Centroid Community CNC Support Forum

polaraligned wrote: ↑Sun Aug 01, 2021 12:11 pm He is in a residential neighborhood, so I am sure there is not 3 phase available other than a rotary converter which I believe Mark is using to power this machine. I would drop the 3 phase, but to each their own. I run my 16x60 lathe on a rotary converter and I hate hearing it running.

The machine would certainly be more valuable on resale if it ran on single phase.

My understanding is he only has single phase as Polaraligned mentions.
I am not sure how he got his voltage output if only 2 of the 3 primaries were connected.

Mark what is the voltage phase to phase and phase to ground on the PRIMARY (LINE) side of the transformer.

As I previously mentioned, I would jettison that 3 phase transformer and the current bridge rectifier and replace them with new ones.
If each core of that transformer is supplying the voltage to a 3 phase rectifier, because we do not know the specs of the transformer, will it be enough to drive all 3 current axis and possibly a future 4th?

Not worth the headache and chances to me....going to do it, do it right. New electronics all the way.
My .02+
Marty

Marty, he is using a rotary phase converter that he mentions on the first page of this thread. As long as Mark commits to using a rotary phase converter to power this machine, he can use the old DC power source to connect to the Allinone and power the servos. So your DC power source is straightened out Mark. You will run this DC power thru the Estop contactor and to the -VM and the +VM of the Allinone. Mark, you might even already have a good contactor that this runs thru that you can reuse. If that old contactor is powered by the 24vdc supply, you can use that instead of using a new 24vac contactor as per the Centroid schematic.

Yes, I am running a rotary phase converter, two actually. I have a 10HP running this machine, a manual lathe, and a manual mill, but never at the same time. And a 25HP running a 13HP CNC lathe. We'll be discussing that lathe further down the road as I am having issues with that, too.

I had looked into having 3 phase run out to the house when I bought a 480V CNC lathe. It was going to be $10,000 just to get it to the house and then they wanted a minimum monthly use, on top of that. Then I would have had to transform everything else down, 220, 110, etc. Ultimately cheaper to go the RPC route. I agree that it would be nice to not have to listen to them run, but I'm not out there 24/7 and I can deal with it.

It'll be a while before I can get back out there. I plan to draw up schematics and get voltages (per Marty's request) before dismantling any further.

I'm just happy to be making progress in the right direction.

Thanks to all for the contributions to the discussion.

Mark

Can someone explain how these "Auxilliary Contacts" work? This is where the 220 comes from to power my servo motors. I forgot to measure the voltage that Marty asked for coming into the 220V transformer. I'll get that.

Mark

Top picture shows auxillary contact blocks. They actuate with the relay.

Second picture shows a suppressor across the contactor coil. The coil is 120vac

Thanks Marty.

I was curious about the markings on the aux contactors. They look like capacitor markings, but them being switches makes more sense. Am I reading them correctly that the two bars indicate normally open and the two bars with a slash across them is normally closed?

Mark

Chevy427z wrote: ↑Wed Aug 04, 2021 10:56 am Thanks Marty.

I was curious about the markings on the aux contactors. They look like capacitor markings, but them being switches makes more sense. Am I reading them correctly that the two bars indicate normally open and the two bars with a slash across them is normally closed?

Mark

Yes on the contacts. You can always verify with your digital meter set on continuity

The symbol that looks similar to a capacitor indicates normally open contacts, that is they are open when the relay is not energized. When the slash is thru the symbol, it indicates that they are not normally open, ie they are normally closed. The slash is a "not" indicator, so they are not open as the symbol indicates.

polaraligned wrote: ↑Wed Aug 04, 2021 5:35 pm The symbol that looks similar to a capacitor indicates normally open contacts, that is they are open when the relay is not energized. When the slash is thru the symbol, it indicates that they are not normally open, ie they are normally closed. The slash is a "not" indicator, so they are not open as the symbol indicates.

Got it! Thank you!

I got some voltages that Marty was asking about. Pic E shows contacts A, B, and C, in yellow. This feeds the 220V 3 phase transformer that in turn feeds my 116VDC power supply to the servo motors when 110VAC pulls in that contactor.

A to B - 271
B to C - 253
A to C - 243

A to ground - 122
B to ground - 232
C to ground - 121

Mark