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Thread: Buying from auctions and 3 phase power

  1. #1
    Join Date
    Jan 2016
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    Seattle, WA
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    Buying from auctions and 3 phase power

    Well, I've jumped into the exciting world of buying tools at auction. I recently won a 3ph '220v/440v' Wilton 20 inch disc sander from a place ~10 miles from my house. Pickup is tomorrow.

    Given the price I paid for this thing, I have some leeway to get it running. Obviously I'd like to do this as inexpensively as possible, but I also want a quality tool. Given that, I have a few questions for those who have done this before.

    First, I'm assuming that when I go to pick it up tomorrow with my Tacoma Tacoma pickup they'll help me load it, atleast with a forklift. It looks like total weight on this thing is roughly 500lbs. Am I wrong? I'll bring a dolly with me, but I can't bring an engine hoist.

    Second, when I get it home I'm going to go over it and look for damage. None was listed, but I understand the risk of an online-only auction. I'd like to test the existing motor before I commit to a VFD (in case I just need to buy a new motor I'll go single phase). Is there any way I can power this 3 phase 3 hp motor, even if temporarily, to make sure the bearings are ok?

    Third, which type of VFD should I get for this thing? It was listed as a 220/440v 3 phase motor. I only see a 220v option or 440v option when I search for a new Wilton, so I'm hoping I got the 220v model. I'm a home shop so I won't put very heavy use on this thing.

  2. #2
    Join Date
    Jun 2014
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    Western PA
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    Hey Ben,

    I have a couple three phase tools on VFDs. It is to the point that i kinda wish i had gone with a RPC at the start. If you think this is the first of many three phase tools, then i might advise you to think about the future. For example, some tools are just not suited to being converted via a VFD. A planer will typically have a feed motor, a cutterhead motor, and sometimes a motor to power the rise/fall of the table. However, if this sander is it, then a single purpose VFD is really cheap and straight forward.

    I hate to say it, but you really should clarify if the pickup has a forklift. Most of the auctions ive purchased from had a forklift, but a lot of the time the forklift is on the docket, so if the guy shows up early to get it, then there isnt a forklift anymore. Theres a good chance you will be good to go tomorrow, but if there isnt a lift, then you are SOL. Best to call next time if it isnt abundantly clear in the pick up instructions.

    Good luck, hope it works out well. Also hope you arent near me!! Once I get a new space and more power, im going to be a whirlwind with machine acquisitions. there was just a martin t-17 that sold at auction for $550, that i would have picked up in a heartbeat if i had the room. If you pay attention and are patient, several deals present themselves each year that are too good to pass on.

  3. #3
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    That t17 had no original parts.

  4. #4
    Join Date
    Jan 2016
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    Patrick, I'm in Seattle so I don't think we're overlapping.

    I guess I'm learning as I go here. I'll call next time. The good news is that I'm forced to go pick it up within the first 30 minutes of opening due to my work schedule. Hopefully the forklift is there or somebody else is still in a good mood. So far this experience has been smooth (bidding, paying, communicating).

    I suspect this is one of the few 3 phase tools that I'll buy (others being jointer / bandsaw). None of them are going to sit near each other as well. I'd like to get a VFD with a brake as I've seen the disc sanders can spin for 5 minutes due to the momentum of their wheels. That worries me from a safety standpoint.

  5. #5
    Join Date
    Dec 2005
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    West Lafayette, IN
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    If that Wilton is like my State youíll want to keep the motor, not an easy motor swap I donít think. Thereís a 99% chance the motor will work just fine. 3 phase motors are pretty bombproof. Taking the end bell off and removing dust buildup is a good idea. Spinning the disc by hand should give you some idea of the state of the bearings. I replaced mine just because Iíd rather do it when I had it apart and I know they are good to go.

    I generally use Factorymation Teco FM50 VFDs. Not the cheapest but still inexpensive and they come with real human support if need be. Order the VFD based on the motor size. If itís 3hp or under no derating is necessary, so a 1/2hp motor gets a 1/2hp vfd. Your Wilton is likely 1hp or under.

    I use a 1hp VFD for both my pedestal grinder and disc sander and spindle sander. I use the same mushroom on/off switch and change the motor plug depending on what machine.

    I have 7 machines on vfdís, so far.

    Lifting point on my State was to sling around the motor, and mine weighs around 450 I think. I took it partially apart to transport since I would need to do so to get it into my basement anyway. So bring some tools with you to do so in case you have to resort to it. And donít transport it standing up as itís top heavy.

  6. #6
    Join Date
    May 2008
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    MA
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    Buy a winch. Some stout planks. The combo will drag a lot of stuff into the back of a PU

    I have a static phase converter I used on a 10hp 3ph belt sander for years. The purists dont like them, but they are cheap (used) and will let you run your machine.

  7. #7
    You can get some great old machinery cheap which run on three phase. Myself I got a rotary phase converter. The one unit will run all my three phase machinery.

