Scale F-117 (Depron) This one is cool!!

[power]

Hi all, recently,Don, a flying buddy of mine. Started to dable in electrics. Now keep in mind this guy has been building and flying for many, many, yrs. I have seen some incredible scale projects come from his shop, most are giant scale. Don had a GWS A-10 donated to him and decked it out with brushless power. After a few flights, Don was well aware of the advances in "E" flight. Now here comes the cool part. We go out flying one weekend and I do not here from him for a little over a week. Then I get this email with the pics of his scale Depron F-117. You have to know Don when I say "scale". He is very particular about detail. Just give a look at the pics :D The ducting, the outline, the airfoil on the tail surfaces........... Can you tell Don is an engineer?

Just looking at his drawings (no cad) are amazing! This was built with no plans, just a scale F-117 book and a true to scale 1/32 plastic model. It has functional retracts, not exactly scale but try get to this point on a build in a little over a week!!! This thing is almost ready to fly. He has the detailing/painting to put on then it is ready for the wind.Some other info: 28" wingspan, 36" long, estimated weight RTF - 26 oz. (with Li-Po and retracts). Twin EDF-55 with the new Hackers, not sure on the model of the motors, TP 3s2100. I will try to get more pics. Check it out!



Mike :cool:

[im-sad]

OMG!!
wow can you ask him to scan his plans????
id love one of these, even if it didnt fly!
mayby just the formers and side panels???

Good luck to him on maiden
adriel

[Paul DF jet man]

that is really cool indeed.

[U812]

Very nice. They will need a pitch gyro. I know. I've been there.

Steve

[power]

Very nice. They will need a pitch gyro. I know. I've been there.

Steve

Steve, I take it you tried a flight without? What happened? Nice looking bird,I like the easy access to the gear on your model. Is it electric? Thanks!

Mike

[Kevin Cox]

Very nice!

[darmar]

Good job.

[Thomas Nelson]

Awesome! Show us more!!

[Flyin Brick]

Keep the pictures coming! Oh ya! Some video too...lol...

[U812]

Steve, I take it you tried a flight without? What happened? Nice looking bird,I like the easy access to the gear on your model. Is it electric? Thanks!

Mike

Yes I did and it seemed ok without it until I pulled more than 45% positive AOA and she didi the most beautiful inverted flat spin you've ever seen right to the deck.

I've built others and some friends of mine built some very scale versions for a film a few years back and they had the same problem. The pitch gyro seems to tame the beast.

Yes it is electric and will soon be a all epoxy glass kit from EAM. The hole wing and belly pan section is epoxy glass too.

Steve

[cyberfly]

Very impressive

[im-sad]

news????????????????///

[power]

Well, I have some more pics coming, here are a few more details; each individual facet is cut from 3mm Depron; the wing and spine are from 6mm Depron. Don is cleaning up the inlet junctions and finishing off the rear fuse/rudder joint. Motors are hacker E3-3700's ESC's are E-flite 20 amp. Quite a bit of Carbon fiber here and there - 1/8 tube leading edges and rudder "spars, .040 rod trailing edges, .016 sheet carbon for the retract mounts, .008 for the battery cooling duct, .100 rod for the struts, etc.
This is all I can tell you as of now. More to come :)


Mike

[power]

Here are a few more pics :)

adriel, I will check on the plans ;)

Mike

[power]

one more,

[Art Newland]

what a natural for flat foam!

[BellX1]

Great build! I'd like to see it in action

[Paul DF jet man]

love the retracts

[Vintauri]

Hey Power,

I did see this last weekend at the pancake fly. He was not flying it but showing it off. It does look very cool. If you let me know when he might fly it I can come try to get some video.

Steve

[U812]

Scratch the gyro. I was talking to Gregg and my friend Rob the other day and as it turns out none of the scale turbine versions use one. So I had other issues with mine.

As soon as EAM makes new molds from my plugs I will build another. It was a long time ago that I built the two 117A's. My guess now that I've learned a great deal more, is more likely a CG issue.

Just thought I should let you know after the gyro lecture I gave before in this thread.

I stand corrected.

