You all probably known this but I had over 80 tenons to make yesterday, and after drinking some deep thinkers coffee, settled in on using my RAS for the project. Slapped on a dado, swapped out the fence, and carefully lowered the blade on a set up piece until the resulting tenon barely fit and I had to do the slightest bit of hand trimming with a rasp.
I set up a stop block to make the tenons exactly 3/4 of an inch.
The shoulder cut was just as easy, placing the piece on its side and against the stop block.
Bottom line was about 20 minutes of set up and about 20 minutes of cutting. In less than an hour I knocked out over 70 perfectly fitting tenons.
This thing smokes my Delta tenon jig or using a table saw.
Boris
“Sir, I may be drunk, but you’re crazy, and I’ll be sober tomorrow” — WC Fields, “Its a Gift” 1934
Replies
O.K., what IS a RAS tennon???
migraine, it's a tenon where the faces of the tenon are cut with a radial arm saw (RAS) in a few passes. A fine use for a machine almost purpose built for the job. Slainte.Website
Or maybe for an anchor weight.
That depends in this case on what you know about woodworking equipment, it's strengths, weaknesses, and how, and what it's used for. Slainte.Website
Doesn't using a dado set in this way leave a pretty rough surface on the cheek? The cheek is the glue surface in this joint, so roughness seems like a bad idea.
Jamie, if you leave the joint just a bo'hair fat, two skims with a shoulder plane on both faces should take care of that if it's a concern.
But mortise and tenons are inherently massively strong anyway, so it's generally not a bother. Off the top of my head I'd cite examples cut with hand saws a couple of hundred years ago that never disguised their inherent roughness, but which are still hanging together today. Their (those tenons) partner was a mortice which was bashed out with mortise chisels and a mallet, and those cheeks generally aren't too smooth either.
I suppose it's true that a precision engineered mating surface is the ideal, but furniture makers aren't engineers working with metals and plastics to 1000'ths of an inch tolerances. Some of the worst woodworkers I've ever come across are engineers that try to impose their micrometer type mindset upon an inexact material-- good ones adapt their knowledge to the material.
I'd make a lousy engineer because I'm too imprecise, but I'm also an awful carpenter because I worry about a half a degree here and there. Slainte.Website
All of that furniture on your website on a radial RAS??? $hit, I'm going to sell all my machines and buy ONE of THOSE new fangled machines;~)
Really, nice work, but I still HATE radial arm saws. I just didn't know want RAS ment
Ha, ha, migraine. Slainte.Website
Swapped out the fence to elminate splinttering. Could a sacraficial fence have worked. My RAS fence has been there since I first bought the saw and built extension tables on both sides with the fence being one piece running the entire length of the extensions to support long sticks for crosscutting. Darn near impossible to just slip in a new fence. How is yours set up to facilitate inserting a new fence.
The only thing I would add to this discussion is that the RAS method for cutting tenons, which I have used many times, requires that the stock lie perfectly flat and untwisted on the RAS table.
The typical RAS fence/table set up is in three parts.
First, the main table which is bolted to the metal frame. I covered this up with some plywood and laminate for cleaner cuts. It is screwed and doesn't move.
Second, is the fence which sits behind the main table and is not screwed nor nailed. It just sits there.
Third is a pressure piece which is attached behind the blade and fence. Thumb screws accross the width of the frame tighten and loosen this narrow strip. When tightened, it also squeezes the fence and holds it in place against the main table.
I have owned three RAS: 2 Craftsmen and an ancient DeWalt, my current favorite. All have had the above set up.
The fence easily pops out by loosening the three thumbscrews (2 for Sears). I have a variety of fences for regular cross-cutting and dado work. I don't rip with it (I have Unisaw) nor do I do precision cross cutting (I have a sliding miter), but for dentile molding, dadoing, tenons, and other job specific work, it can't be beat.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I would add (and I'm sure you did this) to position the workpiece so that the cut takes place close to the back fence just as the blade is coming forward. This prevents making the cut out near the end of the arm where it is more likely to flex and cause problems with the cheeks of the tenon.
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