Thread: Need opinions on Chisel Mortisers against spiral upcut router bits

just my tuppence roger
but the chisel part of the bits usually have to be sharpened before you use them - like all chisels.
maybe the reason you had to pull so hard . . .
the rotating auger cuts out the guts of the timber (like the spiral upcut) and the sharp chisel pares the edge square - the "only" pressure you (should) need is enough to shave the edges and corners. . .
Jedo

I recon if price is an issue the router bit option winns hands down.
check out "rocker's morticing jig".

There is a reason all the big morticing machines have big long hanldes
& those are expecting the hardest wood they will work on is cherry


I'd go the router.

cheers

The spiral upcut bits are a very good option, except that there is perhaps an issue that you won't get the same depth as with a chisel morticer -- my opinion is that you can probably live with that.

You do need to make a jig or use on the router table. The advantage of the jig is that you're not working upside down and blind -- with the jig you see what you're doing.

I looked at rocker's jig as soundman has suggested, but thought it not as elegant as an old Tage Frid design from an old FWW which I slightly improved on. I dislike jigs that take an age to make, and this one didn't, and yet it is as accurate as the microadjustments on your router fence and depth stop. I'm going to try add a pic of it here - but basically its a channel made of two layers of 17mm ply on the base with a 17mm ply leaf each side, all glued and screwed.

The top of the channel is made with hardwood glued on, this forms the rails the router moves on (I have had no problems with sticking in operation, I don't think plastic breadboard material is necessary). I cut a few extra packers that lie in the channel to bring smaller work up to with range of the router depth adjustment. The work is held in with simple wedges. It doesn't come out, you don't need clamps. When you cut, you pull the router toward you, with the fence on your left.

There are two bridges between the sides that rest over the rails and that act as the stops, you have to adjust them for each mortice you cut. That's where I improved on the old Frid design, as my 'bridge' version helps make the whole unit more ridgid and was easier to make anyway. The screws are those knock-down furniture screws with captive barrel nuts.

I have a 'lite' version of my jig, which only takes an hour or so to make. See https://www.woodworkforums.com/f44/precision-morticing-jig-lite-9853 . It likewise uses the router's edge guide, instead of a micro-adjustable fence built into the jig.

Rocker

I've used both methods, but prefer the chisel morticer as its much quicker. I have one much the same as the one you describe - I think all these generic tools come from the same factory.

It will cut Oz hardwoods with ease. Only rider is that for deeper than 15mm you may need two plunges.

There are a couple of issues with these machines:

1. You must have dust extraction hooked up. I have ruined a few pieces when the dust and shavings back up between the work and the fence and skew the piece off centre with disastrous results. I could post a piccy but 2 embarrassed. Non square and true dressed timber will give the same result.

2. The adjustments are a bit of a pain in these benchtop machines. The grub screws and levers that allow new chisels and fence movements are not so well designed and get a bit tedious. But for a couple if hundred $$ it's tolerable.

And yes, any brand of morticer thats meant to fit a bench drill is a joke. The pressure needed to cut our hardwood is substtantial and way out of a drill press specs.

Finally keep your morticer chisels sharp, lap the outside often.