Do you need to water cool erhm a water cooled spindle?!!

[Jonathan]

Just try it and see.

JI think it was Jonathan that said the Chinese spindle were about 80% efficient, so for an 800W spindle surely I'd be looking at a meager 160W heat dissipation

I feel I should clarify this. The spindle is an induction motor, so the efficiency varies somewhat. The efficiency will depend on the load and the speed, so at some point it probably will be 80%. The efficiency will be much lower at low load, but the input power is much lower so overall the power dissipation will not be that great.
I think you're mainly cutting PCBs, so the power required from the spindle is tiny - most of the power is just supplying the losses (bearings, magnetising current etc) so if you just leave the spindle on not cutting anything and see how long it takes to heat up, you'll have a pretty good idea of how long you can use it cutting PCBs.

The situation's very different if you do draw near full power - it will heat up very quickly, but it takes a bit of doing to make a machine for which the spindle power is the limiting factor...

[HankMcSpank]

Ok, thanks to all.

I've now ordered a Toshiba VFD from Italy (as per silyavski's recommendation in this thread - http://www.mycncuk.com/forums/router...-remotely.html), here's the one I went for....

INVERTER VETTORIALE TOSHIBA 0,75 kW 230 Volt MONOFASE USCITA MOTORE TRIFASE 1 HP | eBay (I'll never go larger than an 800W spindle, so this VFD ouight to fit my needs well)

In the meantime, my thoughts turn to the spindle wiring - I've already got an 800W spindle but there was no information supplied, with it - I'm figuring it's likely that these water cooled spindle all have common wiring, so can anyone please tell me what the 4 pins are...



I've seen reference on the net to 'U' 'V' & 'W' for the spindle pins...are these just arbitary abbreviations give to the three phases?

[JAZZCNC]

I've seen reference on the net to 'U' 'V' & 'W' for the spindle pins...are these just arbitary abbreviations give to the three phases?

Those are the correct abbreviations for each phase. The forth wire won't be connected to anything.
Just wire to 3 connectors and if runs in reverse swap any 2 wires. . . Thats it.!!

[HankMcSpank]

Those are the correct abbreviations for each phase. The forth wire won't be connected to anything.
Just wire to 3 connectors and if runs in reverse swap any 2 wires. . . Thats it.!!

but I don't know which pins on my spindle are actually U V & W.....so was hoping someone could say by referencing from the keying prong? (assuming they are all standard?)

[Jonathan]

but I don't know which pins on my spindle are actually U V & W.....so was hoping someone could say by referencing from the keying prong? (assuming they are all standard?)

It's arbitary. Just connect the 3 spindle power wires to U, V and W in any order and all that will happen if the order is 'wrong' is the spindle will spin the wrong way. If so, then as has been said, just swap any two of U, V & W.

[JAZZCNC]

Cheers Jon saved me some typing. .

[Jonathan]

It's occured to me that you might not be sure which are UVW and which is not connected (or earth)? If so then just use a multimeter, set it to measure resistance and check the resistances between all 4 pins - you should find that 3 of them (UVW) are virtually identical, and one is open circuit.

[HankMcSpank]

It's arbitary. Just connect the 3 spindle power wires to U, V and W in any order and all that will happen if the order is 'wrong' is the spindle will spin the wrong way. If so, then as has been said, just swap any two of U, V & W.

I'm obviously having a bad (blonde?!) day.... that's my point, I have no idea which of the four pins on the spindle's connector socket are the actual spindle's power wires (that was the main thrust of the photo earlier ...if those sockets standardized, I'd hoped someone might enlighten me which 3 of the 4 are used)

[Jonathan]

Option two is unscrew the connector and have a look. Whilst your at it you could solder on an earth cable.