SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Oct 02, 2012, 08:44 AM
Phantom Mechanic
PhantomII's Avatar
Westpoint Utah
Joined Jul 2005
162 Posts
I would love to have a plan for the F-16 that plane is awesome!
PhantomII is offline Find More Posts by PhantomII
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 02, 2012, 09:53 AM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,444 Posts
Quote:
Originally Posted by georgy View Post
Just a dumb question regarding the 150 sqr" wing rule: I get the calculation method, but does that mean BIG-WING planes like deltas (Mirage3, Skyray, Dagger/Dart) will be much smaller than eg a Sabre? Theres a lot more wing on those deltas!

Something like the small-wing Starfighter might end up twice the scale of a Mirage-3? Or is the wing area rule meant to tie-down something else?

I don't think this aspect of the wing-rule on the WW2 warbirds was such a "problem" as they all pretty much was the same basic lay-out...

Sorry to complicate things

George
That is a very good question George.

The area rule was put in to give a fairly level wing loading for a given motor package. There will be differences in how they fly due to aspect ratio or delta vs. swept vs. straight wing. That makes them all different scales. It is an issue that I struggle with as well. Take the F-104. I cannot get it up to 150 sq. in. without haveing to use more than one sheet of foam. That is the current situation with the F-16 as well. I would like to keep them to a single sheet of foam if possible. That would be a secondary or tertiary priority.

I am open to suggestions for modifying the rules to a point to make this better for all involved.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Oct 02, 2012, 10:58 AM
Addicted to building...
Freddie B's Avatar
Omaha Nebraska
Joined Feb 2006
5,992 Posts
Quote:
Originally Posted by dz1sfb View Post
That is a very good question George.

I am open to suggestions for modifying the rules to a point to make this better for all involved.

Ken
I'm house re-modeling so I don't have a lot of time, but I was thinking outloud. If we pick a certain 'scale' and just for referance say 1/24th scale (or some set number that makes say an F-16 come out at 150 SqIn), and convert some of the popular choices here (full scale down to model size) to see how thet fair and compare.

Second thought. In making many EDF models over time, some profile, some full fuselage, many that end up in the 6-10 ounce range actually have smaller wing areas than say a WWII Prop job just from design aspects. They fly fast, land a bit faster, but still are very controlable. So if a 'scale' or say 'scale range' (1/24-1/20th) then the smaller full scale ships will have smaller areas, but weigh less, so still land well, and the larger ones will have larger areas but weigh more, etc, etc.

And if a bunch of beta designs get made to a standard 'scale', I'll bet the results would be interesting and fairly consistant within reason because even a design has more of a factor in how a Jet flys, not just it's area. I'd be game to build a personal choice of my own picking, and even hand draw a small print on graph paper, possibly able to scan it so someone else can do a CAD print if desired, or just make it an old style blueprint simply enlarged and converted to PDF format. Reason is I still don't take the time to perfect Sketchup and get rusty in-between the 1 year breaks I take!

Onward.
Freddie B is offline Find More Posts by Freddie B
Reply With Quote
Old Oct 02, 2012, 11:08 AM
Slopeosapien
jonesymj's Avatar
Joined Jun 2006
785 Posts
Quote:
Originally Posted by dz1sfb View Post
In SketchUp if you select just a surface, right click, entity info, a window pops up that gives you area. If you do that with lines it will tell you the length of the line(s) and or curve(s) selected. Nice thing to know in this arena.

Ken
Re: Sketchup question: Well that's easy! Golden! Thanks Ken!

About the Yak, I think that's actually going to be the first one I do. It does have what I see to be an easier design, and probably build too. I'll get into sketchup tonight and see what I can come up with. Here's some info on it too...

http://en.wikipedia.org/wiki/Yakovlev_Yak-15
jonesymj is offline Find More Posts by jonesymj
Reply With Quote
Old Oct 02, 2012, 12:48 PM
Allways the hard way!
georgy's Avatar
South Africa, GP, Germiston
Joined Jan 2012
422 Posts
Did quick measurement on my "PLF" prop-in-slot Skyray. 26.8" w/s
Wing area is +/-285 inch/2. Half that would be NASTY small!

My Eurofighter is 23" w/s with o/l of 33.6" Total wing area is 208 sqr. a Simple PLF like this must fit in a single sheet?

Guess what i want to suggest is possibly capping delta wings at somewhere 200sqr.
Maybe a more professional calculation by a more competant designer will home in on the best practical solution.

Hope this helps a bit

Glad i'm not the boss of this...

George
georgy is online now Find More Posts by georgy
Reply With Quote
Old Oct 02, 2012, 01:32 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,444 Posts
George,
Nice jets! We'll get this sorted out.

When I started the WWII thread, it sat idle for about a year before I got the time and inspiration to really go at it. I am hoping that will not be the case here, as there seems to be alot of interest.

I believe that it is going to take a little experimentation,
Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Oct 02, 2012, 03:33 PM
Proud of Brushless Sprouts
Commander Clumsy's Avatar
Belgium, Flanders, Antwerp
Joined Feb 2007
327 Posts
Woohoo, we got us a Starfighter! Reverse psychology... successful




And how about the English Electric Lightning? Everything about that plane is quirky but there is place up front for a small spinner and a decent airflow around the motor.
Commander Clumsy is online now Find More Posts by Commander Clumsy
Reply With Quote
Old Oct 02, 2012, 08:16 PM
UMs & parkflyers... for now.
davidterrell80's Avatar
United States, VA, Herndon
Joined Apr 2012
2,910 Posts
McDonnell FH-1 as a VLF...
davidterrell80 is offline Find More Posts by davidterrell80
RCG Plus Member
Old Oct 02, 2012, 08:28 PM
UMs & parkflyers... for now.
davidterrell80's Avatar
United States, VA, Herndon
Joined Apr 2012
2,910 Posts
I'm thinking this one... the hawker siddeley buccaneer... as a PLF pusher will be my first one.