Steve

[cyberfly]

I'm learning from this model
http://www.adjets.com/

[pacro]

hope you can make plans

[power]

Hey Power,

I did see this last weekend at the pancake fly. He was not flying it but showing it off. It does look very cool. If you let me know when he might fly it I can come try to get some video.

Steve

Hi Steve, I talked to Don just a day ago and he said he is adding the finishing touches. I will let you know when he is going to maiden. That is, if he does not sneak out and put it up without telling me :D

Mike

[froggy117]

[FONT=Arial][SIZE=7][COLOR=Black]Hi! to everyone who has been watching this thread! Also, thanks to Mike (power) who has posted pix of the "
Depron Dart" (aka F-117) for me. I certainly will post lots more pictures before I fly it.

Steve-In particular, I appreciate your comments-both past and present. I had pretty much reached the same conclusion! I expect the A/C will be "pitch sensitive", particularly at high AOA. All full deltas, blended deltas and "chined" deltas do that (because of the movement of the center of pressure-but you know that).

On the other hand, I have spent quite a lot of brain cells on this design, and think careful placement of the "C/G" ( I really don't like that term!) :) , power/wing loading, control throws and mixing, etc. will help. That, and an observer that will slap me if I even think of trying hi alpha maneuvers!

Also built a 1/72 scale balsa "chuck" model. And spent some time calculating MAC andstuff.

Anyhow-curent status is the "all up" weight is 25 oz with a 2100 3s Li-Po. However I am now struggling with the bane of all scale models - paint!!

Best guess is it will add 3 or 4 oz.

Watch this thread!

DA

[U812]

DA,

Welcome to E zone and a good entrance too. Your plane looks great and it's nice to know you have a handle on it. That's clear.

Is your plan form 100 % scale? Mine is and I've often thought if I fugged here and there I could over come a few issues but being a scale guy I couldn't bring myself to do it.

Well we'll see how it goes on round 4 when I get the new fuse from EAM. I'll be watching closely you can bet.

Steve

[Vintauri]

Hey DA,

Welcome to RCgroups. I ran into "Power" last night at the middle school and he watched me destroy a nice plane that just did not have enough wing bracing. I saw your F-117 at the Pancake Fly the other weekend and it does look nice. I hope I can see it's flight.

I'm going to have to make the jump into a jet if I'm going to be sharing the skies with you and Power. Just makes my little planes seem slow :)

Steve

[Willmsy]

Have Minnesotans take over this thread! Ha I love it.

Matt

[AirX]

Yup not from Minnesota but welcome to the E-zone and particularly the Jets forum.

Eric B.

[froggy117]

Steve,

Yes, the planform is 100% scale-or at least as "scale" as th 1/72 plastic model that I multiplied x4. It appears to match the other documentation I have very well. Basically the airfoil (yes, it does have one :)) is the same "polygon" shape as the top of the full scale. The 6mm depron is sanded at the front and rear to match the carbon fiber L. E. and T. E.

The bottom, however is dead flat for a couple of reasons-but I don't want to waste a lot of bandwidth expounding on ideas that are still "not flown". Rudders are fixed ( I have some thoughts on making them movable) and a reasonable approximation of the rather strange "double diamond" shape as the big one.

Presently, the balance point is at 25% MAC, which is one inch forward of the point where I thought the balsa model (rubber band assisted) flies best. Maybe I should post a picture of it! Any interest, anyone?

Vintauri, 'twas nice to meet you at the pancake fly-I certainly will keep you posted as to first flight schedule, and welcome video of the event!

As a final note (at least for tonight) did "power" mention that this A/C came to be as I was heavily into design/build of a Depron and paper tube SR-71? I've set it aside as the Nighthawk project matured!

[froggy117]

Steve(U812),

With all my comments from the previous post-I am still VERY interested in any balance point location and pilot reports from you and the "kerosene" guys! Thanks!

[Gordito Volador]

DA,

Welcome to the forum. Very impressive Nighthawk project. Please keep the photos and info flowing our way.

Regards, Bill

[power]

[FONT=Arial][SIZE=7][COLOR=Black] I am now struggling with the bane of all scale models - paint!!

