What Type of Motor Will Work for my Homemade Power Carving Sharpener

[Donna Cunning]

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A homemade sharpening system that I think would work just fine if I could just find the right motor to power it. I have two rows--the top row includes a paper sharpening wheel, a leather strop at this point to be used for the larger carving tools and my knives.
The lower wheel is for my smaller carving tools and includes a 3.75" hard maple wheel with multiple shapes, a leather strop and an angled sanding wheel for sharpening v-tools.

My issue is that I have tried to use an induction motor--a delta 6" variable speed grinding motor. Even on high speed it doesn't have enough gumption to get it going.

I would like to avoid spending huge money, thus the homemade system. I would like to be able to vary the speed (I do have different size pulleys on each level) so I don't completely ruin my small/micro tools so here I am looking for help and suggestions.
Thanks very much. Oh, I forgot to mention that I'm lazy and really don't want to hand sharpen.

[Dennis Ford]

On the low cost end; a washing machine motor would do the job (they usually have a couple of speeds and put out good torque). It is not difficult to salvage one from an old washer. Another (and better looking) choice would be a 1/2 hp motor similar to this one (220v): http://www.surpluscenter.com/Electri...OR-10-2826.axd
or this (120v): http://www.surpluscenter.com/Electri...64-10-2647.axd

[Charles Lent]

Go to a local HVAC dealer and ask if they can help you. They frequently pull HVAC air handlers with 120 volt motors of the 1/2 - 1 hp size out of air handlers that are headed to the scrap yard. If they don't have what you need sitting on their shelf they can likely save one for you and have it available within a week. Another possibility is a metal salvage yard. The one near me usually has an open topped dumpster full of motors that are mostly in good running condition, but some aren't. Pick one of the size that you want. If it appears to be in good condition, doesn't smell burnt, and the shaft turns freely it is very likely a good motor. Your cost will likely be whatever they are charging for scrap steel by the pound times the weight of the motor. A 3/4 hp motor will probably cost you less than $5. It's a slight gamble, because you likely won't be able to test it before buying, but the chances of a bad one that passes the other tests above will be extremely slim.

Charley

[Dick Strauss]

To add to Charles' post...HVAC motors often have taps (electrical connections) for three speeds as well.

Where are you located? A local member of SMC might have a motor they would just give you to help you (I know I have a few laying around)

[Fitzhugh Freeman]

I have a NOS Maytag AC washing machine motor that may work, 1/2 HP 120V 60Hz 7.4 Amps 1725 RPM Model S67PXHEH-7631 Part Number "6 2016640-14" (save you typing from the photo). I've never used it but it was new in the box when I got it. I don't believe it is as simple to set up as some motors and very likely is not appropriate. I'd say more about the wiring/starting issues with this kind of motor but I probably would get the details wrong... starting coil vs. running coil, centrifugal switches, etc. I know they reverse but not sure about handling different speeds. In any case, it is heavy, open/exposed to grinding swarf, and about 6.5 inches square except for the shaft, which protrudes another 2.5 inches or so. If local or willing to pay shipping you can have it on the off chance you do want it.

I'm presently converting my older shopsmith to a salvaged DC treadmill motor and speed controller. Rated 2HP, haven't tried running the tool with it but it seems like it will do fine compared to the older 3/4 HP motor, and at least I'll have reverse.

I got the motor and controller from someone who pulled them and sells them but now that I've learned more I think it is often pretty trivial. Turns out many of them use the controller I now have, M60 or M-60. It gives you a rotory pot to control speed. I'll add a reverse switch later. The shaft diameter is 17mm / .67" which is common in auto alternators and pulleys are easy to find. It only has a short threaded end, no keyway, so I ground and filed a flat area and drilled and tapped the hub of the pulley for a set screw.

So, treadmill is one source, used ones show up free on craigslist pretty often around here (bay area). It is hit or miss whether you get one with a controller that is easy to adapt or one that is more computerized.

Others will know a whole lot more about this, plus there is a lot of infomation online on the topic. I do think it would work since people use them to power various tools. Maybe grinders take more than I realized though.

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