5 HP vs 3 HP Cabinet Saw - Which to Buy

[Scott Myers]

I've been in cabinet saw buying mode for a bit over a month now and have it finally down to the PM2000. The real question comes down to 3 HP vs 5 HP. I'm just a weekend warrior, doing built ins in my house, furniture projects, etc. Before, I used my old benchtop saw and used a friend's saw when I had big heavy work to do.

Some people, probably the majority, tell me that 3 HP is plenty. But there are some that say no, get the 5 HP. It's best for dado cuts, ripping thick hardwood without burns, etc. I don't want to buy a 5 HP just to satisfy my inner Tim Taylor syndrom.

So how about some other's opinions on the subject. I'm certain that this is going to be a ride of opinions.

[Doug Shepard]

I've never come close to bogging my 3HP PM66 down with either a full dado stack or ripping 8/4 hardwood (w/ no burning). But if you want the Binford 2000 model, go fer the 5 horsies:-)

[Mac Cambra]

I will tell you that being a person that owned a 3HP Unisaw and now owns a 5HP Sawstop the difference in power has not produced anything that I would consider noticeable.

I tend to agree with all of those folks that say 3HP is plenty. I bought the 5HP basically because I had the same questions as you, throw in the fact that I was spending so much on the saw what a couple hundred extra bucks, why not get the extra power. Hindsight tells me I should have saved the money and spent it on something else. Don't get me wrong, I love the saw as is but I think I would have loved the 3HP just as much.

[Karl Brogger]

5hp. Because there are times when it still doesn't have enough power. There is nothing to be gained with less power. To be honest I think the higher hp saws are safer too. Your less likely to get something to bind on the blade and actually catch. When something does come whipping out the difference in speed won't be enough to notice the difference in pain.


If its the couple hundred dollar difference that is affecting the decision you need to re-evaluate your purchase.

[Michael Lutz]

When I was looking at cabinet saws, I went with the 5 HP over the 3 HP. I didn't want to second guess my decision. In my case it was only $100 more for the 5 hp. I have the PM66 5 HP.

Mike

[Joe Mioux]

What would hurt more; kickback from a 5hp motor or a 3hp motor? ;)

Seriously, I have a 3hp and it is more than sufficient. My old contractor saw was 2hp and I cut some 3x's old hard Oak with it and I never had problem.

Patience with the feed rate helps...... as does a properly squared up blade/fence combination, and a good blade.

Joe

[Jamie Buxton]

Buy the 3 hp saw plus a router. The router will make a bigger change in your shop capabilities than the extra two hp. If you already have a good router, fill in your own choice of tool. The result stays the same.

[Karl Brogger]

What would hurt more; kickback from a 5hp motor or a 3hp motor? ;)


If you can tell the difference you're better than me.:D


I have a screwy way of using a tablesaw. I run material through it as fast as possible. This is especially true when cutting solid stock, as the cut is not a final product, it will always get planed, or jointed.

[Von Bickley]

Buy the 3 hp saw plus a router. The router will make a bigger change in your shop capabilities than the extra two hp. If you already have a good router, fill in your own choice of tool. The result stays the same.


I agree with Jamie....:)

[Peter Quinn]

If you were a pro running that saw hours each day every day often with the blade above two inches high, lots of 8/4 production runs, I'd say get the 5HP no brainer. Nice to have the over head. Worth the few extra bucks over a lifetime. Even if you thought you might wind up on a long job like that I'd say get it, and by long I mean years. But in your home shop? Even a devoted serious part timer isn't going to tax a 3HP powermatic cabinet saw.

I work in a cabinet shop with three 5HP three phase PM66's in use. In my own shop I have a 3HP 66. No difference. Zilch. Nada. Its like, do you want too much power, or WAY too much power at your disposal. My 3HP? No burning, no bogging, spins a dado like a champ. You are only spinning an 1/8" kerf 10" blade, this does not require 5HP and rarely requires 3HP. If you were asking about shapers, I'd say yes, that extra two HP will make a big difference when you spin bigger cutters, but on a TS you never spin bigger cutters than a 3HP motor can handle, even a molding head will be fine.

One real issue in favor of the 3HP is power. My electric company never seems to lower rates but often raises them. Why would you want a bigger wire,, a bigger breaker and a larger amperage draw JUST CAUSE? Every time you push that green button you will be using more power than you need. Given that you do this part time or on an occasional basis this may be of little concern to you, or it may not.

