Are there any good funfly kits out there for an OS .25 FP? I thought it might be cool to have a tiny little stick banger to keep in the trunk.

My Morris Hobbies Pen Knife fits in the boot of my car........John

Boot??? Aren't only Brit's supposed to call it that?

Naw yu see I live way out in da boonies and we have a language all'o our own. I aint got no ideas bout wut demair Brits call em but we call dem hickies a boot................. heehee......Where ever you go you'll always hear somthin new. We had a guy move in our area a while back and we had a real bad communication gap. I was talking about (about is pronounced abite) cows ( I dont know how to spell the word we use for cows) and he thought we were talking about Coyotes. On another occasion we were werking on somthin and sombody gave him the okay sign....You know the last three fingers up and the thumb and index finger together forming a circle.....well the next thing we knew he was ready to fight. Come to find out where ever he came from that particular sign was calling someone an ^$& hole....Who knew???.

The Fun 15, stay tuned.....

Hi MiL,

I'm in Oregon too, about an hour from you up near Banks. Here is a pic of one of my planes. I call it Super Happy Fun Plane. It weighs a smidge of 2 lbs... always less than 2.25 anyway... and although it has a diesel on it in the pic, I now fly it with an FP .25. Very nicely powered.

I am working on plans/pics/article for a model magazine now. If your interested, let me know, could probably send you some drawings shortly.

Foamguy

Hi Foamguy. That would be great if you had some drawings for me. I have Autocad and ProE (CATIA too, but i have no idea how to use it) so i can accept a lot of formats. I found some free plans online for a .09-.25 sized funfly, but i want to modify it some. I actually just started (15 min. ago) to design my own in ProE. I need the practice anyway or i'll forget everything i learned about the program. I think it will be a lot of fun designing and building my own plane, even if it doesn't fly quite as good as some others might.

One quick question, i've never had a profile plane before, do the wings come off like on most sport planes? Or are they permanently attached. I'm trying to think of a good way to have the wings bolt on, i've got a couple ideas, but i'm not sure how satisfied i am with them.

Foamguy,

What radio gear are you running? Standard or mini? How does the plane hover?

Thanks,

Dan

Well I'll chime in here for Foamguy,

I flew it during my spring break. He has HS-81's in it I believe and a 225 or 270 rx pack in it. Yes it will hover on the .25, very easily in fact. It does require some skill, but over all its not that bad.

--Paul

hmm, do you think it would work ok with standard size radio components? That's all i've got and i can't really afford to get micro stuff.

If not, maybe i should enlarge my plans to use with an Enya .49 i have instead. I'd prefer to stick with the .25 if it would still work well with standard servos though...

The standards are gonna work fine, but they are going to add a lot of weight. Doing that will probably put it up in the 2.5 Lb range, which is still really light.

--Paul

Mil,

Standard servos would be fine. In fact, for most folks even better. They only add perhaps 3 oz to the all up weight. You do NOT want to put a .49 on sonething like this. First of all it would destroy itself in short order, secondly its far too heavy. Weight is the most important factor. We strive for the lowest practical wing loading we can get. Also low weight = low intertia. Low wing loading means it will fly extremely slow without stalling and low intertia means you can turn it extremely tight. This particular plane has a wing loading that would make most glider pilots blush. I can fly it all day in a 50' box if I choose to. You really dont even need a runway, just pick an open spot somewhere. Roll out is about 3' or less.

It hovers well, as do most planes of this type. It's not a profile however, but a fiberglass boom.
It's a one piece plane with 42" span. Fits in a Hyundai easliy... LOL.

One last thing though..... if you want the EASIEST hovering plane.... you might look at Don Incoll's Wasp. Mine is fine for me, but I think it could be better with more fin area or a profile as yaw stability.

Foamguy

Thats good to hear, what i'm doing will probably be almost perfect. The only thing that concerns me a little is the span.

I'm using 2 sheets of 1/4x6x36 balsa to cut a profile fuselage out of (looks similar to sud-o-khoi with large side area) between them i will sandwhich 1/4 square balsa sticks. Having that space between the 2 sheets should add a lot of strength because in order for the fuse to break, the sheets will now have to stretch and compress more.

It's going to have a 35" span (similar to the pen knife, which i'm sort of using as a starting point for dimensions) and about a 13" chord (including the 3" wide flat ailerons). That gives... 455 sq. in.

I used profili to export a slightly modified NACA 0018 airfoil into autocad and from there i added spar notches and cuts for LE and TE stock, then printed out templates. I cut the ribs out last night. Using 1/8" balsa for them.

