VS motor upgrade, two for the price of one!!!!

[Odie]

Awhile back, there was a thread where we discussed the merits of a variable speed upgrade for my Woodfast lathe. Well, I finally did it!.....and with the original motor that came out of the lathe.....I built myself a buffing station. It was sort of overkill.....1 1/2hp for the buffing station, but what the heck, it's what I got, I used it! Works great! (I had been using a 1/2hp motor, and the difference is outstanding......no bogging down!)

I purchased the 1 1/2hp 220v DC Leeson motor w/Minarik controller from CSUSA. The controller has a reverse and brake. I think I'm going to use all the features. So far, only made one bowl with it, since completion of the project yesterday......all systems go!

The only drawback is the "hum" of the VS drive......initially that bothered me, but after using it, I can see this is something I can get used to.

Thanks to all those who convinced me to get the VS motor. It certainly is an upgrade that will be well worth it in the long run. I've been changing belts on this Woodfast lathe for 15yrs, and I was being a little stubborn about the changeover......now I'm glad it's done!

otis of cologne

 

[Steve Worcester]

The hum is the fan cooling the transformer thingamajigger

 

[Odie]

Thanks to all who pushed me over the edge to get the VS upgrade on my Woodfast lathe. I've now done two bowls with it, and I've finding out about everything I've been missing all these years! What a great thing!

I was doing an inward slanting bowl, and I was really surprised when I found that a slight adjustment of a couple hundred rpm solved a vibration issue I was having.......couldn't do that with the step pulleys!

Lovin' it......

Thanx

otis of cologne

 

[Midi Haws]

vs motor upgrade

How's it going, is the vs performing well? I am considering upgrading my Woodfast with a 2hp Reliant motor with an Allen Bradley controller. Thoughts?

-Midi

 

[Dave Schell]

I see this original thread is a bit old, but did you ever fix the hum of the VS drive? My Hitachi drive hummed when I first installed it, but after some research I discovered that is due to the "carrier frequency" setting. I have no idea what that means, but after playing with the parameter settings for it, I was able to eliminate the hum completely.

 

[Richard Baker]

Good for you Odie! Dragged kicking and screaming into the 21st century. Awesome buffer, BTW.

 

[Bernie Weishapl]

Great to hear Odie and glad you are enjoying it. Great looking buffer.

 

[Odie]

I haven't logged on to the forum for several days......and, I see I have some "mail" to respond to........

How's it going, is the vs performing well? I am considering upgrading my Woodfast with a 2hp Reliant motor with an Allen Bradley controller. Thoughts?

-Midi

Midi.......

The VS motor and controller are working perfectly. You are really going to kick yourself for not doing the upgrade sooner! Variable speed is such a big improvement over step pulleys, I just can't praise the difference enough!

I did have one near catastrophe awhile back.......when I reached down and accidentally hit the reverse switch while wanting to shut down. You can imagine what happened! The machine screamed and instantly went from spinning forward to reverse. The chuck unscrewed and rammed the bowl into the tool rest. Ruined the bowl, but made me think about what could be done to prevent this in the future. I came up with a magnet gadget that covers the reverse switch.......can't touch that switch without removing the magnet.......it works!

I see this original thread is a bit old, but did you ever fix the hum of the VS drive? My Hitachi drive hummed when I first installed it, but after some research I discovered that is due to the "carrier frequency" setting. I have no idea what that means, but after playing with the parameter settings for it, I was able to eliminate the hum completely.

Hello Dave.......

I just now went back out to the shop and listened for the hum.......yes, it's still there, but to tell you the truth, I guess I've just gotten used to it. I haven't even thought about it for a long time now.

If I could, I'd rather eliminate the hum completely. Can you explain to me what you mean by "parameter settings"? Maybe this is something I can do, as well..........

Good for you Odie! Dragged kicking and screaming into the 21st century. Awesome buffer, BTW.

Tex......

Ha! Dragged and kicking......yeah, I guess you could say that! I guess I'm just like many of us......get set in my ways about doing things the way I've always done it. Sometimes, it takes a crowbar to pry me away from what was, and make me see what should be!

Great to hear Odie and glad you are enjoying it. Great looking buffer.

Thanks, Bernie......

Yep, that buffer has been a great improvement, too. I couldn't live without it, now! I was using a 1/2hp buffer prior to that.......worked, but bogged down all the time. One thing for sure, though.......with all that power.....you make one tiny little mistake, and the new buffer will rip that bowl right out of your hands! 😱 I am wearing surgeon's gloves......this helps to improve the grip.......but, there is nothing that will take the place of knowing what you can......and CAN'T do!

Heh,heh,heh.....

See you later..........spent all night out in the shop last night......and I'm going back for more! 😀

ooc

 

[Steve Worcester]

Hello Dave.......

I just now went back out to the shop and listened for the hum.......yes, it's still there, but to tell you the truth, I guess I've just gotten used to it. I haven't even thought about it for a long time now.

If I could, I'd rather eliminate the hum completely. Can you explain to me what you mean by "parameter settings"? Maybe this is something I can do, as well..........

There is generally a manual that comes with the controller that will outline how to change each parameter. What it usually doesn't explain is what each parameter is and what the ramifications of mucking with it. Some of the parameters if set wrong can make very bad things happen. As far as the reverse, look at setting the ramp down or whatever the slow down period between forward and reverse. It sounds like it is set rather abrupt.

 

[Dave Schell]

Odie - parameters are just the variables of the drive's control program that you can set. If you have the manual for the drive, it will explain how to program the parameters to your desired settings. For example, most drives have a parameter for deceleration time. It you set that parameter to 7, it means the drive will decelerate from the current RPMs down to 0 RPMs in 7 seconds. Most drives have literally hundreds of other parameters as well.

