I’m interested in hearing from workers who mortise using a router for mortise and tenon joints.
I waste the wood with a drill and clean up the mortise sides and ends with chisels.
When using a router for small diameter mortises (1/4″, 5/16″, 3/8″) how do you deal with the shallow mortise that they produce? I see that router bits in that diameter have only 3/4″ of cutting length. I found one that had 1″ cutting length. Even end mills don’t come long enough.
Bits in the larger diameters have cutting capacities of 2 to 2-3/8″ which would probably be adequate.
Are there specialty bits that provide a greater routing depth? Do you deepen the mortise after routing?
I’m going to buy a Porter Cable 2 hp plunge router, and want to try mortising with it.
Thanks,
Rich
Replies
Rich,
I mortice with a half inch bit with a half inch shank. I have gone to 1.5 inches with that without a problem. If your saying the smaller bits arn't long enough to reach the depth..you may be right, I have not tried. Steve Shanesy in a PW article suggested you use "up-sprial straight bit". I have not seen those but perhaps they might be the solution you seek. GL
BG,
Thanks. Yes a 1/2" diameter bit can be had in 1-1/2" cutting length, but the smaller diameter bits have a maximum cutting depth of 3/4". I found some up-cutting and down-cutting fluted mills that have a 1" cutting depth. Nothing longer. That's a very shallow mortise. I'd like to cut at least 1-1/2" if not 2". It seems a waste of time to go with the router if that's all it's going to do.
Rich
Rich, I own a 1/2' shank, 5 inch long, two flute cutter made by WKW. The carbide cutting section is about 3" long, this bit has allowed me to almost completeley route a mortise in doors, to accept the old style locksets. If you are looking for something in 3/8" or smaller, with great lenght, you might have to have one made. I have a guy here in So. California who is great at that. However, the longer thinner shafts means much easier breakage. I have a few 2.5 " long 1/4" shank bits, from who knows where. So they can be had somewhere. Maybe they were specialty items as well at one time.
Mark,
Thanks.
Yes, the larger diameter bits seem to come in adequate lengths. It's surprising the the small bits are not a little longer. I can understand the problem of increasing possibility of breaking.
I'll see if I can have a small-diameter custom bit made.
Rich
Found 'em!
http://www.national-tool.com/HTML/square-XL.html
Some morticer pix, tools, results and cutters at http://www.patwarner.com/morticer.html .
Solid carbide tools are the friendliest tools for inside excavations.
There is a similar jig/fixture featured in a recent article in PW that I have been thinking about making. However, this is designed for mortice only. My question is, is there a design that can made that supports tenon cutting as well as mortice...or is a seperate jig/fixture the only way? Thanks
I finally gave up on router mortising. If you're doing a lot of them, it is not practical. I finally bought a mortiser and a tennoning jig and am very glad I did. I though the $350 expendature well worth it considering how much faster I can complete projects. Plus, I don't design projects any more to minimize mortises like I used to do, so now my pieces are stronger because I don't hesitate to do it right.
When I think about the $$$ I have tied up in routers and bits, jigs, tables fences, etc. (well over $1500), had I to do it over again I'd have only one router and couple of bits and probably two more big machines. The router is a cheap solution to many hobbyist tasks, but it's often not a very good solution. You may want to reconsider whether a new router is really the best investment.
Dave
Dave,
I'm getting the router for other reasons, but I want to try some other techniques. As I said earlier, I usually chop my mortices with a chisel, removing the waste first by drilling out, then pairing the sides and ends.
What were you referring to by a "$350 mortisser and tenonning jig?"
Rich
I'm a big fan of slot mortising and floating tenons. At Work we have a Griggio slot mortiser. On the lower end is the Rojek and Laguna. I know two guys who have them and they are very nice. On a shoe string budget check out the slot mortiser some guy rigged up with drawer slides. It uses a non-plunge router. Issue 141 of FWW. Truly the nicest and simplest way to do mortises. I'm sure it works becasue I knew a guy who made a similar model 15 years ago.
RSL. What kind of bits does the Griggio use? How long are the small-diameter bits?
Rich
Rich
We just use 2 flute HSS endmills...the kind rated for aluminum. Everyone I know who has a slot mortiser uses these. There are some specially made mortiser bits but they cost a lot more and don't seem any better for the money. My friend who bought the Rojek got talked into buying some. He ended up returning most of them. I've been looking to find that back issue of FWW #141. I just can't figure why more people don't go with slot mortisers.
In regards to your bit length question I see 1/4" endmills that have a cutting length of 1-3/4" at $13 in my mcmaster catalog. Commercial mortisers usually run 3,450 to 5,000 rpm. Many have chucks directly mounted on the motor.
Rick
rsl,
Thanks. I have experience with horizontal mortising. I set up an old craftsman 9" radial arm saw as a dedicated horizontal mortiser many years ago. Put a 1/2" chuck on the threaded back end of the arbor with the bit parallel to the saw fence. Used the saw's height adjustment for . . . height adjustment . . . and made a sled that ran along the fence that held the work and accomplished mortise depth. The saw's normal push-pull movement gave mortise length. It worked in theory, but not well in practice because the motor speed was only 1750. Come to think of it, how did I do all the sawing that I accomplished with such a low speed?
I also made a horizontal mortiser with a router. I've never seen any plans for one - wonder if mine was similar to the published one?
A modern plunge router with some thought to the method of holding the work, is a very good mortiser. It accomplishes the mechanics as well or better than some older horizontal mortisers, in a vertical mode.
Any way, it seems that I can get bits long enough to suit my needs in small diameter.
Rich
Edited 8/8/2002 12:55:05 AM ET by Rich Rose
http://woodcentral.com/shots/shot52.shtml
I've made them from old handmills which can be had for scrap prices. Saws run at 3450 not 1725. I ordered that back issue #141 because I'm tired of telling people what a cool set up it is. Closest thing to a real slot mortiser for low cost. Did you use drawer slides for your x,y table movement?
Hmm . . . OK, it guess it was 3450.
No, no drawer slides. It was very primitive. Just the table on which the work rested and the router at a right angle.
Rich
I only use a router to make all my mortises. I use a plunge router with carbide upcut end mill bits, I have a jig from woodhaven. Lately I've used loose tenon joinery- check out the article in the Latest issue of FWW for a great jig. I think router mortising is a great way to go. Beware of throwing money at problems, usually the simplest way is best.
tom
Rich,
I have had very good results with a spiral upcut bit in a router table. The straight fluted bits, on the other hand, just grab real hard in a mortise.
That was then, this is now... I currently use a mortise gauge and (Japanese) chisels to cut all my mortises. I have only recently started designing my mortise widths to match the width of my chisels, but that has helped a lot!
Take Care,
Donald
Rich, the longest small diameter I have found is a 5/16" x 1 1/4" cutiing length solid carbide double fluted bit made by Delta. I could probably dig out the part no. if that were useful. I suspect that strength issues prevent any greater cutting length.
has anyone yet seen and tried the new FMT router jig from Leigh? The ads look enticing.
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