Table Saw blade height

[Aaron Beaver]

Whats your opinions on this? I have seen every where from no more than 1/8" above the wood all the way up to 1" above the wood, BTW the 1" was on the information sheet from Forrest.

[Stu Ablett in Tokyo Japan]

Hi Aaron, I was always told that you want the gullets between each tooth to clear the top of the wood that you are cutting.

Just what I was taught, YEARS ago......... :rolleyes:

[Jim Cunningham]

I'm with Stu,

I have read that you want the gullet to just clear the work in order that the sawdust be exppelled

[Steve Clardy]

Probably higher than most folks.
Less chance of kickback.
Running a blade low has the tendency to push the board up.

[Eddie Darby]

Decisions decisions decisions!

What are you after? A good cut (cross-cut High blade, or a rip-cut Low blade).
Safety ( low as possible ).
Blade longevity ( gullet clearance )?

Blade height was told to me by Forrest blade reps. :rolleyes:

I go with the best blade for the job, with blade stiffners, to get the best quality of cut, and I just clear the gullets for the best safety and blade indurance.

[Jim Hager]

I of course have a different opinion:D I always run my blade with 3 teeth points showing above the material. I teach 8th and 9th grade students this method at school each day and there are definate reasons that I teach that way. 1. Kids are gonna get kickbacks so when one happens if their hand gets drug across the blade backwards when sawing say a 1/4" plywood panel, the blade will not have access to but a fraction of an inch of their hand. 2. We use splitters and guards on our tools here at school ( I don't at home) and the chances of a kickback are minimal but they sometimes happen anyway. 3. I use power feeders as much as possible at home and I have to run the blade low to accomodate the feeder. 4. In my own shop I get awfully close to the blade sometimes with my fingers, the lowered blade at least for me makes it much safer. I do lots of rp doors and routinely rip 2 3/8" pieces with my hand and not a push block.

Just my opinions, not to be taken for the gospel for sure.

[Eddie Darby]

I was taught that kick-back occurs at the back of the blade, when the wood is gripped by the rear teeth, and then lifted and shot forward by the blade. A higher blade equates to a better chance of the wood being lifted. The splitter is to stop the grab of the rear teeth in the first place.

[Cliff Rohrabacher]

High blade settings spray me with saw dust So I prefer to keep it lower. Yah Yah blade guard. I don't use 'em.

Also cutting all those extra air molecules above the work burns extra power doesn't it?

I find that my blades don't burn period. I use a Non-ferrous metal blade w/ Pos rake as opposed to a blade ground for wood. It leaves no tool marks. I rip and cross with the same blade.

[Aaron Beaver]

One of the reasons stated as for wood burning was having the blade to low, that's why I was suprised to see another place say 1/8" but they were stating that for the safety factors like Jim mentioned

[tod evans]

it`s very seldom that i pay attention to blade height, i usually just leave it from my last use. if i was cutting 8/4 and now need to cut 1/4" ply i just do it.....but i too was taught to leave at least one full gullet above the work.....02 tod

[Bob Swenson]

Jim- It looks like you would be a good candidate for a “Sawstop”.


Ten finger Bob.:cool:

[Ed Kowaski]

Chip out on top, raise the blade, chip out on the bottom lower the blade. Having said that my approach is generally the same as tod's

[Eddie Darby]

Somewhat intrigued by this thread, I went and found that Ryobi says in their manual: "The blade depth should be set so that the outer points of the blade are higher than the workpiece by approximately 1/8 in. to 1/4 in. but the lowest points (gullets) are below the top surface."

If I was running a school shop it would be an absolute necessity to have a SawStop! The whole concept of kick-back is a daunting one for beginners let alone experts to have to deal with. If you want to reduce the number of people who enjoy woodworking, then just increase the number of accidents!

[Charles McCracken]

I'm with Stu,

I have read that you want the gullet to just clear the work in order that the sawdust be exppelled

Jim,

Sawdust is expelled under the wood after the leading teeth have made the cut so the blade height won't help with that.


