One common joinery method used in wood working is the mortise and tenon. A mortise is basically a hole in a piece of wood and the tenon is another piece of wood cut to tightly fit in that hole. The tenon is usually secured in place with either glue or a wooden pin or wedge.
The folks over at [WayOutWest] were building a fence and needed a way to cut a bunch of mortises in 4×4 inch posts to accept 2×6 inch rails. Although they had a chainsaw, trying to cut a mortise with it by hand turned out to be super dangerous because the chainsaw would kick up every time the tip of the blade touched the wood. The team had some parts kicking around so they made a fixture to hold the chainsaw as it is plunged into the 4×4’s.
The contraption’s frame is made from an old scaffolding stand and the slides are just pipes inside of pipes. The chainsaw is bolted to the slide and a lever moves it forward and back. A second lever moves the piece of wood getting mortised up and down so that the mortise can be cut to any width. This is a pretty ingenious build that only cost a little effort and will end up saving a bunch of time mortising countless fence posts.
Nice hack but I don’t see any 4X4’s anywhere in the video, last time I checked 4X4’s are square (around 3 1/2″ actual dimension), I’m just sayin’……
http://bit.ly/JuPAkz
If you don’t understand lumber sizes just leave the room.
What part of square don’t you understand? I see 2X6 and 4X6, no 4X4.
There was a 4×4 used as part of the jig.
In fairness I don’t think anyone understands lumber sizes :P
And once again a perfectly nice homebrew tool is criticized and starts a flame war in the comments on HaD
It doesn’t take much, does it?
I didn’t criticize the hack, just the write up if anyone takes the time to read my post.
Considering how dangerous chain saws can be, I think this is a brilliant hack. Bravo, well done.
Perhaps a guard or two would be in order, but this certainly reduced the cut-off-limb factor considerably.
he could have just used a router
Yes, but then we all wouldn’t have the idea “Hmmm, CNC chainsaw” floating around in our little brains.
I was about to post about how someone needs to attach a chainsaw to an industrial robot arm.
Then the Internet did me a solid: https://www.youtube.com/watch?v=vgvlP87Ju5Y
I love chainsaw mills. Especially the home made variety. This is gold.
A really good example of using tools and materials at hand to get the job done.
This is ingenious. If Matthias Wandel approves, who am I to say otherwise. (c:
Why does it not have horizontal travel? Doing a bunch of plunges, then unclamping, moving, reclamping the post and then plunging a bunch more times seems silly. It should have plunged in then cut along the length of the mortise, in the usual chainsaw manner.
Probably because the tip tends to lurch when it bites. If it’s not bolted down sideways, it could become extremely dangerous.
https://www.youtube.com/watch?v=UMrZGBkmUZw
Can’t help but think that an auger drill and a big chisel would actually be faster than this jig, with all the fiddling and clamping and setting up.
The secret is to drill the holes from both sides to get them straight. With a bit of care you don’t really need any sort of jig.
Can’t help but think that if they take that path we will miss the opportunity to learn something interesting, just saying that doing things in the “correct way” not always gives the community the best results, experimentation is the key to learning. And this page is “hack-a-day” not “wood-working-a-day” if you haven’t noticed.
Aren’t you being a little selfish?
If the dude needs an efficient way to make mortises, he could be better served doing it the old fashioned way, and unless they’re completely enamored with their new jig – they may just conclude that it wasn’t worth the effort in the end. It’s their invention for their purposes, and they have no responsibility towards any “community”.
It’s curious how people sometimes try to own other people’s work by stuffing them under some label like “hacker” or “gamer” etc.
>”And this page is “hack-a-day” not “wood-working-a-day” if you haven’t noticed.”
So we can’t comment on how effective for its intended purpose a hack is?