Is it ill-advised to used a stacked dado set on a radial arm saw? I was told once that it will work, but be very careful and (yes) push the saw into the board rather than pull it toward you as you normally would. This, he said, will overcome the tendency of the saw to climb up on the board because of the saw’s extreme tork and the rake angle’s being designed for a tablesaw. He told me this when I said I was planning on using the dado set on a 1950s vintage Dewalt 16-inch RA saw.
Any experience with this? I will cancel the idea if it’s a dangerous prospect.
Replies
Dado cuts on a radial arm saw are not inherently more dangerous than other cuts, particularly when using one of the many negative hook (rake) stacked sets. Check the operator's manual for the saw or contact the manufacturer to make sure it is advised, what size to get, whether to push or pull the cut and that you have the proper guards.
Charles M
Freud, Inc.
Charles MC,
You seem to be associated with Freud right? I've been using my Freud stacked dado set for many years and love it.
I have a question. It never occured to me to pust it through the work piece using my DeWalt 10" Radial Arm Contractors saw. I've always pulled it. Sometime that gets a little hairy. Is pushing a Freud stacked dado an acceptable procedure?
I believe that most machine manufacturers recommend pulling rather than pushing. The reasoning, as I understand it, is that pushing will tend to lift the material off the table which can be dangerous. If you get too much self-feed by pulling you may be attempting to remove too much material in one pass. We all know that a RAS wants to self-feed anyway but trying to take too much bite will amplify the effect. Again, I will defer to the manufacturer of the machine for the final answer.
Charles M
Freud, Inc.
Charles,
I'm going to disagree with you here. I know that you give good advice. But regarding this issue, if you advise against using the dado on the RAS, you are advising against the freud product also. And that puts you in a conflict.
I unequivocally advise against using a dado on a RAS. Hell, I advise against it on a table saw where it's safer. But on a RAS, it compounds the inherent danger in the saw's known problem - climbing over the wood.
I do not care how many workers attest to their years of using a dado on a RAS. It's an unsafe practice. It's as bad as using a table saw without guards and a splitter, and I've gone on record against that also. If a safety cable on a RAS prevents climb, good. Use it for cross cutting , not dadoing.
I do not allow ripping or use of a dado on a RAS. They are foolishly dangerous processes, much better accomplished by other means.
Spend $200 on a router and do the job safely. Or use hand tools. Your limbs are worth much more.
Rich
Edited 11/5/2002 1:33:47 AM ET by Rich Rose
Rich,
I don't disagree with your comments on safety and the radial arm saw. I do disagree that the dado is more dangerous than crosscutting when done correctly. I would never espouse a practice that I felt was dangerous even if I tohought it would affect product sales. Sure, if you stack 3/4" of dado and attempt to cut a 1/2" deep dado there would be a tremendous amount of force pulling the head toward you. But the same dado cutting 1/8" to 1/4" deep would have force more equal to a crosscut in 2" stock. Besides, we offer dado sets that have negative hook angles that are designed to produce less chipping in veneers and laminates and that also lessens the effects of self-feeding. As I said, you should consult the manufacturer of the saw for recommendations of whether a dado can be used, what guards and safety precautions are necessary and how much material can safely be removed with each cut.
Charles M
Freud, Inc.
My old Monkey Ward RAS has a braking mechanism on the arm that will keep it from trying to lurch forward. I did use it all the time for crosscut dado's back when I did cabinets. Never tried dado's in the rip direction - was to chicken! I once tried to rip a board on it and learned that was not something one should do.
Now that I think about it, a RAR would be nice to have. Radial Arm Router! Anyone ever see one?? Would this be the same as an overarm router? My Wards RAS has a 3rd spindle that turns at 20,000 rpm and I used it a lot, but never for cutting dado's that I can remember.
PlaneWood by Mike_in_KatyPlaneWood
Mike,
The RAR router is a viable concept, but flawed compared to the next step in the evolution of that machine.