All,

The idea that a blade will burn if not raised high enough is from using the blade that is not designed specifically for the application. You should have 3 to 5 teeth working in the wood for ripping and 5 to 7 for crosscuts. If you use a 60 tooth crosscut blade and raise it all the way (not recommended!!) you will have the correct number of teeth in the wood for ripping 3/4" stock but the blade geometry will be all wrong. When using the correct Freud blade for the application you will only need the blade 1/8" to 1/4" above the material.

[Eddie Darby]

This would make for a great article in one of the woodworking magazines.

[Aaron Beaver]

All,

The idea that a blade will burn if not raised high enough is from using the blade that is not designed specifically for the application. You should have 3 to 5 teeth working in the wood for ripping and 5 to 7 for crosscuts. If you use a 60 tooth crosscut blade and raise it all the way (not recommended!!) you will have the correct number of teeth in the wood for ripping 3/4" stock but the blade geometry will be all wrong. When using the correct Freud blade for the application you will only need the blade 1/8" to 1/4" above the material.
What about the blades that are good for both, ie. Freud's Premier Blades? Still same rule as far as teeth in the wood?

Also, is there a way to tell how many teeth are ingaging the wood are one time?

[Tom Jones III]

Also, is there a way to tell how many teeth are ingaging the wood are one time?[/quote]

Just set the piece of wood you are going to cut beside the blade and raise the blade to the correct height. When it is at the correct height, count the teeth.

Charles, it sounds like another way to say 1/8" or 1/4" above the wood is to raise the blade so that the topmost tooth is half to completely out of the wood. Is that accurate?

[Charles McCracken]

What about the blades that are good for both, ie. Freud's Premier Blades? Still same rule as far as teeth in the wood?

Also, is there a way to tell how many teeth are ingaging the wood are one time?

The general purpose and combination blades are the main exceptions to the rule.

Tom has the right idea for determining the number of teeth (just make sure the saw has no power).

[Charles McCracken]

Charles, it sounds like another way to say 1/8" or 1/4" above the wood is to raise the blade so that the topmost tooth is half to completely out of the wood. Is that accurate?

That's correct. I usually use the term 1/2 of a carbide tip above the material but went with the measurement to be consistent with the earlier posts.

[Bob Childress]

There seem to be as many opinions on this as there are members. Imagine that!

An interesting article I read a year or so ago argues that to minimize kickback opportunity the saw blade should be 1 to 1 1/2 " above the workpiece. If you want to explore his logic, here a link to the article:

http://home.att.net/~waterfront-woods/Articles/Tablesaw/tablesaw.htm

In summary, it says that the lower profile exerts more backward force than downward force because the low teeth are pushing the piece backward. With a higher blade setting the teeth exert more downward force. Don't know if he is right, but his logic seemed good and I have been setting the saw blade somewhat higher since reading it. Using both a Hitachi blade and (mainly) an LU84, with good results so far.

[Steve Clardy]

There seem to be as many opinions on this as there are members. Imagine that!

An interesting article I read a year or so ago argues that to minimize kickback opportunity the saw blade should be 1 to 1 1/2 " above the workpiece. If you want to explore his logic, here a link to the article:

http://home.att.net/~waterfront-woods/Articles/Tablesaw/tablesaw.htm

In summary, it says that the lower profile exerts more backward force than downward force because the low teeth are pushing the piece backward. With a higher blade setting the teeth exert more downward force. Don't know if he is right, but his logic seemed good and I have been setting the saw blade somewhat higher since reading it. Using both a Hitachi blade and (mainly) an LU84, with good results so far.


Exactly why I set mine higher. Think of the long low arc the blade is making in a chunk of wood. Blade higher, less arc.

[Cliff Rohrabacher]

If I was running a school shop it would be an absolute necessity to have a SawStop! The whole concept of kick-back is a daunting one for beginners let alone experts to have to deal with. If you want to reduce the number of people who enjoy woodworking, then just increase the number of accidents!

I hope the idea of a saw stop would be for something other than kickbacks.

[Aaron Beaver]

There seem to be as many opinions on this as there are members. Imagine that!