DA

Struggling? Yeah right :rolleyes: don't let him fool you, Don is a wizard with paint ;) you should see some of his other planes. Good stuff!! So... time frame for the maiden?? Sat... Sun...... tonite :D

Mike

[fh64_lucky]

ive been reading these forums for a while,,,when u m8s talk about EAM...lol,thats 1 block from my house,sheesh,talk about my wallet always being empty,daves a great guy,he really knows his electrics...he got me to convert from 16 yrs of nitro planes,to a now all electric air force... :)

[froggy117]

Well, not tonite! Hopefully, this weekend-(Memorial Day seems appropriate)but like all "scaley" people, I have to resist the urge to keep adding details! (Memo to self-"more details equals more weight" :) ) . I appreciate all the interest from everyone in this forum, so I feel obligated to keep you posted and not rush things.

'Course, all the "Minnesota guys" can tell you that for the last (2) months our "choice" of weather has been "Rain", "Windy" or "Both"!

[Vintauri]

I hear ya on the weather up here. I tend to wait on all the finishing touches of any scale projects till I have a flight or two in. Just seems things go better when it's not quite finished hehe.

[Willmsy]

Hey, anyone going to Marcee this year?

www.marcee.org

Matt

[froggy117]

Prime, sand, fill...prime, sand, fill...Here are a couple of pix to keep the interest up!

[froggy117]

Finally got tired of sanding and took it to the flying field yesterday. For the curious (me too! :) ), it did not fly on it's first attempt. -But it didn't crash either! Grass field, small wheels and the designer (me) talked the pilot (me, too) into adding an ounce and a half of lead to the nose, "just to be on the safe side!"

It accelerates well on a reasonably smooth surface (pavement), so I may be expecting too much of it to ROG off of grass-but I am not ready to say it won't.

After getting back to the shop, I spent quite a bit of time with the balsa profile. It flies very well-even has " trim tabs"-so I can try different rigging/balance ideas. To make a long story short- I took out the lead out and have a lot of confidence as to it's next attempt.

It weighs just under 30 oz. with a 5.1 oz. Li-Po pack. 4 oz. of "darned paint!"
Pictures attached. I did the decals on my computer/printer. 2d time around came out much better.

[cyberfly]

looks great, good luck on 2nd attempt, don't forget to post video
:)

[U812]

Very nice. Now I want to build another one! Best of luck on the maiden.

Steve

[Vintauri]

Looks great! Let me know when you plan to try again and I'll bring the camera to get some video.

Steve

[CRASH_Jim]

I would love some of your plans. How much? I tried one last year out of bluecore. I used a paper model and blew it up. I don't remember how much. It was a 28" wing span. She never flew. Just too heavy. I was using a VASA 65mm fan. (yeah single fan). Not near the power to weight. It was a bungee launch setup. I'm thinking of trying mine again with either 2mm or 3mm foam VS the 6mm bluecore. I may end up with the dual fans and going a little bigger myself. Here is a photo before the destructive fight attempt. hehehe

[froggy117]

OK guys! Bear with me as I have not spent a lot of time posting to these forums. So, I'll try to answer as many questions from tonight's post all at once, with no intent to offend anyone or not reply to anyone. :)
For Cyberfly and Vintauri - I certainly plan to have the maiden flight attempt on video, no matter what the outcome! Vintauri-let me know how to get in touch with you (via Mike/power, maybe?) and I will try to schedule us getting together.

U812/Steve-thanks for all the input. Obviously, you have spent a lot of effort/time on your version!

Crash_Jim- I am looking at a way to scan/post what I have. I have no interest in marketing this thing-so cost would be very minimal. It really is not that hard to build. You have probably looked at some of the info previously posted on this thread. Mine is about 36" long, 28" wingspan. I didn't keep track of the exact amount of Depron I used-but I think one sheet of 6mm and one of 3mm will pretty mush cover it. Inlet and outlet ducts are made from light poster card. Obviously, yours looks(looked?) pretty good, too! Sad that sometimes our best ideas get reduced back to "rekits" so easily. But if I want a "display only" model, I will buy plastic.

