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Location: Ontario
Thanks for the insight guys. I've had zero experience with VFD's up to this point. I have a solid state phase converter that operates the two lathes but it offers no speed capabilities, straight 60 hz but it doesn't care what the load is up to 10hp. Went that route for the Summit lathe, it has a 10 hp spindle motor, 3/4 hp rapid traverse motor on the carnage and a small coolant pump, all 3phase. I could get a 3phase input VFD but then I'd have to run 3 phase wiring to the cabinet shop and put a remote on/off on the converter.
Free advice is worth exactly what you payed for it.
Greg
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Location: Nova Scotia, Canada
Greg you could use the 5hp motor to build a 3 phase converter and spend the VFD money on a 3hp 3 ph motor for the lathe.
Of course you'd loose the variable speed thing and you'd have to find a small single phase "pony" motor for the converter.
Steve
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.
Posts: 3,002
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Location: Ontario
Having the variable speed feature is the big thing right now Steve. A 3hp three phase motor may fall into my lap before I get to this project so all this may be pointless.
Free advice is worth exactly what you payed for it.
Greg
Posts: 3,002
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Joined: Apr 2012
Location: Ontario
Well a 3hp 3phase motor sort of fell into my lap. Was in the rewind shop to get a fan blade for the mule and asked about used motors.
He has a 3 hp 3phase Yaskawa vfd rated motor thats been sitting there forever. As far as he knows it new. Will sell it to me for $100.
The reason its been sitting is its 6 pole. 1160 rpm at 60 hz.
Should have written down more off the tag, got the model (FEK-I) and thought I'd find out what I needed off the net but can't find anything. Think its old, Yaskawa motors are now made by Marathon.
As with most of my creations I like to base them on something that actually was supposed to work. In this case its a VB36 bowl turning lathe.
Though they don't say Im assuming they use a 4 pole motor at 1800 rpm. It has a vfd with 3 belt reduction ranges. 4:! 1.25:1 and 1:1.5 to give a speed range of 50 - 2600 rpm at the spindle.
So on the slowest speed they're operating the motor at 200rpm.
With a 6 pole motor would it be wise to run it at 133 rpm and a 2.6:1 ratio to get the low speed of 50 rpm. Just dividing they're ratio by 1.5 to match the motor speed which should have 1.5 times the torque.
I'd set my ratios at 2.6:1 1:1 and 1:2.6 which would keep the two sets of pulleys the same and the belt at the same length over the range.
Free advice is worth exactly what you payed for it.
Greg