An interesting article I read a year or so ago argues that to minimize kickback opportunity the saw blade should be 1 to 1 1/2 " above the workpiece. If you want to explore his logic, here a link to the article:

http://home.att.net/~waterfront-woods/Articles/Tablesaw/tablesaw.htm (http://home.att.net/%7Ewaterfront-woods/Articles/Tablesaw/tablesaw.htm)

In summary, it says that the lower profile exerts more backward force than downward force because the low teeth are pushing the piece backward. With a higher blade setting the teeth exert more downward force. Don't know if he is right, but his logic seemed good and I have been setting the saw blade somewhat higher since reading it. Using both a Hitachi blade and (mainly) an LU84, with good results so far.

This seems opposite of what Eddie said in Pos #7 about a higher blade lifting the piece from the back when it comes out of the saw. Definetly would be a good magazine test report.

[Alan DuBoff]

Exactly why I set mine higher. Think of the long low arc the blade is making in a chunk of wood. Blade higher, less arc.Steve,

I have read this several times and really think about the direction of force issue. I can't help but think it is more safe to have the blade higher in that regard, it does expose a great deal of blade if you do not use a guard.

The point Jim makes about kids hands not having much blade to cut their hand on a kickback with plywood for instance, seems to counter this point, but it seems that having the blade low would cause more kickbacks than if it otherwise hadn't been so low.

It seems to make sense to have the blade as high as possible, if one has a guard over the top of it. This is what I'm planning to do with the 5HP table saw I'm getting going.

[Steve Clardy]

Yes. To me its a either this or this situation.
To run the risk of more possible kickbacks with a low blade, or run the risk of hand, finger injury due to high blades.

I run no guards, only a kerf splitter.
Like Jim, I run lots of pieces, with my hands close to the blade.
2" is about as close as I will go without using a pushstick.

I'd rather run a higher blade than have a kickback.
I've had a couple of nasty kickbacks over the years.
I run saws almost every day, so am well aware of the dangers.
And I do have all ten, and hope to keep them.

Different strokes for different folks

[Rick Christopherson]

I of course have a different opinion:D I always run my blade with 3 teeth points showing above the material. I teach 8th and 9th grade students this method at school each day and there are definate reasons that I teach that way. 1. Kids are gonna get kickbacks so when one happens if their hand gets drug across the blade backwards when sawing say a 1/4" plywood panel, the blade will not have access to but a fraction of an inch of their hand. 2. We use splitters and guards on our tools here at school ( I don't at home) and the chances of a kickback are minimal but they sometimes happen anyway. 3. I use power feeders as much as possible at home and I have to run the blade low to accomodate the feeder. 4. In my own shop I get awfully close to the blade sometimes with my fingers, the lowered blade at least for me makes it much safer. I do lots of rp doors and routinely rip 2 3/8" pieces with my hand and not a push block.

Just my opinions, not to be taken for the gospel for sure.Jim,
The problem with this rationale is that your low blade height actually increases the chances for the kickback that you are trying to minimize the damage from. In other words, you may reduce the damage resulting from a kickback, but in the process actually increase the likelihood and frequency of having the kickback occur in the first place.

I have been noticing lately that a lot of woodworkers assume that all kickbacks are the same, and their cause is the same, but this is very far from the truth. There are a lot of different causes for kickbacks, but most of them can be traced back to the low blade height.

I strongly oppose the notion that any sawblade should be raised no more than 1/8-1/4 inch above the workpiece.

The graphic below is one I created recently for a legal case, but conveys the same information I presented several years ago when I first wrote my article on tablesaw safety. (I haven't reformatted this image for the internet, so it will come out very large on your screen. I apologize if this image is not converted to a thumbnail view for the thread...... NOPE! didn't work, so I will manually resize the image so it is not so large.)

http://waterfront-woods.home.att.net/tempgraphics/RAC-10-low.jpg

[Rick Christopherson]

I was taught that kick-back occurs at the back of the blade, when the wood is gripped by the rear teeth, and then lifted and shot forward by the blade. A higher blade equates to a better chance of the wood being lifted. The splitter is to stop the grab of the rear teeth in the first place.
No, this is the opposite of actual. Consider how much effort it takes to ride a bicycle up a hill. Even though two hills are just 10 feet in elevation, it is easier to ride your bike up to the 10-foot rise if it is a gradual slope versus a steep slope. The same is true for how easy it is for a workpiece to lift off the table from the back of the blade. The wood will lift easier when the blade is low and the slope is shallow.