So in conclusion, it does not matter. 5HP if you want, 3HP if you like. I doubt you will be able to tell the difference without looking at the motor plate.

[Jack Camillo]

I had the same question once, and went with 3hp. Wish I did the 5hp. Like someone above said, "what's to be gained by going with the 3hp?" On most saws that offer both, the price is the same or very close.

[Gary Curtis]

For the extra $100 I got my General 350 with the 5hp Baldor motor. Like others here, I haven't run into a situation which 'demanded' the extra power.

But on one piece of 3/4 ply, I managed to stall the blade by twisting the wood. I anticipate sawing an amount of wet wood since I live in a forest.

On the whole, it is slight overkill. By the way, if you were to buy that Baldor motor outright, it would cost close to $500.

Gary Curtis
Northern California

[Dave Lehnert]

I used a 1 1/8hp Shopsmith for years and never had a power issue. I now have a 3hp Jet saw and it is way more power than I would ever need.
For home use you will never wish for the 5hp. My saw never ever has bogged down. If it does, you need to get your blade sharpened.

[Tom Veatch]

...So how about some other's opinions on the subject...

OK, here's my opinion:

An electric motor only develops enough horsepower to maintain it's speed near it's rated RPM. The only time you will ever use any of the extra 2HP will be if whatever you're doing will bog down a 3HP motor.

I've never bogged down my 3HP saw so I would have never used any of the "reserve" power, even if I had it.

Another thing to consider is that it will probably cost a little more to run the 5HP over the 3HP even doing the exact same operations.

Sample Data for a typical 5HP motor:
Efficiency (%):
82.5 (Full Load) 81.3 (75% Load) 77.4 (50% Load) 65 (25% Load)

And for a typical 3HP motor:
Efficiency (%):
82.4 (Full Load) 81.3 (75% Load) 77.4 (50% Load) 64 (25% Load)

Now compare the two motors, but remember that doing a particular task, the 5HP motor may be operating at 50% while the 3HP will be at about 83%. Compare the efficiencies with both motors developing the same HP-lightly loaded 5HP, more heavily loaded 3HP. I expect that you'll find that for every task that requires 3HP or less, the 5HP motor will be operating at a lower efficiency and cost more to operate than the 3HP. Not enough to make a big difference in the electric bill, but it will cost a little more.

Don't forget that in the care and feeding of the 5HP machine, you'll have to size for the maximum amperage draw of the motor. So you're looking at a 240v/30a/10ga circuit while a 240v/20a/12ga circuit would be quite sufficient for the 3HP. So, unless you already have the 30a circuit available, you've got more upfront costs than just the purchase price.

It's a rare hobbyist woodworker that will consistently work a 3HP saw to it's limits and need 5HP. I'd have a different opinion if you were talking about equipping a high volume, high production cabinet shop.

Now with all that said, it's time to state my recommendations. I recommend that you say, "To Blazes with all these opinions!" and go out and buy the one you want!;)

[Neal Clayton]

i have bogged down my 5hp pm66 once. i was trying to rip an old growth 2x6 roughly 10 feet long that had a slight, almost imperceptible cup, and it also had a huge sap pocket in it that i couldn't see beforehand. it was a helluva board, there were about 55 rings per inch in the end of it, so the blade was struggling with it regardless of its imperfections. the stickiness of the sap coupled with a slight bind on the blade stopped it, luckily the board didn't fly off, only reason it didn't was i had some featherboards on the table to try and hold the board, it was too heavy for me to feed completely by hand without any assistance.

that said, i agree with the other statements that there's nothing to be gained from less power, and much less stress on the motor if you have power to spare.

[Cary Falk]

I have 3 hp in my Uni and don't wish for more. If the price was close between 3 and 5, I might make the jump.

[Alan DuBoff]

What would hurt more; kickback from a 5hp motor or a 3hp motor? ;)
Although this not the best way to select a saw, I wanted to point out to you that both spin the same speed, so in theory they will both kickback very similar.

The HP is what determines the torque, and the effect is the ability to withstand resistance. It seems to reason that the speed of the blade will have more effect on kickback than the torque, but that might be a question for someone qualified.

I've seen 2HP saws kickback stock through a wall, so what's the difference? But again, seems like a silly way to select a saw, based on accident potential... ;)

Why don't you try it and report back? :rolleyes:

[Tom Veatch]

... It seems to reason that the speed of the blade will have more effect on kickback than the torque...

