[SBunch]

My craftsman table saw original motor (1/3 hp @ 3450 RPM) is losing power. Cutting through a 2x4 slows the motor down considerably even with new blades. I was given a 3 hp Baldor motor (1725 rpm). The balder is set up with a 110 electrical plug in so it would be a simple wire in to the switch.
Do I need to change the pully on the motor to achieve the higher RPM that the saw had originally? What mods would you recommend for using this motor or, would I be better off to scrap the idea of using the gifted motor and find another to match the original?

 

[woodnthings]

Replacing a 1/3 HP motor with a 3 HP motor is like going from a Moped to a full blown drag bike. I wouldn't do it. I used a 2 HP Baldor on my old belt drive Craftsman and it turn it into "scary" powerful monster. Those Baldor ratings are actual HP, not some calculated, inflated guess by some book learned engineer. I would go with a 1 HP or 1 1/5 HP at most and you will be safer and will work for 95% of all your cuts. The weight of the 3 HP Baldor may break your motor mount, since they are "fragile" to start with and break often.
Bill

 

[JIMMIEM]

I have a Craftsman 10" Contractor TS 113.298240. I am looking to do a motor replacement. According to the motor label it's a 1HP. Do you think a 2 HP is too big?

 

[TimPa]

good advice from Bill.

OP if your motor has a run capacitor, it may have gone bad. could also be a bad connection, poor wiring, etc. unplug the saw and throroughly inspect the wiring from the plug, all the way into the motor. the switch could have corroded or erroded contacts causing your loss of power. i would try to eliminate a lot of things before replacing the motor.

 

[JCCLARK]

There is no 3 HP saw motor that will run on 110 volt.
somethings wrong there.

A real 3 hp motor would be no problem if it's the same speed.
It will only put out the amount of horsepower that is asked of it,
which for regular sawing is almost never.
Just sitting there running you won't notice a difference, but it has to be the same speed.

 

[JayArr]

I think this is a great idea, I think saws usually have undersized motors to begin with and some extra torque and power can only help. Plus it's a free motor!

I upgraded my band-saw with a new larger motor and pulley. You need to change one or both pulleys so that the blade spins at the right speed. In my case I put a 3450 in place of a 1725 so I doubled the size of the pulley at the band-saw and left the motor pulley alone. In your case you need to double the CIRCUMFERENCE of the pulley on the motor so the saw blade spins fast enough. I bought the new pulley from an industrial bearing supply place and I had to know all the specs to deal with them. You need to have the shaft diameter, whether it's a D or has a pin in it, the diameter of the pulley and the size and shape of the belt that will fit into it. There's a couple of hours of research if this is all new to you.

Beef up the mount for the extra weight like Woodnthings suggests, you don't want a tragedy later on if it breaks. Once you've got the new one mounted with the new pulley then you can measure what size new drive belt you will need. You can google drive belts and find out how the part numbers work.

I think the new pulley was about $50 and the belt another $10 so it shouldn't break the bank.

 

[woodnthings]

My craftsman table saw original motor (1/3 hp @ 3450 RPM) is losing power. Cutting through a 2x4 slows the motor down considerably even with new blades. I was given a 3 hp Baldor motor (1725 rpm). The balder is set up with a 110 electrical plug in so it would be a simple wire in to the switch.
Do I need to change the pully on the motor to achieve the higher RPM that the saw had originally? What mods would you recommend for using this motor or, would I be better off to scrap the idea of using the gifted motor and find another to match the original?

As mentioned it's not 3 HP if if it's wired to 120 volts, can't be, never would be. Only "over rated" Craftdman table saws claimed to be 3 HP, but that was some "hypothetical" rating like their 120 volt shop vacs are for 6.5 HP...IMPOSSIBLE!

Take a photo of the Baldor motor name plate showing the voltage and model and then I might believe it .....

 

[subroc]

1/3hp motor on a table saw? Seems under powered to me anyway. This is the first time I have ever heard of a table saw using 1/3hp. Lots of examples of 1/2hp, 3/4hp, 1hp, 1-1/2hp and even larger. 1/3hp? not so much.

What saw model is it anyway?

I am not an electrician. I surely don't play one on the internet. That said, it is doubtful that a real 3hp motor is being powered by a 110v circuit.

Do you need 3hp or is it just a matter that you have an opportunity to get something for nothing and you want to take advantage of that?

I personally wouldn't power a bench saw with anything over a 1hp or maybe a 1-1/2hp max or a 1-1/2hp or 2hp for a contractor saw. Others may differ, they can do what they want.

