So what about these 'ere morticers. For anyone not familiar with them a quick guided tour. What do you look out for ?
A substantial support from which to hang the induction motor that powers the mortice chisel.
Ideally, as we have here, you get two stops that limit the depth to which you make the mortice and also another one that limits how far up does the chisel return. The latter being very useful as it saves you having to keep winding the chisel down through 'dead space'.
In an ideal world, you'll also have a couple of stops at the rear that limit the sideways movement - especially useful when chopping out large mortices that need several passes.
Also as you can see here a sacrificial piece...which saves you trying to drill into the cast iron table. I cocked up here and should have put a proper sacrificial piece on top of the smart bit that you can see in the photo and which came with the morticer. Trouble is that the table is higher than my assembly bench and when I made the extra support to go on top of the assembly table I forgot to factor in a sacrificial piece. There is a much more relevant reason for having a separate or disposable sacrifical piece. I'll let you work that one out for yourselves. Answer at the end
What else ? A decent solid well-engineered table with a couple of decent sized handles for moving the table back and forth and sideways.
On the morticer that I sent back, the handle for back and forth was a horribly small knurled knob that was a struggle to use and it's location meant you kept bashing your knuckles on another part as you tried to turn it.
A decent sized clamp to hold the work
although it fails when morticing hardwood as I found out on the first morticer I ever bought. As you raised the chisel, it failed to release properly from the hardwood and so the hardwood was pulled upwards with the chisel because you're relying on a friction grip from that clamp. Especially noticeable on smaller machines that have a smaller clamp than this. As I type this I'm wondering if a sheet of abrasive glued to the face of the clamp would alleviate this problem.
Of course, on a larger morticer, such as this one, you have the solution provided with a hold-down
I made up an additional support to go on top of the assembly table to bring the stock up to the right level.
You want the chisel to move up and down perpendicular to the table. And if they supply a chisel like this with the machine then throw it away. Apart from being crudely made, bent ad with terrible edges, the shoulder that you reference to when fitting the chisel ...well, some muppet made it tapered, so part of it moves up inside the collar and so you are totally guessing where to set it. Hopeless. That shoulder should be square. I bought a very nice Harima Japanese pattern mortice chisel from Axminster. Nice.
So to work.
First mortice marked out using those Axminster gauges again and mortice cut. Such a long time since I made any mortices with a machine...actually such a long time since I made any mortices. Period.
And, as mentioned earlier, jolly good job that they supplied a sacrificial piece on top of the table as otherwise I'd have wrecked my lovely new mortice chisel.
I asked earlier on why you needed a disposable sacrificial piece of wood. Well the reason is that besides stopping you from nadgering up the end of the chisel, it acts as a backing block to prevent breakout from the underside of the sock and although you'd think that if you were making the same cut each time that it would still work just fine, it doesn't simply because after the first mortice, there's a thumping great hole in it ad it only takes slight misalignment for breakout to occur.
So clever trick. If you're making multiple mortices the same in a number of pieces of stock then you could mark up each piece and then cut the mortice. Or
you could put the next piece underneath the one you're working on so that (a) you have a new 'sacrificial' piece and (b) your chisel as it cuts into it is self-marking for the mortice cut that you're going to make in it. Like this...
Good idea, eh ? Of course, you need to keep an eye on any errors that might drift in but that's easy enough to do. NB Only works if that chisel is perpendicular.
So let's have a look at the result. Looks pretty square to me.
And mating tenon to mortice
Lovely jubbly. Progress. Ready to be glued up.
If opportunity doesn't knock, build a door.