So, he told me to come get the darn thing out of his garage... Big Ole Arn!
#71
The GS3-23PO has an optional braking resistor, to be used with the braking unit, though I don't know if the braking unit itself is part of the VFD out of the box.  The resistor is sold separately.  https://www.automationdirect.com/adc/Sho...GS-23P0-BR

https://cdn.automationdirect.com/static/.../appxa.pdf  (page 20)

But I don't think regenerative braking will do much for you, especially at low speeds.  There's a lot of friction in that two-belt drive as it is, and most VFD's can provide a small amount of braking without the external resistor, though I haven't researched either of the two under consideration.  I disabled mine, as it was only programmable for time-to-stop, not an acceleration curve, so stopping from high speed would trip it out on overload unless I gave it a long enough stop time, but then stopping from low speed took way too long, as it was working on a time-to-stop profile.  So simply shutting off power and coasting was the best profile for my lathe (on older WEG VFD).

And the point about needing a grub screw is very valid - the last thing you want is a chuck or faceplate coming off.  
Eek
Tom

“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
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#72
Good point on the braking gentlemen. At those slow speed, it wouldn't help really.

Okay, I think I'm down to 2 or 3 options. Now, to determine how I'm going to mount the thing. That should help me decide which model. I'm still not positive if I want to have this in the downstairs climate controlled toolroom, or the upstairs toolroom where it'll be easier to clean and have more space.

I'll do some more thinking and respond again tonight.

Thanks for all the help so far. I can't tell you guys how much I appreciate it. Saving me lots of time and I'm learning quite a bit, too.
" The founding fathers weren't trying to protect citizens' rights to have an interesting hobby." I Learn Each Day 1/18/13

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#73
(05-24-2017, 10:38 AM)TDKPE Wrote: The GS3-23PO has an optional braking resistor, to be used with the braking unit, though I don't know if the braking unit itself is part of the VFD out of the box.  The resistor is sold separately.  https://www.automationdirect.com/adc/Sho...GS-23P0-BR

https://cdn.automationdirect.com/static/.../appxa.pdf  (page 20)

But I don't think regenerative braking will do much for you, especially at low speeds.  There's a lot of friction in that two-belt drive as it is, and most VFD's can provide a small amount of braking without the external resistor, though I haven't researched either of the two under consideration.  I disabled mine, as it was only programmable for time-to-stop, not an acceleration curve, so stopping from high speed would trip it out on overload unless I gave it a long enough stop time, but then stopping from low speed took way too long, as it was working on a time-to-stop profile.  So simply shutting off power and coasting was the best profile for my lathe (on older WEG VFD).

And the point about needing a grub screw is very valid - the last thing you want is a chuck or faceplate coming off.  
Eek

Tom is correct that the GS3 drives under 20HP do not require a Dynamic Braking Unit (it's built in) but you do have to purchase a braking resistor. Believe me, you don't need to worry about dynamic braking. This VFD will provide 15% to 20% braking torque on it's own. Just set it up to coast to a stop and forget about it.
Wink
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#74
While checking out the areas I am considering to place this lathe permanently, I had a thought hit me.

1) How far away from the lathe can I mount the VFD?

2) Can I mount it on a wall a few feet away and use the panel unattached from it (if I get one with a detachable control panel?) ?

3) Does the motor hardwire wire into the vfd, or is there a receptacle that the motor plugs into?

4) Does the vfd get hardwired into my 220v box, or is there a plug that I use for my existing receptacle?

5) IF I make a separate control box, how long can I make the cable between the two?


By the way, I did a small turning on it today, just to say hello to my lathe. Kind of a welcome ceremony. I made a funnel.
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#75
Sadly, my Woodfast is still waiting for me to finish the refurb and getting 220V outlets in the shop. So I can not say for sure.

The VFD was hardwired to the motor and had a plug on the other end of the supply cord (where the VFD plugs into the wall outlet).

I think that there is ~6-8' of cable between the back of the lathe and the VFD on its movable (floor-standing) post.

There will be a trade-off between wire size and maximum length of the cable between the VFD and the motor.

If you buy a VFD with a separate wired remote control, there should be a spec included about wire length and gage. That wire is likely DC rather than AC so things might get finicky quicker with cable length on that wire.
"the most important safety feature on any tool is the one between your ears." - Ken Vick

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#76
(05-24-2017, 09:20 PM)Gregory of Sherwood Forest Wrote: While checking out the areas I am considering to place this lathe permanently, I had a thought hit me.

