3phase motors

[Lee Alkureishi]

Hi all,

I've seen it mentioned a few times that used 3phase motors can be found for very cheap - approximately $10 per HP is the figure I've seen quoted.

Can anyone point me in the right direction for where to find such deals? I've checked my local craigslist, but haven't had much luck so far. My local electric motor shops haven't been very helpful either. I'm in the Chicago area.

I'm looking to replace the motors on some of my shop tools - 1 to 2 HP for the most part.

Thanks in advance,

Lee

[Gary Max]

My local metal scrap yard sells them.

[Don Sundberg]

Mechanical contractors, millrights, people who deal in / or salvage used machinery. If they are putting in new equipment they may end up with the old stuff to dispose of. I got my 10 hp motor for free from a local millright / crane service that does a lot of work around here. It came on on old grain bucket elevator that they had pulled out of somewhere. Now I did end up putting new bearings and a fan in it so I probably had $50 invested in it when I was done but it was still cheap. They had told me if it did work to come back. I didn't mind replacing the bearings in it.

Don

[Stephen Cherry]

craigslist, auctions, etc. When you least expect it, they will pop.

[Kevin W Johnson]

Machinery salvage is where I've gotten mine. The best deal was a 2 or 3 hp 3ph for $2. It's out on the shelf and I can't remember which it is at the moment.

Why do you need to replace them? As long as they work, the bearings are easy to replace, and there's nothing else in them.

[Rollie Meyers]

Do you have a RPC, Rotary Phase Coverter, or plan to use a VFD to run them, or are you one of the lucky ones who has 3 phase power? If you only have 120/240V single phase a converter will need to be used

[Lee Alkureishi]

Thanks for the pointers - I'll keep my eyes peeled for them.

I have a vfd, and will probably get another. The variable speed capability is a big draw for me.

Thanks again

[Keith Hankins]

As someone who came to the subject a couple years ago, I can give you a couple things to consider. I found great deals on old 3 phase tools and glad i found them heck of a lot cheaper and better tools. Anyway, two ways to go. the individual vfd's or get a RPC (rotary phase converter) and handle all your needs. For me I decided the RPC was right sense I plan on eventually replacing all my cheap imports with 3 phase tools. I bought mine from American Rotary. Great support and they will work with newbie's to explain things. I had it wired up in no time. I bought the 10hp model (that will drive 7.5hp tools). I don't regret it I bought a northfield planer for 1500 bucks made in the 60's and the only thing i did was replace the blades. New the same planer is 15k. As where to find the motors, I'd reccomend a couple places. www.searchtempest.com will search all the surrounding craig lists based on distance to your zip. Great tool I used it to find a 1934 delta 14" bandsaw for 200 bucks. The second is become a member of the Old woodworking tools forum. http://www.owwm.org (http://www.owwm.org/viewforum.php?f=4). They have a classified section and you will se 3 phase motors pop up all the time. Just have to be patient. I bought a 2hp baldor motor for less than a hundred. I see old unisaws and battleship of jointers go for a song.

[Lee Alkureishi]

Hi Keith,

That's a big part of the draw for me too. As to the RPC vs VFD, the ability to have variable speed is important for me, particularly for my lathe and likely for my drill press in the near future. As such, the VFD seems like a better option at the moment.

Thanks again,

Lee

[Mike Heidrick]

VFDs get real expensive for single-phase-in rated models above 3hp IMO. They make them in 5 and 7 and 10hp but they are pricey. Much cheaper to go the RPC route if you have the need for many of those 5hp+ machines.

A Phase Perfect solid state (no motor needed) phase converter sure would be awesome BUT a 30hp model is 6K though!

[Lee Alkureishi]

True, but I have pretty much no need for any motor bigger than 2HP. For that size, a $115 vfd or two works quite nicely...

[Karl Card]

I bought an old Delta/rockwell 12/14 table saw about a year ago. It had the 7.5 hp 3 phase motor on it. I got lucky and found a guy here who had a 7.5 hp single phase motor that I could use. Got it cheap. I thought I could recoup the cost by selling the 3 phase motor. No such luck, after a year I finally got 50 bucks for it. Advertised that crap out of it and no interest shown at all. Maybe larger cities might be different. But I will say one thing even with a single phase motor that 7.5 saw does not bog down at all, even imported brazilian walnut and rosewoods do not even bog that motor.

[Keith Hankins]

Hi Keith,

That's a big part of the draw for me too. As to the RPC vs VFD, the ability to have variable speed is important for me, particularly for my lathe and likely for my drill press in the near future. As such, the VFD seems like a better option at the moment.

Thanks again,

Lee

Yea, if you only want one then the vfd will do it. If you decide later you like the cheaper better tools, you can always add the RPC and sell the vfd. good luck.