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Sep 11, 2018, 09:19 PM
I Look, Listen, and Learn
Timbo383's Avatar
Build Log

VX-30 build, concept space plane


Found this pic that Dukejet did a boxwing type plane out of that looked and flew pretty good . I wanted to do one that looked more like the picture using canards and ailerons while still making it simple to build....that's the only way I build a plane "simple", I just can't spend countless hours on a build like a lot of the talented guys here.
Anyways here are the pics of the orginal drawings and my simple 2d drawing of it. I'm going with a pusher design with a propped motor...an edf would look cool on this, but it goes against my simple build abilities....ducting, wiring, etc. Got a little bit of work done already and went with anhederal wings because I think it looks cool like that, may build anothe along side it with dihederal wings also just to see the difference between the two flights. Im using cheap depapered DTF and bamboo for this in case it doesn't do well in flight. I did tape the top of the fuse and tacked on the verts for a couple of test glides. Found the aproximat CG and balanced out the battery, motor, and electrics placements and I think I can get this to work.
Last edited by Timbo383; Sep 11, 2018 at 09:28 PM.
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Sep 11, 2018, 10:58 PM
Low And Slow 3D Pilot
OliverW's Avatar
That is a great looking model to design! The nice thing is no one else will have one at the flying field!
Sep 11, 2018, 11:40 PM
Registered User
Pretty plane!
Should fly OK if built very light.
The slight anhedral will require you to react very fast on the sticks, so high wing loading (making for higher stall speed) is something you may want to avoid.
The elevators look very small for the short moment arm they'll have. You might have weak pitch authority.
Sep 12, 2018, 01:40 AM
Kimbers Keeper.
BHOFM's Avatar
This is a plane that will thrive on stabilization! Great job!
Sep 12, 2018, 01:24 PM
skumgummi dave


Dave-
Sep 12, 2018, 08:18 PM
I Look, Listen, and Learn
Timbo383's Avatar
Thanks all. Yeah Nuteman, found out during the test tosses that the plane does have the tendency to stall and roll to the right when it looses momentum. I was hoping it was due to me just tacking on the verts uneven, but I'm betting it is because of the anhedral wings. The drawings appear to have anhedral wings but they are actually in line with each other. I do know that it is suggested that the front canard wing should not be in line with the main wing because it, I think, affects lift or something to that effect. So while experimenting with raising and lowering the wings on the fuse to determine how to proceed with the placement I liked this look the best even tho I do know it's not the best for flight.
I was also assuming because of the shorter moment I would not need that much elevator authority, guess I'll have to make them larger since I was wrong on that...easy fix.
I weighed all of the components with the plane and with a rear mounted motor and I need to use a fairly large 1000 battery to balance the CG. It should come out to just about 200 grams when it's all glued together, would that be heavy for a 28 inch wing span plane? I know putting the motor up front will be a better option for balance and prop wash but I just don't want to do it that way if I can get away with it as a pusher.
Anyways, I have two of the same motor I will be using so I think I'm gonna cut out another from the plans and place the main wing on the bottom of the fuse with canard on top and dihedral the wings...and maybe put the motor up front...and build the two at the same time just to compare build ease, looks, and flights of each. Hard to argue with having two of these.

Oh , and here is the simple PDF....some minor adjustments necessary, including the canopy which I cannot produce because I'm still trying to learn sketchup, and I really need to put some notes on it.... My 15 year old photoshop program is still my go to drawing software since I know it fairly well.
Sep 13, 2018, 12:56 AM
Registered User
Quote:
Originally Posted by Timbo383
I weighed all of the components with the plane and with a rear mounted motor and I need to use a fairly large 1000 battery to balance the CG. It should come out to just about 200 grams when it's all glued together, would that be heavy for a 28 inch wing span plane?
Since a 1000 mAh battery alone weighs about 100 grams, I'm guessing you mean 200 grams for the airframe only (excluding battery, ESC, receiver, motor, servos and hardware). That's about what I'd expect for this design at 28 inch span, so you're within reason there.
The bigger issue is the scale you chose. Without getting into a lot of technical detail, at smaller scale "twitchy by nature" designs get even more twitchy. The plane would be significantly easier to fly at double the span (56 inches is really not all that difficult to achieve, by the way).
If you need the "why" (technical explanation), let me know and I'll try to summarize in a couple of paragraphs.
The alternative version you described will likely be significantly easier to fly at small scale. The gap (in terms of difficulty to fly) between the two will be smaller at larger scale.
Last edited by nuteman; Sep 13, 2018 at 01:07 AM.
Sep 13, 2018, 06:32 AM
I Look, Listen, and Learn
Timbo383's Avatar
Hmmm, I'll have to reweigh it again after work. I thought I saw 200, maybe it was 300. I start work at 4:30 every morning , so everything I do or say after 9 pm can't be trusted.
I almost always make my prototypes small and out of just about one sheet of DTF for several reasons.....cost ( I screw up a wing cut it just costs a dollar more to make another), workspace (half a kitchen table....don't ask), and less structural support (something I lack knowledge in). If it goes together well and flys decent I then make a larger 40 inch or so ws (my local flying area limited field space) version of it after all the construction mistakes are ironed out...unless the smaller version flys good on its own then sometimes it stays that way.

Edit : weighed it when I got home....yep auw is 282 grams, that's including everything but the glue to put the rest of it together. It was 270 last night but I forgot some skewers.
Last edited by Timbo383; Sep 13, 2018 at 07:45 PM.
Sep 16, 2018, 03:27 PM
I Look, Listen, and Learn
Timbo383's Avatar
Got some work done to the front canards servo setup. Not much room to use conventional horns setup and with the battery placement and having the elevators too canted to use a single one, I decided to experiment and it may actually work. I just glued and pinned the servo horns straight onto the elevators....pictures may explain it. Took a little bit of adjusting but they seem to go up/down in unison.
Sep 17, 2018, 04:27 AM
Registered User
Jürgen Be's Avatar
Looks great and very interesting

Jürgen


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