1) How far away from the lathe can I mount the VFD?  I doubt that it matters, within reason.

2) Can I mount it on a wall a few feet away and use the panel unattached from it (if I get one with a detachable control panel?) ?  That's what I do, but I made my own remote from a Radio Shack project box and some standard bits and pieces.

3) Does the motor hardwire wire into the vfd, or is there a receptacle that the motor plugs into?  Mine is hardwired, but you could use a plug and receptacle if you wanted to I suppose.  I don't see the benefit, though.

4) Does the vfd get hardwired into my 220v box, or is there a plug that I use for my existing receptacle?  Mine has a NEMA 6-20 plug (250V 20A single-phase) so I can plug it into a different receptacle if I move the lathe, which I've done several times, though I doubt it's going to move now.  I even have a 6" duct to the headstock, mostly for sanding on the disc, but it also works pretty well for spindle sanding if I shorten it to suit, which is easy (add/subtract short sections, in lieu of something better that I've never gotten around to).  The original on/off switch now serves as the disconnect to the mains power to the VFD, and the remote does all the start/stop/reverse/speed control, as well as a job button.  

5) IF I make a separate control box, how long can I make the cable between the two?  Mine is something like 8 ft long, and I can move the remote as required.  It just hangs off the tool racks.


By the way, I did a small turning on it today, just to say hello to my lathe. Kind of a welcome ceremony. I made a funnel.
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#77
Your VFD can be located away from the lathe, if you want. Just make sure the wires connecting everything are appropriately large. Input to the VFD, output of the VFD, and control lines will all have different requirements.

Control wires are usually low voltage and much smaller than the power lines. I think mine are around 26 gauge and 10' long or so. In that ballpark at least. The manual for the VFD should give recommendations.

In my opinion, the motor should definitely be hardwired to the VFD. My understanding is you can easily blow the VFD if you make it run without a motor attached. Expensive mistake. Some people play wiring games so they can use a single VFD to power two machines, one at a time, but something must always be connected when you got "run".

The VFD usually gets plugged into an outlet with a standard, appropriately sized plug. You can buy an extension cord and cut one end off to connect to the VFD if you want, add long as the other end is for the correct volts and amps.

I put a disconnect switch between the VFD and wall outlet. I lost a VFD during a thunderstorm, so now I disconnect it when I'm not using the lathe. One more button to hit at the beginning and end of a turning session, but good insurance. VFDs​ are sensitive little things.

Good luck!
Tyler
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#78
[Image: attachment.php?aid=2392]

 I'd lose that loose coat around the lathe.  That pic freaks me out.
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#79
Are any of you familiar with the KB Electronics KBAC-29 AC Controllers? I can get one locally for around $100. It doesn't appear to be as programmable...

https://motorsandcontrol.com/kb-electron...cy-drives/
" The founding fathers weren't trying to protect citizens' rights to have an interesting hobby." I Learn Each Day 1/18/13

www.RUSTHUNTER.com
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#80
(05-26-2017, 10:09 AM)Gregory of Sherwood Forest Wrote: Are any of you familiar with the KB Electronics KBAC-29 AC Controllers? I can get one locally for around $100. It doesn't appear to be as programmable...

https://motorsandcontrol.com/kb-electron...cy-drives/

Greg, didn't notice your last question. KB is known for making high quality DC drives, I like the KBAC because it is extra rugged, and the NEMA 4 style by most makers does come with a better potentiometer that is meant to stand up to use.  I have a couple drives that are similar, though not by KB. The lack of programmability is probably fine, though it would mean it was harder to change accel/deccel times-you have to open it up.

I was surprised to see the flyer mention sensorless vector, as it seemed somewhat incompatible with this style drive; indeed a glance at the manual  reveals it as overblown hype. With some semi-fancy equipment (True RMS ammeter that works on VFD output, most don't) you can adjust slip compensation and torque boost, but they provide no procedure for an auto tune. So IMHO it is really only a V/hz model. Also, to get 3 hp from 1 phase input you need the KBAC-29 (1P) with the extra 1P in parenthesis, the regular KBAC 29 is only good for 2 hp  with a 1 phase input.  OTOH for $100 it is a very nice 2 hp NEMA 4 drive.

The manual does have a nice diagram of how much to lower the torque of a TEFC/ODP motor without a fan at lower speeds, indeed they recommend only ODP with fan (and TENV and Inverter duty) motors for full torque at slow speeds. AFAIK TEFC with fan is ok too if not in constant use.
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