Sheeting outer balsa wing panels
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From: Fayetteville, NC
I am repairing a Spirit 2M glider. I read an article by Mark Drela on sheeting the outer wing panels to reduce or eliminate tip stalling. He calls for shaving 1/32" of the top of the ribs from the leading edge back to the spar. Before I get too carried away with my exacto I want to make sure I'm doing this right. 1/32" is not much. Any suggestions or tips before I start shaving and maybe shave too much? There isn't much room in there as the wing in already built. Thanks in advance.
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From: Indianapolis, IN
I think they want you to take off the amount of rib surface that will EQUAL the "thickness" of the sheeting you want to apply. I am assuming that the sheeting is to be 1/32" thick balsa. Since it is a glider, I guess they are trying to minimize the added weight. I was building a 4* 120 and was going to sheet the wing in the same manner. That sheeting was 3/32" thick.
I ended up passing on the modification. A lot of guys have done this succesfully. (I guess this goes without saying.... it is a LOT easier to do the rib mod before assembly of the wing)!!...lownslo
Bob
I ended up passing on the modification. A lot of guys have done this succesfully. (I guess this goes without saying.... it is a LOT easier to do the rib mod before assembly of the wing)!!...lownslo
Bob
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From: Fayetteville, NC
Thanks Bob. Yes the sheeting is 1/32". I hoping someone has a secret tip of shaving that much off the top of the rib without taking too much off or causing any other problems. Mike
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From: Morgantown, KY
If the wing's already built, you're probably either going to have to do it slowly by hand (which would be a pain), or make a jig for it. Get a small piece of tin, copper, or aluminum, like the sheet metal from a heating duct, and shape it so that you can hold it against the bottom of the rib and the top will leave 1/32" exposed, then you can trim it getting all of them the same.
If you've got the plans for the plane, this shouldn't be too hard to do. It is a pain getting the metal and messing with it, but it will give you a template so that you do them all the same and end up with a smooth LE all the way down the wing.
Just thinking out loud here, this advice assumes a constant cord wing, which I don't think sailplanes usually have. You might have to trace the outline of the top of the rib and cut a piece to match that outline, and then glue two 1/32" guides to each end. Then you can hold the guides flush with the top of the rib and cut along the outline, which would only leave to small 'tabs' to cut off of each end when you raise the template. Did that make sense?
Heath
If you've got the plans for the plane, this shouldn't be too hard to do. It is a pain getting the metal and messing with it, but it will give you a template so that you do them all the same and end up with a smooth LE all the way down the wing.
Just thinking out loud here, this advice assumes a constant cord wing, which I don't think sailplanes usually have. You might have to trace the outline of the top of the rib and cut a piece to match that outline, and then glue two 1/32" guides to each end. Then you can hold the guides flush with the top of the rib and cut along the outline, which would only leave to small 'tabs' to cut off of each end when you raise the template. Did that make sense?
Heath
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From: Morgantown, KY
Excellent idea! Hadn't thought about it not mattering if the tops were shifted over a little.
Your drawings are awesome, Minn. What do you use to do them?
Heath
Your drawings are awesome, Minn. What do you use to do them?
Heath
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From: New England
Could Mike just add the sheeting, then add cap strips of same thickness down the rips? or would this add too much weight/effort, or change the airfoil.
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From: Morgantown, KY
Only problem with that method is then you're gonna be sheeting all the way around the leading edge strip, trailing edge, and building up the ailerons, if you want to keep it all uniform. MUCH more hassle.
I'd go with Minn's method. Would be reasonable fast and efficient.
Heath
I'd go with Minn's method. Would be reasonable fast and efficient.
Heath
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From: Fayetteville, NC
Thanks to all for the suggestions/tips. I think MinnFlyer has given me a method I can handle. At least this way if I cut too much off the copy, I can just make another copy till I get it right! That is a great drawing too. Didn't know Photoshop could do all that. Thanks again! Mike
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From: Indianapolis, IN
I reaize this is an R/C forum.... and I apologize for this question.I have to ask about Photoshop. I assume that is a software program. A short introduction to Photoshop may help myself,and others here on the forum, explain ourselves a little better.
Without taking too much time, can someone explain a little bit about it? Is it easy to use, etc.?
Thanks......lownslo
Without taking too much time, can someone explain a little bit about it? Is it easy to use, etc.?Thanks......lownslo
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It's as easy as drawing, it just depends on how good you are at drawing LOL
There are so many aspects to photoshop I couldn't even start to tell you all the things you can do with it. I use it in my line of work, So I'm familliar with MOST of what it can do, but there's still a bunch of stuff that I don't use/need.
It's also pretty expensive ($609)
Here's an idea of just some of the stuff you can do with it... One of my biggest clients sells musical instruments. I will often get 1 picture of a guitar that they sell in many models and colors, so I have to create whatever I don't have a picture of. Here is just a sample of three guitars that I created from 1 image.
(PS Trust me, the girls in Playboy don't look nearly that good in real life! LOL)
There are so many aspects to photoshop I couldn't even start to tell you all the things you can do with it. I use it in my line of work, So I'm familliar with MOST of what it can do, but there's still a bunch of stuff that I don't use/need.
It's also pretty expensive ($609)
Here's an idea of just some of the stuff you can do with it... One of my biggest clients sells musical instruments. I will often get 1 picture of a guitar that they sell in many models and colors, so I have to create whatever I don't have a picture of. Here is just a sample of three guitars that I created from 1 image.
(PS Trust me, the girls in Playboy don't look nearly that good in real life! LOL)
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From: Spring Hill,
FL
Originally posted by MinnFlyer
(PS Trust me, the girls in Playboy don't look nearly that good in real life! LOL)
(PS Trust me, the girls in Playboy don't look nearly that good in real life! LOL)
I wonder if I can get a refund.Great work MinnFlyer! I've been tinkering around with Photoshop for my web site, but don't really understand much of it. I use Picture Publisher for most things because I know how to use it. Then if I need some effect that PP can't handle, I move the image over to PS and play around with it until I get lucky or give up. Way steep learning curve for that program.



Thanks....lownslo
