Compact 8 lathe servo spindle with acorn?

[DICKEYBIRD]

I have a KBCC-125R & a KBSI-240D isolator on my ORAC The R means reversing and it works like a dream. You can go directly from M3 to M4 (CCW to CW) and it handles everything itself. It dynamically brakes to a smooth stop (through onboard power dissipating resistor) relay clacks & it accelerates smoothly in the reverse direction. It comes pre-mounted on a big, fat heat sink. Quite a bargain. I didn't know what I had when I won it on ebay for $75.00! NIB! Everyone has moved away from SCR based DC motor controls so you can find them reasonably priced. KB's old stuff was engineered in the US to live a long time in the toughest commercial applications out there. Old school's FINE by me.

[martyscncgarage]

A servo motor is a DC brush motor. You could run it with a KB Electronics DC controller.
See my Dyna DM2400. It runs a DC brush motor and a KB Electronics motor control fitted with the SI-5 signal isolator. What you need to know is the terminal voltage of your motor and it's HP so you can size the KB Electronics DC control properly. It gets more complicated if you want to reverse the motor but doable. Different KB controller.

I have been looking at the KB website, but there data is cryptic at best. Can you elaborate on what controller I would be looking at for a reversing motor application for the spindle?

I am away from home for the week with limited Internet Access but after digging through my emails, I believe we used a KBMG-212D & SIMG
It has a tach input which our motor could provide. We had just started testing when my buddy passed away. I believe we checked with KB Electronics support and they recommended it.

You need the SIMG for signal isolation. KBIC use the SI-5 I believe

Marty

[frijoli]

A servo motor is a DC brush motor. You could run it with a KB Electronics DC controller.
See my Dyna DM2400. It runs a DC brush motor and a KB Electronics motor control fitted with the SI-5 signal isolator. What you need to know is the terminal voltage of your motor and it's HP so you can size the KB Electronics DC control properly. It gets more complicated if you want to reverse the motor but doable. Different KB controller.

I have been looking at the KB website, but there data is cryptic at best. Can you elaborate on what controller I would be looking at for a reversing motor application for the spindle?

I am away from home for the week with limited Internet Access but after digging through my emails, I believe we used a KBMG-212D & SIMG
It has a tach input which our motor could provide. We had just started testing when my buddy passed away. I believe we checked with KB Electronics support and they recommended it.

You need the SIMG for signal isolation. KBIC use the SI-5 I believe

Marty

Sorry to hear about your buddy. I've been in a similar situation.
So I found I have a KBMG with a SIMG. I also found a 1.5 HP brushed motor, 90vdc. Can I run this motor with that control at reduced hp/rpm? I am looking for regenerative braking, and reversable.

[martyscncgarage]

That I can not answer. Have you checked the manual for the drive to see what what the max HP is? I can't remember and I'm at home, does it need a heatsink for a larger motor?
I'd say fuse both the drive and the armature for the max HP the drive can put out, per the manual, and give it a try.
You have em so give it a go. If for some reason the motor is too much, it will pop the fuse.

Marty

[frijoli]

You have em so give it a go. If for some reason the motor is too much, it will pop the fuse.

Marty

Brute force engineering! Love it.
The drive says 11 amps@90vdc, the motor at 1.5 hp and 90vc is 15.5amps.
The drive at 180vdc is 2hp. I am in between where I want to be. lol

[martyscncgarage]

You have em so give it a go. If for some reason the motor is too much, it will pop the fuse.

Marty

Brute force engineering! Love it.
The drive says 11 amps@90vdc, the motor at 1.5 hp and 90vc is 15.5amps.
The drive at 180vdc is 2hp. I am in between where I want to be. lol

I think it will work at reduced HP

[frijoli]

You have em so give it a go. If for some reason the motor is too much, it will pop the fuse.

Marty

Brute force engineering! Love it.
The drive says 11 amps@90vdc, the motor at 1.5 hp and 90vc is 15.5amps.
The drive at 180vdc is 2hp. I am in between where I want to be. lol

I think it will work at reduced HP

We're gonna' find out!

[DICKEYBIRD]

Holy frijoli! If that's 2 real American (not Chinese) hp, it'll be like shoe-horning a blown big block into a Chevy Vega. My ORAC is based on the same iron as the Compact 8 and it rarely makes a 3/4 hp. Baldor dc motor break a sweat. Are you trying for 4-5K spindle speeds working hard for hours? If so you better water cool the spindle bearings! I stole the 3/4 hp motor NIB for a ridiculous price thinking I'd use it until I could find a something a little more powerful but it's been fine for everything except threading steel at larger diameters. Even then it wasn't a matter of insufficient torque @ threading speeds (it has a belt reduction system added) it has just a little bit of speed variation and Mach's crappy single pulse indexing allowed the Z-axis feed to get ahead. That's what the Acorn's for.

Having said all that, drive on; I'm just jealous. You're not gonna hurt that KB. If you figure out how to use that much power and the KB gets too hot, put a heat-sink & a fan on it.

[frijoli]

Holy frijoli! If that's 2 real American (not Chinese) hp, it'll be like shoe-horning a blown big block into a Chevy Vega.
Having said all that, drive on; I'm just jealous. You're not gonna hurt that KB. If you figure out how to use that much power and the KB gets too hot, put a heat-sink & a fan on it.

I had a V8 Vega!
Seriously though, the way these machines are made with the belt drives from the factory, a 1/2 hp motor has almost no real torque at 2000rpm at the spindle. I can slow it down with my hand.
Emco actually built some with a 3000 rpm spindle motor. I checked the bearing specs and they are good for WAY beyond 3000.
For me having machined all my life, I believe 3k under light-medium loads is great for these smaller machines. Light cuts, high feeds, high rpm is what I am after.
As to the motor, it's a Leeson so I am guessing it's pretty close to real. If I get a full horse at 2000RPM I will be ecstaioc, If I get 3000rpm and a 1/2 horse I'll be in heaven. I do believe the machine itself will NOT be able to use 1/2hp at 3k.

[martyscncgarage]

V8 Pinto was my hot rod Frijole'