Shopping for Mortising Machinery

      Woodworkers discuss the practicality, cost, and operation of horizontal and vertical mortising equipment for door construction. June 2, 2009

It looks like I have a fairly large job coming in making 7 interior doors and a couple matching panels, with another potential order for 4 more next year. These are a contemporary design using 3" wide rails at 1-3/4" thick. My method has been using a double mortise and tenon to increase the joint surface area. I've struggled with a benchtop mortiser, and I'm at the point where I think it would be a good idea to move up to a big boy machine.

What's the advantage to an oscillating chisel mortiser over one without? Is there an advantage to going with a horizontal, or slot mortiser instead?

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Forum Responses
(Architectural Woodworking Forum)
From contributor F:
Have used the Maka oscillating mortiser, which was set up for kitchen cabinet face frames, and cut a hole 1" deep and 1" wide. It was really fast and accurate, but pricey. Always wanted the Powermatic #10, but when I could afford it, I could not find one that was not all beat up. We now have a General #220 and it works great. We use the 1/2" chisel for large doors like the ones you are doing, and make the mortise 2" deep. The horizontals that I have seen being used leave a radiused corner, if that is any factor.

From the original questioner:
Yeah, I figured with the horizontal I would probably have to switch to loose tenons, which might not be a bad thing. Having never used any of the full size machines, though, I looked here for advice first. I do have my eye on an older Oliver that's on the auction site right now, but don't want to bid on something that may not be the right fit.

From contributor C:
We have a Griggio horizontal mortising machine. Castings and all seem very similar to a Laguna I've seen recently. Nice heavy joystick operation uses basic end mills and spiral router bits, much lower RPM than a router. Quiet, good, strong hold downs, heavy stops very easy to set up. I have used it for a lot of doors. Nice 3/4 by 4" deep mortises or as small as 1/8 by 1/4 deep.

From contributor F:
An old timer told me about the chain mortisers and how bad they worked, so be careful.

From contributor L:
I too have used the MAKA, when I was making restoration windows mostly. Depending on the chisel you put in there you could make a hole as small as 1/4" wide x 7/8" long that could be up to 1 15/16 deep with a fairly flat bottom and straight square sides, up to a 3/4" wide x 4 3/4" long x 5" deep hole. And I am sure there were other larger bits available. It was very quick, 3 seconds per hole and semi automatic - you pressed a foot pedal and the machine cycled. I would love to pick one of those up today. Back then in the mid 80's it was going new for about $15K.

From the original questioner:
Thanks for the responses! Aren't chain mortisers more for things like post and beam construction? I haven't seen one in person, but from the pics I've seen, it looks more like a vertical chainsaw than a chisel. I'm guessing a little rough for what I'm looking for.

Am I reading correctly that the Maka can make an elongated hole (1/4" wide x 7/8" long that could be up to 1 15/16 deep) with squared corners in one cycle? If so that would be something to see! Unfortunately it sounds like it's well out of my price range.

I guess I'm still undecided. I know the Oliver 91 or Powermatic 10 would do what I need all day long. But I wonder if the slot mortiser would be more flexible? Decisions, decisions...

From contributor L:
I made tens of thousands of those holes in pine. Took less than 2 seconds to cycle. It is truly an amazing machine when set up right.

From contributor F:
Chain mortisers were used in production of cabinet face frames, so they must cut a clean hole, but I have never seen one work.

Come to think of it, I once used an Oliver automatic chisel mortiser. It was kind of wild how fast the head moved down into the wood and cut a hole. The guy said it was on slow, but once you push the foot lever down, it cut a hole and came back up. I couldn't imagine what it would have been like to have the machine set on a fast speed! The Maka was a similar machine, in that once you hit the foot switch, it cut a hole.

Seems like the foot pedal on the Powermatic 10, or similar machine, like the one we have, will give you a better chance of changing your mind if the alignment was not correct.

From contributor B:
Have you thought about a Domino? I bought one about 6 months ago and it has become the best tool in my shop. Quick, very accurate and strong with multiple tenon sizes. I also have a horizontal mortiser which now sits collecting dust until I can sell it; entirely replaced by the Domino. I think they are around $800.

