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I picked up a radial arm saw at a yard sale last summer. I know many woodworkers don't like them. I tuned it up and put a $70 Rigid 90 tooth blade on it. It cuts beautiful. The only problem when it contacts the wood it wants to grab and shoot across the table at you. I just figured it was an unavoidable part of the design. Maybe this is common knowledge to you veteran woodworkers but I just learned about hook angle.The angle of the took referenced off the arbor. It you have 0% or as close as possible to that, it won't grab. Now my only problem is I have a 6 month old like new $70 blade. Hopefully this was helpful to someone.
 

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If you have a 10" saw, a 90T blade is way too fine except for very thin materials and veneers.

Your best choice would be a negative hook carbide tipped blade and up to and including a 60T for most crosscuts requiring a smooth cut. A lesser tooth count would cut even easier, especially in stock thicker than 3/4".




 

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I use a Forrest Woodworker I, 60 tooth ATB for my RAS. It works great. On stock 2" thick or so, I have to make the cut with a "stiff arm" as it will have a tendency to climb through the stock. Not a good place to have your hand, BTW.
 

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I obviously have a lot to learn, but when I bought the blade, it was before I had my table saw. I was trying to get some precision cuts out of it. It did work for what I was trying to do at the time. The other day when I was talking to the pro that told me about the neg. hook, I don't think he mention the # of teeth. I did talk to him for about an hour and half. I might have missed that part I guess I should pull it off. It's scary. Negative hook 60 Tooth. Got it. Thanks.
 

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Hi bigredc

I was watching some one cutting with a radial arm saw on a program and I noticed that they pulled the motor out to the end of the arm, loaded the board to be cut into the saw, and then turned the saw on. They then cut the board by sliding the saw back toward the post. I wasn't quite sure why they were doing it this way until I tried it with my own saw. No more grabbing and dancing across the table at me.

For years I was sawing from post out, and experiencing exactly what you described. Most of the time now I saw inwards, and have no more problems. Give it a try.

I guess the logical explanation is that if you are sawing outward you are pulling the saw into the cut, and it already wants to pull itself along due to the blade rotation. When you cut inwards you are pushing the blade in the opposite direction that it wants to travel and this gives you a lot more control.

Gerry

PS: I also found that having a little friction on the slider lock knob gives you some additional control.

Gerry
 

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I like that. I'd rather not have to buy another new blade. Now that I have a Freud on my table saw. I would have to buy a Freud for it. $$$$. I'm hooked on Freud.
 

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I like that. I'd rather not have to buy another new blade. Now that I have a Freud on my table saw. I would have to buy a Freud for it. $$$$. I'm hooked on Freud.
Let me know how it goes. I hope I have sent you in the right direction, but if not, I want to know that too.

Best regards.

Gerry:thumbsup: :thumbsup:
 

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RAS Blades

I've had a RAS for about 35 years. If you want the safest blade, you want a negative rake blade. If you use a positive hook blade, it has a tendency to want to feed itself, causing the blade to want to climb the board unless you hold it back. Many of the blades listed for miter saws etc are negative rake, just check the label. 90 tooth is awfully high, depending on what you are cutting, something more in a 40-60 tooth would do you better.

Paul
 

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Discussion Starter #9
Gerry it worked like a champ. Sweet. No new blade for now. I have a nice Dewalt 12" miter saw also, so I only use the radial arm once in a while now.
 

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Gerry it worked like a champ. Sweet. No new blade for now. I have a nice Dewalt 12" miter saw also, so I only use the radial arm once in a while now.
Very glad I could help out bigredc. I feel like I have contributed something useful now.

I found the post about the negative rake angle teeth interesting too. I am considering getting a cross sliding compound miter saw, and I expect the same problem would arise with that type of saw also.

Gerry:thumbsup:
 

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I've had a RAS for about 35 years. If you want the safest blade, you want a negative rake blade. If you use a positive hook blade, it has a tendency to want to feed itself, causing the blade to want to climb the board unless you hold it back. Many of the blades listed for miter saws etc are negative rake, just check the label. 90 tooth is awfully high, depending on what you are cutting, something more in a 40-60 tooth would do you better.

Paul
Thank you for the input. I didn't even know there was such a thing, but it certainly makes sense.

Gerry
 

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Hi bigredc

I was watching some one cutting with a radial arm saw on a program and I noticed that they pulled the motor out to the end of the arm, loaded the board to be cut into the saw, and then turned the saw on. They then cut the board by sliding the saw back toward the post.


