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Can you get a clean cut using a mid price saw and blade?

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Forum topic by MrRon posted 12-05-2021 01:21 AM 831 views 0 times favorited 17 replies Add to Favorites Watch
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MrRon

6260 posts in 4585 days


12-05-2021 01:21 AM

Topic tags/keywords: question sharpening

You need a “precision” ground blade to produce a “precision” cut free of swirl marks and tear outs. If you look at the metalworking area of cutting tools, you will find that metal cutting blades and bits are precision ground and will produce a precision finish. Wood cutting saw blades usually do not have that “precision” grind, at least not at the < $200 level. The reason is; just one tooth be out of set by as little as a .001” will leave a less than smooth cut finish. It is not easy to keep saw tooth set confined to a ±.001”. As the blade cut through the wood (cross cutting), the one tooth that is set .001” further than the other teeth, will leave a swirl mark. Quality of the saw itself factors into cut quality. A saw that has 1 or 2 thous of runout will not give a clean cut. Maybe a blade precision ground with fewer teeth might make a better crosscut than a high tooth count blade. It would be easier to keep the tooth set uniform on a few tooth count set than with a high count tooth set. Bottom line: It would be impossible to get a perfect cut unless you have zero runout on the saw and the saw tooth set is ±0.000”. I guess that is why we have sandpaper.


17 replies so far

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SMP

5085 posts in 1247 days


#1 posted 12-05-2021 01:25 AM

Wood also isn’t perfectly square, flat, etc. if your saw is perfect and your blade is perfect, the wood will move more than that thou. But once its clamped together etc it doesn’t really matter. Plus, if you have a mediocre hand plane and know how to sharpen you can use a Home Depot job saw and $30 diablo blade and then two swipes with a hand plane will make the surface perfect.

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pottz

22444 posts in 2326 days


#2 posted 12-05-2021 01:57 AM

what are you woodworking or making parts for the aero space industry ? those tolerances can be sanded out quite easy.plus no cut off my tablesaw is considered a finished edge.ron seems like you strive for a perfection in woodworking most of us will never achieve.if a 200$ blade is not to your standards,what is ?whats your point with this?

-- working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

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bandit571

30512 posts in 4025 days


#3 posted 12-05-2021 02:32 AM

I do everytime….Dewalt blade in a Craftsman 8” direct drive saw…

-- A Planer? I'M the planer, this is what I use

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therealSteveN

9403 posts in 1916 days


#4 posted 12-05-2021 02:54 AM

Wood moves, so any thoughts about 0.001 kinda tolerance of our cuts are fantasy. Plenty of machine cutting tools that won’t keep that, and they do sport the “precision ground” on the package. I think what you want to talk about are smooth, crisp cuts, that are visible to the eye in passing. Most of the higher $$$ and some of the less than high dollar blades will give these out of the package. Question is, how long will that last? So far I’ve found it’s here more $$$$$ on the blade equates to longer life, and longer period you get the crisp cuts, usually just due to bigger chunks of carbide.

Above and beyond the dollars are which blade for what material? I believe here that the coveted “Combo blades” which are in such high regard, will work well on your classic rip, and crosscut, but start to loose out on Plywood, laminates, and other materials. Even for rips, and crosscuts I can see better results by using a Rip blade, or a Cross Cut blade, than a combo.

Or are you really thinking you need to spend 200 bux to get a crisp cut?

-- Think safe, be safe

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Tony_S

1557 posts in 4425 days


#5 posted 12-05-2021 11:47 AM

Modern carbide tipped saw blades don’t have a “set” in the traditional old school sense. The carbide teeth have a specified clearance from the saw blade plate that is factory ground during manufacturing.
I’ve never specifically measured plate clearances, but I’d be surprised as hell if side clearance tolerances weren’t within .001, if not perfect on any mid range(and up) saw blade, regardless of the number of teeth.

If your table saw (theoretically) has zero run out and you put a brand new saw blade in it, and you’re getting arcs in the cut, the problem would more than likely be the saw blade plate isn’t flat, or your not using the blade properly, not a “set” issue.

The quality of the blade plate it’s self is one of the defining factors between a cheap blade and a midrange and up blade.

There are a handful of different factors that can cause a saw blade to ‘flutter’ and leave arcs in a cut, especially after a blade has been used(abused?) for a short period of time, but “set” isn’t one of them.

