Stewart Corman
29th March 2007, 20:25
<http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4312.jpg
blanks are quickly roughed out with electric handplane set to deepest cut at first and since contour is flat, only ends have to be marked with profile
set planar to 1/64" to smooth out "corners" ...templates get used later
topside templates were cut for 7 stations by printing profile on inkjet at various % factor starting with 9 inch, 8, etc ...trace onto thin plywood, cut close with bandsaw, use sanding drum on drillpress to get proper final shape
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4315.jpg
final "roughing" is pretty good ...template is shown with printer profile
each blade took about 10 minutes ..this is THE tool!
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4327.jpg
sanding started with grinder and 7 inch 60 grit coarse flat "flap" wheel ...careful, this can gouge too easily ....
random orbital 5 inch finishing sander contours very easily ...lots of control "rolling over" leading edge across the cord ...use templates and use straight edge tip to root
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4322.jpg
finished topside sanding and templates match
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4352.jpg
after rounding bottom side leading edge, tubing is inserted 6 inches with glue, predrill for three flat head hardened self taping screws and fill with putty ...do not fine sand ...spray 3 coats exterior spar polyurethane
ready to fly!
blanks are quickly roughed out with electric handplane set to deepest cut at first and since contour is flat, only ends have to be marked with profile
set planar to 1/64" to smooth out "corners" ...templates get used later
topside templates were cut for 7 stations by printing profile on inkjet at various % factor starting with 9 inch, 8, etc ...trace onto thin plywood, cut close with bandsaw, use sanding drum on drillpress to get proper final shape
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4315.jpg
final "roughing" is pretty good ...template is shown with printer profile
each blade took about 10 minutes ..this is THE tool!
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4327.jpg
sanding started with grinder and 7 inch 60 grit coarse flat "flap" wheel ...careful, this can gouge too easily ....
random orbital 5 inch finishing sander contours very easily ...lots of control "rolling over" leading edge across the cord ...use templates and use straight edge tip to root
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4322.jpg
finished topside sanding and templates match
http://i145.photobucket.com/albums/r203/scorman1/Turbine%20project/blade%20construction/4352.jpg
after rounding bottom side leading edge, tubing is inserted 6 inches with glue, predrill for three flat head hardened self taping screws and fill with putty ...do not fine sand ...spray 3 coats exterior spar polyurethane
ready to fly!