Grizzly lathe with VFD

[Willbird]

I would like to buy this lathe

http://tinyurl.com/34ufcb

This is the motor info

Type 2 speed induction
HP 3-4
Voltage 220
Prewired 220
amps 17/8.5
speed 1750/875
cycles 60
number of speeds 2

I would like to use this VFD with it and I will be putting 220 single phase power IN.

http://www.wolfautomation.com/Produc...roductID=18805

I am wondering if it will be reasonably simple to wire the vfd so the original lathe controls will turn the spindle on and off and reverse the spindle...I assume the machine will have contactors in the control box that would control the motor on 3 phase, and I could rewire things so the contactors controlled the vfd.

On the 2 speed motor deal I'm wondering if that can be made to work with the VFD or not ?? The slower speeds are needed to thread...BUT if I could just run the motor at 50% of full speed then it would do the same thing as running it at the lower speed.

Thanks for any help yaal could offer :-)

Bill

[Willbird]

http://www.cnczone.com/forums/showthread.php?t=25061

This thread answers part of my question

the ability to run in either speed was impressive . i expected some balking by the inverter, but as long as motor power is off (ie. 0 Freq!) the two speed switch can be thrown and the control comes online smoothly when called for

So I SHOULD be able to use both speeds of the 2 speed motor :-)

[Al_The_Man]

Isn't that a gear head lath?
If so, why not use the high motor speed and use highest gear and one gear for low speed, this enables you to maintain a high motor speed for low chuck speed.
Al.

[Willbird]

Yes it is a gear head lathe, however it's lowest speed is 45 rpm, this would be with the motor running 875 rpm. The lowest speed with the motor running 1750 would be 90 rpm, which might be too fast for a coarse thread (cutting speed would be ok but you would have very little time to pull the half nuts out if you were threading to a shoulder)

This looks to be how the speeds work out.........

motor hi speed motor low speed
1800 900
1170 585
770 385
510 255
330 165
215 108
140 70
90 45

[Willbird]

http://www.grizzly.com/images/manuals/g0509g_m.pdf

Page 54 has a picture of the control cabinet inside

I see the coolant pump is a 1/8 hp 3450 rpm 3 phase motor too.......another 190 bucks for a vfd to run the coolant pump grrrrrrr hehe.

Bill