# Motor Upgrade Question



## dodgeboy77 (Mar 18, 2009)

I've had a generic Asian floor standing drill press for about 25 years. I like it just fine except for one thing: It only has a 1/3 horsepower motor. This is a problem with bigger Forstner bits in wood and bigger twist bits when I'm drilling steel, as it bogs down. I need Mo' Power!

I could look for a more powerful drill press in the used market but this one has 16 speeds, a new chuck, geared table, new safety switch, etc. and is fine for me, except for the power thing.

I keep an eye on CL for a better 1-phase motor - 3/4 to 1 HP, but haven't found much. I would prefer to stay with 120V. My DP uses a standard mount motor and has a 5/8" shaft and is 1725 RPM.

Here's the question: What other power tools show up used that would have a motor I could use? I was thinking of all those Craftsman/Emerson table saws that are out there, some in bad shape and for cheap. I don't know the RPM on those, though, and suspect they are around 3450, which I couldn't use. I know they are rated at 1.5 HP but being 120V, they are really more like 3/4-1.

Any ideas for hot-rodding my underpowered DP?

Bill


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## Steve Neul (Sep 2, 2011)

Instead of looking for another machine with a similar motor, I would go to mgrainger.com and just get a motor that meets the specifications you need. They have almost any motor in the HP, speed and shaft size you might need.


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## Dave Paine (May 30, 2012)

If you are looking to just replace the motor, also consider Grizzly and Tractor Supply.

Now and again you will see motors on Craig's List.

Lots of tools use 1725 rpm. Sanders, bandsaws.

You could use 3450 rpm if you put a smaller pulley on the motor.


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## woodnthings (Jan 24, 2009)

*Shop the Bay!*

You will probably want a 1725 motor for a drill press. The table saw motors are too fast 3450 RPMs JMO

Like this:
http://www.ebay.com/itm/AO-SMITH-3-...200?pt=LH_DefaultDomain_0&hash=item3cce4f7f58


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## SeniorSitizen (May 2, 2012)

Have you tried slowing the spindle speed down? The reason I ask is often a *** rated motor is on a piece of equipment for a reason and that being the remainder of equipment is rated for that size motor. A half horse is the maximum I would consider in this instance and they are a lot easier to find for sale than the higher HP numbers.


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## dodgeboy77 (Mar 18, 2009)

My slowest spindle speed is 195 RPM (3600 max). The DP has the 1725 RPM motor and that's what would have to go on it if I'd upgrade. Going for a 1/2 HP wouldn't be worth the effort/expense unless I found one for next to nothing.

I realize I can buy a _new _motor for this project but my plan is to keep this on a budget. Otherwise I would just be looking for a good used DP with more oomph. 

I also figured a lot of table saws use the higher RPM motor but sometimes they don't. Woodnthings: I presume that all the motors on your Frankensaw are 3750? If so, I guess most, if not all of the Craftsman/Emerson table saws are?

I had the idea to swap the 1HP motor on my Shop Fox band saw onto the DP, then buy a new, bigger motor for the band saw. The problem is that though the RPM is right, the BS motor mounts on the end and not the side.

Just for jollies I looked at the 3/4HP motor under my C-man Belt/disc sander. It's 3540 RPM.

Bill


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## woodnthings (Jan 24, 2009)

*this is the cheapest I can find*

http://www.grizzly.com/products/Motor-1-HP-Single-Phase-1725-RPM-Open-110V-220V/G2905


Bill, the motors in my saws are all 3450 direct drive. I have a 20" Jet drill press with a 1 1/2HP motor which is so powerful it's scary! I also have an old Craftsman with a 3/4 HP motor which is just fine for all my woodworking. I also have a 1/3 HP mini drill press and that will do a lot of woodworking tasks, but I don't use bits over 1 1/2". 
There are times when extra power is a danger and it's better to have slippage than a spinning workpiece.  

Quite a few more motors here:
http://www.grizzly.com/search/search.aspx?q=motors&cachebuster=1220150023632286

They have had more motors here than this: http://www.harborfreight.com/catalogsearch/result?q=electric+motors


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## cabinetman (Jul 5, 2007)

Keep in mind when changing motors that matching up the motor base might be significant to installing it correctly. My drill presses use 1725 RPM type motors. I would suggest going with the same RPM as the setup on your DP. Stepping down the speed might be possible, but IIRC, the low end torgue of the slower motor seems to work well with drill presses. 



















.


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## dodgeboy77 (Mar 18, 2009)

*Problem Solved!*

Well, I've been keeping my eye on CL and it paid off. Yesterday I picked up a 3/4 HP Baldor motor for $45. It ran and was in nice physical shape. It's 120/240 volt, 1725 RPM with a 5/8" shaft. The guy had it on a power hack saw that he had sold.

I got it on the DP today. Though my old 1/3 HP motor was a 48 frame, the new one is a 56. The only problem that caused was that I have to get a one inch longer rear belt, as the 56 frame has the motor's shaft 1/2" farther from the base than a 48 as the motor's body is wider. The mounting plate on the DP is slotted so the bigger motor fit and both motors have the same 5/8" shaft so the pulley fit (a 48 frame should have a 1/2" shaft but fortunately, this one didn't). Actually, the way the new motor lines up, it looks like the DP was designed for a 56 frame.

The old Rexon motor pulled 7.4 amps and used an 18 gauge cord. The new one pulls 10.8 amps so I replaced all the wiring with new 14 gauge.

Here are before and after pics: 



















I would like to tell you how the thing drives a 3" Forstner bit through a piece of oak, but I can't try it until I get a slightly longer belt tomorrow. 

Bill


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## dodgeboy77 (Mar 18, 2009)

Today I got a belt for the DP and can tell you that it does indeed power a 3" Forstner bit through white oak - and doesn't even slow down! When I first tried it I thought I stalled the motor but it turned out that the belt was slipping. I tightened the belt and it drove that big bit with ease. This is one project to check off the list.

Bill​


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## Dave Paine (May 30, 2012)

dodgeboy77 said:


> Today I got a belt for the DP and can tell you that it does indeed power a 3" Forstner bit through white oak - and doesn't even slow down! When I first tried it I thought I stalled the motor but it turned out that the belt was slipping. I tightened the belt and it drove that big bit with ease. This is one project to check off the list.
> 
> Bill​


Woo hoo, I love to see a happy ending to an upgrade. Nice score on the motor. :clap:


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## cabinetman (Jul 5, 2007)

That was a steal on the motor. Whatever you had to do to get the frame to mount was worth it.








 







.


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## dodgeboy77 (Mar 18, 2009)

<<_Whatever you had to do to get the frame to mount was worth it._>>

Easy-Peasy - the original motor mounting plate on the DP was slotted to take the 56 frame. So there wasn't any fabrication to do. Just get the correct longer belt and bigger wire.

Yes, I thought that was a pretty good deal for a Baldor. I didn't even dicker with the guy. After we wired it up and I saw that it ran, I paid him his $45 and then _I_ ran. :thumbsup:

Bill


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