DA

[Vintauri]

Sent you a Private Message with my contact info.

Looking forward to seeing it in action!

[pacro]

plan plans PLEASE

[Excogitate]

Great looking plane!

EX

[froggy117]

Well, it flies/flew! For about 10 seconds. CG is still too far forward, and I think I need more control deflection. It rotated nicely after using up most of the available runway and climbed out fine. But the (stupid) pilot - me- was so worried about high AOA that he relaxed the up elevator a bit too much and the prevailing wind sort of stuck it into the ground. I always knew it looked like a lawn dart!
Damage was surprisingly light-the Carbon Fiber tube leading edges absorbed most of the impact. I actually thought about that when I was designing it.

So I am already fixing it. A little Depron here, a little Depron there; already redoing the elevon linkage and hinges, etc. I am not discouraged! This is what happens in a development project! Every one who was present thought it was "cool" just to see it airborne. Me, too!

I will post some more pix tonight!

DA

[Flyin Brick]

Did you catch it on video? Keep up the good work, cant wait to see this thing flying.

-Eddie

[Willmsy]

I was there!! It was great until the moment we knew it wasn't going to pull out of the decent, then it was OOOohhhhhhhhhh Noooo! We walked over to the downed plane and like DA said, there really was minimal damage to the plane, just came down a little more on the nose than the rest but, really not too bad.

I don't think anyone had any video of it, (I forgot to bring my camera to the field that day).

All I have to say is that it was Cool to be there to see it.. and I can't wait until he lets loose some plans.

Matt

[AirX]

Congrats, looking forward to seeing more of it.

Eric B.

[EngineerW]

It appears that the bottom of your 117 is totally flat. If it is you may have a tough time getting it to fly because on the real one the bottom and the top together form a reflexed airfoil to give you a positive pitching moment. If the bottom is flat, then you will get a pitch down moment when the wing and fuselage lifts which will make things hard to fly if at all.

Hopefully its not flat but more like the real one

[Mustang5]

until I pulled more than 45% positive AOA and she didi the most beautiful inverted flat spin you've ever seen

This happens because the F-117 has a very swept but high aspect ratio wing (~70 deg wing sweep and an aspect ratio of 4.3)(the aspect ratio is the square of the wingspan devided by wing area ((WS^2)/WA)) Well anyways since the f-117 has very swept wings, it is able to go to very high AoA before stalling (For example U812 flew his at 45% AoA) . But on the other hand, very swept wings also have a strong tendency to tip stall, that is, when you do manage to get them to stall... Now for most planes when they tip stall they snap a wing over. But because the F-117s wing tips are litterally behind the fuselage, when the tips stall the wing looses its stabilizing lift or in other words the center of lift of the wing moves considerably forward. in doing so the plane acts as though it is tail heavy and you get "beautiful inverted flat spins". As a result, to solve this problem all you have to do is add things to the plane that you would normally add to prevent tip stalls such as wing tip twist (washout). But if you add wing twist, because the wings are so swept, you would have to add alot of twist for it to be effective.

I have added a picture as a quick rule of thumb on what wings have unstable (in the pitch direction) stall charicteristics. The red dot represents the F-117s wing. Notice how it falls well within the unstable catagory.

I hope this helps so that you can tame the high AoA flight :D

BTW I love your F-117 very nice looking and very scale. Glad to hear it only suffered minnimal damage. Good luck on your next flight!!! And post videos!!! :D

[Flyin Brick]

Any new flight reports?

[magicruss]

great plane can't wait for plans this one looks great on the table as well as it should in the air.
had a paper model of this one thought about enlargin it but your plan looks great any timetable on plans?
later
Russ

[froggy117]

No, I haven't made any more flight attempts! The plane and I are oth rarin' to go , but the weather hasn't been too cooperative! Minnesota!

Here are a few new pictures showing what we've been up to. The first shows most of the damage from sticking it into the turf. Split/shattered the first few inches of the C. F. tubes (leading edges). Tranalation-most of the impact energy went into the tubes and not much into the Depron facets. I peeled back 2/3ds of the top shell; just to make sure that the fan mounts and ductwork were un harmed. By the way, this is the designed method of fan access!(Scalpel!) The only "hatch" is the canopy (to check the receiver and steering/retract servos).

