So I'm contemplating dipping my toes into the CNC world for the first time:
I found a late 80's Shizuoka STN mill with a Bandit2 controller. looks to be very well kept, and clean, low hours, and I was able to see it running. the current owner used it as a toll makers/prototyping mill for several years at his work, and then bought it from his old company and has had it in his garage doing light duty for the last 5-6 years. has power drawbar, cooling built in (flood and mist), and was a conversion done by a professional company ,not someone just adding it all on without having done it before. about 20 cat40 holders are included, as well as a computer with Bobcad17 already loaded and ready to go.
The guy wants me to come up with a fair offer on it (nice negotiating ploy) and let him know. So... What's a reasonable value on something like this? once I have a ballpark, I'll see if that's in the range of what I can afford and then work on negotiating with him.
I've spent a bit of time watching eBay for one of these. They've generally went around 1500-2000 with a bandit. I seen Reliable tools, well known eBay vendor, get $5K on one.
This is one fine piece of iron, box ways, 4 hp head. I'm assuming you have the tool changer.
The bandit is an obsolete control, holding value way down. I'd only buy if you're willing to change out the control in the not too distant future.
thanks for the feedback! If the controller goes bad, what would I replace it with? from the research i've done, It looks like the bandit is both a motor driver and a logic/code controller combined. is this standard practice, or is this now broken out into discreet components? I've seen a PC based system that they call a controller (mach 3), but i cant imagine that there's a multi-amp draw motor driver on a card inside the PC...
yes, I'm a complete noob at this,so forgive my simplistic questions, but I've gotta start somewhere. CNCs ease of repeatability and ability to do complex profiles fascinates me and i want to get there in the smartest way possible.
O.K. I don't know the Bandit specifically, and I don't know the machine in question either -- but what I would *expect* is real servo motors, not the steppers which things like Mach-3 drive), which have servo amplifiers, tach feedback (at least for DC servo motors -- I'm not sure about AC servo motors), and the computer will have D-A (Digital to Analog) converters to generate a speed and direction command to each servo amplifier. The amplifiers are typically separate modules, which are scaled to handle the power needed for the specific servo motors involved, and the D-A converters produce things like 5-0-(-5) volts output range or 10-0-(-10) volts output range (with negative voltages running the servo motors backwards).
Typically -- the computer is in one area, and the power circuitry (the servo amplifiers) in another -- perhaps mechanically joined but with separation panels, or perhaps separated. The Anilam controller which I had at work before I retired was a box containing the computer on an arm above the table and to the right of the head, and another box at the base of the mill's casting containing the power circuitry to drive the servo motors.
I believe that the Mach-3 setup has low level step and direction outputs, which require a driver module to boost that to the voltage and current needed -- but unless the Mach-3 has analog voltage outputs to talk to the servo amplifiers, you would have to change the motors as well.
an old enough one (like my old Bridgeport BOSS-3) will actually have high-power stepper motors, resulting in a limit to the maximum speed when just moving the cutter to where you want to start cutting, and that would probably accept the output from the Mach-3. (I'm converting the Bridgeport to servo motors as are used in the later models, and the controller will be a PC running a real-time version of linux with the free EMC package (from the NIST (used to be NBS)) driving a Servo-To-Go board to produce the analog voltage outputs.
Well ... you have what I can give you -- quite a bit of guesswork, since I don't know either the machine or the Bandit controller -- but I do know some other systems.
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