Yesterday's learning experience

[collinb]

So I'm building this box. It's a simple cabinet extension in the kitchen. Nothing special, really.

But I did the joints mortise & tenon.  My first real project doing that.

Cutting the tenons with the old Craftsman Universal Jig went well.

The mortises, on the other hand ...

The Jet machine has a tough time cutting a really smooth edge.

Or maybe it's the user.

(I haven't yet figured out a good enough excuse to effectively cast all the blame on my tools.)

I ended up taking my 1/4" chisel and smoothing out the edges of the mortise.

This gave it a good fit.  Spent an 20 minutes or so beyond the rest of the cutting.

 

What it seems like is this: Developing precision techniques and getting to know my tools well enough to mature these techniques takes a lot of time.

[RichardA]

Yup, time and patience! Oh, and lots of practice!

[Guest]

It is difficult (almost impossible) to get smooth walls with a hollow chisel mortiser. Super sharp chisels help.

[collinb]

It is difficult (almost impossible) to get smooth walls with a hollow chisel mortiser. Super sharp chisels help.

 

Had they been even close it would have worked, or at least seriously minimized manual intervention.

[Coop]

Collin, it's kind of a neat feeling doing your first mortise and tenon, isn't it. Do you know that they make a sharpener for the chisel? I didn't until recently. Like all other blades, I'm sure mine will work better when I get mine sharpened.

[Dave H]

I remember an earlier post by you with alignment issues with the chisel bit, go back to that thread and, heed some of that advice. if your expecting perfectly flawless sockets I would say look to the router and a simple home made jig and a bushing if it's a saw tooth effect on your sockets it's an alignment issue it takes a little fussing around with the chisel bit that's where the patience comes in set up of process is always what makes or breaks the project.

[Guest]

Best practice with a HCM is to cut a series of square holes, leaving a thin wall in between each hole.  It seems counter-intuitive, but if you try cutting overlapping holes the bit tends to wander into the direction of least resistance.   After you cut your series of small holes, just use a chisel to remove the thin wall between each hole.  I got that tip from a Bob Lang book (I believe) and it does work much better.  

[collinb]

I remember an earlier post by you with alignment issues with the chisel bit, go back to that thread and, heed some of that advice. if your expecting perfectly flawless sockets I would say look to the router and a simple home made jig and a bushing if it's a saw tooth effect on your sockets it's an alignment issue it takes a little fussing around with the chisel bit that's where the patience comes in set up of process is always what makes or breaks the project.

 

I did read the posts.  It helped.  But it may take more practice to get things all figured out.  It seemed to be chisel alignment was just a little off.  Enough to make the edge not quite smooth enough.

And I did learn about the overlapping problem ( or should I say "3/4" problem) on youtube.  It is the right way and it is how I've done things.

[shaneymack]

One other tip Collin, cut your mortises FIRST! Its is much easier to adjust the tenon to fit the mortise than the other way around. 

[Tom Cancelleri]

Sharpening the chisels will help. If the alignment is set right you shouldn't have any ridges in the side walls of your mortise. I always take a milled piece of scrap and test out my setup for any tool before going to my workpiece.