any more, after using servos.
But, in larger sizes, its 5k, so..

If you dont need the power ??
a 2.5 kW servo system is only about 2-2.5k.

I use mine at 1:3 with timing belts.
So, 0-1000 rpm, but I get
90 Nm TORQUE !!!!
(peak)

For comparison, a Haas 11 kW St10 has peak toqrue -1300- rpm at 102 Nm.

[motorhedmike]

Okay, after a lot reading through the 1979! Blueprints, and staying far away from the machine for now, I think I need to find a way to integrate a control with the dc servos w/resolvers, and the dc scr spindle drive. The main issue(s) being that the amps take a +-15v command signal, which I suppose I could handle with relays- and the resolvers are excited (powered) by an amp that is in the ginormous cab that I want to ditch. Anyone have ideas on motion cards? I haven't committed to a software yet, but I am really familiar with Mach. UPDATE- it looks like the k-flop/ kanalog combo might do the trick. It generates 15v command signal. I am open to other suggestions though.

[my-cnc]

Resolver decoder is quite complicated unit. I suppose it won't be easy/cheap to find right control board.
Are you sure it's resolver, not encoder ?

[motorhedmike]

I think, after looking at the X and Z motors, that I can install encoders in place of the resolvers. I'm guessing I'll use a couple of AMC brushed DC drives- simple enough. The only thing left is the spindle, which is a 7.5hp Powertron with a tach and a Contraves Systrol 15hp 4200 DC full wave drive- which means it's instant reversing- cool for rigid tapping. I would like to use the motor but I have only found a new DC drive that is full wave for a little under $500, which isn't bad. On the other hand, I could go to an AC motor and a VFD. Would this be able to instant reverse? with a shunt resistor? I remember a Haas HS1 I used to run had a VFD and could rigid tap, but I don't know what type of motor the spindle had. Also, anyone have recommendations on a motion card for use with mach 3? It's 2 axis, spindle, 8 position tool changer, coolant.

[motorhedmike]

Can anyone give me some recommendations on which controller to use? I've looked at PMDX, Homann Designs, Dynomotion, UCCNC, Mesa, (I'm a little intimidated by the learning curve of Linux CNC, but I installed a Fagor 8055I on a waterjet that is basically a Linux control, and I have to say- BULLETPROOF. But it should be for $14k.) Anyway, it seems ethernet is the way to go- I just don't know the pros and cons of these platforms on a lathe. Any suggestions would be very helpful.