From contributor D:
The Maka is the way to go if you have the volume. Perfectly square hole, smooth sides, square ends. Easy to set up, easy to operate and faster than light. There are a few available now (Ex-factory, IRS), and bargains with the current collapse of the American furniture industry. Still expensive. They are no longer made - Maka is now CNC tech, but parts and service come from Dankaert near Atlanta.

Chain mortisers are a bit rough, and the exit is rougher. Most folks using them will plane/shape the edge after mortise to clean up tearout.

I think a solid horizontal mortiser may be best for you to start with. Use the square chisel for your muntins. Lots of price difference. You will get better quality and accuracy from the middle European ones - in my opinion.

Building doors requires good practice and reliable accuracy. Inaccuracies have a way of adding - or multiplying - as you go if you don't strategize ahead of time to catch, reduce, eliminate or cancel them.

From contributor K:
I use a Multi-router for face frames and love it. I make my own loose tennons for any size I want and any degree of fit. But when you want to get into mortises deep and wide, the vibration gets to be too much. If you are doing mortises 1/2"w x 2" or more in depth, the bigger machines like the Griggio already mentioned would be better.

From contributor A:
We've got an old Maka that has made several thousand doors for us. Parts are no longer available for our old model but it still works. There are other manufacturers of the oscillating chisel style machines. They are fast, produce a very accurate mortise and easy to set up. Seems like there should be some on the used market, cheap!

From contributor R:
The Maka is an excellent machine as others have pointed out, however it does not cut square ends, so the tenon corners have to be relieved. The only oscillating mortiser that can accomplish that feat is an Alternax. It requires 3 chisels - the center tool oscillates and the two side tools cycle in and out. The result is the same as a hollow chisel machine. It was made in France but I don't know if they are still available. These machines can also mortise end grain like a slot mortiser so loose tenons can be used. The tooling for both the Maka and Alternax is very expensive compared to a hollow chisel machine or slot mortiser.

From contributor L:
Funny, I used a MAKA machine for 4 years. I don't remember having to chisel out corners. If you mean a square bottom corner, it is true, but that is rarely necessary for the bottoms to be square.

From contributor R:
My point is it doesn't cut square cornered mortises. I will concede you are right, if your tolerances are sloppy enough, you do not have to deal with it.

From contributor L:
I don't know what MAKA machine you were using, but the one I used cut perfectly square corners. I used to make windows with square cornered tenons and they fit perfectly. You never said if you were talking about the hole it cut or if you were talking about the bottom of the hole.

From contributor R:
Maybe this will help. We are apparently talking about different ends. The corners at the tenon end (there's that word again) have to be clipped if a reasonably tight fit is desired.

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From contributor L:
Yes, that is what I was talking about. The bottom of the hole is not square. But it rarely needs to be. There is no reason that the tenon has to fill every square mm of space. And comparing the time it takes to clip the corners of the tenon to a hollow mortiser or the extra cost of a 3 head machine to get the square bottoms really isn't worth the time to speak about it.

Nice drawing, but you forgot the waves at the bottom of the hole the MAKA produces, LOL.

From contributor D:
Mortise and tenon joints do not get their strength from tenon end grain contacting the bottom of the mortise. Rather from close fit with the sides of the mortise. The ends can add some strength, but this is end grain of the mortise, so is unlikely to add strength beyond mechanical.

The word 'mortise' comes from the Latin word for death, hence the English words 'mortal', 'mortuary', and others. The referral is to a grave, and indeed, a grave has a bottom. As a side note, the word 'mortgage' comes from the same root, apparently meaning 'pay until death'.

From contributor A:
I can't see that the rounded corners at the end of the mortise have any effect on it. I always leave a little clearance there anyhow for excess glue and just to make sure the tenon doesn't bottom out too soon. Our Maka could be used upright or horizontal; we almost always used it horizontal. Tooling isn't all that expensive and stays sharp a long time. It can be easily resharpened. Ours came with several stop rods and flip stops. If you happen to need really long mortises, just move the work down and plunge again. 90% of the time we use a loose tenon, works great. We’ve got several doors in the plant that were made this way 18 years ago, still fine. Made my parents' exterior doors and storm door same way about 16 years ago, still fine. The chain mortisers I've been around used oil on the chain, and some would usually get on the work (yuk!). Hollow chisel machines tend to leave some variations between plunges. The rotary bit machines seem to do a fine job if the correct bits are used. But they do leave the corners rounded.

