What's a good combo blade for an early Unisaw?

[Pete Bradley]

I'm just starting a resto on a 1940 Unisaw with a 1HP bullet motor. I'm an amateur woodworker. I expect to use the saw for crosscuts in solid hardwoods and rough cuts to break down sheet goods and softwoods from time to time. I have a 20" band saw (1949, fabulous machine) which I expect I'll continue to use for most rips.

I'm sure there are some people out there with experience on similar machines. I'm interested in recommendations on a good combination blade which I can keep on the saw most of the time. Given that the motor was intended for steel teeth, would a thin-kerf blade be best?

Please no posts telling me to upgrade to a 5HP motor from Grizzly. That's not what this project is about.

Thanks,

Pete

[David Weaver]

Someone is going to tell you a thin-kerf Forrest woodworker II, so it might as well be me. I think Amazon has been running sales on them lately and I've seen people say that you can get them for $73-$80 shipped lately.

I've used one on a craftsman cheapo contractor saw and on a delta hybrid of mine - in both cases, it was the single thing that did, by far, the most to increase the saw performance. Results with it are great.

Scott Spencer has a nice list of blades, price and how they perform. You could probably pick a blade out of his list if it's thin kerf, and run with it.

You might change your mind about the ripping once you use a good thin-kerf blade on that saw. It's a lot cheaper to use a good table saw blade than it is to run through bandsaw blades, and your saw will probably handle a good thin kerf blade pretty well on 4/4 and sheet goods on the saw. Not to mention, if the saw is tight, there won't be much work to do to clean up the edge - in some cases, none if it's not exposed.

[Bill Huber]

I have an old Craftsman 8 inch saw and it only has a 3/4 hp motor on it, now that is what you call underpowered....

I really get great performance out of Freud Diablo blade. I resaw 2 1/4 hard maple with them and they work very well.
They are really cheap also, the 7 1/4 in that I use a $14 at HD.

The sell the 10 inch in a 24 and 40 tooth model and I really don't think for the money you can beat them.

[Jamie Buxton]

IMHO, folks get too concerned with horsepower in a saw. The only thing horsepower brings you is the possibility of a higher feed rate. A 1 hp motor in your saw can cut anything that a 5 hp motor can. You might have to feed the stock a little slower, but it will still cut the wood.

I'd put a good-quality combo blade on the machine. Freud's what's in my shop, but anything like that will work. Then keep the blade sharp. If it starts dulling, get it sharpened. Your saw will be just fine.

Oh yeah... My personal experience with thin-kerf 10" blades is that the quality of cut isn't as good as the full-kerf blades. It seems that the thin-kerf ones flutter a bit. Other people strongly believe in thin-kerfs, so YMVV.

[Steve LaFara]

I think you will be surprised by the power of the old Bullet motors. As they are repulsion induction, your 1hp will act more like a 3 hp newer style. I have the same motor in a '39/'40 Unisaw and use a full kerf WW II most of the time but do use a 24t Frued rip blade if I'm going to rip a bunch of stock. Will a thin kerf help? Yes, but it's not really neccessary especially for cross cutting. I've not bogged mine down yet.

Congrats on the new saw!

[Phil Thien]

I think you will be surprised by the power of the old Bullet motors. As they are repulsion induction, your 1hp will act more like a 3 hp newer style. I have the same motor in a '39/'40 Unisaw and use a full kerf WW II most of the time but do use a 24t Frued rip blade if I'm going to rip a bunch of stock. Will a thin kerf help? Yes, but it's not really neccessary especially for cross cutting. I've not bogged mine down yet.

Congrats on the new saw!

+1 what Steve says. The RI motors have a different power curve that provides plenty of horsepower for cutting thick stock. No need to go with thin kerf blades unless you're trying to preserve expensive stock.

[Cliff Rohrabacher]

It's more a question of arbor speed and the wood and the type of cutting you'll be doing.

I'm one of those people who almost never change blades. I'm only going to sand anyway.

[Pete Bradley]

Oh yeah, the old Marathon R/I motors are in a different class from modern motors. I have a 1HP in my band saw. Gobs of starting torque at very low amps, serious momentum once it's running. I was familiar with the bullet motor from a distance, but I was still surprised how big/heavy it is.

The workmanship inside is amazing. Basswood wedges in the armature and hand tied strings on the windings.

I have a 3HP Century R/I that's just waiting for a vintage planer to come along. Besides being gigantic, it's a brush lifter design, so it makes an awe-inspiring "Fweep!!!" sound as it fires up.

Pete

[Pete Bradley]

Blade RPM is about 3150.

Pete

[scott spencer]

Hi Pete - I don't have any experience with an R/I driven Uni, but for the uses you describe I'd be inclined to go with something like the Infinity's brand new redesigned Super General 40T 010-044 with a 30 degree Hi-ATB grind or a 60T Freud LU88R010. Both tend crosscut more cleanly than typical general purp blades, handle sheetgoods better, yet will still rip pretty nicely to ~ 6/4".

The Super General is a full kerf (0.125"), the LU88 is a TK (0.94"). The "SG" leaves a more polished edge due to its tighter side clearance, and has humongous teeth....very quiet and extremely well made precision blade. The LU88 is one my favorites for all around versatility in < 6/4" material and great value.
http://www.infinitytools.com/images/1413.jpg
77311

The Tenryu Gold Medal is a 40T GP blade with a mid kerf of 0.111", which might make it reasonable compromise for your saw if you'll need a bit more ripping power.

[Jim Becker]

A "standard" 1/8" kerf combo or GP blade is what I'd put on that saw for the intended purpose. While Forrest gets the nod in my shop, there are some other very nice blades from Freud, Ridge, Amana, etc., that will fit the bill. You don't need a thin kerf blade, IMHO, unless you are running a benchtop saw. That old motor you have is a very powerful machine as compared to similar "rated" motors of this day and age!

[Paul Gatti]

I have a 1956 Unisaw with a 1.5HP motor and I'm using a Forrest Woodworker II thin kerf blade. The thing works great. The cuts are very clean and smooth and it moves through most wood like a hot knife through butter.