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Building Tips and technical articles. => Building techniques => Topic started by: Bootlegger on July 03, 2018, 06:34:36 PM
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Guy's when you are shaping the L/E on your wing do you use a templet for shaping, or do you have a better way? I am thinking about on a L/E such as a Sig Twister. Thanks a lot... y1
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There's enough inaccuracy in a Sig Twister that you can just eyeball it.
If I want real accuracy, and it's not too sharp, I mold the LE.
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One thing about a stunt model, you get out of it what you put into it. By all means, use a template. I have seen Twisters with absolutely un-shaped 1/2" square sticks in the leading edge and they actually flew acceptably for the person at that time. But a nicely shaped leading edge with no lumps or bumps looks really nice and really nice looking always flies better!
Type at you later,
Dan McEntee
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You can make a tool to shape the leading edge accurately. Walter Umand from built right fly right models includes pieces to make one in his kits. It's simple.
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Maybe somebody will chime in about how they did it years ago, on their award winning R/C plane? y1 Steve
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I use a long sanding block until the LE matches the drawing.
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I too make a sanding block/tool about 2" inch long with the airfoil cut into it with a table saw and medium grit sandpaper glued to it. I try and avoid blades of any kind when shaping the LE but that is just me. Once I have the basic shape I use a 12" block to final shape then very lightly hand sand to smooth it out. As long as you get the right curve any method here works as long as you don't try and do it TOO FAST. I do the same for the stab. Put some masking tape (I use blue painters) on the sheeting (if it has sheeting) where you want the shaping to stop. It is super easy to sand too far back and get flat spots.
By the way, save your sanding tools. They are great for building a 2nd one or repairing the one you just used to show everybody what the 4th corner of a hourglass can look like in a thermal downdraft.
Ken
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Good morning Gil. I used a sanding block varing the grades of sand paper and removing material slowly. This is done by eyeballing the LEnand feeling The smoothness of the wood. Thank God our eyes are young! Lol
Tim
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Here's what I use. And I make them on my table saw! It's simple once you figure it out. The trick is to take really "SMALL" (1/16" or less) cuts until you get the desired depth you want.
First raise the blade to the desired depth (NO, you're not going to cut yet) Then see where the cut starts and ends. Then (here's the tricky part) place a fence at the desired angle 30-45 degrees etc., and clamp it to the saw.
Next lower the blade down to 1/16' or less and run a cut (watch those fingers!) It should slide easily along your fence. Continue until the desired depth it reached.
Add sand paper and have at it!
OBTW I rough cut my LE's with a wood plane first to get them close.
Here's a photo.
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Nice Jerry!
So one of those is in that Colossus kit i bought, right? <=
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Here's what I use. And I make them on my table saw! It's simple once you figure it out. The trick is to take really "SMALL" (1/16" or less) cuts until you get the desired depth you want.
First raise the blade to the desired depth (NO, you're not going to cut yet) Then see where the cut starts and ends. Then (here's the tricky part) place a fence at the desired angle 30-45 degrees etc., and clamp it to the saw.
Next lower the blade down to 1/16' or less and run a cut (watch those fingers!) It should slide easily along your fence. Continue until the desired depth it reached.
Add sand paper and have at it!
OBTW I rough cut my LE's with a wood plane first to get them close.
Here's a photo.
Gerald:
I make my blocks just like yours but I flair the sides and run the sandpaper over the flair. I kept getting score marks from the edges of the sandpaper - that fixed it.
Ken