Changing motor size on TS (22124)

[hermit]

Just for curiosity sake, do you think it would be possible to change the 1 3/4 hp motor on a table saw, say the Craftsman 22124 since thats what I have, to maybe a 3 hp? I'm not looking to do it, but since the saw is built like a regular cab saw anyway, I was wondering if say 10 years down the road, the motor blows, it might be something to consider if I wanted more oomph, without the cost of a new saw. Just wondering.

Todd

[mpc]

Can't say much about the mechanical bits of the saw since I don't know the guts of that model. A few things to consider though:
* startup torque - bigger motor is likely to "spin up" quicker, twisting the whole saw body a bit more. Is it strong enough to resist that?
* Any "fuse" parts - sometimes a sacrificial part is included that's designed to break/shear if the blade jams. It could be a simple little roll pin (those skinny metal tubes you drive through a metal shaft to lock it to some other part) or it could be a shaft with a machined skinny section in it. If you install a larger motor, the fuse assembly might "trigger" prematurely - either from startup torque or when you're making a cut in some hardwood that might've been too much for the factory motor but is now "okay" for the new motor.

Things that most likely would NOT be okay with the new motor:
* Wiring.
* Power switch.
More horsepower in the motor means more current draw and/or running on 220 volts instead of 120. Either way, the wiring and switch probably will need to be upgraded to match the new motor.

mpc

[LCHIEN]

Can't say much about the mechanical bits of the saw since I don't know the guts of that model. A few things to consider though:
* startup torque - bigger motor is likely to "spin up" quicker, twisting the whole saw body a bit more. Is it strong enough to resist that?
* Any "fuse" parts - sometimes a sacrificial part is included that's designed to break/shear if the blade jams. It could be a simple little roll pin (those skinny metal tubes you drive through a metal shaft to lock it to some other part) or it could be a shaft with a machined skinny section in it. If you install a larger motor, the fuse assembly might "trigger" prematurely - either from startup torque or when you're making a cut in some hardwood that might've been too much for the factory motor but is now "okay" for the new motor.

Things that most likely would NOT be okay with the new motor:
* Wiring.
* Power switch.
More horsepower in the motor means more current draw and/or running on 220 volts instead of 120. Either way, the wiring and switch probably will need to be upgraded to match the new motor.

mpc

That's a good analysis.

I'm generally a believer in theskills of engineers. I would imagine the saw is designed as a system with component strengths based around the power used by the original motor.
replacing it with one of a larger size will compromise many of the design decisions made by the engineer. Not to say it won't work but you risk problems.

do you have a Tim Taylor (Tool Time) complex?

[Knottscott]

...but since the saw is built like a regular cab saw anyway, I was wondering ... Todd

Todd - The 22124 has cabinet mounted trunnions, but other than that, it's not really built like a regular cabinet saw. The front and rear trunnions of a full size cabinet saw like a Uni or PM66 are connected by a huge cast iron arm. On the 22124 they're connected by beefed up connecting rods, more similar to those used on a traditional contractor saw.

That said, Steel City does offer a hybrid with a similar design to the 22124's that uses a 3hp motor (35606) ....I've heard rumor that it's beefed up to accommodate the larger motor. Their 35601 uses a 1-3/4hp motor and uses the same trunnions. Just thinking out loud here...but maybe, just maybe the trunnions on all three models have enough strength to handle the 3hp motor, but there's no way I can be sure and am not suggesting that they are....just wondering myself.

trunnions for a Griz 1023 3hp cabinet saw (similar to a Unisaw, PM66, General 650, Steel City 35612, etc.):


A top view of the 22124 trunnions, which are a similar concept, although allegedly not as beefed up:


Steel City 35606 3hp "hybrid" trunnions:


Are you using good quality thin kerf blades? Blade selection and good alignment can make a huge difference in the "oomph" you perceive. I've seen the 22124 cut 3" hard maple at a relatively good clip, and have heard others mention similar performance.

[cgallery]

Wouldn't the frame size be different anyhow? It certainly wouldn't be plug and play, I wouldn't think. And it is a single-belt drive. I would wonder if a single belt could transmit that much power?

[ExYankee]

I have been looking into motors and belts and sheaves for my Makita 16” BS and I have a Grainger catalog that has great ref info on power transmission. Seems that its more than just the raw HP of the motor, pulley (sheave) pitch dia. comes into play as does belt size and number of belts.
Here the specs I found.

Sears 1.75hp 120/240v 15/7.5 amp. (7.5 amps @240v)
Steel City 3HP 230v 12 amp (11.5 amps@240v)
Grizzly 3HP 220v 18 amp (16.5 amps @240v)

I think the pictures Dustmight posted tell a lot. If you look at the pics of the Sears and the Steel City it’s a fair guess to say they come out of the same factory.

So assuming that Steel City is not having problems with their 50% stronger motor, you could drop an 11.5 amp motor in, assuming you have 220V.

But more revealing is the Grizzly power train. They used THREE belts which given the pulley dia and HP is called for. They might get by with 2, but I’m impressed they didn’t
I see that they offer the same chassis with a 5HP and both show three belts.

I think the pulley set up really is the limiting factor in the Sear/Steel City design. Bigger power needs more belts and/or bigger dia pulleys.

When I pulled up the Steel City manual I expected them to be from Pittsburg, but I smiled when I saw Murfreesboro Tn , that’s 10 miles down the road from me, and Powermatic is a mile away, maybe I will take a tour and see how the tools look in person.

[hermit]

Thanks for all the info guys. It seemed to me that the motor wasn't saw specific like the BT or Dewalt, and could be easily interchanged. Its obvious to leave well enough alone. The saw cuts everything I need it to. I am not displeased at all.

And Loring, I guess I do have some sort of Tim Tayor thing going, cause I recently screwed around with my DC. BTW, I had to remove the blower assembly again yesterday, because the impeller slipped and was rubbing. I never had a problem until I dismantled it to try the bigger motor. I really need to learn to leave well enough alone!!

thanks again,
Todd

[LCHIEN]

Thanks for all the info guys. It seemed to me that the motor wasn't saw specific like the BT or Dewalt, and could be easily interchanged. Its obvious to leave well enough alone. The saw cuts everything I need it to. I am not displeased at all.

And Loring, I guess I do have some sort of Tim Tayor thing going, cause I recently screwed around with my DC. BTW, I had to remove the blower assembly again yesterday, because the impeller slipped and was rubbing. I never had a problem until I dismantled it to try the bigger motor. I really need to learn to leave well enough alone!!

thanks again,
Todd

In a DC, the HP is dictated by the impellor. Changing the motor to one ten times bigger won't put a bit more power or CFMs into it than it already has with the original motor.

[Knottscott]

Thanks for all the info guys. It seemed to me that the motor wasn't saw specific like the BT or Dewalt, and could be easily interchanged....
thanks again,
Todd

The 22124's motor is on a standard NEMA 56 frame, so if the need should ever arise, it shouldn't be hard to find a replacement to fit.

[Jeffrey Schronce]

I don't see how anyone can argue that the Steel City 3HP unit has "beefed up" trunnions compared to the 1.75 SC or 22124. Those photos look identical.

[gsmittle]

. . . I guess I do have some sort of Tim Tayor thing going . . .

Nah, not until you blow something up!

g.