how to use vfd for old cnc mill

[machinehop5]

i want to mess around with the lube system a bit more to make sure that its working properly before i get too aggressive with the spindle speed

...good idea...the waylube too. maybe write a little warnup program for xyz

[mactec54]

changed the settings as instructed and its working now. forward and reverse work. i changed the initial startup frequency to 60 so the motor runs at the designed speed. I left the max at 100 hz but i dont know why I would ever use that. I have a 2 speed with hand crank for speed adjustment so I will probably just run it at 60hz all the time.
I dont have an automatic tool changer so manually setting the speed doesn't seem like an issue.

I have not started working on bringing in the signal wires to control the VFD.

i want to mess around with the lube system a bit more to make sure that its working properly before i get too aggressive with the spindle speed

It would mean that you don't have to turn the hand crank to change the speed you just command the speed in your program and the VFD Drive will run it at that speed, so that is why you would use it with the 100Hz setting which is conservative for your spindle motor, at 120Hz the motor will double it's rated speed which it can do safely

[jaysihn]

It would mean that you don't have to turn the hand crank to change the speed you just command the speed in your program and the VFD Drive will run it at that speed, so that is why you would use it with the 100Hz setting which is conservative for your spindle motor, at 120Hz the motor will double it's rated speed which it can do safely

so the motor is safe to double speed but what about the spindle bearings? i think the max speed on the hand crank is 3000. if i wanted to leave it in that position and over-drive the motor, do you think the spindle bearings can handle 5-6k RPMs ok? that would open up the ability to do some smaller diameter cutters

[machinehop5]

so the motor is safe to double speed but what about the spindle bearings? i think the max speed on the hand crank is 3000. if i wanted to leave it in that position and over-drive the motor, do you think the spindle bearings can handle 5-6k RPMs ok? that would open up the ability to do some smaller diameter cutters

... higher speeds more heat. Depending on your machine condition, Vbelt drive, gearbox lube/mist system, temperature, etc...running at very high speeds for short periods probably ok.
...safely is a matter of opinion.

[Al_The_Man]

so the motor is safe to double speed but what about the spindle bearings? i think the max speed on the hand crank is 3000. if i wanted to leave it in that position and over-drive the motor, do you think the spindle bearings can handle 5-6k RPMs ok? that would open up the ability to do some smaller diameter cutters

I have generally used the typical 4 pole motor, as yours appears to be, at least twice the plate frequency when incorporating a VFD,
I speculate that the motor manuf. probably produces 2 pole motors also, so I would imagine that he would use the same balancing and bearing specifications for the whole line of motors. 2 & 4 pole alike.
Al.

[Jim Dawson]

That particular motor that you have is rated at 6000 RPM max, I have the identical motor on my mill. I would not run it over 4500 RPM. I'm guessing the spindle would take 6K RPM with no problem. If you need higher than that, then time to add an auxiliary spindle.

[mactec54]

That particular motor that you have is rated at 6000 RPM max, I have the identical motor on my mill. I would not run it over 4500 RPM. I'm guessing the spindle would take 6K RPM with no problem. If you need higher than that, then time to add an auxiliary spindle.

Not with this standard 4 Pole motor you are not going to run it at 6,000 RPM, it's rated RPM is 1725 so 3450 is around the max for this motor, did you check the motor he posted

[Jim Dawson]

Not with this standard 4 Pole motor you are not going to run it at 6,000 RPM, it's rated RPM is 1725 so 3450 is around the max for this motor, did you check the motor he posted

Yes I looked at the motor he posted. I have exactly the same motor on my mill. I actually looked up the specs on the motor when I was doing my direct drive conversion and the Baldor data sheet says the absolute max RPM on that motor is 6000.

I don't just come up with this stuff off the top of my head.

[jaysihn]

Yes I looked at the motor he posted. I have exactly the same motor on my mill. I actually looked up the specs on the motor when I was doing my direct drive conversion and the Baldor data sheet says the absolute max RPM on that motor is 6000.

I don't just come up with this stuff off the top of my head.

thanks Jim. I'll keep the max freq at 100 Hz until i've got some time on the machine and get more comfortable with its limits.
did yours have the weird brake on the motor? I took that off tonight - none of its wires were hooked up.

[Jim Dawson]

When I was still using the mechanical variable speed on mine, I normally ran between 30 and 90 Hz. That covered all of the speed range I needed. It was just easier to reach up and turn the knob on the VFD key pad than to crank the mechanical variable speed unless I needed a large adjustment. I had the VFD mounted where the motor switch would normally be on a manual mill. After running manual mills for about 45 years, it felt normal to reach up into that area to control the motor.

