Anyone know about increasing the hp on a table saw?

[jwoldsr]

I actually have two Craftsman 10" bench type table saws. I bought one of the in the early 70s, and inherited the other from my father-in-law. His is a little older than the one I bought.

They are both good tools for most things, but the bog down while ripping, especially hardwoods like hard maple.

I have toyed with the idea of changing out the motor with one of a higher horse power, but I do not know what that might do to the saw. Has anyone tried that, or know anything about it?

[mpc]

typical problems trying a motor swap:
* Will a different motor use the same bolt pattern? Will it fit into the saw body as you run the blade up/down and use the blade tilt? You may find there isn't room for a larger motor with the blade tilted to a 45 degree bevel cut.

* If you plan to significantly increase the HP you risk over-stressing the structure of the saw. Especially when the blade jams or bogs during a cut; that puts a lot of twisting stresses into the saw guts. A higher HP motor is likely physically heavier too... leading to a faster wear rate on the blade height & bevel angle bearings.

* A higher HP motor means more amperage... the wiring and switch may not be able to handle it. That's a safety hazard.

* Cost might be more than just buying a different used saw that already has more HP.

Unless the saw was originally offered in several HP variants, my gut reaction is significantly increasing the HP of the motor has a few safety risks: wiring/switch amp capacity, physical strength, etc.

Some things you can try to help the existing saw + motor:

* Use a "thin kerf" saw blade. It cuts a narrower so there is less work for the motor. Thin kerf blades are readily available and work as well as a normal thickness blade.

* Blade you're using is sharp, right? And clean - pitch buildup causes lots of drag.

* Proper tooth count for the type of cut you are making. A high tooth count gives a cleaner cut for cross-cuts (i.e. cutting perpendicular to the wood grain) but typically will load up with sawdust when cutting thicker boards. Lots of teeth implies smaller gullets between the teeth; when those get loaded with sawdust during the cut that sawdust ends up making a lot of drag and heat. Going to a smaller tooth count will give you larger gullets making for an easier cut in thick workpieces. For rip cuts a lower tooth count is pretty much essential... and rip blades will have larger gullets too.

* When ripping thick stuff, make the cut in two passes.

* Fence is aligned properly to the blade? If the outfeed end of the fence is closer to the blade than the infeed side that squeezes the workpiece into the blade - lots of drag and a serious problem too: that's what leads to kickback. A mis-aligned blade is less noticeable on shorter cuts than for long rip cuts... so even if it "works okay most of the time" double-check the alignment.

* Are you sure the power outlet feeding the saw is good? Saws require many amps to work properly... outlets with marginal wiring, poor connections (excess resistance), etc. may work okay for lights or hand tools but will suffer voltage loss when feeding high-amperage tools like a table saw. Using an extension cord also introduces additional resistance and is a common problem. Extension cords should have thick wires to minimize their resistance. One way to test an outlet: get a small desk lamp with a 50 to 75 watt incandescent bulb. Plug that into the same outlet as the saw is using... turn on the light and note how bright it is. Then turn on the saw. If the light dims at all, that outlet is not sufficient for the saw. If the light stays bright, run a scrap board through the saw and make a cut. Have a helper watch the light - NEVER use any power tool while looking elsewhere - and if the light dims with the saw loaded then the outlet might still be the problem. If you are using an extension cord, plug the light into the end of the cord with the saw - get a 2 or 3 way splitter if necessary. When the saw is actually cutting wood, the light should not dim much at all if the power wiring is satisfactory.

Hard maple will slow down all but the beefiest of saws. Even my fairly beefy bandsaw breaks a sweat on hard maple. If all the potential problems I described above are okay in your shop then just make multiple passes and/or reduce the feed rate to whatever your saw can safely handle.

mpc

[RodKirby]

MPC:

Yours is one of the best (most comprehensive), replies I have ever seen on this forum - well done

[jwoldsr]

Hey, mpc.

Thanks for the input. Your insights are just what I was looking for. I'll try the suggestions you gave me.

I have a nice little shop, and there is room left in my breaker panel since I switched out the electric range and hot water heater for natural gas. That relieved about 60 or 70 amps. Maybe I'll hire an electrician to look it over.

If I peddle both saws and put a little with it, I can find a more powerful saw. Iwould still need to convince my wife that I really really neeeed another tool.

Thanks again,
jw

[Richard in Smithville]

Hey, mpc.

Iwould still need to convince my wife that I really really neeeed another tool.

Thanks again,
jw

Just wait until she really needs you to build something

[LinuxRandal]

typical problems trying a motor swap:
* Will a different motor use the same bolt pattern? Will it fit into the saw body as you run the blade up/down and use the blade tilt? You may find there isn't room for a larger motor with the blade tilted to a 45 degree bevel cut.


mpc

While I do agree with the general post of the above, I do not remember reading the age of the saw. After WWII, some of the early saws that were available, especially the less then 10" models (I believe some of the early 10" models, just never had one), came motorless. They gave general motor sizes which sometimes included frame sizes (this will deal with bolt mounting patterns). Some time in the 60's was when we saw motors changing how they were rated. and saws that used to be 1/2hp or 3/4hp, now were listed as 1 1/2hp. So more information may be needed, but I do agree with the blade first directions.