The speed the blade is turning determines the speed at which the kickback projectile will depart the blade. Assuming that the overall gearing ratio is the same and that both motors are turning the same RPM, then the blade speed will be the same in both cases.

The only time the 5HP would kickback harder/faster than the 3HP would be if, at the point of kickback, the cut was requiring the motor develop more than 3HP. In that case, the 3HP motor would be turning slower, AKA bogging down, while the 5HP would still be turning at or near it's rated RPM.

[John Thompson]

I recently sold a 3 HP to up-grade to a 5 HP. Do I notice a difference in my electricity bill? Not really. Do I notice a difference in ripping 8/4 and under stock? Not really. Did I notice a difference in ripping 2000 linear feet of pecan (hickory) as I did about 6 weeks ago with 12/4 or 3" in 10'-12' lenghs? Yes indeed as I was able to feed faster without a burp compared to when I ripped 4000 linear feet for the same customer that hired me a year ago when I still had the 3 HP TS.

If the OP which stated he just does this on week-ends is using 2" and under (more likely 1" to 1 1/2") stock as he most likely will.. 3 HP is all he will probably ever need. If he has intentions of doing it every day with any thick stock which I doubt.. he should get the 5 HP as I see it.

It would be rare to see a 3 HP in a large commercial concern especially if a power feeder is used where the TS is used all day long. There's a reason but it would not effect most of us to the point we had the need for over 3 HP IMO.

Sarge..

[Eric Larsen]

Just FIVE horsepower?

I have my saw attached to a Lamborghini Reventon engine. 650 hp, and 650 ft/lb of torque. I can rip 8/4 ipe at 200 feet per minute.

Well, actually, no.

I have a 3-phase, 5 hp motor attached to a phase converter that gives me a useable 3hp. I've run hundreds of board feet of lumber through my 3hp equivalent and have never wished for more power.

However, I do agree with all the people who say, "you'll never wish your saw had less power." So get what your budget dictates.



So how about some other's opinions on the subject. I'm certain that this is going to be a ride of opinions.

[Rick Fisher]

I have a 5hp cabinet saw. I have never owned a 3hp. I wanted the 5hp because I planned on ripping 6x6 fir, flipping it over and ripping it again.

The blade is entirely buried in the wood. The saw has zero problem cutting that way, but I dont know if its really working that hard? I dont push really hard, it could be that a 3hp would work just as well..

One nice thing about a 5hp is that it doesnt ever seem to slow down under normal conditions. Again, I dont know if a 3hp would either.

[Andy Casiello]

Regarding kickback potential, I agree that the force will be based on the speed of the blade (which will either be at standard operating speed, or something less based on resistance the motor is facing at the time).

In most cases of kickback is the motor being bogged or not? My guess is not. Therefore kickback potential would be equal.

Two cars of equal weight and rolling resistance. Car A is a 100 HP car - can go 80 MPH. Car B is a 400 HP car - can go 80 MPH. The tree they hit at 80 MPH doesn't car which car had more HP..

edit: Uh, which saw? 3 HP is already overkill for my home shop needs.

[Don Bullock]

Scott, I can only speak for myself. When I bought my SawStop I had the same choice. The 5hp was $200 more than the 3hp at the time. For me, considering the total cost of the saw, $200 wasn't much for the upgrade so I bought the 5hp. That said there may be more for you to consider that just the difference in the cost of the saw. My 5hp SawStop runs best on a 30 amp 220 circuit and the 3hp can run on a 20 amp. I don't know about a Powermatic.

Do I need the extra power? I haven't yet. Since my shop is not being used much and I've stopped all my major projects due to my pending move, it will be a while before I can truly answer that question. I'm still glad that I decided to buy the 5hp.

[John Thompson]

I have a 5hp cabinet saw. I have never owned a 3hp. I wanted the 5hp because I planned on ripping 6x6 fir, flipping it over and ripping it again.

The blade is entirely buried in the wood. The saw has zero problem cutting that way, but I dont know if its really working that hard? I dont push really hard, it could be that a 3hp would work just as well..

One nice thing about a 5hp is that it doesnt ever seem to slow down under normal conditions. Again, I dont know if a 3hp would either.

