Thursday, 5 April 2012

My New Rock And Roll Saw...

My next major project is a new combo tool cabinet come bench. I have everything for it worked out on paper so I am now in "collection" mode; finding the materials and specialty tools needed to get the thing built.

I posted about this design back in June of last year and I'm mentioning this now because the design is in the Campaign style and I wanted you all to know that I was working with this style long before Chris Schwarz started his campaign build. 

The design calls for drawers and lots of them, all installed in multiple carcass cases that will make up two storage units each made up from stacking three carcass cases on top of each other. The bottom case for each will be 11" high, one for a saw till and the other for other high items, and the remaining two cases in each will be 7" high each with its own unique number of drawers. With them stacked on the base stand and the bench top placed across them, I'll end up with a bench at proper height. The reason for this type of design is its versatility. I can stack them as explained for a workbench, or I can do away with one of the bases and stack them all together on one base. The design will also allow me to change the stacking order to best suit my work habits, or to suit my mood, whichever the case may be.

As each pair of drawers in the individual cases will require a divider, and I can't think of a better joint to use for them than a sliding dovetail. I love this joint as it is strong and seeing a dovetail on the end of a wide piece is just downright cool. I made them all the time when I worked with a table saw, but not so much now that I'm a tool pusher. They are both complicated and a hell of a lot of work to make by hand. The blind variety are also a royal pain in the butt to make. With that in mind, I have been working with Matt Cianci over on The Saw Blog on coming up with a new saw design, one specifically designed for cutting the two sides of all the blind sliding dovetails this project calls for.



While sliding dovetail saws are not something new, our design does have a few unusual features.

One of the biggest problems with cutting a blind sliding dovetail across a carcass wall is that the toe of the saw always digs in and makes a royal mess of things. Doing some experimenting, I came up with the idea that if the saw's plate was arched, the digging in problem could be overcome. By giving an 11" long plate a 58" radius, it ends up arching up ¼-inch front and rear. Using the centre section to cut across the wider width of a carcass, the toe will not be able to bury itself during the cut. If the cut is blind, tilting down the heel of the saw as you go deeper will keep it from nose-diving and when the majority of the cut is done in this manner, you can tilt the heel up and use the toe to finish it off blind.

As the two cuts need to be equal in depth, I figured a depth gauge would be just the ticket so I came up with a design for a curved one to match the curvature of the blade's arch. I then took a page from the old filletster planes and came up with an adjustable setup. I think the design will allow me to cut pretty accurate depths whether cutting across the board, or tilted up while cutting the blind with the toe. I designed the gauge to also work as a fence, planning to have it run up against the cleat instead of the blade. I just think this will be easier to work as there will be some distance between my hand and the cleat, keeping the skin on my knuckles in the process, not to mention saving the saw's set for another day.

Matt was a lot of help to me coming up with the handle's "hang", or angle of attack. At first I had it set to 34º, but Matt suggested it would be too difficult to work and suggested I bring it down to 24º, which is still higher than a normal handle hang. We did agree on the placement, though, as bringing it forward so the grip is over the heel of the saw will help to keep it against the cleat.

Wanting the thing to look good as well, I decided on making the body out of zebra wood and the handle and horn out of ebony. I think these two woods work well together with their strong contrast in tones.

The result of all of this is that Matt is now looking for an old piece of .028" plate stock and I'm sourcing out a place to buy a hunk of ebony that won't cost me more than what I paid for my last new car.

The project should be fun to put together, but with a total cost probably in the $250 to $300 range, I sure hope the damned thing works.

Peace,

Mitchell