Are you using a VFD?

Wondering if you are using/used a VFD if you might share your experiences in terms of the details of setting it up, your experiences with a given motor(s) and any other insights into selecting a VFD & motor combo??

Thanks,

_-_-bear

Reply to
BEAR
Loading thread data ...

I have 2 of them, one on a lathe, other on a Bridgeport mill. I have a 1 Hp Magnetek GPD333 (made by Yaskawa) on a 1 Hp Bridgeport with the stock US Motors motor. It works very well, even though it is supposed to be used on 3-phase input only. I also run a Westwind air bearing spindle motor up to 24000 RPM with the same inverter at its maximum frequency, 400 Hz.

On the lathe, I have an 11 KW Toshiba Tosvert (forget the model #) that is not usually sold in the US. I also run this on single phase 240 V power, and the Sheldon

15" lathe has a 7.5 hp motor. The not sold in the US thing was significant, as the Toshiba drives people in the US were very happy to get me a manual for it, but it was clearly a literal translation from the Japanese, and quite hard to follow. The needed information was strewn all over the manual, in charts and diagrams and tables from front to back. It took a few days to figure out how to get everything working. On the lathe, especially, the dynamic braking was a big plus, as it took 15+ seconds to wind down by itself from the high speed range. With the VFD, it stops in one second. I also added a jog that is real handy when trying to engage certain gear selections.

Jon

Reply to
Jon Elson

I do this daily in the course of my employement as a machine tool mechanic. What do you need to know?

At home, I have a Yaskawa PC3 5hp inverter running on 220 single phase and operating the motor on my Gorton MasterMill. A speed pot and a forward/reverse gives me infinate control, and the ability to tap with instant reverse. If Im running a shell mill, with heavy, high torque cuts, I kick the head into Low range and simply eat up the metal.

If running the VFD on single phase..rate the VFD at least 1.5 or more hp higher than the motor. If running on 3 phase..rate it at least the motors rated HP.

If you have multigroove pulleys, pick the middle range and normally run there. If you must run very slow..change the pulley to a lower range one. This keeps motor RPM (and cooling) up there along with the proper torque. VFDs tend to poop out torque wise at low rpm settings.

Be sure that your machine and tooling is capable of running at the speeds VFDs are capable of running. A big old chuck designed to run at

500 rpm...may become a grenade at 1500 or 2000 rpm. Avoid setting the max hertz output of the VFD to more than 120 hz. Many motors will not like the higher freq. Nor will their bearings. Doubling motor speed is about the max you should do, unless the motor is specifically rated for VFD, high hz input.

I recently put a 1/2 hp rated Horizon single phase to 3 ph VFD on my Delta/Rockwell drill press. The motor is 3/4 hp..a true 3/4. It runs it well, though it starts a bit slow and takes a few seconds to come up to speed, which I suspect is unique to the VFD itself, and not the size of the motor/ mismatch. The only issue I have with this old VFD..is that it doesnt reverse very well, so cannot use it for tapping. So I use a tapping unit. But the ability to tweak the rpms is invaluable.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Reply to
Gunner Asch

I've not much to add to the other replies, except to say that I'm using 3 VFDs - a couple of 3 HP Mitsubishi FR-220E models to power a Clausing 5914 lathe and a Clausing 8540 horizontal mill, both with 2 HP motors and an Hitachi L100 that powers a 1 HP motor on a KO Lee surface grinder. All are powering the original motors and the Clausings are nearly 40 years old and almost certainly *not* inverter-rated.

My usual approach to wiring is to run 220 VAC from a sub-panel to a fused disconnect box and from there to the VFD. Rigid conduit up to the disconnect box and LiquiTite between the disconnect and VFD and VFD and motor. So far I've been able to wire the on-tool power switches to control terminals on the VFD (in a separate run) of LiquiTite to provide motor for/off/rev on the lathe & mill and for/off on the grinder. The disconnect lets me shut off power to the VFD when it is not being used, though others accomblish the same thing with a cord and plug.