As for carrier frequency, here is how my Hitachi manual explained it: "The maximum available inverter current output is limited by the carrier frequency and ambient temperature. The carrier frequency is the inverter’s internal power switching frequency, settable from 2kHz to 12kHz. Choosing a higher carrier frequency tends to decrease audible noise, but it also increases the internal heating of the inverter, thus decreasing (derating) the maximum current output capability."

The default of my drive was at 3. I kept bumping it up until I could no longer hear a hum. I think I ended at about 9.

What kind of drive did you use? Maybe I can find the manual online and help you find the parameter for carrier frequency.

 

[Bill Boehme]

I did have one near catastrophe awhile back.......when I reached down and accidentally hit the reverse switch while wanting to shut down. You can imagine what happened! The machine screamed and instantly went from spinning forward to reverse. The chuck unscrewed and rammed the bowl into the tool rest. Ruined the bowl, but made me think about what could be done to prevent this in the future.

Odie, I am sorry to hear about your near disastrous incident and I am glad the only casualty was the bowl. Steve is very correct in mentioning the importance of reading and understanding the manual so that you properly set up the controller.

What happened when you hit the reverse switch is not what I would imagine happening under normal circumstances. That is why it is very important before venturing into doing something like this to invest enough time into learning how to set up the controller or else find someone who already knows how to set one up. This is also why I do not encourage anyone without training to tackle a variable frequency drive installation on their own.

As Steve mentioned, acceleration/deceleration (aka, ramp-up and ramp-down) are critically important parameters. Beyond the safety consideration, this parameter is important to prevent the drive train from tearing itself apart from hard starts. It is also a significant operating improvement over freewheeling stops. The amount of acceleration/deceleration needed is somewhat dependent on the inertia of the load so that it does not unscrew the chuck or spin a tapered insert in the spindle socket. If you routinely mount huge pieces of wood, you should consider setting the acceleration/deceleration time to 10 seconds or even longer along with a maximum spindle speed of about 500 RPM. A small bowl blank would probably do fine with an accel/decel time of 4 seconds if you are not running the spindle any faster than about 1200 RPM.

Also, as Steve mentioned, the manual writer's assume that you know the technical terminology since the target audience is the trained installer technician. None of the parameters should be ignored UNLESS you know that they are not applicable to your application. If the controller and motor are the same brand and designed to work together, the job is often simplified and the system may be self tuning. In other cases, it is necessary to manually load parameters based on manufacturer's motor data, which sometimes is not available from the manufacturer because the motor being used was not designed for inverter duty (Inverter Duty is a whole 'nuther story which I addressed in a prior thread).

BTW, the source of the hum that was discussed a while back is high frequency vibration in the motor that results from the carrier frequency of the PWM output from the controller. For AC induction motors, this frequency typically ranges between 1 kHz and 8 kHz. Choosing the "right" frequency involves some performance trade-offs. The best power conversion efficiency from electrical power to mechanical power occurs at the low frequency end, but with a great noise penalty and slightly reduced motor life. This is best for unattended locations. Most controllers have a "quiet mode" where the carrier frequency is set above 5 kHz. This saves wear and tear on the ears, but is a bit less efficient. In the "quiet mode", the motor also lasts longer both mechanically and electrically.

EDIT: One final note -- Reverse switches should always be "guarded" regardless of the type of drive system.

 

[Odie]

Odie - parameters are just the variables of the drive's control program that you can set. If you have the manual for the drive, it will explain how to program the parameters to your desired settings. For example, most drives have a parameter for deceleration time. It you set that parameter to 7, it means the drive will decelerate from the current RPMs down to 0 RPMs in 7 seconds. Most drives have literally hundreds of other parameters as well.

As for carrier frequency, here is how my Hitachi manual explained it: "The maximum available inverter current output is limited by the carrier frequency and ambient temperature. The carrier frequency is the inverter’s internal power switching frequency, settable from 2kHz to 12kHz. Choosing a higher carrier frequency tends to decrease audible noise, but it also increases the internal heating of the inverter, thus decreasing (derating) the maximum current output capability."

The default of my drive was at 3. I kept bumping it up until I could no longer hear a hum. I think I ended at about 9.

What kind of drive did you use? Maybe I can find the manual online and help you find the parameter for carrier frequency.

Dave......

It's a Minarik controller purchased along with the motor from CSUSA. It came as a prewired and set-up unit. I don't know, but, I am assuming the settings were done there.......?

It does gradually return to 0 rpm when shut down. I read the manual when I made the installation.....don't remember the specifics off hand, though. I do remember warnings about hitting the reverse switch while in forward motion......exactly what I did accidentally! :mad: I'd have to refer back to the manual to know for sure, but I don't believe there is any accommodation in this controller to deal with a reverse switch being engaged while in motion forward......it's definitely a "no-no" in the first place, so I'd understand why it probably isn't engineered specifically for that contingency.

Steve's warning about possible problems with screwing around with the parameters, makes me a little leery about fooling around with it......that is, without spending the effort to sit down with the books and study the matter in detail......which I probably don't have enough desire to do.....yet! The hum isn't really all that bad......been using it for a long time like that, and as I said, I just don't really notice it anymore.

I think I'll just leave well enough alone......and just live with things as they are! After all, things are working well just like they are.......as they say "if it ain't broke, don't fix it." 🙂

Bill......I think this post addresses some of the issues you discuss in your post, as well. One thing for sure, that magnetized reverse switch cover is something that will remain on this controller......forever! Ha!

ooc