# Upgrading saw motor to 3hp



## MJ1989 (Aug 23, 2017)

Hey everyone!

This is my first post on woodworking talk and I could use some help with my table saw. 

It is a craftsman 113.***.*** mid 1980's table saw with a 1.75hp 110/220v Motor. My girlfriend and I are building our own house together out in the country and we are cutting a lot of 4/4 red oak for flooring and I want to do shiplap flooring with a dado set. I believe the motor is undersized, and gets a little bogged down with the oak. I currently use a 20 tooth diablo thin kerf blade, and the wood just doesn't move quite as smooth as I would like.

So I bought on craigslist a Doerr 230v 3 HP motor. I'd like some more understanding on how to properly set it up. I believe the standard starter switch on the craftsman won't work. Does anyone know what switch/starter I need to get? Magnetic? Anything under $30?

The saw will be powered from a generator with a 240v plug. Any help is appreciated!!!

Thanks,

Matt


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## woodnthings (Jan 24, 2009)

*Good for you on the house in the country!*

I recommend these switches and have them all over my shop on bandsaws, table saws,and router tables. You don't "need" a magnetic switch if the load is under 20 AMPs like these:
http://www.grizzly.com/products/Pad...151?utm_campaign=zPage&utm_source=grizzly.com


or a mag switch:
http://www.grizzly.com/products/Mag...101?utm_campaign=zPage&utm_source=grizzly.com

Your generator should handle a starting current of around 25 AMPs and run current of around 17 AMPs or so, and those numbers are "estimated". I hope your motor came with a wiring diagram or that's the next post you will be makin'.... :wink2:


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## GeorgeC (Jul 30, 2008)

You are correct on the switch. You will need a switch that is rated for 220/.240 volts.

Can you explain shiplap flooring. From what I have seen called shiplap flooring on the internet it looks nothing like shiplap to me. By definition shiplap implies boards that overlap.

George


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## woodnthings (Jan 24, 2009)

*I have ship lap Cedar siding*



GeorgeC said:


> You are correct on the switch. You will need a switch that is rated for 220/.240 volts.
> 
> Can you explain shiplap flooring. From what I have seen called shiplap flooring on the internet it looks nothing like shiplap to me. By definition shiplap implies boards that overlap.
> 
> George


 this is ship lap:











I have channel rustic siding:


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## GeorgeC (Jul 30, 2008)

Wonder shy they call it shiplap? It does not look like shiplap.

George


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## FrankC (Aug 24, 2012)

GeorgeC said:


> Wonder shy they call it shiplap? It does not look like shiplap.
> 
> George


Looks like traditional shiplap to me, these days designers seem to have another idea of what it is, flat boards, tongue and groove, anything that is nailed butted together on a wall, guess they just like the name.


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## TimPa (Jan 27, 2010)

I would be slightly concerned about doubling the hp on a saw, not designed or built for it. it should go without saying that buying a 3hp saw would be a better way to go. unless the saw came in an (optional) 3hp configuration.


also, as an option, you can keep the switch you have and install an intermediate motor contactor between the switch and the motor. just make sure whatever you buy is rated for the 3hp or the current rating on the motor plate. of course this will likely require an increased amp capacity outlet, and power cord, and plug.


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## woodnthings (Jan 24, 2009)

*Years ago ...*

I replaced the 1 HP Craftsman induction motor that came with my Craftsman 100 table saw from the late '60s with a 2 HP Baldor induction motor :surprise2:

That thing was scary powerful and tore through anything I passed over it. When I parted out the saw for the table, I still kept both motors. I used a double pole double throw switch rated for 20 AMPs on 220V and that worked just fine. Anything rated at 3 HP should have it's own 20 AMP circuit and the proper plug, as Tim said. I don't know if the bearings will sustain any additional "wear" from the bigger motor, but if so, they are easy enough to replace... BTDT.

The real danger, in my opinion would be from kickback! You are not going to stall that motor either intentionally or accidentally. :|

Further, if you don't have a splitter on the saw, kickback is almost a certainty. You don't necessarily need the blade cover/guard, but the splitter plate keeps the work registered against the fence for the duration of the cut. Without it, the work can come away from the fence, rotating up and over top of the spinning and and is "returned to sender" faster than you can say that. :nerd2:

Those are the cautions I would have with this intended plan. Oh, and one other is that the motor mounting plate may not be strong enough for the weight of the 3 HP, but that remains to be seen.....


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## FrankC (Aug 24, 2012)

On many of the contractor style table saws if you install a longer motor, which a 3HP likely is, when the blade is tilted to 45 degrees the back of the motor will be higher than the surface of the table. It can be worked around by altering the mount, just something to think about.


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## Catpower (Jan 11, 2016)

Most 3 hp and larger motors do not have overload protection, you will need to get a motor starter, a contactor with a thermal overload

Check the data plate of the new motor, if it has an overload built in it will say it does, I don't ever recall seeing a 3 hp with it

Youcan get the contactor and proper overload from these folks, always have been the lowest price and great customer service

http://www.factorymation.com/Contactors_Overloads_qs


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## MJ1989 (Aug 23, 2017)

Thank you all for the help and good ideas!!!!


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## Quickstep (Apr 10, 2012)

*Is this a three phase motor?*

One more thought. Do you know if the motor you bought was a single phase or a three phase? If it's a three phase, you're not out of the woods yet...


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## allpurpose (Mar 24, 2016)

A question not asked yet is your saw bent driven or one of the 'motorized' versions? Belt driven is much easier to swap as the motorized is a direct drive saw. 
I have a motorized version so before I decide to swap motors I'll probably just get a new saw before trying to align the entire motor..


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## MJ1989 (Aug 23, 2017)

The motor is single phase. I wired it up today and got it running! I'm using a 30 Amp industrial toggle switch, and a 240v plug on SJOOW 12/3 wire. So far so good. Next steps will be to mount it, put a new pulley on it, and cut some wood! Woodnthings, I will be sure to put the splitter back on before cutting wood. Thanks for the advice. Also, its definitely a belt driven motor. It's a big cast iron saw, and it weighs a lot. My Amish neighbor has an 8HP! gas motor on the same saw...so I'm hoping bumping up to 3 HP will be OK....Though I do believe he made some modifications to the saw to be able to handle such a large motor.

Thank you all for the interest and advice! Now that I've got it running I'll let on that I paid $40 for that motor on craigslist!


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