Mortising techniques

Hi. A general question regarding Mortising machining techniques. I have a hollow chisel machine which is pretty ok - however has its inherent limitations in harder woods and deeper mortises

What have peoples experiences Been with other Mortising machines - horizontal boring machines, maka mortisers, and other router based machines - wood rat, pantarouter etc?

I’ve been working on a new bench and the massive construction has pointed uP some limitations in my current ability. My least favourite method is router technique with an edge guide - that seems to me to the the technique most likely to have a fail

I have a modest Delta mortiser and it has done well even with hard woods and larger mortises--cheaper chisels that came with the machine too.. Make sure the the augers and chisels are sharp and stick with smaller sizes. I most always use my 1/2" and make multiple passes as needed. Patience is a virtue. A sharp set of hand mortise chisel helps with fit and finish as well. Good luck

Drill Bits (and Their Cousins Mortising Bits) and Router Bits all have their limitation in predetermined size and depth. Like John, I have a modest bench top Delta, and it has served me well. Shop around for different sizes of the mortise bits. Rockler and Woodcraft seem have a basic set, while Lee Valley has an impressive selection. I tend to shy away from router bit mortising, because the holding and guiding the router requires a well thought out and sturdy jig, and things can go South easily and quickly. Also learning how to sharpen, actually hone, the chisels before you use them makes a horse of a difference in the quality of the cut, if the mortise is showing. Bob Van Dyke has a nice video on Fine Woodworking on how to do this, which takes only a minute in the May June 2002 issue. It may be a free video.

It also helps your options if you learn how to chop out mortises the old-fashioned Paul Sellers method. Better options as to the width (limited only by your chisel set) and no limitation on depth.

Bottom Line for Me: Delta Mortiser with sharp, well honed chisels is my go-to tool.

When I went looking at a bench top mortiser I couldn't find anything that I would open my wallet for until you got to the General 75-050 series. This put me half the way to the price of a good floor machine so I waited. My concern here was through mortises. I have run a Mortise Pal for going on 15 years. Combined with the appropriate bits it meets 90% of my mortising needs. Fate landed a Domino in the shop and I still have to really try to use it. I have an upcoming project for my own home and will force the use there. This may encourage my use for other things or it may end up in the Classifieds ;-)

Larger mortises are drilled and squared with chisels but, I wouldn't turn away a good floor mortiser that could run 1" chisels. The frequency of need (like when making a bench) doesn't qualify the floor space . . . yet. Maybe the next time it comes up I will go ahead and flip for one. It may be sooner rather than later as my designs seem to be calling fro wedged through mortise construction for aesthetics. For now, a router and a drill press do the job.

What about a chain mortiser like Makita 7104L?

I have not seriously considered a dedicated mortiser for my workshop as there is limited space. I either chop with a mortice chisel or use a router. However, I do wonder whether I could use one anyway since my local hardwoods are seriously hard. My question is what are the harder woods where a mortiser is no longer an option?

Regards from Perth

Derek

Spend the time and effort sharpening your mortising chisels and you’ll find even a modest bench top machine behaves well. Sure, more power is indeed nice on the mortiser but the more time you spend on the chisels, the better that machine will get.

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Originally Posted by Mark MacLeod

Hi. A general question regarding Mortising machining techniques. I have a hollow chisel machine which is pretty ok - however has its inherent limitations in harder woods and deeper mortises

What have peoples experiences Been with other Mortising machines - horizontal boring machines, maka mortisers, and other router based machines - wood rat, pantarouter etc?

I’ve been working on a new bench and the massive construction has pointed uP some limitations in my current ability. My least favourite method is router technique with an edge guide - that seems to me to the the technique most likely to have a fail

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This subject has been explored previously here https://sawmillcreek.org/showthread.php?282075-How-useful-is-a-mortising-attachment-on-a-jointer-planer-combo

and here

My choice of machines for mortising; Maka or Maka style swing chisel mortisers for traditional square end mortices.
And Balestrini automatic slot mortisers for round end mortises for chair making.

