While you were researching the VFD drive, did you find anything about the number of poles they can drive? I am looking at adding VFD to my band saw and to slow it down enough to saw steel, I figure on fitting an 8 pole, 750 RPM 3 phase motor so I don't have to mess around with extra belt reduction.

None of the VFDs I have looked at have much detailed info and don't specify how many poles they can work with - that might mean they don't care but I don't want to buy all the parts and then find they don't work together.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

I haven't, but one would imagine it would be no different to any other pole count motor. It's just outputting a frequency. Fairly sure it would be fine.

There's a 400hz limit on the chinese VFD's, not that most induction motors will run that high without flinging apart mind you, lol.

Try get the vector control ones if you can, they are very cheap now and should have more torque at low RPMs. http://www.ebay.com.au/itm/1HP-0-75KW-380VAC-VFD-Inverter-Variable-Frequency-Drive-Inverter-Vector-Control-/400829219554?pt=LH_DefaultDomain_15&hash=item5d534882e2

haven't read up on how good they are though yet.
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www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Thanks for the link; after much googling, it seems the motor is going to be harder to get than the VFD. Perhaps I will convert the mill first as the motor is much easier to order on line.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Can't say i've come across any 8 pole motors. Is it not practical to put a simple reduction setup on it with a 4 pole motor?

Also put a tachometer on the lathe. The stock sensor is hillariously long so it doesnt fit anywhere. Had to make my own with honeywell hall effect sensor and a random magnet. So so happy with it




Also had enough of the motor fan sucking in swarf, some mesh should fix that!


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www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

That sensor feed into the VFD for the space vector drive or just to a tacho?
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Mechanical engineers build weapons, civil engineers build targets

Just to the tachometer, no point wiring it in and trying to decipher the PID stuff, the motor is hugely oversized. Probably needs a proper encoder to work decently at low RPMS anyway. That can be done when its CNC lathe time
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www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Great idea with the mesh in the fan guard! My band saw has a single stage reduction and while I was able to buy a slightly larger pulley for it there just isn't any space for more reduction. That Conlon motor site mentions at least 6 pole motors, which might be enough with the bigger pulley and a vector drive VFD. Jimmy from Conlon rang me about my order and mentioned a big shipment just arrived, so I will ask about the 6 pole motors.

What did you use to display the RPM on the lathe?

BTW, does that VFD mill at work still have its original 2-stage pulleys in it? I was looking at mine and there seemed no way to run a belt straight from the motor to the quill without the column getting in the way.
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Australian 2015 Featherweight champion
UK 2016 Gladiator champion

I think we put a bigger pulley on the motor.

Incidentally, that's a 6 pole motor too
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The Engine Whisperer - fixer of things

Yep, it has an enormous iron pulley on the motor which causes the belt to just clear the column. The motor is super over size so it has full torque from very low rpm even with next to no gearing.

The tach is this http://m.ebay.com.au/itm/131040969953?nav=SEARCH

From testing it'll run on 6-24v, has a 5v output and triggers active low. Quite decent given the money the sensor is just too awkward to use on the lathe.
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www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz