Hughes P21-J MKIII Devastator - Swappable
- Thread starter localfiend
- Start date
I cut out the lower wings, but I think the angles on the wingtips need to be less extreme. Gonna have to rework them.
Lower wing and canard completed. Went with an airfoil on the canard. Dunno if it will help out at all.
132 grams so far including 2x 9 gram servos which probably weigh more than 9 grams. I should check on that.
132 grams so far including 2x 9 gram servos which probably weigh more than 9 grams. I should check on that.
Looking good! Really starting to take shape now.
Thanks guys. I'm quite pleased with how step one of the expected project outline is going.
Expected Project Outline:
Step 1: Make it look like a Devastator and not be too hard to build.
Step 2: Balance the danged thing
Step 3: Crash horribly on the maiden
Step 4: Come crying to the forums looking for input
Step 5: Start all over again and repeat as many times as necessary.
Working on the fuselage now. Completely scrapped my first design and have started over. Hope to have a workable fuse setup done by tomorrow. If all goes well, the maiden could be pretty soon.
Expected Project Outline:
Step 1: Make it look like a Devastator and not be too hard to build.
Step 2: Balance the danged thing
Step 3: Crash horribly on the maiden
Step 4: Come crying to the forums looking for input
Step 5: Start all over again and repeat as many times as necessary.
Working on the fuselage now. Completely scrapped my first design and have started over. Hope to have a workable fuse setup done by tomorrow. If all goes well, the maiden could be pretty soon.
Got the second fuse prototype done. I'm still not liking this one. Square sharp angles just aren't right. Maybe once the poster board and canopy get added to the top and add some curves it will start looking more like what I want. The top of the upper wing will be all covered up, and it will be curved all the way to the tip. It really needs to some guns and rockets as well.
I don't want to go full blown balsa style and make a curved fuselage. While it would look the best, I don't want to make this a time consuming build. Maybe something octagonal?
One good note, without any electronics it balances right on the spar of the lower wing, so I think I'll be able to get this thing balanced without doing anything too crazy.
Time for bed...
I don't want to go full blown balsa style and make a curved fuselage. While it would look the best, I don't want to make this a time consuming build. Maybe something octagonal?
One good note, without any electronics it balances right on the spar of the lower wing, so I think I'll be able to get this thing balanced without doing anything too crazy.
Time for bed...
Looking good! Needs a cockpit though.
Got the second fuse prototype done. I'm still not liking this one. Square sharp angles just aren't right. Maybe once the poster board and canopy get added to the top and add some curves it will start looking more like what I want. The top of the upper wing will be all covered up, and it will be curved all the way to the tip. It really needs to some guns and rockets as well.
I don't want to go full blown balsa style and make a curved fuselage. While it would look the best, I don't want to make this a time consuming build. Maybe something octagonal?
One good note, without any electronics it balances right on the spar of the lower wing, so I think I'll be able to get this thing balanced without doing anything too crazy.
Time for bed...
WOW!
I've been doing a bunch of reading today on what you need to do to balance a canard plane. It is not easy, especially when you add in a biplane design - something that doesn't really exist in the modern world. The only one I can think of off the top of my head is the Wright Flyer, which didn't exactly fly well.
You have to take into account how much lift will be generated by each wing, and on a wing like this, well, good luck. The wing design I'm using is partly on purpose, and partly expedience. I'm hoping the under camber wing tips will help with low speed, in addition to the step that's the width of the ailerons. It's closest in approximation to a KFM-8, which is experimental without a lot of supporting data. That's all before you deal with the sweep, bent wingtips, polyhedral, dihedral, anhedral, wing interference, and canard interference.
So, after a bunch of fuzzy math, I've decided to guess. CG is gonna be set just in front of the top wing as a starting point. I'm sure it will probably get moved, probably back. The good news is that it can moved with little trouble, battery position should have a long range.
Got the landing gear, horizontal stabilizers, and servo linkage figured out.
I think I'm not going to mess with the cockpit until after the maiden flight. There's too many things to change if I have to move the wings around.
If the weather is good tomorrow and I'm not too busy, we'll get to see if this thing will fly or not. I may borrow the neighbors airstrip so I have asphalt to take off of.
