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Lathe VFD?
- Thread starter Susquatch
- Start date
I use the gearbox and keep the motor in a constant speed mode. My logic is that I want to spread the wear around on the gears. If I use the same gears all the time it will shorten their life.
I do the exact opposite David.
The best VFD Rated motors can only be run at double the max speed but 1/1000 of the minimum speed at full torque.
Just below that are the 10 and 20:1 motors that can typically be run at 50% higher speeds (90 Hz) and 1/10 or 1/20th lower speeds (6 & 3Hz).
My mill motor is a full 1000:1 motor. So I set my belts to reach the half rated speed at 60Hz and then use the VFD to go to full speed or as low as I want to go. There is plenty of torque for tapping.
My new lathe motor just arrived. It is a 10:1 motor. (6 Hz to 90Hz).
I plan to install it as a straight replacement and only use the speed controls to go slower than my current minimum or to increase speed on the fly as cutting diameter goes down when I'm parting. My lathe is an oil bath gear head so speed changes are as easy as moving two levers. But it's minimum of 70 rpm is too high for my liking. The VFD will give me 7rpm if I should ever want/need it. My goal of 40 to 50 is easy peasy.
As I mentioned in my earlier post, another really nice advantage of a VFD is the ability to reduce the rate of acceleration to avoid stressing the machine.
And last but not least, and not yet mentioned, is the silky smoothness of a motor running in sensorless vector control mode. That has to be seen, heard, and felt to be believed.
Today I discovered a very serious downside to a TECO brand VFD. I want to put mine someplace safe, but I also want convenient access to programming it. So I tried to buy a remote control for it....
EMotors wants over $200 for it. I can buy a whole VFD for that!
Many competitive VFD's provide a removeable moveable control unit free.
Now I'll have to figure out where to put the VFD so it is accessible.
EMotors wants over $200 for it. I can buy a whole VFD for that!
Many competitive VFD's provide a removeable moveable control unit free.
Now I'll have to figure out where to put the VFD so it is accessible.
Rauce
Ultra Member
How close is your machine to a wall?
If it’s close to a wall you could have an enclosure with a door on the wall next to disconnect. Run the wires for low voltage control seperate from the three phase wires from the VFD to the machine.
If it’s not near a wall mount the box somewhere on the base cabinet of the machine with reasonably easy access.
If it’s close to a wall you could have an enclosure with a door on the wall next to disconnect. Run the wires for low voltage control seperate from the three phase wires from the VFD to the machine.
If it’s not near a wall mount the box somewhere on the base cabinet of the machine with reasonably easy access.
It is near a wall. I have a 3 ft corridor behind my lathe to facilitate cleanups once a decade or so. I'm behind schedule by several years. I don't really want cables back there to trip on and I'd prefer not to have to ever go back there. If I mount it on or in a base cabinet, it will never get touched. Bending over to reach or even see things that low to the ground is for 60 year old youngsters.
As you can prolly tell, I'm not happy about this situation. I had expected that keypad to be 20 bucks not 200.
I had originally planned to make a small hat for my gearbox to hold my DRO. I think the hat is going to get a lot bigger and become a box with a VFD in it.
How often do you expect to change programming on it?
Once I had my mill vfd dialed in I never changed the programming again.
If you configure it for external control you can use the original forward/reverse switches(or any type of switch) and use a potentiometer to provide variable motor speed
I mounted the the vfd in a box above the the headstock. By cutting a hole in the front of the box I can see the display.
Rauce
Ultra Member
Yeah resetting a fault is the main reason I put the display/keypad remotely with my other controls on the hendey.
It was easily removed but the extension cable was an accessory. I could have cobbled something together myself I guess but I ended up buying an old stock original (the VFD I have is discontinued). The best price I could find was $80 USD. Some automation suppliers I found online wanted $200+ just for the cable.
I’m not surprised though. The main customers for this stuff are big industrial corporations and they’ll pay that without hesitation. I work for one so I see it all the time.
It was easily removed but the extension cable was an accessory. I could have cobbled something together myself I guess but I ended up buying an old stock original (the VFD I have is discontinued). The best price I could find was $80 USD. Some automation suppliers I found online wanted $200+ just for the cable.
I’m not surprised though. The main customers for this stuff are big industrial corporations and they’ll pay that without hesitation. I work for one so I see it all the time.
Totally agree. Not sure that I would splash out on a remote panel for that.
Surely an extension cable for the panel could be found or made.
its good to see what the fault is.
My Baldor vfd's on my big lathe and bandsaw use standard phone ext cables (rj25) to remote mount the display.
The existing panel cannot be removed the way that many others can. So an extension cable won't work. However, there is a plug in port that looks a bit like a female Ethernet cable connection.
I think you are right.
I'll prolly do what @Darren did.
Dabbler
ersatz engineer
The version that @Susquatch and I have don't have a detachable display. Thus the exorbatant cost for the extension display. @Janger paid for the detachable display up front,
Ironman
Ultra Member
Speed control and on/off switch are easy to put outboard on a small panel. This is accessed from the 24 volt terminal strip. A 5kohm pot and an on/off switch will give you everything for your mill. When I did this on my Craftex mill I found the only issue was to know spindle speed accurately, as I was using high speed steel then. So I put a little reader on the spindle pulley to give me rpms, as the VFD can show motor speed only.
Then I switched to carbide and rpm and ipm became a non-issue.
Then I switched to carbide and rpm and ipm became a non-issue.
@John Conroy - Did you use a hole saw to cut that beautifully round viewport hole? or something else?
Dabbler
ersatz engineer
On TECO VFDs you have to enable this strip with the appropriate confuguration options. This will disable the buttons on the front panel of the VFD, Just so you know!!!
-- How do I know? @Janger's came configured that way and was a stumper for a few hours!!! It looked like a dead VFD...