For the dimensional relationships between all the different part i've just been looking at other FF planes and using the T.L.A.R. method. This is my first attempt at either design or scratch building. It may be slightly overbuilt, if so, i figure the worst that can happen is it's a little heavy and instead of being a good FF plane it'll just be a cheap small sport plane.

Here's the stats i've determined so far:

Span: 35
length: 39
Airfoil: NACA 0018 (slightly modified to move "Fat" part a little further forward)
Wing centerline on the thrust line, stab centerline 7/8" above
Stab LE 12" behind aileron TE
Stab span 16"
Fin height: 10" (from bottom of fuse
Wing LE 5" from front of fuse.

If anything looks terribly wrong there, please let me know. The main reason the span is 35" is because that way i can use single pieces of 36" stock for LE, TE, spars, etc. and because thats about what the Pen Knife is (36"). As for the fuse length, first i figured it should be the same as the wingspan, but the TLAR was telling me there just wasn't enough space between the aileron TE and the stab LE so i added 4" to the fuse in that space to come up with the 39" total length.

I think i'll draw up the fuse on Autocad after i finish this post. I'll try to put it up here so maybe i can get somebody to tell me that it'll never fly before i build it

lol, i was looking at it again and now the fuse looks too long, i shortened it by 3". Now it's one inch longer than before. All the change is occuring in the section of fuse between the aileron TE and stab LE, nothing else is modified. I've done a little cadwork, i'll post an image so you can see what i'm talking about.

1/4" balsa sides?? That sounds a little beefy to me. The SuDoKhoi is build from 1/4" sticks and sheeted with 1/16".... You might gain allot of weight if you go with 1/4" stock.

you mean the 40 size SuDoKhoi has a fuse that's only 3/8 thick? wow, that doesn't sound very strong to me, it sure looks thicker than that in some pictures i've seen... you're talking about balsa sticks or hardwood?

Like is mentioned, this is my first attempt at design and i thought it might be a bit overbuilt. I wish i had built some FF planes before so i would know what i was doing. Oh well.

Here's another update on my plans. Do you think i should lengthen the wingspan?




Shoot, here's a link to the dwg file while i'm at it.

Opps... I mean 1/8" sheeting for a total of 1/2".... On a smaller plane I would be tempted to go with the 1/16" sheeting...

so you think i could get away with 1/4" sticks in the middle and 1/8 inch sheeting? Seems a little thin to me, and just by the feel of the 1/4 sheeting, it really doesn't seem very heavy... but weight IS critical in FF planes so maybe i'll switch to 1/8.

for a plane this small you could probably go with 1/4 sticks and 1/16" sheeting.... Or you could do like my aeron plans show and use 3/8 stick's with 1/16" sheeting.... Either way, make sure you get really good glue joints for strength.

Here's a picture of my scratch fun fly so far... work will be slowing drastically as i am now back in school again after about 6 weeks off.

That looks pretty cool MiL... How much did it weight?

i haven't a clue, i dont have any kind of a scale. I'm guessing it's a bit heavy though. I ended up using the 1/4 sheeting since i already had it and might have the added benefit of holding up better to any 'mishaps' i may have, since this is after all meant to be sort of a practice plane... the one i'm not afraid to crash

Well, i took the plane out for the maiden flight today. Flew great, better than i ever expected. I only got one 5 minute flight in before it got too dark to fly, but it felt pretty good. Slows down to a crawl, roll rate is insane, stall was pretty gentle and occured incredibly slow. I didnt do too much vertical stuff but it should be unlimited and with a better prop capable of hovering and such. Although, it may be a little too heavy to hover really well, i'm not sure it will have quite enough beans to pull up out of a hover. I have an OS 25FP with a 9x6 master airscrew right now. I'm thinking a 10x3 or 4 APC should really give it some thrust.

Can't wait to get it all trimmed up and dialed in tomorrow... i think this is gonna be a fun plane to fly

Wow... got any picutures of the finished plane? I've got an old 25 sf laying around... how about the .dxf file?

i'll take pictures tomorrow. I do have an autocad file but i want to fix it up a bit before i release it to anyone, it's pretty rough right now.

Now i kinda wish i had taken your advice and built it with lighter side panels ain't that the way it goes... I didn't exoect it to work this well so i didn't put a whole lot of effort into it... i hope it will hover, maybe i can cut some holes in the side or something. I think the tail and wing are designed fairly lightly, and i didn't put any landing gear on at all, just hand launch and set it down in the grass. That pretty much leaves the fuse as the only place to save weight... i guess the radio components too, but i'm not interested in spending much if any money to get it lighter. A couple times i've had to remind myself that the whole idea of this project was to do it CHEAP.