Next picture shows the revised elevon /servo link. More throw, less differential, very rigid.

Third picture is of the replacement 1/8 th C.F. tubes, with .070" C. F.rod reinforcements. Also shows where I sliced the 6 mm Depron platform to replace the crumpled structure from Picture 1. By the way, I use CA (Zap, thank you!) almost exclusively for carbon to carbon joints. It does eat Depron so most everything else used "Sobo" glue from the craft store. It seems identical to RC 560 .Note that NO glue joints failed from my attempt to stick it into the ground!

The last two pictures show how I relocated the battery aft (between the exhaust ducts-a very tight fit!). I then relocated the (2) ESC's to the previous battery "tunnel". Should get better cooling and easier to access. All the wiring is 18 ga. silicone "minimum" (16 ga. from the battery to the ESC's).Dean's connectors throughout-as seemed appropriate for the amperage and still minimize weight. All the servo extensions are "custom" made by me using 30 ga wire.

Again, I really appreciate all the comments from this thread! I believe it will fly-but nobody said this is an "easy" subject!

DA

[Willmsy]

You Sir, are a magician with depron.. I only wish I could someday be as accomplished as you. Hail to the King.

Matt

[dickj]

I can see you are of the old school innovative builders.
Thank you for finally showing how a build should look.
Your attention to detail reminds me of the best
builders I have known over 50 years.
Today, all you'll hear is "let us have the plans".
Do your own thing until you get it right for you.
One of us here will appreciate it.

Dick

[froggy117]

Willmsy, you flatter me! But, since you saw the "bird" last; here is a picture of the repaired nose-see, I didn't bother with the probes or new decals, yet!

[Vintauri]

Hey DA,

Too bad I missed the MARCEE event. I was planning on getting up there but plans changed. Can't wait to see you give it a try again. Feel free to call me for the next event. I'll have my camera's charged! :)

Steve

[froggy117]

Vintauri,

Of course, I'll call! I wouldn't dare to fly it again without video!

DA

[froggy117]

I can see you are of the old school innovative builders.
Thank you for finally showing how a build should look.
Your attention to detail reminds me of the best
builders I have known over 50 years.
Today, all you'll hear is "let us have the plans".
Do your own thing until you get it right for you.
One of us here will appreciate it.

Dick

Dick-I appreciate the kind words-attention to detail and not losing focus on the end result is what it's about! And-I have always done my own thing! But I still pay attention to all the supportive comments that have been posted on this thread!

DA

[Willmsy]

Looks Great!

Matt

[Vintauri]

Okay so there was another attempt to fly this great looking plane last evening.

I was lucky enough to be out in the heat to tape the event and it was well worth it. It took a few attempts and some CG adjustments but it finally took to the air. It was not all perfect but progress was made!

Check out the video to see the fun.

The small version is about 5 mb and can be found here (http://www.vintauri.com/planes/videos/Stealth_small.wmv).
The larger version is about 20 mb and can be found here (http://www.vintauri.com/planes/videos/Stealth.wmv).

Please right click and save it to your computer when viewing thanks.


Steve

[Flyin Brick]

Wilbur and Orville would be proud. That was a great leap forward. It looked awesome in the air, Congrats!

-Eddie

[Gordito Volador]

I would call that success. I am sure that the next flights will be even better. Congrats!

Regards, Bill

[im-sad]

plans??? :)

[pdawg]

Your the MAN!!! it flies

[Willmsy]

Much better performance than what I had seen.. Nice tweeking. Hopefully the repair goes well on that last impact... :(

Great Job.

Matt

[AirX]

Congrats on the success. The flat bottom airfoil profile worked pretty good.

Eric B.

[power]

It was great folks, I never thought I would get the chance to "hand launch" a 117 :cool:

Steve, great video! I like how you included the part where I said "if it just would have stuck in the ground like the first time" :o

A lot was learned on that fine evening. I know it will fly again. Heck, Don has probably got another half framed up :D

Mike

[froggy117]

Yeeeeeesss!! It really does fly! Many, many thanks to Vintauri and Power for their help, support and awesome video! Now, if I could just get the pilot to pay attention!