Yep.. on the 6" stock on flipping it over as with all stock over 3" on a 10" saw you have to or take it to the BS.... ;)

Can a difference be distinquished when ripping 6" stock with the blade buried by flipping it over? Yep... and you better keep several sharp rip blades on hand and several at the sharpener if you do it very often. :)

Sarge..

Sarge..

[Scott Myers]

I appreciate the feedback from everyone. The kickback isn't the concern, but rather bogging down under heavy load, as in putting a wide dado in somehting like hard maple. You bog down, you heat the motor, you risk burning the wood, etc. Sounds like the majority of the concensus is to just go with the 3 HP. I was leaning this way anyway and will probably go this way, unless the Binford bug bites me just before I have them scan the plastic! :D

For anyone that may be interested, I was reading what some were saying about kickback. I'm an engineer myself and understand the dynamics involved. There is NO DOUBT that the damage a 3 HP can do to you is as much as a 5 HP, due to the fact that the force produced by the 3 HP under a dynamic situation is WAY GREATER than what your body can stop. Each motor can easily produce 4 times its normal HP for a second or 2, pulling 4 times the current from the electrical circuit. Circuit breakers are even designed this way to be able to put up with the starting inrush. (If you have never done so, put an ammeter on one leg of a motor circuit the next time it spins up. Try your dust collector. My 2 HP 230 V single phase dust collector pulls nearly 60 amps of inrush for 2 seconds on a 30 amp breaker. This is within standard NEMA specs on a 2 HP motor.) If you just converted this all to lbs of force at the blade tip, you only get 15 lb or so of force at the speeds involved. However, this doesn't take into account the intertia of the spinning mass involved, which is the real culprit. The forces are a combination of an acceleration due to friction transferring the torque to the board and finally when the board catches, its the same as a hammer striking a surface calculation - an impact calculation. I pulled out my old engineering physics book and groaned. A complex differential equation (calculus) physics problem to say the least. There has been a lot of money spent over the years for measuring and estimating impact forces. (Think car crashes.) Suffice it to say that if the motor armature/arbor/blade mass are perhaps 10 lb total, the forces produces at the moment of kickback can probably be estimated to be in the thousands of lbs of force under perfect conditions. Luckily, most kickbacks dont' transfer everything into the board, but some are certainly bad as everyone here will attest to.

So whether a horse (3 HP) or a bull (5 HP) kicks you, your body only produces so much inertial resistance and both are going to do some serious damage as you can't resist such forces. Without doing the math and just making some quick estimations, a lightweight board with little interia of its own could easily hit you with more than 1,000 lbs of force under kickback with a 3 HP motor driving the blade, provided the blade really catches the board good and tranfers all the torque to it. No wonder boards fly through walls so easily.

[Ted Torres]

I appreciate the feedback from everyone. The kickback isn't the concern, but rather bogging down under heavy load, as in putting a wide dado in somehting like hard maple. You bog down, you heat the motor, you risk burning the wood, etc. Sounds like the majority of the concensus is to just go with the 3 HP. I was leaning this way anyway and will probably go this way, unless the Binford bug bites me just before I have them scan the plastic! :D

For anyone that may be interested, I was reading what some were saying about kickback. I'm an engineer myself and understand the dynamics involved. There is NO DOUBT that the damage a 3 HP can do to you is as much as a 5 HP, due to the fact that the force produced by the 3 HP under a dynamic situation is WAY GREATER than what your body can stop. Each motor can easily produce 4 times its normal HP for a second or 2, pulling 4 times the current from the electrical circuit. Circuit breakers are even designed this way to be able to put up with the starting inrush. (If you have never done so, put an ammeter on one leg of a motor circuit the next time it spins up. Try your dust collector. My 2 HP 230 V single phase dust collector pulls nearly 60 amps of inrush for 2 seconds on a 30 amp breaker. This is within standard NEMA specs on a 2 HP motor.) If you just converted this all to lbs of force at the blade tip, you only get 15 lb or so of force at the speeds involved. However, this doesn't take into account the intertia of the spinning mass involved, which is the real culprit. The forces are a combination of an acceleration due to friction transferring the torque to the board and finally when the board catches, its the same as a hammer striking a surface calculation - an impact calculation. I pulled out my old engineering physics book and groaned. A complex differential equation (calculus) physics problem to say the least. There has been a lot of money spent over the years for measuring and estimating impact forces. (Think car crashes.) Suffice it to say that if the motor armature/arbor/blade mass are perhaps 10 lb total, the forces produces at the moment of kickback can probably be estimated to be in the thousands of lbs of force under perfect conditions. Luckily, most kickbacks dont' transfer everything into the board, but some are certainly bad as everyone here will attest to.