This is correct. But If it just isn't possible to do it this way then pull it as slow as you can and hold on tight. knowing how to use the tool, cuts your work time in half. Oh yea and may save a finger or two.
 

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Hi Handyman

I definitely hold on tight if I am cutting outwards, and as I mentioned, I like to have a little friction on the slide lock too. I shudder to think what that puppy would do to a hand if you lost control, and were in the wrong place at the wrong time.

Gerry
 

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Ok...I have to step in here for clarification: The difference in a "positive" tooth profile and a "negative" profile is that a negative has no hook, or rather, cuts by literally "rubbing" the material off, as opposed to "peeling" it as in a conventional tooth profile. Now here is the interesting part. As a machinist knows, any negative rake or "hook" on a cutting tool will not "climb" into a cut, but rather must be forced, and it takes a lot of power to cut with neutral or negative profiles....many general use woodworking tools, like the common RAS by Sears (Emerson Electric) won't perform well with these blades.

On the positive, the cut from a neutral or negative hook is usually great, since they do not "tearout" the material in the cut.

Cutting from the front of the saw to the post changes the equation, since the operator is not trying to "climb" the blade in the cut, or rather, on top of the cut. This application would see little advantage to a negative rake blade. For those of you that wonder about this, think of the applications where you take an old skil saw blade and reverse it to cut plastic, or thin plywood...a trick I learned before I knew the why. When cutting vinyl siding, we use a dull carbide blade reversed in the saw for great effect.
 

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I jst came across this discussion and the piece about cutting "backwards" with a RAS is intriguing. Question: do you remove the blade and reverse it, or leave it as is for "normal" sawing? I'm going to wait until I get a reply before I try it. tom in vt.
 

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Hi Handyman

I definitely hold on tight if I am cutting outwards, and as I mentioned, I like to have a little friction on the slide lock too. I shudder to think what that puppy would do to a hand if you lost control, and were in the wrong place at the wrong time.

Gerry
My new Craftsman RAS that I haven't gotten to use yet is supposed to have a electronic feed or feed speed control to prevent the climbing.

I know first hand what a table saw can do a hand but the RAS kinda makes me crinch thinking about it.
 

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I jst came across this discussion and the piece about cutting "backwards" with a RAS is intriguing. Question: do you remove the blade and reverse it, or leave it as is for "normal" sawing? I'm going to wait until I get a reply before I try it. tom in vt.

The blade stays the same way....DON'T DO IT! :no:

It is much more dangerous! :thumbdown:
 

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I jst came across this discussion and the piece about cutting "backwards" with a RAS is intriguing. Question: do you remove the blade and reverse it, or leave it as is for "normal" sawing? I'm going to wait until I get a reply before I try it. tom in vt.

I would strongly recommend using tools and blades the way they were intended. If you have doubts what that is...read your owners manual. The most common method for cutting is with the saw seated to the rear, the subject material is placed against the fence, and the saw is pulled through. You could pull the saw all the way out, place the material against the fence, turn on the saw, and push the saw to the rear.


That procedure IMO, is movement intensive. With the saw out, you have to set the material, and maybe reach on both sides to get it where you want it. In any case do not reverse the mounting of the blade. Using a carbide tipped blade backwards can knock off the carbide teeth (tips).


Heavy users of RAS's use a cutterhead return, which is a recoil that returns the saw motor to the rear from any distance on the arm. It's a great safety feature. Some codes require professional shops to have them installed.






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In all the RAS manuals it says "PULL"

As there is a simple reason. With the saw resting behind the fence and the workpiece securely held against it with Left hand , you slowly PULL the blade into the work. offering a little resistence as you PULL toward you.
Now for the reason, as the teeth first enter the work, the cutting action of the spinning teeth is pushing the work downwards into the table regardless of the type of hook, pos or neg. This pushing action continues until the work is cut through.
If you were to PUSH the blade as it's held against the fence, the first teeth contacting the work would tend to lift it up off the table..:thumbdown: NOT good!:no: It's really simple physics, not personal preference or emotion or habit or "that's the way my Dad did it. Every RAS I've ever seen in a lumber yard or cabinet shop or wholesale mill is pulled into the work.

Under no circumstances do not reverse the blade on the arbor. IT may not pose a safety issue but it won't cut worth a damn, just make friction only and make lots of smoke. ;) bill
 
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