Originally Posted by
peter gagliardi
If you don't have the room, then a slot mortiser that is router based makes sense.
All of the machines discussed so far will cut accurate enough mortises that once glued will hold better than the wood fibers surrounding it.
However, saying that a router is more accurate, is quicker to set up, makes joints quicker, and has better or less upkeep than a dedicated chisel mortiser is in my opinion flawed.
First and foremost, induction motors don't even have to try to be able to outlast a universal motor- it is inherent in the design- it just will.
Then, there are the bearings- super high speed small bearings that are sealed in a router cannot possibly last longer than the much,much larger open, and sometimes oiled, or greasable bearings used in a stationary machine. Just look up the load and hour ratings to failure, again, by design.
There is currently an aweful lot of the worlds woodwork - furniture and millwork alike that was done with a hollow chisel machine, I would almost bet the majority of shop made goods that have mortises were produced that way over the last century and a quarter.
John is hawking pretty hard about his design of a router mortiser, and trying to sell plans, which is fine by me, but if that system is that good, quick and accurate, businesses would have developed and adopted it 125 years ago.
Businesses, and the free market are pretty good at analyzing the cost/benefit side of the equation, and they wouldn't survive long with shoddy work, lots of machine upkeep, or long setups.
I think history backs the hollow chisel mortiser as an accurate, and fast method of producing quality joinery with reliable and fast setup by a skilled operator.
I have 2 hollow chisel mortisers, and 2 chain mortisers, along with the large Domino- essentially a router based mortiser.
The Domino lives in it's box, until there is an odd job that the others can't do.
It is a good and accurate machine, but it is not in my mind fast enough or versatile enough for production work.