So whether a horse (3 HP) or a bull (5 HP) kicks you, your body only produces so much inertial resistance and both are going to do some serious damage as you can't resist such forces. Without doing the math and just making some quick estimations, a lightweight board with little interia of its own could easily hit you with more than 1,000 lbs of force under kickback with a 3 HP motor driving the blade, provided the blade really catches the board good and tranfers all the torque to it. No wonder boards fly through walls so easily.

OUCH! :eek:

Good Luck on your new purchase, Scott!

Ted

[Scott Myers]

Power isn't an issue. I do my own wiring and have two 30 amp 230 VAC circuits in the shop now. I don't even bother with installing 20 amp 230 VAC circuits. (See my earlier post about motor inrush.) Working in the industrial world for years, you just got in the habit of a 30 AMP 230 VAC circuit being the "starting size" of typical 230 VAC circuits, with some exceptions where extra protection of equipment is needed.

On the price of the upgrade; What really twists my shorts is that Powermatic wants a $400 premium to upgrade from a 3 HP to a 5 HP motor. ($2700 VS $3100 for a 50" fence version) Everyone in the industrial world knows that the difference in price between 3HP & 5 HP single phase motors is somewhere between $100-$200, depending upon motor quality. (I've bought a lot of them) And considering that Powermatic doesn't use Baldor motors any more in their PM2000 line (With the exception of the Woodwerks custom program), the price upgrade should lean toward the lower $100 mark. So unless they are providing much heavier pulleys, wider belts and some other unseen upgrades (which I doubt) when you get a 5 HP, it's just price gouging to charge an additional $400. Plain and simple. Stuff like that makes me wonder about parts down the road, not that I would need any. Are they going to gouge me there too?

It's more than reasonable that General only charges $100 for the upgrade... and a Baldor motor no less. Quite generous really. And Sawstop only charges $200 for the same upgrade? Also quite fair. Powermatic should be ashamed, but I am sure they are not.

Perhaps I should reconsider my choice based on this alone. But I like the features of the Powermatic. (Whaaa!) Yes, I'm whining.

[Charles Krieger]

My PM2000 is the 3HP variety and for my home shop it has proven to be more than adequate. I enjoy the PM2000 and I think you will too. Only problem with my PM2000 has been the caster system which became impossible to crank. :mad: It was fixed under warranty.:cool:

[Scott Myers]

Yes, the Caster system is extremely attractive to me, due to my fairly small shop. I have heard of the problems many have had lowering the saw. Hopefully, this bug is worked out now.

[jim oakes]

On the price of the upgrade; What really twists my shorts is that Powermatic wants a $400 premium to upgrade from a 3 HP to a 5 HP motor. ($2700 VS $3100 for a 50" fence version) Everyone in the industrial world knows that the difference in price between 3HP & 5 HP single phase motors is somewhere between $100-$200, depending upon motor quality. (I've bought a lot of them) And considering that Powermatic doesn't use Baldor motors any more in their PM2000 line (With the exception of the Woodwerks custom program), the price upgrade should lean toward the lower $100 mark. So unless they are providing much heavier pulleys, wider belts and some other unseen upgrades (which I doubt) when you get a 5 HP, it's just price gouging to charge an additional $400. Plain and simple. Stuff like that makes me wonder about parts down the road, not that I would need any. Are they going to gouge me there too?

.

Sounds like you are getting close to an answer Scott.

I had a 3HP model 66 I bought new in 1972. I ripped lots of thick hardwood in my commercial shop. I replaced 3 HP Baldor motors more than once . If a 5 HP was available back then at a reasonable cost I would've put one on, but I don't think it was an option.

I have a 3HP Shop Fox saw now in my hobby shop and it works as good as my 66 did, but I don't rip for hours at a time anymore.

Why not get 3HP and if you wear it out, get a 5HP Baldor.

[Erik Frederiksen]

This is slightly off topic.

This thread made me curious about motor ratings, and I looked up the jobsite table saw made by Bosch, model 4100. The power of its motor is listed as Max hp 4.0.

Are they rating hp differently? Can anyone explain?

