# Question to Grizzly ‘A1S’ style (G1004/1008/0728/etc) mill owner regard VFD



## WEL0058 (Oct 7, 2021)

Hi first post in this forum,

I have a 40 year old Taiwan A1S mill sold as a Select model ‘1/2V‘ 7x30 1HP knee mill.  Have a thread going on over here:

https://www.hobby-machinist.com/threads/my-new-select-1-2v-milling-machine.91514/

l have started milling with this mill and notice some big gaps in the speed ranges.  Was planning to convert to VFD down the road but now starting to collect parts for the conversion.  Looking at using Baldor 1.5 HP IDNM inverter motor.  Not sure on which VFD to use yet.

Posted in this forum since Grizzly has currently sells the largest volume of these A1S style knee mills.  Looking for some feedback from users who converted their mill to VFD.    Also interested in any DRO comments.  Will be doing this Yuriy’s TouchDRO since already using the TouchDRO on my lathe.

Thank,

Bob G.


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## B Clem (Oct 11, 2021)

Bob, I have converted two milling machines to VFD's. One (Bridgeport Clone) was purchased with a three phase motor and the other I replaced the single phase motor with a three because of the smoothness and speed control. The Jet (8x36) smaller mill has a Leeson VFD but I have gone to using the cheaper Huanyang because the ease of programming and reliability. My CNC mill (8-30) has a Hitachi VFD - has about 25 years of service on it - controlled by Mach3.
There is no reason not to use a VFD on your lathe. I'm ready to convert my Jet 1440GH to three phase but I do not wish to vary the speed, just run the three phase motor full speed and use the Gear Head for speed changes. The programming is about the same but controlling the VFD will be easier with less 'apparatus' to convert.

Hope this helps...
Bill C.

BTW: Your milling machine is identical to the Enco 8x30 which is what I converted to CNC. Changed to ball screws and used servo motors for the axis drives. I did this way back when converting a mill to CNC wasn't so cool! Started with Mach2 then about ten years later converted 'up' to Mach3 then updated until Artsoft stopped upgrading Mach3 - still makes chips just fine. 
As far as a DRO; go to DROPROS.com and check what they offer. I just purchased a tenth readout From them for a surface grinder.


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