SEMCO 1000 Retrofit with AC servos and Mach3. . . . MONSTER BLU . . Her Name.!!

[Neale]

I had a similar but smaller-scale problem recently, which is why I asked! I have a lathe with a 3HP/2.2KW motor, 415V/3ph, of course. Without major dismantling and rebuilding the motor, I couldn't do the old delta-star conversion trick. I ended up buying a 240V-415V VF inverter, which is fine up to a point, and that point comes when there is heavy load on the inverter. I run it at 50Hz as the lathe has its own variable-speed drive but although the lathe should go up to 2500RPM, above 2000 the load (not cutting, just idling so to speak) is sufficient to trip the inverter. The problem isn't load as such, but the fact that the input is single-phase rather than the three-phase that it was originally designed to use, compounded by the fact that there is a rather crude voltage doubler to go from 240 to a nominal 480 in front of the inverter. If I could find a big 240-415 transformer that would help. That lot runs off a dedicated 16A supply which is fine. I suspect that if you look into it, the cheapest option might be to go for a three-phase supply to the workshop. It might be cheaper than a massive inverter. Still, you've got plenty of time to save up the pennies! Like everyone else, I'll be watching this one with interest.
[EDIT] Just had a look at those Digi-Phase converters. Haven't come across those before. Unfortunately there isn't quite enough information to see what they can do, although they do sound a step up from the simple rotary converter.

[JAZZCNC]

I suspect that if you look into it, the cheapest option might be to go for a three-phase supply to the workshop. It might be cheaper than a massive inverter. Still, you've got plenty of time to save up the pennies! Like everyone else, I'll be watching this one with interest.

Already have and it's No go not enough spare supply they say. Daft thing is Sub station is at side of my house so would be easy to get into shop.
Doing this also comes with other hassles like tariff is higher for 3 phase and I'd be pulling mostly just from one phase costing me more to run house and rest of shop. Then I have the potential of Counsil hassling me why I have 3 phase in a domestic building.! . . . Can of worms I don't need.

I can run the motor from 240v no problem thru VFD but obviously I loose torque. i've had it running from 2.2Kw VFD already and with a little help from Jonathan I tweaked the V/Hz ratio and got it running with decent amount of torque at nominal speeds which is 33hz for de-rated setup. This still gave 1800rpm and couldn't stop the motor. But at higher speeds it dropped away to point not usable.

But with 5.5Kw Vfd then I might be able to live with the de-rated torque and still have enough for smaller cutters at higher speeds.?
That said I don't see the point of having a MONSTER MIll that performs like Fairy so would like it to be all it can be.!! . . . . If that means Aldi Beans on toast for several months then so it must be.!!

[audioandy]

About bloody time!

[JAZZCNC]

About bloody time!

Sorry do I know you Ugly.!! . . . . Any way talk abart kettle calling Pot black bet that Old Iron ain't moved since last time I saw it. . .

I'll give you a tinkle some time mate.

[audioandy]

You are right Dean it's not moved, what I was going to do this summer!

Now it's too cold.

Catch up with you soon.

Regards

Andy

[gatesy]

Any updates on how the chinese servos and drives are performing?

[JAZZCNC]

Any updates on how the chinese servos and drives are performing?

Nope sorry still just spinning on the bench. . . . . But very nicely.
Need 36hr days then I might get chance.!