[Charles Krieger]

I have found it easier to leave the casters down so the saw can be rolled into place. Once the saw is located I stick some 3/4" boards under the base (but not the casters) which lifts the casters off the floor. The saw is then very solid and I don't have to go through the up/down cycle each time I move the saw. Casters are still a very nice feature but a mobile base would work as well maybe better.

PM has made some changes to the caster system however I do not know if my saw is pre or post the caster changes. In order to get my casters to work the technician had to grease the flange of the caster shaft. I suspect that if I use the casters I will find that sawdust and dirt will eventually make the operation as difficult as it was before. Suffice to say I am happy with the arrangement that I am using now and I do move my saw every time I work in the shop (3 car garage). Some zerk or zerx (sp) type fittings for lubricating the caster flanges would be helpful but none exist.

The new Delta saw might warrant your consideration as well. I have not yet seen the new version of the Unisaw but the riving knife feature sounds like it is superior to the PM.

Even though I suggest you look at the new Unisaw I am happy with the PM 2000 and would buy it again!

[Anthony Anderson]

I bought a 5hp, because it was a cheap upgrade. I am sure that 3hp would have been plenty. But I couldn't add the extra 2hp later, so I went with the 5hp. Either way, I'm sure you will be happy.

[Scott Myers]

Ignote the HP rating. Since 4 HP is an odd and not normally manufacturered motor size (would be VERY expensive to produce as it would be quite special), I suspect they are playing games with the HP rating, as so many manufacturers do.

Here's the easy way to find out any motor's true continuous duty HP.
Look at the fully loaded amperage draw on the nameplate. Then compare this with a chart from Baldor, Leeson, or other motor manufacturer for general purpose motors. Wherever your amperage rating from your namplate cooresponds the the motor manufacturer's chart for general purpose motors will give you the true continuous duty HP rating.

I took a quick look at the specs on the 4100. It says 15 Amps. That's a true 3 HP motor.


This is slightly off topic.

This thread made me curious about motor ratings, and I looked up the jobsite table saw made by Bosch, model 4100. The power of its motor is listed as Max hp 4.0.

Are they rating hp differently? Can anyone explain?

[Scott Myers]

Charles,

Now you're making me doubt the value of the built-in caster system. :(


I have found it easier to leave the casters down so the saw can be rolled into place. Once the saw is located I stick some 3/4" boards under the base (but not the casters) which lifts the casters off the floor. The saw is then very solid and I don't have to go through the up/down cycle each time I move the saw. Casters are still a very nice feature but a mobile base would work as well maybe better.

PM has made some changes to the caster system however I do not know if my saw is pre or post the caster changes. In order to get my casters to work the technician had to grease the flange of the caster shaft. I suspect that if I use the casters I will find that sawdust and dirt will eventually make the operation as difficult as it was before. Suffice to say I am happy with the arrangement that I am using now and I do move my saw every time I work in the shop (3 car garage). Some zerk or zerx (sp) type fittings for lubricating the caster flanges would be helpful but none exist.

The new Delta saw might warrant your consideration as well. I have not yet seen the new version of the Unisaw but the riving knife feature sounds like it is superior to the PM.

Even though I suggest you look at the new Unisaw I am happy with the PM 2000 and would buy it again!

[Scott Myers]

MAkes sense Jim

[Jerry White]

I took a quick look at the specs on the 4100. It says 15 Amps. That's a true 3 HP motor.

Scott and Eric,

I suspect the Bosch saw operates on 120 volts. If so, at 15 amps full load draw, that would put the motor power at closer to 1.5 HP.

Jerry

[Rick Fisher]

Scott and Eric,

I suspect the Bosch saw operates on 120 volts. If so, at 15 amps full load draw, that would put the motor power at closer to 1.5 HP.

Jerry

That Bosch is a universal motor, A 4hp 115V motor would draw about 40 amps. I have a machine with a 4hp 220V motor and it is rated at 19.5 amps.

Bosch, like Shop Vac Hype it up. Its the rating the motor has just before the factory installed smoke comes pouring out. :)

[Stan Urbas]

Scott, I used a Shopsmith for a number of years and lack of power was always an issue. But it NEVER burned the wood. Burning will be caused by a dull blade or a blade out of alignment. My inclination would be to go with the 3HP for your application. Another things to consider is how many amps the motor draws. The 5HP could require a bigger circuit than you have.

[Tom Veatch]

...I looked up the jobsite table saw made by Bosch, model 4100. The power of its motor is listed as Max hp 4.0.