No, mine did not have that breaking system, I think that was added by the machine builder. The Baldor braking system is different on motors equipped with that.

[machinehop5]

i am just trying to educate myself.

control not responding to PIC

...me too.
and something that is still stuck in my mind following your thread is the photo of the Dynapath unit you posted early on. Almost all of the cards seem to be in the wrong slots. But, yet you say the machine powered up ok...... if, you are having any trouble with odd behavior. Be on the outlook for problems...like axis missing information on screen, positioning errors, soft keys, keypad functions,mode selecting, programming or anything odd. Or maybe the photo is not the card configuration of your machine currently is. Looks like the Battery is missing too

This message will self destructed in 15 secs, after answered...
DJ

[mactec54]

Yes I looked at the motor he posted. I have exactly the same motor on my mill. I actually looked up the specs on the motor when I was doing my direct drive conversion and the Baldor data sheet says the absolute max RPM on that motor is 6000.

I don't just come up with this stuff off the top of my head.

Post the spec's sheet then he has a 4 Pole motor, they have not made this motor in years so don't know where you got the spec's from I have all there motor catalogs for the last 10 years and it is not a listed motor

[jaysihn]

Post the spec's sheet then he has a 4 Pole motor, they have not made this motor in years so don't know where you got the spec's from I have all there motor catalogs for the last 10 years and it is not a listed motor

pretty sure its closer to 30 years old.

[jaysihn]

...me too.
and something that is still stuck in my mind following your thread is the photo of the Dynapath unit you posted early on. Almost all of the cards seem to be in the wrong slots. But, yet you say the machine powered up ok...... if, you are having any trouble with odd behavior. Be on the outlook for problems...like axis missing information on screen, positioning errors, soft keys, keypad functions,mode selecting, programming or anything odd. Or maybe the photo is not the card configuration of your machine currently is. Looks like the Battery is missing too

This message will self destructed in 15 secs, after answered...
DJ

battery is there. I had this machine sitting without power since October 2019 and when I got it powered back up it didn't have any battery warnings.
maybe this is an even older delta10 unit that had the cards in a different order?

[Jim Dawson]

Post the spec's sheet then he has a 4 Pole motor, they have not made this motor in years so don't know where you got the spec's from I have all there motor catalogs for the last 10 years and it is not a listed motor

That motor is close to 30 years old. The data sheet that I found no longer seems to be available on the internet. It was several years ago that I found it and apparently I did not download it. When ABB bought Baldor, it seems they took down all of the old data sheets.

[machinehop5]

...I dont think the Dynapath 10 were smart enough to monitor battery condition.. easy to check with a voltmeter and power off. should be more than 3VDC if good. Battery only holds programs and offset memory during power off. There is a date on the battery maybe if, you look close. No biggee you have bigger fish to fry with this project. Keep going

[jaysihn]

Attachment 445184

my serial number is pretty close to the 60,000 when they started delta10 with 6MHz hardware. makes me think its probably from 1986-1988.

[machinehop5]

Attachment 445184

my serial number is pretty close to the 60,000 when they started delta10 with 6MHz hardware. makes me think its probably from 1986-1988.

...looking back those were some good times...Cutting edge. of G code robots. Nice that the machine you have is in great shape...looks like.
https://en.wikipedia.org/wiki/Intel_80186

https://www.ebay.com/itm/Dynapath-42...gAAOSw9~Ne3utl

[mactec54]

so the motor is safe to double speed but what about the spindle bearings? i think the max speed on the hand crank is 3000. if i wanted to leave it in that position and over-drive the motor, do you think the spindle bearings can handle 5-6k RPMs ok? that would open up the ability to do some smaller diameter cutters

The spindle bearings can handle over 10,000 RPM in general the spindle is not the problem it will be the variable drive in the head that will fail first 4600 is usually about the max for a variable drive without a lot of mods that is about the max for a head like that , the only way to get high speed it to remove the variable drive and direct drive

[mactec54]

That motor is close to 30 years old. The data sheet that I found no longer seems to be available on the internet. It was several years ago that I found it and apparently I did not download it. When ABB bought Baldor, it seems they took down all of the old data sheets.

If you went to the trouble of looking up a motor like this you would of saved the spec's for it

But it is Just as I thought you have no such spec's for this motor and there never where, don't quote things unless you have the information to back it up, it tells you on the name plate if you no anything about motors like this, that it is it is a 4 pole 1725RPM motor the most it could safely do is double the nameplate RPM you would have to use 200hz to get it to run at 6000 RPM and that is not going to happen with this motor not being an inverter duty motor