Using a Radial-Arm Saw to Cut Dadoes

A radial-arm saw is good for repetitive cross-cut dadoes, but dangerous for ripping. Here, woodworkers discuss equipment alternatives for efficient, accurate dadoing. November 10, 2006

I've been looking at radial arm saws from Delta, specifically the 10" model, for the purpose of keeping a dado on for cutting dados for bookshelves and furniture work. I was wondering how safe ripping and running grooves with a radial arm saw is, and why I can only find them from Delta - has some other method of crosscutting or mitering wide boards and running dados the short length of long boards phased it out? For the work I've done in the past, I usually set a fence on the piece and run the router, but against grain cuts are messy and moving the fence every cut is too time consuming.

Forum Responses
(Cabinetmaking Forum)
From contributor P:
For many years, my only power tool was a mid '50's vintage Dewalt radial arm saw. While that's thankfully in the past, I remember that running dados crossgrain was easier on that saw than with any other method. That said, I feel that ripping or plowing grooves in rip mode is more dangerous than any other method. The consequences from a kickback are not worth it, believe me. I have a friend who is lucky to have his hand from such an accident. A tablesaw is the way to do those cuts. It's much safer, and the depth of cut is easier to control. For simple crosscuts or miter work, many shops now use sliding compound miter saws, although you're limited to around 12" capacity. Radial arm saws are still available for those who want them. Try Dewalt, the Original Saw Company, and Maggi, in addition to Delta. We have a large Wadkin in my shop now, but use it solely for crosscutting rough lumber before running it through the other machines.

From contributor D:
I agree with everything that contributor P wrote. If you have enough use for the RAS doing crossgrain dados or cutting tenons, then sure, it's a great solution. Forget about ever using it in the rip direction. It's so dangerous and inaccurate as to make it off-limits, as far as I'm concerned.

From contributor N:
The bad part of a radial arm saw is, with base cabinets, you will not be able to dado a complete panel in one pass. With uppers or cabinets limited to 12 inch depth, it will work fine.

There is a company called Saw Trax that have some affordable machines that may be better suited for what you want to do. Either their panel saw with a router insert or their floating panel router coupled with a quality straight router bit should be much better than a radial arm saw for running dadoes.

From contributor K:
You might want to consider spending a little more money than the RAS would cost you. A HerSaf panel router would be ideal for this application. The bits are screw on type, and allow you to change the bit diameter by unscrewing the bit from an arbor mounted in the router collet. The bits are available in many sizes. One real advantage of this system is that you can use a bit that is .015" - .030" larger or smaller than a 3/4" diameter bit. Comes in handy for panels that aren't running a true .750" in thickness. Jigs and templates can be easily fabricated for doing repetitive dadoes and/or miters. A new panel router will set you back at least $4500.00, but they are available used for considerably less. Check any used equipment for squareness of cut. Another advantage of the panel router is consistency of the depth of the dado.

From contributor F:
Do you have a face frame table? A friend showed me his basic jig for routing dadoes on his face frame machine. Other than a dust collection problem, all you need is a straight edge and a bunch of blocks for quickly locating the dado start point. Clamp the cabinet part and straight edge with the clamps and rout. Square, straight, even depth, and best of all, it's basically free - all you need is some scrap materials and your router and face frame table. It's way too easy! I think I'll start calling it our TrueFaceFrame (no cost or low cost).

From contributor L:
In case it hasn't been made clear enough, I'll add my two cents... Don't use the R/A saw to rip. Years ago when it was my only saw, I used it for everything. Until a piece I was ripping kicked back so hard that it went through the wall. I was very lucky, and very scared that day. For rough sizing, it's a perfect saw to crosscut with. Stay safe.

From contributor R:
I use a 14'' Maggi every day. It will cross cut 25'' and up to 31'' if I lift the plywood up into the blade, and be within 1/64th square (if I keep all sawdust off the backstop). I was very impressed with the made in Italy quality. I was like you, looking at smaller, lower priced saws. That big Delta is 5K and was out of my range at the time.

As posted above, ripping is dangerous. I was told by my uncle that when he was ripping, it pulled the board up under the blade, sending it through the wall. The real bad thing was that it warped the arm on his saw, and from that day on, his massive old Dewalt was nothing more than a sawmill.

I don't really baby my Maggi, but I treat it with respect because it's probably the most dangerous saw ever invented. I think with a smaller saw you could flip over the base cabinet sides and it would be close enough for dadoing, it's just a lot more work flipping over a piece of wood to finish the cut. I use my RAS for many things, but I hate changing blades, so I have a separate table saw with a dado blade on it. Look on E-bay for a radial arm saw. Large 3 phase are cheaper than a new 10'' Delta, and you can get a saw that will cross cut your dadoes in the base cabinets. Some people only put a 1/2 shelve in their bases anyway, and by the way, my Maggi has an adjustment for every way you could imagine, so it can be fine tuned to be accurate as needed.