We did learn a lot. Went from "tail heavy" to "nose heavy" (moved the battery) because that was the only (2) choices we had at the field-I hate field mods. ;) (Don't even ask about the "spike the nose in the grass" trick!)
The results were not totally unexpected. "Final" balance point was basically the same as at MARCEE-but with more elevon throw and a tick more reflex.

It flew, but I decided after (1) circuit holding full "up" elevator :eek: to land and "tweek" it a little more. Easy - I have the JR 10x set up so that I can change the "reflex" with the "Aux 4" knob. That's the setup on the last flight.

"Bonus question!" How many people out there would have thought this thing could be hand-launched?

Anyhow it has excellent slow flight manners (just watch the AoA!).Yaw stability is solid, roll sensitivity a little high (but, remember, I have a lot of control throw on "hi-rate") and pitch stability is (almost surprisingly) quite good. Biggest problem is visually orientation on the wings. It is VERY hard to tell which wing is down and not "reverse"the aileron inputs!

I have seen a lot of airplanes with the caption reading something like "looks like nothing else in the air"...Well, believe it when it comes to F-117's!! At any rate: the sun was low, I misjudged the roll attitude, and when I realized what was happening-tried to "roll thru" and catch it before it hit the ground. NOT!

So, even though it is readily rebuildable...I am going to call this the "V-1" version..and have already started on redrawing a "V-2" version.

Why? Because I want to change the thrust line...This should cause a stir! I will post more thoughts later. ;)

DA

[Ed Waldrep]

As far as orientation goes, you could put something on the bottom to help see which side is up. There are two things I'm thinking of that were placed on the full size at one time or another. One full size had an American flag type of paint job on the bottom for a short time, and another had a big white circle with the Skunkworks skunk in the middle. I believe it was just black and white so cutting that out of monokote trim sheet may be relatively easy. Or you could just go with a couple of white stripes on the bottom of the wing.

A friend of mine lost one of his large glow Aviation Design F-117s at the Dixie Jet Rally in St. George Utah a couple of years ago when he got far out and fighting turbulence, he rolled the wrong way. It didn't stick in the ground, it came back in a body bag!

Photo was taken by UncleJoe I believe.

[Gordon]

"looks like nothing else in the air

Hi DA

That might be the case, but it does look brilliant in the air. Those highly swept wings and vee tail remind me of the swallows, swifts and house martins which tear through the air above our house and garden looking fabulous in flight chasing their supper every evening in summer.

You've got a really handsome bird there and I congratulate you, Vintauri and Power on your brilliant video - quite a cliff-hanger :cool: and your success.

Gordon

[Keith43221]

Froggy, I was wondering what Retracts you were using and how well they held up under the 30oz of the very nice and scale model.
Thank, Keith

[magicruss]

plans please

[Thomas Nelson]

Congrats and condolences, DA! But even as you've already suggested, trial and error is an integral part of the design slash scratch-building scene. Kudos for the success you've already achieved. Looking forward to where this one ultimately goes!

Sincerely

tn

[AirX]

Yup v2 needs to be explored... :)

Eric B.

[froggy117]

Ok-I'll try to catch up on comments on this thread! Please don't be offended if I don't reply to everyone's comments directly! I am still "new" at posting replies - and I am a lot better modeller than a typist!

