How much power should I expect?

[HopefulSSer]

My Mk V is an earlier one with the 3/4 hp motor. I know later they uprated the motor to 1.125 hp which implies to me that mine will be somewhat underpowered. But how underpowered?

I'm finding that with a combination blade installed (freshly sharpened in 1992 per the sharpie marker on it, but it seems little used since then) and trying to rip a soft pine 2x4 in half, I can very easily stall the motor unless I use a painfully slow feed rate, much slower than I would use on my grandad's old Rockwell table saw. I tried some JPW on the blade -- that helped a little but not much. Does this sound typical? Am I getting all that I should expect from it?

(BTW, the two drive sleeve bearings and the quill bearing are all brand new and spin freely, the idler shaft bearing is not new but spins freely, and everything is cleaned & lubed. And the table & fence are square to the blade.)

Thanks!

[JPG]

Combination blades are grossly inadequate for ripping anything 'thick'. Gullets too few and too shallow. Adjust speed control to slow it down and also slow feed rate.

[RFGuy]

My Mark V is newer so I believe it has the 1-1/8 HP motor. Mine is a bit rarer because I purchased it from the factory as a 240V machine, but my understanding is no increase in HP as this is just a wiring change to accommodate the higher voltage. Mine has bogged down a few times in the past, e.g. with a 4x4 redwood post, 8/4 cherry, etc. For me, sometimes it has been a dirty sawblade and other times it was a slipping drive belt. For the latter, you just need to adjust the drive belt tension (assuming belt is still in good shape). Whenever I don't think a cut is going quite as well as I like, I clean my sawblade and am amazed every time how much easier it is cutting after I clean the blade. Pitch and resin from the wood quickly dulls it by attaching around the teeth of the blade. How old is that 1992 sharpened blade and what brand is it? I would be very hesitant to continue using a blade that old that hasn't been re-sharpened since. Think of a dull sawblade like a dull knife. Both are dangerous because you will try to force it to cut and not have the proper control when an accident happens. I am a big fan of Forrest sawblades (https://www.forrestblades.com/) but they are expensive, but you can re-sharpen them over and over and over again. So in the long run it is cheaper to own a premium blade. Others prefer to buy cheaper blades from the big box stores and replace them more frequently. Not saying one is better than the other, but just stating my preference. By the way, Forrest can make sawblades in any bore size, so if you prefer 5/8" they have this, but can also do the Shopsmith 1-1/4" bore size. Lastly, if you are ripping you might want a dedicated ripping blade (20-24 tooth) and save the combination blade for crosscuts. You will be amazed how much better a ripping blade cuts on the 3/4" HP motor. Hopefully others will respond here and give you their experience with a 3/4" motor Shopsmith. I don't have any experience with that particular motor.

[edma194]

I had a Shopsmith carbide ripping blade that I gave away to a friend in need. Shoulda kept the blade and let the friend suffer a little.

So slow down the blade as stated above, that will give you more torque. And with the 3/4 motors you can only saw so fast.

If it hasn't been sharpened in 30 years then it can't be all that sharp.

[JPG]

Howcome EE's tend to purchase 240v SS's? I lost 1/8hp doing so way back when. Never missed it! Only stalling occurs with poly-v belt slipping(ripping 3+" stuff).

[RFGuy]

How come EE's tend to purchase 240v SS's? I lost 1/8hp doing so way back when. Never missed it! Only stalling occurs with poly-v belt slipping(ripping 3+" stuff).

Yeah, I never have regretted the decision. I have always had a dedicated 240V in my shop for it and if I didn't then I would just pull a circuit myself. Does it give me anything for it? Unfortunately no. Even though I knew the basics of motor design, etc., I believe I had a misguided perception at the time that a 240V motor hookup would be quieter and better balanced (less vibration) than a 120V connection. Unfortunately, it is a single phase 240V so no real improvement with me going 240V on it.

IF I ever upgrade to a PowerPro then I am ahead of the curve with the dedicated 240V outlet...a 3HP SawStop might be a more likely upgrade though.

[DLB]

Great topic. I've used 3/4 HP, 1-1/8HP, and PowerPro, but mostly 3/4 HP. I liked the 3/4 HP when it was all I had, but I can't imagine a set of circumstances where I would again use it for a Table Saw. Yes, it is pretty easy to stall. Most stalls can be prevented by careful control of feed rate. Some can't.

There are, as you know, many factors besides HP in this equation. Some of them you can control. Soft wood, especially common 2X, is not necessarily easier to rip than hardwood, but we can't really control that if we need to rip a common 2X. We can use sharp blades with narrow kerf, and rip blades when ripping. To some extent we can manage runout, which results in a wider kerf, but it ain't cheap to do so. Fence alignment is also a factor in how wide a kerf we cut. Sometimes slowing the spindle speed helps. Correct table height matters.

We don't always want to control everything we can control. Most 'experts' would say a narrow kerf blade is appropriate for Mark power output. But I generally choose a full kerf. Ideally with low runout, but that adds cost.

- David

[HopefulSSer]

At a shop I worked in when I was in high school, we had a table saw that would continually overheat and shut down. They converted it to 240v and the problem stopped. Makes sense -- fewer amps for the same power.....

As to my blade, all the markings are long gone but it's got a 1.25" arbor so.... SS? Maybe?

Although it was sharpened last in 1992 it is still quite sharp so I don't think it ever saw much use (pun intended) after being sharpened.

Good suggestion about slowing it down. Speed is something I've never had to think about before with a table saw. They're either on or off.

Eventually I'll invest in some newer blades!

[RFGuy]

Okay, let me go against the grain here (pun intended). I get the logic for why members here are saying to slow down the saw blade speed (not talking about feed rate). The Mark V has essentially a mechanical transmission with the sheave design, so going slower should increase torque. I have only had mine bog down a very few times and in the moment I never tried to raise or lower sawblade speed to see what effect it might have. My instincts, in this situation, have always been to raise sawblade speed (if cleaning, new blade, etc. don't work). I would think greater rotational inertia matters more than torque here (favoring higher blade speeds), but I could be wrong. Does anyone have direct experience with raising/lowering sawblade speed during binds? Or is this a case where we think lower speeds will help solely based on the logic of higher torque? Just curious.

[chapmanruss]

Trying to rip a soft pine 2 x 4's in half can be as hard on the saw as cutting hardwood. Something not mentioned yet is moisture content of the wood. Again something that adds to the difficulty of cutting the wood and higher moisture content is more commonly found in 2 X 4's. For my two cents worth here I would go with a ripping blade as opposed to a combination blade for the same reasons already stated. Although a combination blade is designed to do both ripping and cross cuts it is a compromise and does not do either better than blades designed for the specific purpose. Not something I commonly do but I have used my Shopsmith Model 10's to cut through 2 X 4's which have a 1/2 HP motor. It takes a sharp blade and slow feed rate to do it.