Some of these factors can be the reason that a lot of people believe that sliding compound miter saws aren’t for, and can’t be used for precision cuts.

Truth be told…you’d be very surprised how many very experienced, professional woodworkers can’t tell the difference between a sharp saw blade and a dull saw blade until well beyond dull.

-- Lj's...The place to post what you had for breakfast and then do your utter best to complicate the hell out of the simplest of questions.

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Woodson59

64 posts in 2472 days


#6 posted 12-05-2021 12:33 PM

I’m thoroughly confused, Forrest blades don’t cost over $200 unless it’s a dado set. I’m perfectly happy with my $79 Freud fusion’s. Are you jointing an edge, truing your saw with machine squares and using finger boards?

Hell I’ve Diablo blades put a fine finish on a cut, doesn’t last as long. I mean at 10,000 rpm that out of whack tooth will hit your board top, center and bottom of cut equally proud if you’ve set up your saw properly and your arbor has no wobble.

I’m assuming you’re talking table saws, but $600-700 saw and a $80 dollar blade can leave a mirror finish in my experience. And if it walks a hair to a minute bow. Put a hand plane on it.

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ljislink

28 posts in 158 days


#7 posted 12-05-2021 03:34 PM

TO the OP, I used a 1hp 50 buck (well tuned) 40 year old craftsman 10” TS with a Freud glue line blade and it made “perfect” rips. I could assemble the rips weather they were a 1/4” thick up to 5/4 and if grain was close you could not even see a glue joist in the work. My saw had at least .002” run out and had the fence just a hair offset to help with kick back. I never checked the surface with a microscope but there were no visible machine marks on the cuts.
Anyway for few hundred bucks you can get “perfect cuts”
If you would have said it’s impossible to cut wood on a table saw to .000” I would agree.

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bbc557ci

673 posts in 3416 days


#8 posted 12-05-2021 03:50 PM


TO the OP, I used a 1hp 50 buck (well tuned) 40 year old craftsman 10” TS with a Freud glue line blade and it made “perfect” rips. I could assemble the rips weather they were a 1/4” thick up to 5/4 and if grain was close you could not even see a glue joist in the work. My saw had at least .002 run out and had the fence just a hair offset to help with kick back. I never checked the surface with a microscope but there were no visible machine marks on the cuts.
Anyway for few hundred bucks you can get “perfect cuts”

- ljislink

+1 for the Freud glue line blades, or most any of their rip blades. TS set up is key regardless of the blade used. But I can understand MrRon’s quest for perfection…sometimes I drive myself nutz lol.

-- Bill, central NY...no where near the "big apple"

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Lazyman

8869 posts in 2729 days


#9 posted 12-05-2021 04:33 PM

My cheopo Marples combo blade yields both rip and crosscuts with no swirl marks. The edges look like I ran a hand plane over them, even after several years of use, albeit relatively light use.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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MrRon

6260 posts in 4585 days


#10 posted 12-06-2021 07:07 PM

I found Tony’s video very interesting. My pet grievance is tear out, not so much swirl marks. I know there are means to prevent tear out especially on crosscuts, like applying tape to the surface to be cut and scoring blades on saws so equipped. Sometimes it’s hard to get a crisp edge, although this seems to occur mostly with soft woods.

Funny thing, I used to have a small saw sharpening business over 30 years ago and I would sharpen carbide blades for local woodworking businesses. They had blades that were very expensive, hence the $200 figure. These blades were meant to do production cutting, so had massive amounts of carbide and a thick plate (no thin kerf blades). I took my time carefully as I didn’t want to bugger up an expensive blade. I still have my carbide grinder (Foley) and I sharpen my own blades. I couldn’t get anywhere as good a sharpening as shown in the video.

View HokieKen's profile

HokieKen

20733 posts in 2480 days


#11 posted 12-06-2021 08:06 PM

For machine tools, if you want a mirror surface finish with no tool marks, you use a single-point cutting tool that’s beefy and rigid. If you want a glass-smooth cut surface, get a blade with a 1/4” saw plate and a single cutting tooth. The blade has to be balanced to accommodate the single cutter and the saw has to be set up well. You’ll also need to be able to vary spindle speed and maintain constant feed rates depending on the wood being cut. Which needs to be dead flat. And your miter gauge and/or fence have to be dialed in perfectly too.