 

[JayArr]

You can't really oversize an electric motor, the physics of the motor mean that it'll only do what it's asked to do. a 3HP motor at X RPM just spins a blade. All motors of this type are just trying to maintain their set RPM speed, it's not like it's making the saw blade hit the wood harder than a lower HP motor. The teeth on the blade hit at the same force and speed no matter what HP motor spins them, these factors are determined by the size and weight of the blade and the RPM. The difference is how much force is required to stop that blade.

A good analogy is pulling a wagon with a horse, you can pull an empty wagon with one horse. You can also hook up a team of 8 clydesdales and pull the same empty wagon, the clydesdales don't necessarily mean the wagon will go any faster, you could still go slowly down the road with the clydesdales. If you load the wagon one horse may have trouble pulling it up the hill but the clydesdales won't.

 

[FrankC]

To me the scariest moment on a table saw is when a board stalls the blade, which can happen with an under-powered motor, and you are trying to do two things at once, keeping control of the board and finding the stop switch.
If you go to a larger motor tune up your saw, and use a splitter or riving knife because you will not be able to argue with the saw in any circumstance.

 

[TimPa]

without seeing the op's saw, it is not wise to recommend that he replace the oem motor (assumed to be anyway) with one 9 times more powerful! it was engineered that way. again, without seeing all of the associated particulars. bigger is not always better.

OP how was the saw working for you before it began losing power?

 

[shoot summ]

I don't see a 3HP motor turning the saw into a scary monster. If you "gear" it correctly the blade speed should be the same. You will need to insure it will mount, that the rotation is the same, and that you can power and switch it.

 

[Kudzu]

Only "over rated" Craftdman table saws claimed to be 3 HP, but that was some "hypothetical" rating like their 120 volt shop vacs are for 6.5 HP...IMPOSSIBLE!

If I am not mistaken, those claims are calculated on the start up in rush, the power surge the motor has for a that brief instanat. So yes, it is BS.

 

[woodnthings]

I don't see a 3HP motor turning the saw into a scary monster. If you "gear" it correctly the blade speed should be the same. You will need to insure it will mount, that the rotation is the same, and that you can power and switch it.

Here's why I considered it "scary". I couldn't stall the 2 HP motor like my previous 1 HP. I never had a lickback on the 2 HP, but it would have been substantially greater than the 1 HP which I had experienced a few times. Additionally, I had no splitter on that saw at the time, which made it more prone to kickbacks. It had nothing to do with blade speed, rather the increased torque from that motor. A 3 HP would be even worse, and for a "rookie" it wouldn't be anything I would recommend.

 

[shoot summ]

Here's why I considered it "scary". I couldn't stall the 2 HP motor like my previous 1 HP. I never had a lickback on the 2 HP, but it would have been substantially greater than the 1 HP which I had experienced a few times. Additionally, I had no splitter on that saw at the time, which made it more prone to kickbacks. It had nothing to do with blade speed, rather the increased torque from that motor. A 3 HP would be even worse, and for a "rookie" it wouldn't be anything I would recommend.

Stalling a saw is improper use IMO, not picking on you, I think stall regardless of HP is an operator issue which could be a number of things including improper blade selection. Kickback is absolutely an operator issue.

 

[woodnthings]

Stalling a saw is improper use IMO, not picking on you, I think stall regardless of HP is an operator issue which could be a number of things including improper blade selection. Kickback is absolutely an operator issue.

A saw will "stall" if the kerf closes on the rear of the blade ... no fault of the operator what so ever. I've had it happen numerous times and it's just the nature of some hardwoods. Using a saw without a splitter is not advised for that reason. No matter the blade thickness either, in my experience. Actually, "stalling" is the best out come rather than "propulsion", back at you.

 

[JCCLARK]

To properly rate a saw's HP you have to go by the amp draw as stated on the motor plate.
that's the only true motor rating.
A true amp rating is about 10 to 11 amps per each horsepower.
A true 3HP will draw over 30 amps total.

See chart

AMP DRAW BASED ON HORSEPOWER - LoadHook.com

www.loadhook.com

 

[JCCLARK]

A 1 hp saw can kick back a board just as fast as a 3 hp saw.
(ask me how I know)
Sometimes the smaller ones can be even worse because some lower powered saws
actually run the blade a little faster at 4000 RPM's.
My 3HP saw is a little slower than that.

 

[_Ogre]

View attachment 424421

You realize that is a 3 phase motor

 

[_Ogre]

Interesting... A new guy posts up a question for a 1/3hp table saw... and no one bothers to ask for more details
Yes, you may have, I couldn't read much more without having a heart attack from laughing
Stop and think about it