Robust VFD Question

[Clay Fails]

Hello all,
I am turning with a Robust American Beauty with the 3 HP motor. It is fitted with a Toshiba VF-S15 VFD.

After turning hundreds of bowls in the past 4 years, recently the drive has begun cutting out under load. I don't mean belt slippage, I mean complete electrical cutout.

Has anyone else had this issue, and if so, what parameter on the VFD did you adjust? I'm guessing it has to do with amp draw, but have not yet dived into the parameter list.

Please don't suggest I contact Robust, because I did and the response was maybe I should learn how to turn. I would have given that some thought had I not already successfully turned a cajillion bowls and this is a new phenomenon.

thanks in advance,

Clay

[Jeffrey J Smith]

Clay - I’ve got the same configuration but, with a lot of use over 6+ years, have experienced no problems so far with the Toshiba VFD. Surprised to hear of the response from Robust, they’ve always bent over backwards to be helpful on the few occasions I’ve asked.
Have you tried letting the VFD reset - power completely off, unplug, cycle all switches, let it sit for 15 minutes before powering up again? Checked your 220 circuit to make sure its not fluctuating?

[allen thunem]

call brent at robust

[Clay Fails]

Jeff, thanks for the response. Yes, I've tried all the re-setting, turning off, etc. Not sure how to check my 220 V circuit though. I have found the issue to be sort of random, but usually occurs when cutting hard wood like say maple burl. I'm using sharp tools and same technique as for all bowls. Once the issue starts, it seems to linger for a period of time. In other words, VFD trips out. I restart, trip out, etc. Then I might for several bowls and days with no issue. Then it's back again.

[Clay Fails]

Allen, thanks for the response. I tried that, and while he was cordial, he was more interested in getting me to take lessons from a mentor than discussing why the VFD is tripping out. I have to believe the 3 HP motor on this lathe can handle way more torque than the VFD is allowing. I have some experience adjusting VFD's on water pump motors, and in my experience it can just be a parameter needs adjusted. I'll figure it out on my own. I was just hoping maybe someone else has had this issue.

[Roger Chandler]

Brent is a stand up guy, and stands behind his product. Are you regularly using extra heavy cuts on your roughouts? I have stalled a 3 hp American Beauty, on more than one occasion, but unless you are really hogging off wood with heavy cuts I wonder about things. Just from an experience standpoint, I have a lot of it, with a number of different lathe units. Maybe you could fill in more details on how you are working on the lathe, so we might have some ideas on how to help you.

[Clay Fails]

Lathe5.jpgLathe2.jpgLathe3.jpgLathe4.jpgLathe5.jpgRoger, thanks for the reply. I have attached images of the maple burl that tripped the VFD today, along with some of the tools I use and my grinding wheels. I have 6 CBN wheels and the Tormek system, and gouges from Thompson, D-Way, Carter, Mahoney, etc. i know how to sharpen a tool so that is not an issue. On this particular maple burl I first mounted the piece between centers and turned a tenon on one side. I roughed the outside at that time, then reversed and put the tenon in a Vicmark 4 jaw chuck. The piece then sat on the lathe for 3 or 4 days until today when i finally had time to work the inside part. That's when the VFD started kicking out. Again, I'm not talking about stalling the motor with a heavy cut or squealing the belts. I'm talking about an electrical cutout, which to my mind, has to be the VFD trying to protect the motor based on overload of some input (e.g. amp draw). Once this failure mode starts, it cuts out on just about every cut. I might turn the lathe off, unplug it, switch the breaker, etc. and maybe it will be good for a day or two. Then BAM, back again. This typically only happens with fairly hard woods, like the burl in the photos, not green wood. I still have to believe the motor is capable of significantly more load than the VFD is allowing to transfer to it. Maybe there's more to this issue, and if so I'm all ears.

[John K Jordan]

Allen, thanks for the response. I tried that, and while he was cordial, he was more interested in getting me to take lessons from a mentor than discussing why the VFD is tripping out. ...

Perhaps a simple way to test the VFD: Take your piece in the chuck to another turner with a known healthy lathe and see if the problem goes away.

JKJ

[david privett]

If you think you are trying to pull to many amps thru the vfd ,do you have or know someone who has a inductive amp meter (they can be had a harbor freight and not pricy ) you will have to make a short extension with just a single layer of wire insulation to go between the plug and the reciepticle . Then just clip on the probe on the hot side and turn away and kinda watch the meter . You will have to test both hot legs. That should tell you exactly what is going on amp wise.

[Clay Fails]

David that is a good idea. I do have a clamp style amp meter but would need to construct a line splitter for 240v ac. I may give that a try. The other way would be to set the vfd to display amps and have someone view the LCD display while I turn.

[Eugene Dixon]

or use a GoPro/cellphone video to record amps?

[Reed Gray]

Um, are you on high speed range or low speed range. I have one of the early Beauties, and it has 3 speed ranges, which I prefer. I use the middle range almost exclusively. Enough torque for heavy roughing and coring, and speed up to 2200 for smaller bowls. Brent helped me tweak the converter, which is a Toshiba. I wanted lower speeds on the low range for sanding. I do get a bit more belt squeal when turning. I am guessing that the belt is getting a bit worn after 10 years.

robo hippy

[David C. Roseman]

Clay - I have no experience with that VFD, but isn't it throwing an error code when it trips under load?

Is this the drive that you have: https://www.toshibadrivesandmotors.c...15s-2022pl-w1/

If so, I'm also assuming you've already downloaded the user manual for it. But here's the direct link:

https://www.toshibadrivesandmotors.com/wp-content/uploads/2017/02/S15-IO-Manual.pdf

See pp. 344-352 in the pdf for troubleshooting of a trip.

Also, this might be helpful: http://www.manualsdir.com/manuals/212570/toshiba-tosvert-vf-s15-series-option-unit-function-e6581830.html?page=31

[Clay Fails]

Reed, mine is the two-pulley setup and I'm on the "low speed/high torque" setup.

[Clay Fails]

David, thanks for the links. Yes that is the drive in question. I hope to find time this weekend to troubleshoot the issue and will report back on my findings.

Thanks again to all for your input.