Thread: Mortising Attachment.

I vaguely remember something similar, except that it was on a Durden Pacemaker combination saw. I believe that the mortising drill chisel assembly is still available, a square hollow block with slots on the side sharpened on the base with a drill bit inside???
Kryn

Originally Posted by popawisky

Anyone got a map and compass. Totally lost my way looking for the appropriate forum, anyway I'm here.
Probably not allowed to mention a popular woodsmith magazine, however, the latest has an article on mortising machines.
I can remember my grandfather back in the fifties with an electric drill with drill press attachment. The press had a mortising attachment that looked remarkably like the mortising bit on a modern machine.
Does any remember these old drills, possibly Lightburn???????? don't know.
Pete

DrillPressMorticer.jpgPete,

I bought a Chisel Mortiser Attachment that was designed to fit onto a Drill Press about two years ago. The one I bought is no longer on sale (probably a good idea on the retailer's part). It looked something like the device in the attached photograph. A Chisel Mortiser that attaches to a drill press sounds like a good idea, but in practice, they don't really work all that well when hooked up to a drill press. The drill press doesn't have enough leverage on the plunge mechanism to be able to drive the chisel mortiser into the timber. The mounting collar that goes onto the drill press was pretty "Heath Robinson" in design, and never worked very well. The whole thing was pretty much a waste of nearly $200 on my part.

I ended up buying a dedicated Chisel Mortiser (http://www.carbatec.com.au/carba-tec...ortiser_c20063). When I bought it they were on special for about $350. The four different sized Mortising Chisels that came with the Drill Press Attachment are a standard shank size and fit the Carbatec Mortising Machine. The rest of the Chisel Mortiser Attachment went into the garbage after I'd finished telling the very well known supplier of woodwork equipment exactly what I thought of his Mortising Drill Press Attachment.

Regards,

Roy

I've got one. You can have it (free) if you want. You collect.

I have an old Multico morticer. The original benchtop Morticer, and a gift from my dad. It performs well, and has all sorts of fond memories & associations with it.

A friend has a drill stand attachment, which is troublesome & slow, but at least it works. The major problem with his, which is similar to the drill press attachment you describe & illustrate above, is lack of leverage. My Multico has a long, strong lever handle together with a cast steel rack & pinion to apply pressure to the chisel. Phenomenal pressure is required to drive a chisel into wood: a 1/2" chisel requires 4 times the pressure of a 1/4" chisel, a 3/4" chisel (which is beyond my Multico's capability) requires nine times the pressure, and a 1" chisel 16 times!

My mate's drill stand, whilst restricted to 1/4" chisels, has a permanently bent handle from the pressure required. In a drill press you will be putting massive pressure through the rack & pinion and quill assemblies too. The only drill stand the I've seen that's designed for this sort of pressure is the old Record Power (Sheffield) DMS26 cast iron drill stand, which is purpose built for high quality Record Power cast iron Morticing and Guillotine attachments. At about 22kg + it has the mass & strength to absorb high morticing stresses, and more importantly the offset parrallelogram linkages to provide the necessary gain in leverage.

I am going back to when I was a kid. The "Chisel" was square with a drill bit thru the middle. Probably good for light work only.
Interesting how tools evolve, and what provokes memories.

Originally Posted by popawisky

I am going back to when I was a kid. The "Chisel" was square with a drill bit thru the middle. Probably good for light work only.
Interesting how tools evolve, and what provokes memories.

I disagree. The hollow chisel was first developed (i think by Multico) in the early part of the last century. Using a non-threaded auger to remove the bulk of the waste, it doesn't require a particularly powerful motor to drive. A 1/2 HP induction motor (375w +/-) is ideal for chisels < 5/8" running at "doublespeed" or 2800 RPM, a 3/4 HP for < 3/4" @1400 RPM, and a full 1 HP (a mere 750w +/-) for a 1" chisel, again at normal speed. As the auger removes the bulk of the waste, and relies only on pressure, unlike Scotch or Jennings pattern augers it can work at relatively high speeds and low wattages. It relies on only a single spur and one cutting land to do its work, although there are different "English" & "Japanese" patterns here also.

As such, even a simple relatively lightweight Morticer can remove the waste from large diameters and deep mortice slots relatively quickly and with an accuracy the envy of many an aspiring woodworker. It just needs to be designed correctly. Obviously the larger bits require substantially greater, heavier & stronger castings to perform these duties, and the biggest "industrial" rated machines from the likes of Warco, Sedgwick et. al. are floor standing machines in the hundreds of kilograms or a ton or more.

There was also for a while some time absolutely beautifully designed relatively "lightweight" machines from Multico that combined strength and mass reduction through clever design. These machines had quite sophisticated workpiece AND head adjustments in four and even five axes to allow repetetive 90 degree and angled morticing that could be repetetively and accurately accomplished in sizes substantially larger than the mere chisel capacity would suggest. These machines became the mainstay of, for example, bespoke door & stairmaker's workshops, and were perhaps an "analog" version of latter day CNC machines.

Even my simple, unsophisticated 1/2" bench model has the capacity to accurately & relatively quickly produce (by accurate marking and reversing) mortices of 4" depth and 2" or more width if necessary and unlimited length!

The East Asians have, through imitation and aggressive pricing, effectively killed off the manufacture of these more traditional machines. Nevertheless these newer machines are not without problems. One that I've experienced myself is in cheap, inconsistent & inaccurate chisel manufacture, which creates problems with binding, poor chisel/auger interfaces, out of square & plumb facets, heat generated destruction of a bit's temper, and soft metals not retaining edges. Yet there are also quality Japanese chisels (available at a price) that are the equal of the best available from Clico or William Ridgway.

Another problem common to many of these lesser quality machines seems to be in the hold-downs. Traditionally there were seldom any vertical hold-downs fitted to any but the smallest of them. Instead an ANGLED horizontal pad fitted with a substantially wide handle or crank were fitted to a shaft with a low geared rolled acme thread. This provided quick, accurate and secure workpiece location and adjustment.

Yet many of these imitators' machines have poorly concieved and executed horizontal clamping mechanisms that simply can't do the simple task of accurately & securely preventing the workpiece from binding to the chisel! A classic case of poorly imitating the machine without fully understanding the underlying principles behind its design.