[Steve Rowe]

I raise mine to clear about 1/8" above the wood. I have seen the demonstration of the Forrest by 3D Sales (if I remember correctly) at one of the Woodworking Shows. The stated basis for this was soley to get a cleaner cut. I bought the blade and tried their method and mine and found essentially zero difference in the quality of the cut.

Since then, I have been to Marc Adams School and Kelly Mehlers School. Both of these schools require the blade to be raised no higher than necessary to make the cut. Kelly is the author of the Tablesaw Book and a DVD on Mastering the Tablesaw. I will continue to rely on these folks as experts on tablesaw safety as their logic on this topic makes a lot of sense to me. Given the fact that most woodworkers remove the guards and splitters from their tablesaws, is seems like an unnecessary risk to have blades sticking way above the workpiece.

With respect to the gullet theory to clear the chips, I have heard that long ago as well. This stated purpose doesn't make sense since the blade is cutting on its way down and not up, hence there are no chips to clear above the wood. There is a lot more gullet clear of the workpiece below the table than could ever exist above it.

Just my .02 (which BTW is worth a lot less today than it was 20 years ago since it has not been adjusted for inflation)

Steve

[Chris Padilla]

Use a bandsaw for ripping...hazard minimized! :)

[Aaron Beaver]

Jim,
The problem with this rationale is that your low blade height actually increases the chances for the kickback that you are trying to minimize the damage from. In other words, you may reduce the damage resulting from a kickback, but in the process actually increase the likelihood and frequency of having the kickback occur in the first place.

I have been noticing lately that a lot of woodworkers assume that all kickbacks are the same, and their cause is the same, but this is very far from the truth. There are a lot of different causes for kickbacks, but most of them can be traced back to the low blade height.

I strongly oppose the notion that any sawblade should be raised no more than 1/8-1/4 inch above the workpiece.

The graphic below is one I created recently for a legal case, but conveys the same information I presented several years ago when I first wrote my article on tablesaw safety. (I haven't reformatted this image for the internet, so it will come out very large on your screen. I apologize if this image is not converted to a thumbnail view for the thread...... NOPE! didn't work, so I will manually resize the image so it is not so large.)

http://waterfront-woods.home.att.net/tempgraphics/RAC-10-low.jpg

Thanks for the pictures, not sure which way to go but higher "seems" to be better but there is always going to be a debate. Goona have people that run it low and never have a problem and same with high. The paper that came with my Forrest blade said to run it high so I will go with that for now.

[Frank Fusco]

I had hoped for a clear cut answer to this question. Lots of good information but still a variety of opinions. Not complaining, just pointing it out. Actually, this is no different than many other subjects. Another passion of mine, sport shooting and guns. Ask on a forum for advice, fifty responses will get you sixty opinions. As for the kick-back question, I have had one very nasty kick-back. The 'kick' without a doubt came from the back of the blade. I saw it happening a tiny fraction of a second before getting hit in the solar plexus and going down for the count.

[Ian Barley]

I'm with tod in not giving it much attention but I generally have the blade showing at least an inch or so just because I sometimes cut 2" stock but usually cut 1" stock. After that the pros of one choices seem to balance out the cons of the other.

[Jim Becker]

With the exception of very thin strips that I need to be able to ride the push block over the blade, I raise the blade above the wood so at least one gullet fully clears the wood most of the time. For the former, it's just high enough to make the cut through plus a "scoosh". (Technical term... :) )

[Steve Clardy]

With the exception of very thin strips that I need to be able to ride the push block over the blade, I raise the blade above the wood so at least one gullet fully clears the wood most of the time. For the former, it's just high enough to make the cut through plus a "scoosh". (Technical term... :) )


Is you "scoosh" a hair, or half a hair:confused: ;) :)