Are they rating hp differently? Can anyone explain?

Just about anytime you see a device rated as "Max" HP, and it doesn't just apply to universal motors, you can pretty well count on that being a "calculated" rating using the product of Voltage X Locked Rotor Amperage and having little or no resemblance to the actual power the motor will develop in use.

Here's a good reference (http://www.kevinsbrady.net/motors.pdf)to the details of that abominable practice.

[Scott Myers]

Jerry,

You're absolutely right! I just think 220 VAC when I think table saws. Contractor saws are not 220 VAC. Duh. So yes indeed, 1.5 HP on the Bosch. But that makes sense as many saws have 1.75 HP motors (just before the jump to a true cabinet saw) that have TRUE 1.75 HP motors on them.


Scott and Eric,

I suspect the Bosch saw operates on 120 volts. If so, at 15 amps full load draw, that would put the motor power at closer to 1.5 HP.

Jerry

[Jacob Reverb]

The only time the 5HP would kickback harder/faster than the 3HP would be if, at the point of kickback, the cut was requiring the motor develop more than 3HP.

...or if, at the instant of kickback, the increased load that caused the kickback in the first place either caused the belts/sheaves to slip, or caused the weaker motor to slow down slightly (a very real probability). Either way, it seems to me a wrongheaded way to choose between 3hp and 5hp...but I just like to argue.


Now compare the two motors, but remember that doing a particular task, the 5HP motor may be operating at 50% while the 3HP will be at about 83%.

As far as I know, once they're running, induction motors use the same amount of current regardless of whether they're loaded or freewheeling.

[Scott Myers]

I believe I will move forard with the 3 HP version. I expect it will be just fine (and then some) for the amount I will use it. I am used to that HP anyway, so I know it will work for me fine. It realy came down to whether anyone really notices the difference between 3 & 5 HP. It seems that except in special cases where thick resawing or the like is done, no one notices any difference.

Thank you everyone for your input.

[Jon Grider]

My 12 year old PM 66 has the 3HP Baldor. To be honest, I have bogged it down a few times while ripping ply and thick boards and getting them askew. It has not occurred often though and has not been a big deal in my part time shop after pushing thousands of feet of hardwoods and ply through it. My feeling is that a sharp blade and proper technique is more valuable than the extra 2 HP.

[Tom Veatch]

...
As far as I know, once they're running, induction motors use the same amount of current regardless of whether they're loaded or freewheeling.

I know of at least one induction motor that doesn't behave in that manner. The 5HP motor on my cyclone, measured with a clamp on ammeter during construction and testing draws a variable amperage depending on the load.

Some of the data points that I remember explicitly are as follows. With the blower housing inlet and outlet blocked, essentially free wheeling, it draws about 8 amps. Installed on the cyclone and connected to the ductwork with one blast gate open the draw is appx 16 amps with some variation depending on the specific blast gate. Dismounted from the cyclone with the housing inlet and outlet wide open and unrestricted the amperage draw is about 22 amps. With the blower wheel unshrouded in free air, it draws a whopping 44 amps - at least until the circuit breaker trips. Listed full load amperage is 20.8 amps.

[Dave Bender]

Scott, unless you plan on using a powerfeeder then go with the 3HP motor, a 5HP motor will do nothing for you except cost more.

[Scott Myers]

Well, I plunked down the money today for the saw. I went with 3 HP, however, I did not go with Powermatic as I originally thought I would. Instead, I opted for the extra safety of the Sawstop. I cringed paying for it as they are pricey. However, it takes a load off of my mind with my young sons around who are always very interested in my tools. It only takes a second for me to turn my back, even thought I am pretty strict about being in my workshop.

[Karl Brogger]

I've got two young nephews running around my shop with some frequency. Most of my equipment is on a sub panel, I trip the breaker for for all of the motorized sharp stuff. The little monsters love pushing buttons.:D

[Scott Myers]

I too have everything on a subpanel and trip the breakers off. But have I ever forgotten to turn the breakers off? Unfortunately, yes. Yeah, it cost me about a $1,500 premium, give or take, for the Sawstop, but I can breath easier. Nothing can maim you in a woodshop so quickly like a tablesaw, IMO. Sadly, I'm sure there are a number of others here that would attest to that.

[Andy Casiello]

Good choice. You can't go wrong if with the Sawstop if you can swing the extra premium. My next TS will be a Sawstop, even though I love my Griz.