  8. #8
    Join Date
    Nov 2009
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    Monster starting load on that sander. Worked on one in Caterpillar's Model Shop. It was a rare situation where you ran it all the way up to full speed. 75% of the time we'd run it up to around 3/4 speed, shut it off, sand the parts, and it would still be running when we walked away. I'd swear it takes 5 minutes to come to a stop. In the pattern makers shop, they turned them on in the morning and shut them off before going home. Especially the 36" sanders. Took too long to wind up. I never timed a full start up, but had to be around 20-30 seconds. That's a lot of load for a VFD.

  9. #9
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    A disk sander can be used as an extra idler motor to add more hp to a rpc setup. To brake that sander you will need a vfd that actually has braking terminals. Many smaller China ones do not or they have the terminals which are not actually connected on the circuit board electrically to anything. My Huang Yang 3hp vfd has the terminals visible and mentioned in the manual. But a careful inspection shows there is no circuit trace to the terminals.
    Most home shop guys would do nothing with the braking circuit antway or maybe install a heating coil for a braking resister and think it is doing some good. "it works so well it doesn't even get warm."
    Electric. stove heating elements are often used as a resistance dump load.
    Bill D.

  10. #10
    Iíd definitely bring some tools along just in case you need to take it apart. Hopefully someone will be around to help load. Thereís a good chance it could be tipped into the bed of your truck but Iíve never loaded a big disc sander so Iím not 100% sure on that.

    Iím pretty sure itís possible to test a three phase by connecting two leads from a 220v power source and wrapping a cord around the pulley and giving it a pull to get the rotation going. Iíve never tried this but have read about it being done. Iíd probably just pull the trigger on the VFD and test with it.

    Youíll want to take a look at the motor plate to confirm it can be changed to 220v. If the motor is 440v only then it can still be done but requires a transformer. Again, never done it, just read about it.

    One thing Iíve actually done is Iíve put a TECO FM50 on my 3ph bandsaw. It works great and has a brake feature but my bandsaw has a foot brake so I programmed it to coast. You may need to add a brake resistor given the mass of the 20Ē wheel. I love the soft start and my saw builds up to full speed over a few seconds. YouTube has some great how-to videos.

  11. #11
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    Read the rules very carefully... Many machinery auctions do not allow buyers to load out anything. They have to pay a bonded rigger to forklift it to your vehicle. This can be a scam of only one rigger allowed so they can jack up prices and pay a kickback to the auction house. I would expect around $500 to load out your machine. They might charge $50 dollars to wheel it out on a handtruck or under their arms.
    Bil lD.

  12. #12
    Join Date
    Jan 2016
    Location
    Seattle, WA
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    Lots of good info.

    I read the rules carefully and there’s nothing about hiring a rigging company. I’ll watch out for that in the future.

    This is a 3hp 20inch model. It’s literally identical to the Powermatic 20 inch disc sander (clearly was made in the same factory). After some research, it’s a 220v/440v motor, you just have to wire it differently.

    Forgive my ignorance on the brake controller wiring - the extra terminals on the VFD would go to a massive resistor, nothing to do with the motor wiring, right?

    I saw that the Huan Yang VFD’s (which seem low priced) want you to contact them if you’ll be using a brake resistor and they special make them. Any advice on other low price VFD’s to go with?
    Last edited by Ben Grefe; 11-13-2019 at 12:10 AM.

  13. #13
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    Yes, On the Huan Yang I am familiar with you attach a big resistor to the braking terminals only. No other wiring needed. But that wiring has to be safe and not touchable. I would mount it inside the machines steel base out of the way. It needs some airflow to allow cooling. Mine is mounted inside my lathes hollow plinth
    Bill D

  14. #14
    I encountered a situation like this buying a 3 phase 16" 1,100lb powermatic planer via auction. Had to rent a giant lift gate penske truck. I did pick up a jointer on the same trip.

    Regarding the motor. I had 5hp 3phase I successfully wired with a hyunwang (spelling) VFD from amazon. It was a pain but it worked....temporarily. I was using the dryer outlet as my plug and the breaker as my on/off. Not ideal but it worked until one day the VFD popped.

    If you're going with a VFD go with a brand with tech support. I ended up swapping in a 5hp single phase a new magnetic starter which equaled what I paid for the planer. I sold the 5hp 3ph motor for $50.

    Finding a motor shouldnt be a problem if you match frame mount. A 3hp vfd will be $200-$300 for a good brand. They don't like being unplugged and be sure to wire a switch to turn on the VFD and not us plugging/unplugging it to turn it on.

  15. #15
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    A big rotating mass like that will generate back EMF for a long time as it coasts down. This back EMF can fry a VFD's power buss by backfeeding. So it is probably a good idea to have resistor to soak that up before it damages the VFD after many runs.
    Bil lD.

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