But, you know... this one could be a push-pull a'la the Do335.
davidterrell80 is offline Find More Posts by davidterrell80
RCG Plus Member
Old Oct 03, 2012, 06:40 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,444 Posts
Hawker Hunter Maiden flight report
1. I put three batteries through this model today. Adjusting the battery aft until finding what seems like the optimum CG, which was at the rear of the aileron servo case (not the mounting tab). I will be repositioning the elevator and rudder servos aft so that the battery can sit on the CG.
2.Pitch response was acceptable once the CG was found. May add some TE to the elevators.
3. Roll response was super sensitive. I had to put the pushrod in the 3rd hole from the end on the servo horn to tone it down, and rate was set to 50% on the radio with 60% expo. Still a bit twitchy. Truncating the ailerons and fixing the tips should slow this down to a more docile rate and allow full use of servo travel. I will try this once the CG has been tuned for the battery at the CG.
4. The rudder was mildly effective. A little more throw and it will hold knife edge flight. May add some TE to this surface as well.
5. Flaperons were causing serious nose down pitching. This effect was so pronounced that at one point I reset up the radio for elevons and flew it without the elevator. It not the most responsive this way, but the throws were way down. Then I plugged the elevator servo into the aux1 channel on the rx and mixed the the elevator to aux1. Then the pitch response was super sensitive. I used +100 so there was full deflection. This may have merit if it is tuned down.
6. Power system performance was more than adequate with unlimited vertical on 3s.

Summary
Some tuning and adjustments to the design will make this more fun to fly. Right now its kind of a handful.


Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Oct 04, 2012, 05:09 AM
Allways the hard way!
georgy's Avatar
South Africa, GP, Germiston
Joined Jan 2012
422 Posts
Ken,

Maiden on my Mig was somewhat the same... It flies, but not exactly what I was hoping for

Crappy, but good enough to keep at it! The o'll school fees

Good luck with the "tuning"...

George
georgy is online now Find More Posts by georgy
Reply With Quote
Old Oct 04, 2012, 06:56 AM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,444 Posts
Quote:
Originally Posted by georgy View Post
Ken,

Maiden on my Mig was somewhat the same... It flies, but not exactly what I was hoping for

Crappy, but good enough to keep at it! The o'll school fees

Good luck with the "tuning"...

George
Mostly the roll rate is so fast. I am going to split and fix the outer 3" of aileron. This should slow it down to a more comfortable rate, and make the flap portion more functional. Flaperons on a swept wing tend to act like elevons due to the end of the aileron being so far behind the CG.

I posted some more pictures in post #2 of the new servo and pushrod setups for the rudder and elevator as well. I am much happier with these.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Oct 04, 2012, 07:11 AM
Danish? Don't U eat that??
DKChris's Avatar
Denmark
Joined Jan 2008
240 Posts
Somehow this would seem to me to be an ideal candidate: deHavilland vampire/venom (Vampire shown)


I imagine you might even be able to get away with flying it with elevons in front only and no dedicated elevator in rear, allthough it might cost some manouverability. Would simplify a lot though.
DKChris is offline Find More Posts by DKChris
Last edited by DKChris; Oct 04, 2012 at 07:17 AM.
Reply With Quote
Old Oct 04, 2012, 08:45 AM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,444 Posts
Definitely a good candidate DKChris!

Would need some carbon tube or dowel in the booms. Pusher, or tractor? I think pusher would look best.

Totally agree that elevons would be the simplest, and probably worth trying.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Oct 04, 2012, 09:38 AM
Danish? Don't U eat that??
DKChris's Avatar
Denmark
Joined Jan 2008
240 Posts
I'd consider making the booms a little bit higher than scale and gluing flat 3x0.5mm carbon strips into horizontal slits down the middle of each boom, or maybe using 6mm Depron or FFF with 6x0.6mm carbon strips for the booms for even more strength; would be easy to do and should work nicely.

If you have thin carbon roving a single strip going around top an bottom of the boom would be even stronger, and if done right possibly also lighter(careful on the glue amount), but it can be a bit more hassle to do. I'd make a "negative" frame that fits the outside of the boom piece(Save the remains from cutting out the boom/rudder pieces), cover it with PE tape and place the setup with frame and boom piece flat on some PE plastic on a flat surface. Then i'd wet out the roving with laminating epoxy on a different piece of plastic (I'd lock one end of the roving piece down before wetting with a piece of wide packing tape), and when wet out completely, i'd scrape the excess out with a plastic card or similar. Then I'd wrap the boom piece with the roving and lock it firmly in place in the frame with weights on the flat surface to keep it pressed tightly on the foam edge while it cures. Maybe put an incandescant bulb desk lamp over it to accelerate the curing.

Also, you could probably get an advantage using the 2 servos as angle support blocks between the wing and the front end of the booms.

Definately pusher! For a 30-35" span plane it would have to be a 4,5-5" prop max though; the dental drill sound would be inevitable.....but what the heck.....
DKChris is offline Find More Posts by DKChris
Last edited by DKChris; Oct 04, 2012 at 09:54 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Sporterizing dz1sfb's Hawker Hurricane, SEMFF WWII Combat Plane. Freddie B Foamies (Scratchbuilt) 152 Dec 17, 2012 09:59 PM
Video Semff combat sortie 8/28/2012 mav913 Electric Plane Talk 2 Aug 29, 2012 11:29 PM
Discussion Indianapolis Area combat SEMFF WWII combat dman65 Electric Combat 1 Sep 12, 2010 12:35 PM