Ed W. - I certainly get a sense of "deja vu" looking at that picture! Great picture! Unless of course, you are the owner/pilot! The "orientation" problem is not so much being able to tell the top from the bottom. It is detecting the first 20 degrees or so of roll when flying parallel to the flightline. The wingtips get blanked by the fin tips, the "wedge" shape of the cockpit is almost exactly matched to the leading edge sweep, etc. I am quite certain it was Lockheed's plan - as part of it's (justified!) "Low Observables" package! :)
I have some references to the "flag" version; but had not heard of the "Skunk works logo" version. That is worth considering!
I am building "V-2" out of white Depron-for first flights, I think I will only paint the top surfaces flat black!
Gordon-I like your comparison to swallows! "Brilliant" is good, too! The more time I spend on this thing, the more I appreciate the brilliance of the people who designed the original.
Keith-I am using Robart "1/2A" mechanical retracts. At least that's what they were called when I bought 'em years ago. They are still available. If you can't find the "nose gear", just use the small tailwheel retract. Same mechanics! There some pix earlier in this thread. No problem with the 30 oz. wt. You have to be a bit careful with the linkage, as the "downlocks" are marginal. The first "flight video" clip, I had to "pancake" it pretty hard-no damage to the retracts or mounts-but all (3) of the 1/8 carbon fiber gear struts sheared neatly!
Thomas Nelson and AirX-I have seen some of your projects-and picked up a lot of ideas from them! I am still a "newbie" at this electric jet stuff. So I thank you for the positive comments!

I am mostly done with the "V-2" plans-still the same overall size- but quite a few changes! Since this post is running a little long, I will post more later.

[Kevin Cox]

Great job DA. I'm sure V2 will be even better!

[Vintauri]

Hey DA,

Glad the plans are coming along.

I don't know how your stock of Depron is but I was thinking of placing an order for some more. Let me know if you need any and we can combine the order.

Steve

[roccobro]

Stunning. I can't wait for plans as I have very little scratch build skill.
Congratulations!

Justin

[Ed Waldrep]

Quote:
"It is detecting the first 20 degrees or so of roll when flying parallel to the flightline. The wingtips get blanked by the fin tips, the "wedge" shape of the cockpit is almost exactly matched to the leading edge sweep, etc."

I understand what you mean Froggy, that makes sense, hadn't occured to me before. A logo on the bottom would be good but when the plane is rolling toward you perhaps some other markings would help. I was going to suggest some white on the wingtips but maybe a patch of white halfway out on the wings would work better. As you rolled toward yourself, the white on the far side would become visible when not blocked by the fuselage. See one stripe, you're banked a little, see two stripes, you're banked more.

What a cool project. Makes me wish I hadn't abandoned mine a ways back, I didn't get very far.

[froggy117]

Ed W. - Yeah, I am thinking right now that I will leave the outer 2" or so of the tips white. This works well for me on sport/aerobatic A/C.

For the thread - Here is my "shopping list" of changes for V-2:
1. Redesign the wing for more lift-change the "mean camber" line."
It will be near scale- a "hexagon" of 3 mm Depron that pretends to be a semi-symmetrical airfoil. Dihedral - sort of -flat across the top of the spars.

2. Change the "thrust line" to give about 2 degrees of "down thrust". I figured out my present setup is actually about 1/2 degree "up thrust". So-when you think about it-a "flat plate" airfoil must fly at some angle of attack. (Yes, it does have reflex :) )But, with the thrust line parallel to the "flat plate";trying to lift the nose with control deflection is to some extent counteracted by more "up thrust". This should generate some "discussion"!
But, I am still adding "downthrust". (The way I designed this is really cool, I think-but I will save the details for later discussion!)

3. More thrust. Not that it really needs it-but as we used to say when I was drag racing: "If some is good, then more is better, and too much is just enough." So I am putting the Hacker 3700's back in the A-10 and have Hacker 4900's on order.

4. Lighten it up a bit-leave off the wheels, retracts, 2 servos, etc. I know, everybody likes the retracts (me, too!), but it is so easy to handlaunch and land that I want to see if leaving the holes for the wheels off the bottom of the A/c helps performance. Kind of an "oxymoron", eh! :o

I will post pictures as this develops, of course.

[AirX]

What I saw from the video was it needed a little more power, seemed like the flat bottomed airfoil worked well. I have a Hacker 4900 in one of my EDF55's and it is definitely more power than the speed 300 it came with I did test it on my test stand and my Kokam 1500 3s pack ws asking for some help as it could not hold voltage higher than 9volts under load need to test with my Polyquest 2200 3s pack.

Cheers,

Eric B.

