servo spindle speed control... Shizuoka

[Daniel Wilcox]

I have a Shizuoka AN-S with what looks like a servo and encoder mounted to a sailsbury drive. It's the standard equipment for a bandit 1 and quickdraw toolchanger on these machines, i believe. I'm in the middle of an EMC2 retrofit, and i was wondering what is the best way to incoorperate this into my build. I tried using a vfd, but it doesnt have near enough torque for what i want, so i think this is the only option.
I was wondering if i should use the encoder on the speed control, or should i try to put an encoder on the spindle, so the servo just turns till the spindle gets to the specified rpm's? Not sure if this is easily doable with EMC2. The servo is controlled by the quickdraw toolchanger's logic, i believe, so would it be best to continue using that somehow, or should i but a new servo drive and start from scratch? Can emc control a servo that isnt moving an axis?
I am using stepper motors for driving my machine, if that matters.
I am VERY new to EMC.

[chester88]

'Can EMC control a servo that isn't moving an axis? '
Yes you could use ladder logic or write a HAL component to control it. ( I assume you mean you want to use it to control a tool changer)
Not sure what you mean with your first question but I am not familiar with a Shizuoka AN-S
(I'm don't know what it is in general - milling machine, drive, toolchanger?)

[HuFlungDung]

I have no idea what a sailsbury drive is, but I had a good salisbury steak the other day

I've never seen the rpm changer on a machine, but I heard of them. I don't think there was any intelligence to the drive I was thinking of, it was more like a replacement for the manual hand crank to operate the variable speed drive. So it probably counted turns or perhaps relied on some kind of timing trick to estimate where the speed was. Since Bandit used percentage spindle speed commands, you never did command rpm directly with it, S99 was max speed with the motor at full rpm. Now with an rpm changer, I suppose you left the motor running full speed all the time (which was likely an annoyance) and used the S commands to control the rpm changer.

To get good torque on your motor, you could step up the motor size and get a vector drive VFD from Baldor. Encoder feedback is the ticket that makes a vector drive work so well. The vector drive also runs exactly at the commanded rpm. However, I only used floating tap drivers to tap with, but they worked well enough for me to afford a Haas later on

If your Shizouka was like mine, it had about a 2hp motor on it. I bumped that up to a 5hp, and took the v-speed sheaves off, and put in a poly-v belt drive, and a vfd. I should have used a vector drive but didn't know any better at the time. The spindle would stall out in low rpm tapping with 3/8" taps.

Actually, I have two step pulleys with poly-v profile for a high and low range, but the shift has to be done manually, so typically it was left in high range. I'd run that machine as fast as 5000 rpm. If the job warranted a low speed session with more power for tapping, then, I'd opt to run the whole program with the belt in 'low range'.

Incidentally, I chose a spindle motor with a spring brake on it. This was to help stop the spindle from free wheeling when the tool changer impact wrench was doing its thing.

[KIMFAB]

On my AN-S I have what appears to be a dc motor connected to the speed control driven from the quickdraw. Haven't had time to play with it yet so I took it off temporarily and am turning it by hand.
It looks like the motor turns it and position is fed back by detents on the control dial with microswitches. I'll post pics when I get back from my trip.