From contributor E:
I don't know your situation - shop size, manpower, etc. But if the bench top mortiser can get the job done, use it. Why don't you calculate how much time goes in to your operation. Where is the bottleneck? The mortise for those doors in my shop wouldn't be a bottleneck.

With that said I have a Maka and two older hollow chisel mortisers. The Maka hands down is faster and more accurate to use. Although tooling can be expensive.

From the original questioner:
I'm basically a one man shop of about 2k sq ft with the basics as far as machinery goes. Up until now I've used a bench top mortiser and TS tenoning jig for all my mortise and tenon joinery, doors, face frames, etc. With an order coming in for 6 doors and a panel and another order for an additional 5 doors and 5 panels on the way, it seems like a good time to make an investment in something that will decrease the time needed to make the joints as well as increase the quality and accuracy of the joints.

I think after reading many of these posts and really thinking about what would be the most flexible in my shop situation, a slot mortiser may be the best bet. I would then switch to loose tenon joinery and hopefully increase my production a good amount. After the joinery, the only other bottleneck would be not having a large enough sander to run the doors through. But as a widebelt would be far more expensive than the mortiser, that'll have to be the next upgrade.

Of course now the problem will be to find a decent one for a decent price. They don't seem to be as plentiful on the used market as some other machinery.

From contributor A:
If you just make your parts accurately you don't need to use a widebelt. Cross grain scratches are a bear to get rid of and the bump up at the rails caused by the widebelt adds to the time to finish sand. If you are willing to buy a $100K+ widebelt you can get away from those problems.

From contributor B:
I've made hundreds of windows and dozens of doors. Initially I used an old PM 2A HCM and it worked fine but slow. I later discovered and purchased a PM 2A chain mortiser. The chains are available in 1/4, 1/2, 3/4 and likely other widths. The table traverses to accommodate various lengths and there are depth stops. Compared to manual HCM it's pretty fast. One of the disadvantages of the chain is the rounded ends. As you know, one does not always want a through mortise. Furthermore, regardless of how much time I spent on set up and chain tensioning, I still could not get accuracy within 1/32. The chains just have some slop.

As everyone mentioned, MAKA is the way to go. FYI there was recently a nice one for sale on Ebay, with lots of tooling for $5200, which is a great buy. It's now expired but the dealer is in the Chicago area. It's Freeze and Sons and Brian is in charge of this item.

By the way, how are you making your tenons?

From the original questioner:
I was very interested in the Maka at first, though after speaking with someone who seemed very knowledgeable about what they could and could not do for me, I ended up going with a slot mortiser instead.

My initial thought was, and is still, to go with floating tenons. I haven't completely ruled out using a solid tenon, but my tooling budget is spent, so if I chose this route it would be using the tablesaw to cut them. The doors I've done in the past used a double mortise and tenon joint for added strength as the stiles were 2-1/2" wide. On these doors the stiles will be slightly wider, maybe 3", but still narrow enough that I may keep the double tenon joint.

I have 2 installs to finish up this week and then I'll be giving the new mortiser a trial run to see how she does. Once I get a few test joints set up, I'll make my final decision on how to proceed.

From contributor V:
I am a recent convert to the horizontal mortiser and loose tenons. The machines are affordable, fast and accurate. The conversion to loose tenons allows for shorter pieces of wood to be used, cut lists are simplified with less chance for error, tenons can be cut from scrap en masse and stored for use.

Another important consideration is how you are cutting your tenons (integral, not loose). Few of us have real tenoners (single or double ended). Shapers can take large heads but it is still somewhat inconvenient for long rails. Loose tenons remove all that effort.

From the original questioner:
Both jobs are now completed and went well. I ended up with a used Bini horizontal slot mortiser. A very simple, heavily built machine that's easy to setup and use. I cut double slots 3/8" x 1-1/2" x 1-3/4" deep in all my parts and made loose tenon stock from the leftover scrap materials. Using loose tenons made for easier/better alignment, more efficient use of stock, and faster fabrication overall.

I wasn't 100% sure if such a specialized machine would be a good investment at first, but now I'm completely satisfied I made the right choice.

From contributor O:
I'm partial to slot mortisers myself. Glad to see your projects were completed without a hitch.

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