[froggy117]

Picture 1 is a loose "mockup" of most of the components for "V-2". Grey foam is 6mm; white is 3mm. Nothing glued at this point. Picture 2 is a little bit "off topic". It is a picture of the rear fuse of my "own design" 80" Edge 540. Uses approximately 80' (yes, feet :) )of 1/8th carbon fiber tube - it is unbelievably light and strong. I post it as "food for thought" to show what can be done for all you "scratchbuilders" out there! More pictures to follow!

[Vintauri]

Looking good DA.

I'm looking forward to the next attempt. I'm working on a couple jet type things of my own but for now they are mostly pushers and not EDF's.

I've already informed my wife of some plans of large amounts of Balsa and Foam in the basement this fall and winter. If you get this design worked out well I might have to try my hand at one.

Steve

[AirX]

Very nice structure on the Edge 540. Very good use of carbon tube. The structure for the F-117 looks good too. Keep them coming.

Eric B.

[Figge]

Just wonder if the plans is ready now? I'm been looking for EDF F-117 plans for a long time and found this thread yesterday.

[Vintauri]

I was out flying with Froggy and Power last night. The F-117 V2 sounds like it is about ready to be glued together. I'm sure Froggy will chime in on that.

He still needs to test the new design.

[froggy117]

Well, the plans are drawn to the point that I want to see how it goes together-but not to the point that I would publish them. I intend to prove out the design (by flying it :cool: ), so all those who have requested plans-please be patient! :)

Here are some pix of the subassemblies:

First the battery box-6mm Dep.sides and "ribs" for cooling channels-.008" c. fiber for the top.

[froggy117]

Next the spars:

6mm Dep. capped with .007" by .25" unidirectional c. fiber top and bottom. I used a flat "shelf board" covered with Saran wrap as a fixture surface with a piece of 3/4" aluminum angle as a backstop. Mix a "little"5 min. epoxy, apply to spar, sandwichin the c.fiber-add weights. Wait "5 minutes or so"-peel and trim any excess epoxy. Repeat (7) more times! You end up with (4) really cool spars that weigh 11 grams (all four). takes about an hour.

[froggy117]

Here are the pix!

[froggy117]

Now we can start hacking up sheets of Depron. Each half of the "wing" is cut from one "standard' sheet of 3mm (white- in this case; but it doesn't really matter-since we have to paint it in on of the many exotic color schemes available :) ).Transfer the shape from the plan-it's all straight lines-and glue the biggest cutoff piece back on to form the "platypus' tail. I highlighted the joint line gray, so you can see it in the picture. Mark all the former lines on each piece, as well as the "crease lines" for the bottom facets.

Glue on the .125" c. fiber tube leading edges and the .050" c. fiber rod trailing edges and "platypus" trailing edges. I covered the plan with waxed paper first! Note that the trailing edge pieces are flush to the bottom surface of the Dep.

Use a straight edge (metal yardstick or meter stick) to scribe the previously marked "crease lines". A regular .7 mm mechanical pencil works just fine. Using your hands, the straightedge and a little patience (Thomas Nelson, where are you? :D ), fold every facet up about 15 degrees or until you think it looks like the bottom of a "117". Refer to these pix!

[Foo_Flyer]

Subscribed!!!!!!

[froggy117]

Check the fit between the left and right side (you know the old saw about "you did build a right and a left, didn't you?" :rolleyes: ) and glue the (2) together - just on the "flat panel" (see the blue tape on the bottom :) ) for now. I taped it first, folded one half back, applied glue, folded it back and weighted it to the plan. Just like joining balsa sheets together for wing skins! I think I remember balsa!

[AirX]

I want to make a small contribution to your effort. Here is a picture of the bottom of a model of an F-117.

Eric B.

[froggy117]

Eric- Thanks! I had heard at least one was painted this way for some sort of V.I.P. show. But all I have ever seen were sketches or paintings or models. I like it!! I thought I was being funny when I said there were many "exotic color schemes". Will post more pix tomorrow.

DA

[froggy117]

Line up the battery box and glue it in place-

[froggy117]

Wing tip blocks made from (2) layers of 6mm and (1) layer of 3mm "scrap" Depron-

[froggy117]

Now for the spars, first the "front"-