Lathe Motor Help

[Jud96]

Thank you guys! I think I going to go with a 3ph 1HP or 1-1/2HP motor with a VFD. This has been suggested many times on this forum and other forums where I asked the same question. It also seems that going with a common 56 frame motor will work as long as I get the right size pulley to work with my lathe.

 

[WSnyder]

A single phase motor's power is pulsating, Wherein a 3 phase motor's power is smooth. And the single phase pulsating power is translated into the surface finish.

For sure and no argument but on these Rockwell’s the surface finish doesn’t seem to be affected using a single phase motor. With the Reeves drive you have 3 chains of belts linking the motor to the spindle so it seems to get washed out. Mine is 1ph and you can’t see it in the finish.

 

[Sniperhandle]

These VFD's are user friendly and High Quality. You have to order the reverse stuff separately though.

https://www.amazon.com/KB-Electronics-KBAC-27D-Enclosure-Frequency/dp/B01AOCLIEU

 

[Sniperhandle]

For sure and no argument but on these Rockwell’s the surface finish doesn’t seem to be affected using a single phase motor. With the Reeves drive you have 3 chains of belts linking the motor to the spindle so it seems to get washed out. Mine is 1ph and you can’t see it in the finish.
View attachment 1511037

Cool it's a single pulley also, So that makes getting a pulley easy.

 

[Sniperhandle]

https://www.grainger.com/know-how/equipment/kh-infographic-nema-frame-guide

Make sure you find out what RPM motor your lathe requires.

 

[BuffaloBill]

Good decision to go 3P motor and VFD. The VFD brings many advantages and makes a lathe such a treat to use. The installation and programming may be tedious, but is worth the effort. My VFDs are all Hitachi and have given me no troubles.

 

[Jud96]

Question for those that use a VFD. How do you convert the displayed RPMs from the motor to the actual spindle RPM? Is that possible? Also, can I just use the lathes RPM adjustments instead of the VFD variable speed control? Thanks

 

[LVLAaron]

Yes, you'll still use the lathes gearbox - I mix it up so I don't wear out any particular gears, but I'm probably over thinking it.

For RPM - Most people who wire up a VFD also install an RPM gauge. Lots of info and builds at hobby machinist forums.

 

[LVLAaron]

I'm lazy though... on my speed dial - I just put a mark where the motor runs at 60hz. So if RPM is important, I'll put the dial there use the gearbox normally... adjust up and down from there with the dial.

 

[Jud96]

Yes, you'll still use the lathes gearbox - I mix it up so I don't wear out any particular gears, but I'm probably over thinking it.

For RPM - Most people who wire up a VFD also install an RPM gauge. Lots of info and builds at hobby machinist forums.

Did you install an RPM gauge on your lathe? And do you use the variable speed of the VFD to control your RPMs? I’m debating on hiding my VFD in the cabinet and only using it as a converter and using my lathe’s original variable speed control, or making a bracket for it and using an RPM gauge. I’m not very skilled with electronics and the instructions for my VFD are a little confusing for me.

 

[LVLAaron]

Setting up a Tach on a Precision Matthews PM 1440TL

Had a request on my YouTube channel to provide more detail about the tach I have on my PM 1440TL so figured it may help someone here as well. Short video, but should have enough detail to help anyone out. My lathe happened to come with a nice collar already on the backside of the spindle for...

www.hobby-machinist.com

My VFD is tucked away in a box I never open. But I have a dial that controls the frequency.

 

[Jud96]

Setting up a Tach on a Precision Matthews PM 1440TL

Had a request on my YouTube channel to provide more detail about the tach I have on my PM 1440TL so figured it may help someone here as well. Short video, but should have enough detail to help anyone out. My lathe happened to come with a nice collar already on the backside of the spindle for...

www.hobby-machinist.com

My VFD is tucked away in a box I never open. But I have a dial that controls the frequency.

Awesome thank you!

 

[lost okie]

A three phase motor is a wise choice. I managed an electric motor repair shop for quite some years. The single phase motors biggest problem is the internal centrifugal switch. It almost invariably dies first. Start stopping repeatably kills it.
A three phase has more torque with less amps.
Running your vfd to slow your motor will decrease your torque, set it at 60 hz.
Check your motor dimensions to 66 frame specs. Most lathe oem motors have something off in their dimensions; usually shaft size is different.
good turning!