D.N.U. monokote
08-18-2010, 01:15 PM
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RE: D.N.U. monokote
Well, it will be stronger and easier to use, but frankly weight is such a flight performance killer I'm counting all the ounces that can be saved and going there. My birds fly much better. so the loss in streingth is offset by a better flyer. Just my 2Cents. ENJOY
08-18-2010, 05:46 PM
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RE: D.N.U. monokote
I think you can fairly accurately work out the weight difference with a few minute's pencil work and this link: http://fatlion.com/sailplanes/weights.html and a bit of googling other covering weights.
Hmm, in fact.. a few minutes on AutoCAD plus some bugger factors and these numbers spew forth (rounded here and there as you can see):
Total wing area, top and bottom = about 380 sq in * 1.1 for overlaps, curvature etc = 418 sq in
Fuselage surface area = 37.5 + 37.5 + 7.9 + 14.8 + 36 .1 = 134 sq in * 1.1 = 147 sq in [side + side + top front + top rear + bottom]
Stab/elevator area = 79 sq in * 1.05 = 83 sq in
Fin/rudder = 9.1 *2 + 5.5 * 2 = 29 sq in * 1.05 = 31 sq in
Total = 679 sq in = 4.72 sq ft.
It might be out +- 10% but so what, it will still let you figure out if you care about the difference between the covering types. I agree lighter is better of course.
Edit.. more numbers on covering:
Nelson Film = SoLite = LiteFILM @ 20g/sq.m
Solarfilm (Airspan) @ 23g/sq.m
Solarfilm (Litespan) @ 29g/sq.m
Solarfilm (standard) @ 42g/sq.m
TopFlite (transparent MonoKote) @ 57 g./sq.m
TopFlite (opaque MonoKote) @ 75g/sq.m
Hmm, in fact.. a few minutes on AutoCAD plus some bugger factors and these numbers spew forth (rounded here and there as you can see):
Total wing area, top and bottom = about 380 sq in * 1.1 for overlaps, curvature etc = 418 sq in
Fuselage surface area = 37.5 + 37.5 + 7.9 + 14.8 + 36 .1 = 134 sq in * 1.1 = 147 sq in [side + side + top front + top rear + bottom]
Stab/elevator area = 79 sq in * 1.05 = 83 sq in
Fin/rudder = 9.1 *2 + 5.5 * 2 = 29 sq in * 1.05 = 31 sq in
Total = 679 sq in = 4.72 sq ft.
It might be out +- 10% but so what, it will still let you figure out if you care about the difference between the covering types. I agree lighter is better of course.
Edit.. more numbers on covering:
Nelson Film = SoLite = LiteFILM @ 20g/sq.m
Solarfilm (Airspan) @ 23g/sq.m
Solarfilm (Litespan) @ 29g/sq.m
Solarfilm (standard) @ 42g/sq.m
TopFlite (transparent MonoKote) @ 57 g./sq.m
TopFlite (opaque MonoKote) @ 75g/sq.m
08-18-2010, 08:27 PM
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RE: D.N.U. monokote
That's enough to think about. On one hand, you'll "get away" with it just fine in pretty much every case, on the other hand it's enough that you should feel guilty about adding that much dead weight to the airframe. On a lighter airframe you're in the neighbourhood of 10% of the airframe weight.
08-18-2010, 09:47 PM
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RE: D.N.U. monokote
Got to go with ProBro on this one too. I fly a lot in an uncut field. I always go with monocote or ultracote. I'd rather go with radical RC batterys, carbon fiber pushrods, ect... and keep the strength and ease of use. For the extra 1/2 oz, burn another 10% nitro and 1 less shim
08-19-2010, 06:53 PM
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RE: D.N.U. monokote
Well, I guess that what I really think too, though it's hard to tell from my babbling. It will work fine. I have a stoutly built old Jr Falcon with Monokote that weighs far more than a DNU ever could, it zips around merrily and I've thermalled it.
08-20-2010, 02:46 PM
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RE: D.N.U. monokote
just cover the plane with Monocote and fly it.
I covered mine with Oracover which is not light at all and it flies well.
Selecting the wood and other components you use has a much bigger impact on the over all weight.
I covered mine with Oracover which is not light at all and it flies well.
Selecting the wood and other components you use has a much bigger impact on the over all weight.
08-21-2010, 10:42 AM
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RE: D.N.U. monokote
Considering some time ago the status quo for 1/2A airplanes was 20-24 ounces, going from 12 to 12.5 ounces or 11 to 11.5 ounces seems almost trivial doesn't it?
08-21-2010, 11:15 AM
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RE: D.N.U. monokote
Yes but the status guo in what we expect has risen while the weights dropped.
Some years back I covered a 1/2A model slightly larger than a DNU in MonoKote and put on some fairly flashy monokote trim over top as well. The weight difference from the bare frame ready to cover to covered was 1.5 oz. I was quite shocked at the time. But remember that I DOUBLE covered about 1/4 to 1/3 of the model by adding the trim. And this added weight was being "piled" onto a 6 oz airframe so it seemed like a lot. The model still came out at 16 oz ready to fly though.
The fatlion list shows what seems like an average for MonoKote at around 6.5 gms per sq foot. At 4.7 sq feet for the DNU that's 30.5 grams or just a little over an ounce. That fits in with my own long ago weight gain on my own model. Notice that unless you go to tissue and dope there's really not a huge gain to be made in a lot of the options. Only a couple of the new parkfly films are on there though. But even those are still about half the weight of MonoKote. So at best you'll save roughly 1/2 an oz. And the durability issue is well worth considering. As mentioned there's likely better places in the structure's design, material selection and similar to make up that 1/2 oz that's going to go into the covering.
Some years back I covered a 1/2A model slightly larger than a DNU in MonoKote and put on some fairly flashy monokote trim over top as well. The weight difference from the bare frame ready to cover to covered was 1.5 oz. I was quite shocked at the time. But remember that I DOUBLE covered about 1/4 to 1/3 of the model by adding the trim. And this added weight was being "piled" onto a 6 oz airframe so it seemed like a lot. The model still came out at 16 oz ready to fly though.
The fatlion list shows what seems like an average for MonoKote at around 6.5 gms per sq foot. At 4.7 sq feet for the DNU that's 30.5 grams or just a little over an ounce. That fits in with my own long ago weight gain on my own model. Notice that unless you go to tissue and dope there's really not a huge gain to be made in a lot of the options. Only a couple of the new parkfly films are on there though. But even those are still about half the weight of MonoKote. So at best you'll save roughly 1/2 an oz. And the durability issue is well worth considering. As mentioned there's likely better places in the structure's design, material selection and similar to make up that 1/2 oz that's going to go into the covering.
