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General control line discussion => Open Forum => Topic started by: Larry Renger on January 19, 2017, 01:50:25 PM
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Here is a model I just completed for demo flying indoors at the next AMA Expo. It is the Voodette. (051)
It is made from two Styrofoam meat trays trimmed at an angle and joined to form a symmetrical airfoil.
The rib areas were cut out and SLC covering applied for a 1/4 ounce weight savings (plus helping with CG location).
All up weight with a 2S 160mAh LiPo battery is 2.81 ounces. The wing area is 78 sq.in. Lines are 10 lb test, 15 ft long.
The next version will have a much longer nose so I can get rid of a bunch of noseweight.
It has flown, but so far, only level as this was before cranking up the rpm and lightening the model. I hope to do some more testing at Randy Heydon's indoor flying session Monday.
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Very cool!
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What a great idea. Looks like fun. I'll have to add 'ribs' onto next weeks shopping list :)
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I like it.
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Maybe you could engineer the cutouts in the shape of ribs to place between the skins for structure?
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Sorry, I don't undrestand your comment. ???
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If you are referring to the yellow comment, the foam packages come in different colors,
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No, the rib thing.
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Sorry, I don't undrestand your comment. ???
I couldn't tell from the picture if you had ribs between the platters. If you do I was thinking the "holes" in the wing could be cut in the shapes of the ribs (if there are any) so you could save some time, but on further examination it looks like there aren't any ribs.
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Nope, no ribs. The don't seem to be needed.
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Actually, I was kinda thinking that the meat trays used to package a full rack of ribs just might be the perfect wingspan required.
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Hi Larry,
That's so cute! What motor and prop? Thanks.
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I have no Idea where I got it, but the motor is a "BL1504". The diameter is 18mm and the magnet shell measures 6 mm. The prop is a GWS 6x3
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Thanks Larry, I googled that motor and it's a 8 gram motor with a Kv of 2200. If you are going to make another one with a longer nose then you can possibly put the timer and esc behind the motor like my 1/2A Sparky. It comes out neatly if you cut the wires to be just long enough. If you remove all the connectors and solder the wires directly, like the F3P guys do, then it also saves a lot of weight.
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I flew the Voodette again yesterday. Bleagh! :'(
First flight, I thought mayby it was just noseheavy, so I pulled all the easily removable weight out of the nose. NO improvement! It flies level, and at best can fly just a bit higher than level. It flew with full up control and fell out of the air when the motor quit. Plenty of power, but just way too high a wingloading.
I figure I need a 50% increase in wing area and 20% decrease in weight to get some performance. Total re-think on the structure. Those meat trays are just too heavy and small.
An outdoor version with a .010 would probably be a blast! ~^
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I have an indoor electric combat on the board, but have not looked at it in several years. I did electrify a Lil' Satan, and it flew fantastic. Maybe try copying those numbers a bit. I used the 1/2 A power system from Brodak.
My design however is more in line with what Larry Driskall's old LiteHawks look like. Swept foamy, with a boom. It is a little smaller though. Working out the power system for an electric combat model may be tricky. Mark Rudner is finding outrunners to create too much torque to allow the model to turn well. In my experience, the out put spline on the in runner motors bend and break easily. So these are just some things to keep in mind.
I think indoor combat demos are a great idea though, and it is something I will be working on eventually. Good luck
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The major limitation driving this design problem is that I am limited to 15' lines. That is all the ceiling height there is to work with. Even so, I will have to be very careful on overheads. HB~> Wit that short line length, speed becomes a critical factor. 2 second laps are not fun!
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Maybe think in terms of the flat foamy designs? Large wing areas will not require long lines. It should be easy to prop down the speed. Those flat foamies actually hover with all of the power they have, and can have very slow top end speed. A flat foamy voodoo? Nothing wrong with a plate airfoil, if the loading is down.
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Keep trying Larry, I'm sure you'll get it sorted out. For the mark II version use more foam less wood & metal (you'll be surprised how durable and resilient Depron really is). For the record I hate GWS props, they're too flimsy. Stick with APC.
I have been having a lot of fun with Igor's indoor Gee Bee this Winter. 250 sq in, 7 oz on 16' lines, 4.8 sec laps, 3mm thick flat plank airfoil (although it does glide like a brick when the motor stops).
Paul
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The major limitation driving this design problem is that I am limited to 15' lines. That is all the ceiling height there is to work with. Even so, I will have to be very careful on overheads. HB~> Wit that short line length, speed becomes a critical factor. 2 second laps are not fun!
Larry, what about a Queen Bee? 15' lines is what the original flew on, I started an electric one a few years back to fly in our warehouse with the same limitations as you have. Then, a tenant moved in... The full article is available on-line and a fun read.
http://www.outerzone.co.uk/plan_details.asp?ID=8169
Curt