Another run completed, this time it took (including blank preparation, milling clean both faces with a 1/2" bit) 5 hours and 15 minutes from start to finished blade.
Add another 20 minutes or so for sanding.
Roughout was quick and pretty painless, no glitches. The Makita is a lot more quiet than the Porter-Craple was, until the router really starts to work, then the noise level goes up quite a bit.
The bit is pretty worn, we'll have to get a couple of new ones tomorrow !
The modifications to this blade are:
A slightly 'thicker' profile, we added two millimeters (3/16") of flesh to the center
A 4 cm (1.5") increase in root chord length
a reinforcement section near the root of the blade that morphs into the blade profile in 50 mm
a little more fiddling with the blade profile gained us a bit more twist from the same 2" blank, we're now getting 4.5" of rise out of a 2" blank !
If you're interested in what the 3D simulator for the cutter table looks like then click here, warning , this is a VERY large image !! This site won't allow me to use a 'target' tag, so you'll have to use the 'back' button to get back to fieldlines.
pictures follow:
Milling flat the blank:
Beginning of the roughout, notice how the sawdust stays in the groove, this leads to a lot of heat buildup
Pass one complete:
closeup of the beginning of pass two:
pass two complete:
pass three complete:
Roughout finished:
Clear view of the roughout being 'transformed' into the final cut, notice how close the roughing pattern is
Beginning of the last pass on the frontside, here you can clearly see the reinforcement at the root:
last pass of the front of the blade, sorry for the blurry image:
View from the tip, backside up:
view of the twist at the root:
closeup of the root, what looks like a sharp cut off at the back is actually a less than 45 degree slope
