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Snell Boring Machine Operation

Started by flyingparks, March 14, 2017, 07:52:11 PM

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flyingparks

This is simply a step by step mortise cut for anyone who might need want it. This process works great for me and my mortises are done pretty efficiently. Please add any advice if you have any. I started cutting mortises with only a mallet and chisel. In fact, those were the only two tools I used on a small frame I cut (until I bored holes and made pegs. I have used my friend's Makita chain mortiser. They work great, especially when you encounter a hidden knot. With a $1700 price tag I have yet to buy one. I also am not completely sold on the clamping mechanism that comes with the Makita. A little wonky if you ask me.  :)

So I opted to buy a boring machine. First reason was cost. Second reason, I like the idea of doing everything without needing power. Sure it's a little more chisel work, but that's why we do this right? I bought a Snell from Jim Rogers. It works wonderful and he took a lot of care when sending it out. I also bought a 1 1/2" boring bit and a "stop". The stop works similar to the stop on the Makita. It's a depth stop. Most of the mortises I cut are 1 1/2" and 2". I have a matching bit for each. This eliminates much of the chisel work. It also forces you to be very careful about setting your bit in the right place.

In this photo, I have my mortise laid out. It's 1 1/2" wide, 4" long and 4" deep.


 

In this next photo, I have drawn a line down the center. This will be the point where I line the center of my bit.


 

Then, I make a series of marks along that center line. I start from one end and mark 3/4" in. Then from the other end. This allows the bit to cut up right to the edges go the mortise. The, depending on how long the mortise is I either measure 1 1/2" from these points until I get close to the center ( for long mortises) or in this case I make a mark at the center of the mortise (in this case 2").


 

So that is the setup. Now I align the bit with each of the marks.


  

 

Start boring. As soon as the actual bit touches the wood I set my depth stop. Pictures aren't so good here. ::)


  

 

I keep an eye the machine and the stop as they get close. The stop will not actually stop the machine from boring unless you tighten it mechanically. I just watch and when they touch I stop. A full turn in reverse on the pedals, engage the track ( ??? :P) and bring the bit back up. Repeat. Repeat.


  

  

  

 

Clean the mortise out and there you have it: a mortise that still needs a little more chisel work, I know.  ::)

I really enjoy using this machine. They certainly get it done. One note: you can't have very much overlap on your holes. A little is okay.

Don P

Good visual  8)
One other thing you can do, I usually put my chisel on the line at the ends and give it a couple of good taps to keep the tearout down on the end of the hole.

flyingparks

I knew I would get called on that! Hehe. Yea I was excited to take photos I guess. Rest assured the other mortises were scored.

Don P

Sorry to be "That guy"  :D. I've been chopping them this week for the chain machine. If you get set up even a skosh outside of the line with that it tears up a good flake. Today was pretty nasty so I made the first brace and a couple of router jigs to make housings for them.

Jim_Rogers

After scoring the perimeter of the mortise with a utility knife to prevent tear out beyond the line(s), I move my bit over a 1/16 (on the center-line) so that it doesn't get that close to the end of the mortise.
Other than that I think you've got it OK for all your step by steps.

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Heartwood

Two more considerations I'd suggest:
Make the mortise 1/4" deeper then the tenon length to avoid interference.
Make sure the face your boring from is square and parallel to reference planes or else shim the machine to be so. Use a square on the base of the machine to check.

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