The only minor problem was with the Hitachi because the original were momentary push buttons for start and stop. The Hitachi L-100 lacks the built-in logic to use this setup directly as it expects a sustained "on" contact closure. A tech note from Hitachi provided wiring for a small control relay and diode, which fixed that problem for around $15 at Radio Shack. I think that this is referred to as "3-wire control" and has the benfit that a power outage will shut down the motor until power is back up

*and* the start button is depressed again. The drum switches on the lathe and mill will power either back up when power comes back on unless I manually turn the switches to off.

Mike

Reply to
Mike Henry

Does your Hitachi make the motor "sing"?

I have one ..about a 2hp..cant recall the model number at the moment that Id originally put on my drill press, and it made the motor "sing"....very high note, right at the edge of my (very bad) hearing range. Almost a hydraulic or servo sound....

I didnt like using it on the drill press, as it required coming to a full stop before it would allow you to reverse directions, so I stuck on the old Horizon, saving the Hitachi for another future project.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Reply to
Gunner Asch

Not so that I've ever noticed, though that could be my hearing. I test pretty well, but others are bothered by high frequency noise that I don't seem to hear as much. Did you try changing the carrier frequency?

Mike

Reply to
Mike Henry

I have two L100's, one on the lathe and one on the mill. They both cause the motors to sing at certain speeds, the mill worse than the lathe. I think it has something to do with motor quality as the mill still has it's Taiwanese motor and the lathe has a nice new Leeson.

Reply to
Jim Stewart

Mine is pretty old, though NOS and there is little that can be changed..no programming keypad etc etc. I think its a 1994 model

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Reply to
Gunner Asch

I own 2 different brands of VFDs. Both brands have adjustable "carrier frequency" that can be tuned to minimize the noise.

I have 2HP Leeson motors on a couple machines that are inverter duty rated. I run the carrier freq at 10k (max) on these machines. There is no noise and they run very smooth. I run the carrier freq much lower on standard motors. For example I run around 1.6k on the rockwell surface grinder and a little bit more on the rockwell mill. The rockwell vertical motor is the loudest of them all and someday I will replace it with a modern motor because it also has mechanical resonances and some speeds which is very annoying.

chuck

Reply to
Chuck Sherwood

According to Gunner Asch :

[ ... ]

Hmm ... on the Hitachi ones which I have, the programming keypad is an option -- it goes in place of a pop-out piece on the main cover. I got a keypad with each of mine, and an extension cable for each so I can remote the keypad while I am tuning things up.

And things like the reverse speed can be programmed as well. You might need to add a resistor to absorb the excess power being shunted from the motor during the slow-down part. (You can also tune how quickly it will slow down and accelerate.)

Enjoy, DoN.

Reply to
DoN. Nichols

Well, that kind of sucks. Have you had a look through the manual to see if there was an optional keypad (as DoN suggested) or maybe a way to set parameters through a cable to a PC or laptop with custom software. Another possibility is that some of the VFD controls serve a double function and allow parameter programming via a funky sequence. You've probably already thought of that, though.

Mike

Reply to
Mike Henry

Ayup.... I work with VFDs daily. This older unit is pretty bare bones.

Gunner, Owner, Coyote Engineering. Machine Tool service and repair

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Reply to
Gunner Asch

We have a teeny one we use to power a german made rotary table. It is sold by automation direct, they have some amazing pricing.

(We use a rotary table on a vertical mill, with the axis vertical, to mill the OD of some pretty big parts, as well as face grinding rings.)

I ordered 3 of them, and when the box arrived, it looked about the right size for one unit. I was disappointed that we only received one. Upon opening the box, I found 3 boxes inside. Each box iside had a generous amount of packing. The thing is maybe 3 x 4 x

5?

It set up quickly and has given no trouble at all.

I'd love to install one on one our cnc mills as a spindle drive. I forgot about the dynamic braking, that's a real bonus for production work. It's too bad they use resistors to throw away that energy, if someone came up with one that stored it, like with caps, what a sweet deal that would be.

Reply to
Jon Grimm

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.