Hi all
Any one used the spindle 2 board? For £20 + speed controller, it looks like a good option for controlling routers etc
Is a VFD and 3 phase motor worth the money?
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Hi all
Any one used the spindle 2 board? For £20 + speed controller, it looks like a good option for controlling routers etc
Is a VFD and 3 phase motor worth the money?
Yes used a few of them, Roy developed them initially for us as the Sieg and the American KB controllers have the pot at mains potential.
Just wiring straight in using the same logic supply as the rest of the breakout / driver system causes lovely bright multi coloured sparks and bangs [ don't ask ]
Like all of Roy's boards I have used, they have worked with no problems and done what it says on the box which isn't hard as they don't come in a box.
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I have a VFD and 3phase on the lathe, and since it accommodates two motors I plan to change the mill to a 3phase and run both off the same VFD (not at the same time of course!)
Cheers guys , what VFDs and power motors are you using, Am I correct in assuming that a 3ph motor is more powerful? or is that only when they are run at 415 volts?
:beer:
All sorts, some generic Taiwanese el cheapo ones, IMO's Telemechaniques, Yaskawa and Fuji.
Motor powers from 0.25 Hp up to 7.5 Hp
Technically horse power is horsepower regardless of single or three phase, what does alter is the amount of amps pulled to get this power.
However the 3 phase goes come out on top as getting 3 pulses per rev it doesn't bog down as much as a single phase motor with one pulse per rev when a load is applied.
They are smoother, less vibration and with a VFD the 3 phase can have speed control, something the single phase one can't have.
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I thougt you can control the speed of a 1ph motor with a triac based controller. seen them for about £10Quote:
They are smoother, less vibration and with a VFD the 3 phase can have speed control, something the single phase one can't have.
Do these only control the speed and therefore have reduced power as well?
Seen a couple of VFDs on ebay for £150. dose this seem about right?
Only if they are PM motors (permanent magnet). 1ph motors with AC field coils cannot be controlled this way as they are synchronous to the AC input frequency. PM motors are low-fractional HP output.
Thats about right for a sub-1kw (.5 - 1HP) VFD. You must match the VFD to the motor.
Nothing is ever simple eh! is it just the max curent that is the issue when matching it to the motor?Quote:
Thats about right for a sub-1kw (.5 - 1HP) VFD. You must match the VFD to the motor.
Looks like I will have to research this a bit more, know of any good sites
Does this look like a good VFD,
http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=230343452299
Is 1.5K enough for decent mill? what size are you running your mills?
Thanks
Three phase motors and single phase motors rated at the same power and speed will give the same torque and speed as each other. (Thus the same power)
Power is (Torque*Speed/9550) so if you reduce either speed or torque the power will reduce.
So if you have a 1KW motor rated at 3000 RPM and you reduce the speed to 1000 RPM, then the power will be 333W. (assuming the torque stays the same)
You can only control the speed of an AC induction motor by varying the frequency, and this is only with a three phase motor.
A three phase motor comes Star or Delta and motors under 7.5KW are normally 220V Delta and 380-415V Star; you can use a single phase inverter and connect the motor in delta to run it from a single phase supply.