I guess my point is that comparing the finish achieved by machine tools in metal to the finish in wood off a table saw blade isn’t really a valid comparison :-)

-- I collect hobbies. There is no sense in limiting yourself (Don W) - - - - - - - - Kenny in SW VA

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Madmark2

3264 posts in 1930 days


#12 posted 12-06-2021 08:19 PM

Like any chain, a cutting system (saw, blade, fence, material, technique) is only as strong as the weakest link. Upgrading to a top end blade isn’t going to help your cuts if your fence is sloppy or if your saw wobbles.

Don’t let “perfection” get in the way of “good enough to sell”. A little, say tear out, on a hidden piece isn’t going to show or impact the fit. Most wood pieces aren’t visible for close inspection on all six sides so even a bad chunk of tearout can be easily hidden. Not every edge of every piece is critical. Table tops & frames get a lot of scrutiny. Undersides, insides, and backs, no so much. Overdoing things that never show is a waste of time, resource, and aggravation.

My saw is tuned and aligned. It spins smoothly and is dead-on square (parallel) to the miter slot. I use a ZCI and keep things nicely waxed.

I use Freud “triple ground” (top & both sides) blades that leave glassy crosscuts and gluable rips. I keep my blade lightly waxed and crank it down after cutting to prevent kickback, unplanned depth of cuts, and flanging it with the rip fence.

I use an Incra rip fence & miter gage for repeatable cuts on multiples of 1/32” +- 0.002”. Both are true in all three axis and carefully zeroed. I have the M1000 miter gage for precise angles and a Wixey angle cube for setting bevels. I use a Digital height gage for setting bit/blade heights for accurate dado’s and rabbets.

Hardwoods tear out less than soft. Tear out is essentially eliminated by using a sacrificial backer. Some woods (like fir) are stringey and tend to tear more than others. Wood moves in minutes so holding 0.001” is generally unrealistic. A too smooth finish may actually impede gluing as most glues like a little “tooth” for best grip.

Swirls also show in soft woods more than hard. They tend to show more at fast feed rates than slow. Generally swirls indicate slight misalignment (lack of parallelism) between the blade and fence. The fence is usually the culprit as many don’t lock perfectly, flex, or shift alignment. This is the reason I moved to Incra fences 20+ years ago and never looked back.

Technique helps in using backer boards, appropriate feed rate, proper hold downs, etc.

If museum quality work was easy, everyone would be doing it.

-- The hump with the stump and the pump!

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MrRon

6260 posts in 4585 days


#13 posted 12-06-2021 08:27 PM



For machine tools, if you want a mirror surface finish with no tool marks, you use a single-point cutting tool that s beefy and rigid. If you want a glass-smooth cut surface, get a blade with a 1/4” saw plate and a single cutting tooth. The blade has to be balanced to accommodate the single cutter and the saw has to be set up well. You ll also need to be able to vary spindle speed and maintain constant feed rates depending on the wood being cut. Which needs to be dead flat. And your miter gauge and/or fence have to be dialed in perfectly too.

I guess my point is that comparing the finish achieved by machine tools in metal to the finish in wood off a table saw blade isn t really a valid comparison :-)

- HokieKen

True, a metal cutting machine is more precise than a wood cutting machine. I have both metal and wood cutting machines in my shop. I can work to thousands and tens of thousands on my lathe and milling machine so you can see not getting precision cuts on my wood saw bothers me. When I’m woodworking, I tend to apply metal working tolerances.

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SMP

5085 posts in 1247 days


#14 posted 12-06-2021 09:34 PM



True, a metal cutting machine is more precise than a wood cutting machine. I have both metal and wood cutting machines in my shop. I can work to thousands and tens of thousands on my lathe and milling machine so you can see not getting precision cuts on my wood saw bothers me. When I m woodworking, I tend to apply metal working tolerances.

- MrRon

Just don’t check double check your work 6 months later when the wood has swelled/shrunk 1/8” with its season expansion! That’ll really freak you out!

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HokieKen

20733 posts in 2480 days


#15 posted 12-06-2021 09:43 PM


True, a metal cutting machine is more precise than a wood cutting machine. I have both metal and wood cutting machines in my shop. I can work to thousands and tens of thousands on my lathe and milling machine so you can see not getting precision cuts on my wood saw bothers me. When I m woodworking, I tend to apply metal working tolerances.

- MrRon

That pretty well sums up the learning curve for me when I first started dabbling in woodworking :-)

-- I collect hobbies. There is no sense in limiting yourself (Don W) - - - - - - - - Kenny in SW VA

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