You have to take into account how much lift will be generated by each wing, and on a wing like this, well, good luck. The wing design I'm using is partly on purpose, and partly expedience. I'm hoping the under camber wing tips will help with low speed, in addition to the step that's the width of the ailerons. It's closest in approximation to a KFM-8, which is experimental without a lot of supporting data. That's all before you deal with the sweep, bent wingtips, polyhedral, dihedral, anhedral, wing interference, and canard interference.
So, after a bunch of fuzzy math, I've decided to guess. CG is gonna be set just in front of the top wing as a starting point. I'm sure it will probably get moved, probably back. The good news is that it can moved with little trouble, battery position should have a long range.
Got the landing gear, horizontal stabilizers, and servo linkage figured out.
I think I'm not going to mess with the cockpit until after the maiden flight. There's too many things to change if I have to move the wings around.
If the weather is good tomorrow and I'm not too busy, we'll get to see if this thing will fly or not. I may borrow the neighbors airstrip so I have asphalt to take off of.
Looking good on it's own legs! Are you just using a beef equivalent motor?
Yeah, pretty much. Specs are pretty close I believe. NTM 28-30A 1200kv. Gonna try it on 3s with a 10x4.7 SF prop and see what happens. I want to make sure I have plenty of thrust for testing, a canard biplane is going to have a lot of drag under the best of circumstances.
Weight without battery is 387 grams (landing gear could probably be lightened, and this particular power pod has combat mods making it really heavy). I think a 2200mah 3s is ~119 grams. So ~510g AUW. Motor should put out ~1200g thrust. Heh, maybe I should throw on a 55 gram motor instead.
I really hope this flies. I want to do some air combat with it.
Last edited:
I'll build a brigand with maximum armor
You'll never be able to "shoot" me down.
You'll never be able to "shoot" me down.
I'll build a brigand with maximum armor
You'll never be able to "shoot" me down.
Hah. I used to hate fighting those. Stupid rear turrets.
Make sure you have the latest 1.2 patch (some of the later game discs were already patched).
http://www.fileplanet.com/52484/50000/fileinfo/Crimson-Skies-v1.02-Patch
Then go here and download the csfix file. It's in the lower left hand side.
http://timeslip.chorrol.com/
The above fix is pretty cool, makes a bunch of changes that eliminate crashes in newer operating systems. It also gives you an editable .ini file, so you can force the game to run at a higher resolution. I'm playing at 1920x1080. When you use the fix and change the resolution, the menus and mission briefing stay small, but the game itself is full screen and looks quite good for what it is.
Even dug my old joystick out of the attic, and it works great.
Yep, once the bugs are worked out I'll be posting the plans along with a full decal set. If the prototype works out well, I may even think about some beta plans to get some feedback before full release.
Mac82
Foam scraps? I got plenty
Yep, once the bugs are worked out I'll be posting the plans along with a full decal set. If the prototype works out well, I may even think about some beta plans to get some feedback before full release.[/QUOTE]
Now that's an idea!
I know I'd definitely be happy to help you with bats testing the design.
One thing I think that you should include is the functioning canard. You had mentioned that you where going to use 4 elavons or the canard. I think you would get better control with the canard and the 4 alerons but we can test out bolth
Now that's an idea!
I know I'd definitely be happy to help you with bats testing the design.
One thing I think that you should include is the functioning canard. You had mentioned that you where going to use 4 elavons or the canard. I think you would get better control with the canard and the 4 alerons but we can test out bolth
Yup, not enough control
First flight went as expected. I decided to hand launch since that's the only way I was going to get video. It may have gone better from the ground, but I want this plane to be hand launch able.
Didn't seem to have any elevator authority at all, so I'm going to swap the nose with my functioning canard design. Probably would have flown with more air speed, but that's too fast to bother with.
Think I'll give the functioning canard a try from the ground and we'll see what happens. I think before I start changing wing or canard shape from scale I'll scale the plane up. It can get a good deal bigger and still fly well with the chosen power plant, and be easy to build. Right now it's slightly smaller in overall size than the baby blender.
Similar threads
