Pietenpol-List: Re: Bending Allowance
Posted: Fri Oct 22, 2004 9:59 pm
Original Posted By: "Catdesign"
Jake:Tony Bengelis covers this in his book "Sportplane Construction Techniques" by tellingus to make the bends first and then the ends are measured to see how muchto cut off. Also, he never drilled any holes until after the bends are made.(page 40) Quote from Tony..."There you have it.....a fitting with the correctheight and base dimensions." Not a very professional way to make fittings, butthey will be accurate...consistently more accurate than many you'd make usingthe metal working formulas involving bend allowance charts, setback tablesand that sort of thing."Regarding the spacer: Look just to the left of the line giving the dimension "3-1/4"between the two end attach holes of the pulley bracket and it calls out3/32" ply both sides. If I interpret the plan correctly this 3/32" ply wouldbe shaped like a piece of pie...the bottom flush with the spar and the top wouldbe against the spar joint strap.Finally...I hope this helps....and I can't say enough about how much Tony's bookshave been so helpful to this amateur plane builder.________________________________________________________________________________
Jake:Tony Bengelis covers this in his book "Sportplane Construction Techniques" by tellingus to make the bends first and then the ends are measured to see how muchto cut off. Also, he never drilled any holes until after the bends are made.(page 40) Quote from Tony..."There you have it.....a fitting with the correctheight and base dimensions." Not a very professional way to make fittings, butthey will be accurate...consistently more accurate than many you'd make usingthe metal working formulas involving bend allowance charts, setback tablesand that sort of thing."Regarding the spacer: Look just to the left of the line giving the dimension "3-1/4"between the two end attach holes of the pulley bracket and it calls out3/32" ply both sides. If I interpret the plan correctly this 3/32" ply wouldbe shaped like a piece of pie...the bottom flush with the spar and the top wouldbe against the spar joint strap.Finally...I hope this helps....and I can't say enough about how much Tony's bookshave been so helpful to this amateur plane builder.________________________________________________________________________________