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Building Tips and technical articles. => 1/2 A building. => Topic started by: Larry Renger on April 16, 2007, 11:21:43 PM
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My Sky Sport took 1st and 2nd at the Palmer Memorial contest over the weekend. I loaned the model to Bart Klapinski, and of course he whupped me by 50 points with my own airplane. I expected no less. He scored a 492. That is why I am "DesignMan" not "PilotMan".
We fly 1cc models intermixed with the "expert" Profile 40 planes in an attempt to keep the judging on a standard level. (We usually are as good or better). I absolutely hate it when someone scores 60 degree angle loops with 35 points "because that's pretty good for a little plane". Small planes MUST be judged on the same basis as big ones, or we will never progress. Anyone who has had the pleasure of seeing Dave Shirley's plane fly can attest that truly competitive small models are possible.
Anyway, I'll try to post a photo of the model. It is due to come out in Flying Models in a couple of months, then as a kit from RSM some respectable time after that. The model has 160 sq. in. of area, and is powered by a modified Brodak .049 mk 1. The mods are a rebalanced and fitted crankshaft and a Nelson head. Prop was a Master Airscrew 5.5x4, fuel is 15%-10-10 Excalabur. I think that it might have been a bit heavy on the Nitro, as it was difficult to get a really comfortable needle setting. Lines were 45' of .008 cable and the handle was an RSM/Renger "Even Ultamater 1/2A handle". ( I had some new ideas and nobody but me could get his fingers into the previous design).
So now the model has been flown in competition (and won!) with a National Champion, Bart, plus having been test flown by others - Ted Fancher, Brett Buck, John Wright. When they speak, I listen!
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#^ #^ Congrats Larry!
Question: what did you do to your handle design? Picture?
I have been using them (from RSM) for a few years w/o any problems, just added the tie wraps I mentioned to you a long tme ago.
I'm curious.
Thanks,
Roger Vizioli
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Brag away, we don't mind!! Congratulations, looks (and sounds) like a great little plane. I've been flying my LittleAxe every chance I get this Spring (well, two days so far) and am convinced someone good could set some awfully high scores with it...it's a real joy to fly. These little planes have potential.
160 squares...what does your Sky Sport weigh? The LA is 10 oz., + or -, with 200 sq. in., currently using a BigMig .061, though a good .049 could fly it as well, I think. I'm just finding it easier to get a good run out of the .061.
--Ray
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First off, on the handle, I increased the size of the handle by 10% so most people can get more than 3 fingers into the opening (I have small hands, I guess). In addition, the spacers now all have the retention holes way out as far as they can go. To accomodate this, the handle has slots, not holes, so any size spacer can be used. The electrical ties are no longer needed! Finally, there is a center hole for a bolt and washer to lock the control-line position.
The Sky Sport has 160 sq.in. wing and weighs in at 8 ounces. Despite the small size and light weight, it punches through wind remarkably well. Conditions at the Palmer meet were brutal at times, and the plane came through with flying colors (pun intended).
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First off, on the handle, I increased the size of the handle by 10% so most people can get more than 3 fingers into the opening (I have small hands, I guess). In addition, the spacers now all have the retention holes way out as far as they can go. To accomodate this, the handle has slots, not holes, so any size spacer can be used. The electrical ties are no longer needed! Finally, there is a center hole for a bolt and washer to lock the control-line position.
Thanks Larry. Handle size, as is, is fine for me.
Spacer holes and slots, will have to try it on one of my handles.
Center hole - easy mod.
Many thanks!
Roger
The Sky Sport has 160 sq.in. wing and weighs in at 8 ounces. Despite the small size and light weight, it punches through wind remarkably well. Conditions at the Palmer meet were brutal at times, and the plane came through with flying colors (pun intended).
Sub 10 oz. models, wonder if i will ever build one that light! :-) Roger
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Very interesting, our wing loadings are virtually identical! Maybe we've hit on a "magic number" for 1/2A stunt--namely 20 sq. in. per ounce. I think I'll analyze all my 1/2A designs just to see.
--Ray
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Ray
For what its worth, my Baby Barnstormer is 20.7 sq inch per oz. The IBTW and Micro Barnstormers are both at 25 sq inch per oz.
Clancy
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Ray,
To add to your wing loading info. data bank-
Baby Pathfinder, 236 in2, 12 oz = 19.6. Flies great!
Roger
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I have to bring this up, sorry! Google my name and read the article on 3-D wing loading I did for Model Airplane News. It is real, it works, it solves a LOT of problems in comparing models. I don't even want to talk about weight/area, it is meaningless!!! Theory and experience prove it. 3-D wing loading will let you realistically compare a "Queen Bee" to a "Strega" and understand the performance differences. Sorry to rant (I do that a lot), but the message just doesn't seem to get across.
In the article, I propose a formula that will allow, not only size comparisons but a pretty good cut at comparisons of models with different aspect ratios. Cool, huh?
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Thanks Larry, I'll check it out.
--Ray
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from what I understand----bart kaplinski could fly a barn door and beat the pants off anybody!!!!!!!!!!!!!!!!!!
larry jaconetta
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True, and worse yet, you can never fly your plane as well as you did before after seeing what he can do with it. Intimidation!
And, by the way, I did a misstatement. The Sky Sport has 180 sq.in. wing area. As such, it has a 22.5 sq.in./oz. wing loading. Somewhat heavy compared to the numbers quoted above, and perhaps that explains the good wind penetration.
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True, and worse yet, you can never fly your plane as well as you did before after seeing what he can do with it. Intimidation!
And, by the way, I did a misstatement. The Sky Sport has 180 sq.in. wing area. As such, it has a 22.5 sq.in./oz. wing loading. Somewhat heavy compared to the numbers quoted above, and perhaps that explains the good wind penetration.
You mean somewhat light, don't you? More wing per ounce. I know we're quoting the ratio backward from the norm, makes it a little confusing.
--Ray
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Yuh got me, pardner! n~