Time for working with a new saw! This time its a 5-1/2′ two man cross-cut for felling and bucking, cuts on the push and the pull, with four cutter teeth to every raker. I’d been needing the use of a larger capacity saw for bucking logs prior to ripping with my whale noko, because my madonoko isn’t really meant for cuts over about half a meter. Now, I’ve made some pretty epic cuts larger than that with time and patience, but even after careful straightening by metate Mark my madonoko still wanted to wander on the opposing side of the cut, and it gets to be a real struggle to layout for boards on the end of the log when the surface of the end grain is concave.
I’ve resisted the idea of two man saws for the simple reason that its damn hard to find another guy to get on the other side of the saw. If you do, damn, that’s a good friend, I tell you!
But a saw like the one in the picture above can be used by one person quite effectively as long as the cut is plumb.
And! There’s some very interesting tools used in dressing these large saws accurately. The jig at the top of the picture above does three things. First, it can hold a file in a curved shape for jointing the tops of the saw teeth to the same level. Second is a pin gauge for setting the height of the raker teeth when peening over the hook. Lastly is another height gauge for finish filing the rakers to a consistent height, accurate to the thousandth of an inch. The tool at the bottom left is the setting spider, the subject of today’s post. How about some instructions?
And learn from the master filer I learned from, a fantastic set of videos that include a bit of hammer straightening of saws.
The spider is used as a gauge to accurately determine the degree of set in each tooth. Simple and brilliant, it immediately struck me that such a tool could be easily made and used on maebiki-oga.
You’ll catch this if you watch through the videos above, but basically the spider has a small difference in height between the long arms. Placed on the saw you see how it rocks back and forth. If the long arms rock the tooth needs more set, if the short arms rock the tooth is over set. Its important to note that this tool only works if the plate of the saw is quite straight, flat, and even of thickness.
I started by cutting a cross out of some mild steel a bit thicker than 1/8″.
I stuck it in a vise to bend the edges over, filed a flat land on all the feet, and leveled them to the same height on my diamond stone.
Then one leg could be lowered by grinding with part of the spider off the stone, checking how much material had been removed with a feeler gauge. For the large cross cut saw the spider was set at about .012″, for my maebiki-oga I adjusted the spider to gauge .010″ of set, which with a plate thickness of .085″ gives me a kerf just under 1/8″.
Luckily the plate on my saw is pretty consistent and flat, so I got right to work checking my set. Up to this point I’ve been setting by eye by sighting along the plate held flat. If you have an oga saw with a rough hammered surface you’ll have to depend upon setting by eye. I still don’t completely trust the spider, but it is a great analytical tool to gauge how well I’m setting, and weather I’m actually seeing the degree of set correctly. As it turns out, I had over set one side and under set the other, probably due to the change in orientation of the saw when flipping it to peen the teeth over.
For setting teeth you need a small anvil, mild steel is okay, as long as it has a rounded edge that allows the tooth to make contact in the right spot. The teeth of a whale noko are hard enough that if you were to strike the tooth while unsupported you run the risk of breaking it.
With the plate held in your lap at a lowered angle to the flat you can place the tooth line on the anvil and strike the upper third of the tooth.
I’m using a new hammer for setting, a cross peen with a ‘v’ shaped edge, not rounded, that is basically a large single edge version of a Japanese setting hammer. If you use too light of a hammer you find yourself whacking the tooth with a rather random amount of force. Adjusting the set within a thousandth of an inch requires control. Also, bending teeth back that have been over set on such hard steel is not an option, they just break off, so get it right or you’re stuck with an over set tooth until you sharpen it down a bit.
Happy sawing! I hope more people now are getting these big saws ready for the cut and avoiding the hassle of a chain-saw.