In reading through the preview plans of the "3" I noticed that the four 1/4 inch steel "straps" that help tie the spar halves together are supposed to be heated treated to 125,000 psi. On another drawing sheet it also provides a Rockwell numbering range of 26-29 I believe, or something close to that (don't have the plans in front of me so proceeding via memory which isn't what it used to be ).
Anyway, since this a/c wasn't built by me I am attempting to make sure it is airworthy prior to the first flight, and am therefore interested in determining if the original owner complied with this note or not. I discussed this with an aero engineer friend and he said one method measures the hardness but the other test method requires a sacrificial piece to destroy.
My question therefore is: What are you all doing re. this testing requirement on your birds?
Additionally, I just replaced the fuel sender on our fuselage tank, and found that the gauge reads 3/4's when I hold the float in the fully raised position. Is there an easy procedure to figure out how to calibrate this to make it more accurate. I imagine I will need to add a resistor to one of the wires to get make it more accurate...
Thanks for your inputs...
Doug Lomheim
OK City, OK
RV-3 Restoration
https://www.dropbox.com/s/vbnwr2iiioujoxx/Spar 14 inch plate.jpg
Anyway, since this a/c wasn't built by me I am attempting to make sure it is airworthy prior to the first flight, and am therefore interested in determining if the original owner complied with this note or not. I discussed this with an aero engineer friend and he said one method measures the hardness but the other test method requires a sacrificial piece to destroy.
My question therefore is: What are you all doing re. this testing requirement on your birds?
Additionally, I just replaced the fuel sender on our fuselage tank, and found that the gauge reads 3/4's when I hold the float in the fully raised position. Is there an easy procedure to figure out how to calibrate this to make it more accurate. I imagine I will need to add a resistor to one of the wires to get make it more accurate...
Thanks for your inputs...
Doug Lomheim
OK City, OK
RV-3 Restoration
https://www.dropbox.com/s/vbnwr2iiioujoxx/Spar 14 inch plate.jpg
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