With the router mounted above the work, it is at the end of a flexible arm (accuracy problems), it is loud and in the face of the operator (safety issues) and dust and chips are flying everywhere, especially at the operator (safety and accuracy in seeing the work issues).
Much better design is the pin router which places it below the table and the work with the radial arm holding a pin which simply references the position of the router bit below. The pin guides templates, patterns, etc. in wonderful quiet, freedom from dust and chips, extreme safety and high accuracy.
R
Given the amount of wood being removed at once by a stacked Dado blade would you say that a wobble plate type of dado would be less likely to climb and therefore actually be safer?
Thanks
John
http://www.craftsman-furniture.com/shop.html
John- To answer your question- no. It all comes down to how much of a bite you take with either blade. Like a router table ,take multiple bites , everything in degrees. Also wobble blades don't cleanout as good as stacked and why would you want something that wobbles on your motor shaft that is meant to run true. In the long run it can't be good for the motor's bearings. - Kris
KRISLU is correct. The amount of load on the machine and the amount of pull generated by the cutter are relative to the amount of material removed and the hook angle of the cutter. A wobble will produce the same forces as a stack of equal hook angle except, as noted, the addition of the wobble to the arbor. To my knowledge, the only machine manufacturers that endorse the use of wobble dado cutters are the ones that also sell wobbles and there are no wobble dadoes that I'm aware of that have negative hook angles.
Charles m
Freud, Inc.
Where can one find dado blades with zero or negative hook angles?
Freud offers the SD200 series and the SD500 series with -12° hook angles. They are available in 6" and 8" diameters:
The SD206 Pro Dado is a 6" diameter with 10 teeth on each outside blade and two wing chippers.
The SD208 Pro Dado is a 8" diameter with 12 teeth on each outside blade and two wing chippers.
The SD506 Super Dado is a 6" diameter with 20 teeth on each outside blade, four wing chippers and an extra 3/32" chipper.
The SD508 Super Dado is a 8" diameter with 24 teeth on each outside blade, four wing chippers and an extra 3/32" chipper.
Any Freud dealer can provide these. Many Lowe's and Home Depot stores carry the SD208 and you can check the dealer locator on our website:
http://www.freudtools.com
Charles M
Freud, Inc.
Rich -
Respectfully, you are wrong about the RAS. Dadoes, in fact all cross cutting operations, are far safer on the RAS that a TS. Why? Because you can see the blade on the dado. No guessing. Crosscutting, any kickback goes away from you unlike a table saw, and there is no need to move heavy or awkward pieces, as the saw carriage moves.
IF you-
1 - properly set up the machine. This means dead on with no play. With an older DeWalt, this is no problem. Many other saws cannot be set up right. I think this is the cause of much confusion. Mine is accurate to .002"
2 - low, or preferably, negative hook angle blade. This pretty much eliminates self feeding.
3 - know and understand the machine. People lavish care and learning on the use of their tablesaws. When the cut is incorrect, the user assumes it is their fault. People never bother to set up or to learn the proper operation of a RAS and blame the machine when the cut is incorrect.
I really don't want to start an argument. I sit out almost all of these discussions, but couldn't help myself here. I'm a DeWalt RAS devotee. In fact, I like mine (1956 MBF) so much that I realize I don't need a table saw. There is nothing that can be done on a table saw that cannot be done as well and as safely on a RAS. Knowledge and understanding are the key.
If some of you out there want to really learn how to use the RAS go the the late Wally Kunkel's website at http://www.mrsawdust.com. Buy his book and read it carefully. I have no connection with them other than a desire to have folks really know the value of the DeWalt RAS.
Mike Prisbylla
The House Fixer
Pittsburgh PA
It's a DeWalt thing, you wouldn't understand
Mike- I could not have said It Better !!!!!!!
Ditto Mike, its all in knowing your tools and how to use them. Funny, when I first got interested in wood working I was extremely frightened by whirring blades, etc. Now that I've had a chance to work with a few three fingered folks I'm no less frightened but I've learned to read the manuals more carefully.
Dont get me wrong, safety for myself is a definite concern but if we get down to it, droping a toilet seat on your #### when your three years old can cause permanent damage also... And... Those darn things dont come with instructions that a three year old can read....