[BobSch]

If I peddle both saws and put a little with it, I can find a more powerful saw. I would still need to convince my wife that I really really neeeed another tool.

Thanks again,
jw

But if you get rid of two saw and buy one, you'll actually downsizing by one tool,right?

[jwoldsr]

Bob, you make an excellent point! I could do the whole upgrade masquerading as a “down-sizing.” I I like the way you think .

I knew joining this group was a good idea.

John

[eezlock]

increasing the hp on a tablesaw?

First thing here , I would assume that you are talking about using a 120volt
power source to increase the power output of the saw...right? The best and cheapest way is have a 220 volt line installed for a table saw instead using a 120volt line. A 120 volt line isn't going to be able to supply enough amperage
to boost the hp above 1 1/2 hp. It will take a 220 volt to do that. Most good
heavy duty table saws operate in the 2-5hp range on 220volt power. These are the bigger Powermatic 66's, older Delta unisaws and others like that. Some good table saw motors are dual voltage motors capable of being re-wired from their 120 volt operation to 220 volt by following wiring changes on their info. plates. You might consider those options before buying another saw.

Others here have suggested a sharp blade and thin kerf blades, this is good
advice also, but good saw alignment, tuning and and adjustment are very
crucial to ANY saw's performance. Just changing a motor my seem to be the
answer, but is rarely the answer to the problem.
Hope this helps........eezlock

[LCHIEN]

other's have made the point that changing motors is sort of a last resort and may not be a good idea if the saw is not capable of handling a larger motor.

You don't really tell us what the starting point it... is it a 10" saw, some of the older craftsman table saws were only 8"! Whats the model and or what are the nameplate ratings of the motor?
as others mentioned, ways to increase the apparent power of the saw... clean, sharp, thin kerf blade. Right number of teeth (24 usually in a dedicated ripping blade, costs about $25). Aligned saw and rip fence.
A change to 220V by rewiring the motor if possible, or if stuck at 120V, power cords of 12 or 14 gauge, no extension cords, etc.

[jwoldsr]

They are both 10" saws, and are 120 volt systems. I do not think these motors are dual wired for conversion to 220V. The circuits are 20 amp properly wired with 12 ga wire, but the outlet is actually rated at 15 amps. I checked, and that is commonly done and not a violation of code. Weird.

I changed all to outlets rated for 20 amps. Truthfully, I did not know there were separate outlets for the different amperages. I made several cuts with the same blade, but made three passes on 1 ½ hard maple. It worked, but the light still dimmed when I powered up the saw.

I will also tune up the saw and add a 30 amp circuit which code requires 10 ga wiring. That will answer the power supply questions.

I have ordered a Freud LU87R010 10-Inch 24-Tooth FTG Thin Kerf Ripping Saw Blade to dedicate to ripping.

I will also start hunting for a used 220 V more powerful saw – maybe one I can clean up and re-tune. I am making the LOML a replica of her grandmother’s big old oaken rocker. If I time this just right . . . .

[LCHIEN]

A 30A 120V circuit requires yet another (and obscure) connector. Its obscure because usually anything requiring power equivalent of 30A @120V is usually engineered for and better off with a 15A circuit at 220V.

Unless your saws are specifically rated to run at 30A/120V (very rare) I would not waste my time putting in bigger wire and a 30A breaker. You risk damaging the saw or worse. If you find you need that much power then you will be better off getting a 220V saw, maybe 3 HP.

In the meantime, if you only have a few cuts to make and don't want to buy a new saw, try making a rip cut a bit more than 1/2 way through then flipping the wood over and cutting the other half at which time it will fall free. You should use (and probably should all the time anyway) use a featherboard to keep the wood to the fence so that you cut lines up well.

[jwoldsr]

Thanks, LCHIEN.

It still looks like a 3hp or better replacement saw is an good approach, but in the meantime, I tried your multiple pass idea several times, and of course that does work much better, even with the wrong type blade. When my new blade arrives, that will help even more.

Btw, I dont like my shop made feather boards very much -- I have to c-clamp them in place. Anybody have an idea about shop made feather boards that I could anchor to the miter slot somehow. My old saws do not have the t-type slots.

I should clarify something else. The LOML is actually pretty supportive. She sleuthed Craigs List and bought me a nice barely used Delta dust collection system that moves 1260 cfps, and it can be converted to 220 volts. Shortly after that, she bought me a great dust filter for my birthday! She's always doing stuff like that.

[pelligrini]

Btw, I dont like my shop made feather boards very much -- I have to c-clamp them in place. Anybody have an idea about shop made feather boards that I could anchor to the miter slot somehow. My old saws do not have the t-type slots.

You can use these: http://www.rockler.com/product.cfm?page=16423&Max=999 or something similar that's shop made. I think there was a tip in one of the recent wood magazines about some shop made miter slot fixture blocks. I'll see if I can find it tonight.

This rip positioner jig from Woodsmith shows a miter slot fixture bar: http://www.woodsmithtips.com/2012/03...t-ripping-jig/
(I might have to build that jig too)