Maka mortisers were made in two sizes, a small machine series, Sm series; cuts smaller mortises, cuts faster than the larger machines. More suitable for furniture , windows, cabinet doors etc.
The Larger STV/ RDB mortisers made in single head or multi head machines, widely used in commercial or industrial settings for entry doors and craftsman style furniture etc. can cut mortises up to about 7" long x 1-1/2" wide x 5 " deep in one pass, can use a wide variety of single, double blades, cut a combination of shapes and sizes, there is no other machine that can compete with the speed, accuracy, size and variety of mortises these machines can make.
The Sm machine is blistering fast, clean and accurate.

The Balestrini are made from the factory to do fast work, with a little tweeking you can make them do incredibly clean precise mortises. Fast and efficient.



https://www.youtube.com/watch?v=KJUJ796jxls

This is a Maka Sm 6P-II that i rebuilt last year, showing a variety of cuts made with this machine.


https://www.youtube.com/watch?v=1i8zrqGRspA

Quote:

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Originally Posted by Derek Cohen

I have not seriously considered a dedicated mortiser for my workshop as there is limited space. I either chop with a mortice chisel or use a router. However, I do wonder whether I could use one anyway since my local hardwoods are seriously hard. My question is what are the harder woods where a mortiser is no longer an option?

Regards from Perth

Derek

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For my hollow chisel mortisers, I've found that the limitations aren't so much hardness as how well the chips clear the auger bit. White pine, of all things, can sometimes be difficult, if the resinous wood wants to stick to the auger bit and jamb up the chisel. Rock hard white oak (probably close to those reinforced concrete woods you use down under) can sometimes be easier, if the chips cut cleanly and don't get caught on the way out. How well sharpened the chisel is makes a lot of difference.

At some point, the wood could be so hard that the auger bit snaps. To compensate you can slow the feed, but again at some point if you go too slow, the chips don't carry away the heat fast enough and the wood starts to burn. Abrasive woods would compound this, as they would be dulling the chisel and the auger bit, making them both work harder and causing them to cut less cleanly.

Here is my”Woodgears “ router based mortiser. It does a nice job and wasn’t that hard to build.

I have a Powermatic bench top HCM, a Domino DF500, shop-built router mortising jigs and a PantoRouter. I rarely use the PM HCM (twice a year?) or the shop built router jigs, but pretty evenly split usage of the Domino and the PantoRouter. The advantages of the PantoRouter are that it makes integral tenons and is capable of making much larger M&T joints than the Domino. The Domino is quicker to set up and use and can be taken to the work as opposed to taking the work to it.

I'm now using a plunge router and an FMT Pro jig from Leigh. I've gone through about every other way of making mortises and tenons. The FMT makes both the mortise and matching tenon very repeatably, and with no need to go back and fine tune the fit of either. Any tenon of a given size will fit any mortise of the same size, so hand fitting it is never needed. Expensive, yes. But if you have a lot of them to make, it quickly pays for itself. The normal cuts are rounded end type, but they offer a template that lets you make square end tenons. Then you get to square the ends of the matching mortise with a chisel to fit them. I never found the need, so never bought the template for square end tenons.

Charley

To make big mortises with a bench top mortiser, just rough out the mortises with a forstner bit in a drill press. A bench top mortiser will do fine skimming the walls off a roughed out mortise. Your chisels must be sharp, no matter what.

I have a little delta bench top mortiser. It was all I could afford when I was starting a business. I made thousands of mortises with it. Now I have something bigger, and cast iron.

The Maka mortisers I have used require a lot of learning to get them running well. The pneumatic powered hydraulic systems require maintenance and repair. If you like working on machines, they're a lot of fun. Learning how to sharpen the chisels by hand so that the chips are formed in he correct shape to eject cleanly was so satisfying to me.