David A Ramsey
Feb 13, 2005, 06:36 PM
You can get rid of the Xacto blades and planes, but you're gonna need a table saw and a router table. A band saw will work in place of the table saw, but not as nice a cut as a triple chip 80 tooth carbide blade.
To hold the balsa blade blanks, I use a piece of oak as long and high, or a bit longer and higher than the blank. The width of this piece should be 4" to 6" so you can maintain a good grip as you guide the holding fixture against the fence while riping the two major blade angles. For my right tilt table saw I cut on the left side.
You can build up the thickness for the blade holding fixture by laminating some clear 3/4" pine and then trim square.
To hold the blade blanks to the fixture, I use double face crape tape. I use a new piece for every cut. A balsa blank is lined up along the bottom edge of the fixture. After a cut the blank is carefully lifted off the tape. The balsa fibers that transfer to the tape are minor, but make the piece of tape unsafe to hold another blank.
Two angles are cut, leading and trailing edge. Draw a cross section of the airfoil on a piece of paper and determine the high point, usually 25 - 30 percent. measure the angle at the leading and trailing edge curve tangents and set the saw blade angle. I make a test cut to make sure of the angle. Cut all blanks for one angle, reset the saw angle and cut the other.
To finish the airfoil I use some small bit of double face tape to hold the blade to a firm surface and block sand to final shape. As the major shape is done on the table saw, it's easier to final sand to a consistant shape for each blade.
Blade holder and weight slots are cut on a router table. I'll have to get a picture of that later.
The best double face tape, for this purpose, is available from McMaster-Carr Supply Co. www.mcmaster.com The general part number is 76405A"00". The last 2 numbers depend on the tape width.
For flat bottomed blades this works quite well.
Do I need to say; Keep you hands clear of the saw blade and don't stand in line with the object you're cutting on the table saw ???
David
To hold the balsa blade blanks, I use a piece of oak as long and high, or a bit longer and higher than the blank. The width of this piece should be 4" to 6" so you can maintain a good grip as you guide the holding fixture against the fence while riping the two major blade angles. For my right tilt table saw I cut on the left side.
You can build up the thickness for the blade holding fixture by laminating some clear 3/4" pine and then trim square.
To hold the blade blanks to the fixture, I use double face crape tape. I use a new piece for every cut. A balsa blank is lined up along the bottom edge of the fixture. After a cut the blank is carefully lifted off the tape. The balsa fibers that transfer to the tape are minor, but make the piece of tape unsafe to hold another blank.
Two angles are cut, leading and trailing edge. Draw a cross section of the airfoil on a piece of paper and determine the high point, usually 25 - 30 percent. measure the angle at the leading and trailing edge curve tangents and set the saw blade angle. I make a test cut to make sure of the angle. Cut all blanks for one angle, reset the saw angle and cut the other.
To finish the airfoil I use some small bit of double face tape to hold the blade to a firm surface and block sand to final shape. As the major shape is done on the table saw, it's easier to final sand to a consistant shape for each blade.
Blade holder and weight slots are cut on a router table. I'll have to get a picture of that later.
The best double face tape, for this purpose, is available from McMaster-Carr Supply Co. www.mcmaster.com The general part number is 76405A"00". The last 2 numbers depend on the tape width.
For flat bottomed blades this works quite well.
Do I need to say; Keep you hands clear of the saw blade and don't stand in line with the object you're cutting on the table saw ???
David