Milling machine as a mortiser

[andrew whicker]

Hi all,

I don't look often, but when I do it seems there are absolutely no used mortising machines out there. Something I've always wanted (someday) was a knee mill. There's a place near me that has had a Cincinnati Contour Master for sale forever (years and years). They re build these machines and sell used.

Does anyone do this? Can I use a mortising tool w/ a knee mill?

Given how much more a milling machine can do than a mortising machine, it seems like the extra money spent would be worth it.. but it's an entirely different rabbit hole to go down as well. And I don't know anything about milling machines.

[Jim Becker]

AFAIK, you absolutely can do this. Mills cut wood just fine. Just keep in mind that they are not designed to be "speedy" because their main focus is on milling metal which has its own requirements that are most often different than what we can do with a material like wood. What you do gain is some pretty kewel precision in lateral movement of the cutter that's also repeatable. Brian Holcomb used that to good effect on a requirement for an angled slot on the bottom of a chair seat when we were playing with something a few years ago so I've seen this work. He has a nice Bridgeport available.

[Kevin Jenness]

I think you would find a knee mill accurate but cumbersome for mortising due to the slow gear feed on the table. Perhaps one with motorized spindle and table feeds would be practical.

As with most specialized woodworking machinery finding a good used mortiser requires systematic and patient searching and probably will require shipping. Hollow chisel machines are most common but there are slot mortisers to be found, in fact there is a Bacci oscillating slot mortiser in MA and a manual Griggio machine in PA on Facebook now. The JDS Multirouter is still available new and is a capable slot mortiser. If you want lots of square holes in a hurry there's a swing chisel unit also in PA on Facebook and Mark Hennebury has a rebuilt Maka for sale.

A Festool Domino 700 is an excellent and versatile solution for mortises up to 14mm.

[Richard Coers]

A knee mill in a wood shop would quickly have the slides and threads gummed up with a goo from the way oil and sawdust mixing together. The spindle speed is slow for cutting wood. A Domino machine would take up way less space and cut the mortises 100% faster and tons lighter. The Pantorouter is another great option and it's $745 cheaper than the Multi-Router. Pantorouter also has incentives quite often. Then you get a machine to cut mortises and tenons, as well as finger joints and dovetails.

[Mark Hennebury]

There are lots of used mortiser for sale, depends on what you want, hollow chisel, round end or square end, automatic, manual, what size mortises, length, width, and depth, Single or double, haunched, angle end etc. three phase or single, bench-top or floor model, single head or multi-head, And what you budget is, and what productivity requirement's are. You can maybe cut 30 mortises an hour on a Mill or 600 per hour on an automatic slot mortiser.

I have a few machines available and maybe be able to help you if I know what you want.

[Wes Grass]

Are you thinking hollow chisel?

Dont know about a Cincinnati, but the quill feed on a Bridgeport isn't anywhere near as tough as a good drill press.

[Andrew Hughes]

Milling machine tooling or bits are kinda short aren’t they?
I have a couple bits I bought for cutting Brussels quadrant hinges. Maybe they can cut one inch deep

[Bruce Page]

A knee mill in a wood shop would quickly have the slides and threads gummed up with a goo from the way oil and sawdust mixing together. The spindle speed is slow for cutting wood.

Not entirely true. I have had a knee mill in my shop for 30 years with no noticeable wear on the ways. As long as the way-wipes are in decent condition you shouldn’t have any problems. I do most of my wood “milling” in the 700-1200 RPM range. It cuts just fine.

My bench has 30+ mortise & tenons, all cut on the mill. (see very old pics) I think a dedicated mortiser would be much faster, but mortise & tenons are certainly doable on the mill.

A conventional knee mill, if you know its capabilities, is very handy in a wood shop.
JMO

[Brian Holcombe]

I’ve occasionally used the mill for round end mortises, using dedicated machinery works a lot faster.

If you have good dust collection and your mill is oiled routinely, it’s fine. I have a few machines with dovetail ways, and they all require constant oiling to keep the ways clean.

You can also get way covers to minimize the issue.

[Warren Lake]

we machined Corion on a bridgeport it work very well. I used tons of high speed end mills in a makita router. 1 1/2 2" and even 3 cutting but that had too much vibration and dangerous as well. That was a plunge before i got the big porter cables and they would have been better. The milling machine blew me away to zero a bit then just count off a digital read out to .0005. Nice way to measure.

[Richard Daugird]

There once was a machine sold by Grizzley(?) called a Wood Mill, looked like a metal cutting milling machine with a hole in the middle of the table, and the RPM range was optimized to use either wood or metal. Google doesn't find it.

[Bill Dufour]

Theoretically a rotary broach could be used to drill square holes. i think they max out at 1.5 or 2.5 times width for depth. You would have to arrange a guide so it started square to the side of the workpiece.
Bill D

[andrew whicker]

so the tooling used for a mortiser is unique and not something that fits into drill chuck?

The quill on this Cincinnati has a 3.5" travel... so not very much. I haven't heard back from them on price yet, but I'm assuming it's an awkward price point the more I think about it. You can buy desktop milling machines (CNC) for a little over 10k where I think having a fully outfitted knee mill (DRO, X and Y feed motors) would probably be the same price.. right?

It just annoys me to have a tool that takes up as much space as a mortiser and it has only one function. AND it doesn't solve the male tenon problem at all. If I do get a setup for mortise and tenon, I'd love to have the Japanese tenoner, but the times I've looked they are no where to be found. I did find someone that made their own and has drawings available.

OTH, the more I think about how much it will (probably) cost to get a knee mill going, it will probably no longer make financial sense?

[Michael Schuch]

Screenshot 2024-04-12 065333.jpg

The chisel for a mortise machine is square. The square portion of the chisel has to be held still while the round cutter in the center turns. You would have to have a special collar custom made to mount a morticing chisel on a mill.

I prefer a radial arm saw with a dado stack for cutting square corner tenons. A tenon jig on a table saw also does a nice job.

A mill is going to cut a mortice with rounded ends. This will require you to square the mortice with a chisel manually or cut a rounded tenon.

A router setup dedicated to cutting rounded mortices would be cheaper and take up less space than a knee mill. It would probably not be much slower than a mill either. I have seen somewhat complex router jigs to cut tenons with rounded ends.

There is a reason dedicated morticing machines exist... they are quick and efficient at making square sided mortices.

[andrew whicker]

I didn't know there were that many options. I assumed the old iron machines were hollow chisel type and manual.