Thursday, 10 March 2011

Trouble Coping…

In my quest to cut a better dovetail, I have started to focus on each aspect of the process to determine where I can improve, looking at both my performance with each, as well as the tool’s.

The one area that I see problems with is the cutting away of the waste. I have accepted the common suggestion that I use a coping saw to remove it, but the problem I have encountered is finding the proper saw.

Originally, I became enamored with a specific style of coping or fret saw that started when my wife bought one for me at the Christie Antique Show about five years ago. I found the design irresistible and to say I have picked up a few more of that same design would be an understatement.



They are nice saws. They all hold their blade relatively taunt, and all have frames that have limited flex under stress. What none of them do, however, is allow for blade rotation. This means they are great for some projects, but not for cutting away dovetail waste in a wider board.

I then dug out the coping saw I have shuffled along with me for who knows how many years now. It is marked, “Great Neck No. 28”, and I probably bought it in the late 70’s, but I doubt I used it since completing the project I bought it for way back then. It allows the blade to be rotated 180˚, although not necessarily at an even rotation for both mounts. The frame, however, is quite stiff. Using it, because of the inability to fix the angle at either mount, I discovered the blade was twisting like crazy.

So the search was on for the perfect coping saw…ha! Good luck with that one. The reality is, if Chris Schwarz can’t find one, who can? He has been writing about his coping saw adventures for years.

His latest post on this subject is one where he road tests the new Knew Concepts Aluminum 5” Fret Saw. Putting my aversion to all things new aside, I went into his article with an open mind. Nice saw, but…

It isn’t the most attractive thing I have ever seen, but between the clamping mechanism and the stiff aluminum frame, I think it may be a winner. I’m still debating buying one as the thing is $95, which would mean about $130 landed here in Canada. It also limits the blade rotation to 45˚ in either direction. While this is better than the zero rotation my favorite saws provide, and the sloppy 180˚ rotation my hardware store special has, it is not the ideal rotation I would like, which would be 90˚. I also have a true dislike of all things red, and this saw is definitely that.

Figuring if I’m in for a nickel, I might as well be in for a pound, why not make my own.

Being a complete novice at this, I did my usual research and decided that the tried and true bow saw style of frame made the most sense. Because I have never even held one, let alone used one, I have no idea how they work or feel, but their design just makes sense to me.



The big attraction to me is the double handles, as I believe they would facilitate cutting the waste away with a draw stroke, and then flipping the saw over and removing the little wing left with push strokes. What I don’t like is the traditional tensioning cord. To me, it looks like a fisherman’s nightmare when it comes time to change a blade, so I figured I would replace it on whatever I built with either a turnbuckle or a simple threaded rod.

As I had no focus whatsoever as yet on the clamping mechanism, I disassembled the Great Neck saw and scooped its parts. I also wasn’t going to spend any time creating the frame either, because this exercise was simply to find out if the basic design principle would work, so I used some Eco-Dowels I already had. Because I didn’t know if a turnbuckle or wing nuts at either end of a threaded rod would be best, a trip to Home Depot resulted in coming up with the parts that would allow me to test both within one set-up. The result of all of this isn’t going to win any beauty awards, but it did give me a huge amount of feedback regarding my thoughts on the subject.



While crude and seriously ugly, this thing really works. It offers some serious control while allowing for quick cutting. It is light and reasonably robust. I was afraid that it would be top-heavy and therefore, prone to flopping from side to side but using it, I didn’t find that at all. The turnbuckle is out and the threading rod is in, but I do have to figure out a way to capture one end of it to speed up the tightening. It also definitely needs a second handle, but I am not too sure the traditional style of them is the one to go with.

So “Prototype Saw One” is a winner and it is time to start the fine-tuning.

Peace,

Mitchell