Bottom line.... If you don't know what your doing with a tool ask for help from someone that does... I assume that is the reason for the original post.
I’m delighted to know that you own, have fully tuned up avidly use the same saw that we own. We got ours in 1970 when we were doing a major remodelling; it never got the place it deserved, until now. It’s got a very pleasant and central place in our new 24x34-foot shop extension, along one of the long walls with infeed and outfeed fences all lined up. We put it in line with our Dewalt compound miter saw, as well as a dewalt 12 inch planer, which slides out of the way when not in use.
Last year we got a manual for it and did some basic tuning: took the play out and got it adjusted square. Yesterday I checked out the book you mentioned, mastering the RAS. Fascinating.
Also, in the RAS manual, among its functions are listed routing and shaping. I talked with the company that sells parts and maintains these old machines (can’t recall their name right now), and one of the techs told me they don’t sell the router/shaper head anymore because too many woodworkers got hurt with them (including him!). So I abandoned pursuing that feature, though it had sounded like a useful function.
One question I have is on the guard. Our saw didn’t come with a guard. Do you use one? I understand there are two options: the shoe guard that climbs up over the board as you make the cut, and the chain guard. Any recommendations?
Also, out vertical adjustment crank is very stiff. Do we need to take it apart to clean it up?
Frankly, at this point we don’t use the saw very much, because we have the other dewalt; and it’s incredibly noisy (and rather intimidating with no guard). I was told that the noise (must be audible a couple miles away) might be caused by the blade. We have a 16 inch Freud combination blade on it. Are they naturally so loud? We do love the saw--quite a wonderful piece of equipment.
The noise from the blade is likely caused by the lack of a guard. Even with a guard, the combination style blades on a RAS can make noise. The large gullets every 5 teeth catch a lot of wind and have a siren effect. Perhaps someone who has a similar saw can recommend a guard that will be ear friendly.
Charles M
Freud, Inc.
It is the fact that there is no guard which is why it is so loud. I use the Freud Lu8411 combo ( no affiliation with Freud) on my ras and tablesaw and both machines are perfectly acceptable noise wise. Also blade size attributes to noise, the bigger the blade the more noise you will have. My ras is a 12" but I always use the lu8411 ( which is a 10" blade). I do have on hand a Freud lu84r012 (which is Freud's 12" combo blade) just in case I need more cutting capacity. When I use the 12" blade there is a lot more noise! - Kris
The noise could be the bearings showing their age. I have an old Monkey Ward RAS and its screeches like a banshee. The bearings have been replaced on it once. As far as the crank being stiff, a cleaning could be the solution. I am not sure how the elevation mechanism in yours works, but mine has basically a big screw threaded up the post. When I inherited mine, it was stiff as could be, so stiff I stripped some of the gears, but thats another story. Long and short, I pulled it all apart and cleaned and greased, and now its much better, not great, but much better.
Can anyone comment on the shoe-type guard on the old dewalt RAS. Does it work ok without being too much of a nusance? It would be good to hear a little about it before spending the $150 or so that it would cost. thanks.
If it's any consolation, I've seen Norm do it on his show. What he did do though, was take a couple of passes at it, if I remember correctly, but definitely pulled the blade through.
I bought a new Craftsman RAS this past spring and one great feature on it is a motorized cable that controls the speed of the saw as it tracks on the arm. The days of climbing cuts are over. IMO, for RAS's it's equivalent to sliced bread.
Don
The RAS was made for cutting dado's! I use mine all of the time and with a fairly inexpensive set of basic Delta dado blades. I always pull, it is safe and very efficent. Like any other power tool, just think about what your doing. Think about it, how far can the saw travel ? 15" maybe ? It is not going to run off the end of the arm and up your chest!
I make sure all cuts on a RAS are done on material which is clearly marked with a line or an X that indicates the safe zone. If your hands are out of the hazard zone then your in good shape. Go for it!
This forum post is now archived. Commenting has been disabled