Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin (Account/Technical Issues)  |  Contact Global Moderator
September 19, 2020, 11:58:42 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 2 3 4 5 6 [7] 8 9 10 11 12 13 14 ... 31   Go Down
Print
Author Topic: CATAJETS: Design and Development  (Read 68575 times)
0 Members and 1 Guest are viewing this topic.
FAAMAN
Silver Member
****

Kudos: 3
Offline Offline

Australia Australia

Posts: 144


Even bumble bees can fly !!!!



Ignore
« Reply #150 on: October 12, 2010, 09:20:13 AM »

Caley, what a cool subject, I really look forward to the model. Cool Cool

Pit I agree with you, the catajets have to be bigger to reduce wing loading and slow their glide characteristics, the smaller w/span models events happen far quicker due to their higher loading and larger frustration factor !! Grin

Here's some pics of how I'm fitting my HP.115's elevons so I can adjust trim (being that deltas are difficult to trim), I've used the grain at 45deg so I can "droop" the tips without affecting the whole elevon. I've done a bit of research and it seems it'll help stave off tip stall like washout does, only not as efficiently as washout does, everything's a compromise in this hobby Grin

Cheers all,
Neil
Attached files Thumbnail(s):
Re: CATAJETS: Design and Development
Re: CATAJETS: Design and Development
Re: CATAJETS: Design and Development
Logged
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #151 on: October 12, 2010, 09:39:38 AM »

Pete, I imported the 3-View into MS Paint. It sized out at 6 inch wingspan, so I doubled that size. My view is that the tiny ones are too difficult to paint and detail. I'm keeping the tail feathers per the 3-View, and will make it a chuck glider. If that won't work, I'll slice off the tail feathers and enlarge things. The stab is embedded about 1/4 the way up the fin, so removing things will be easy. Because of the wood I have, paint will be all I add. I'm hoping that won't warp the wood like the Helmsman did. So far the paint hasn't caused warping on other models.

Parts are cut out. I just need to sand them and put it together. Not sure what the CG would be. It has a very long nose, so it probably won't require a lot of ballast.

Caley
Logged

What's stall speed?  Undecided
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #152 on: October 12, 2010, 05:28:52 PM »

Correction on the wingspan. It actually will be 8.25 inches. Somehow my Paint program burped and gave me an incorrect printout. I think what happened is that it remembered the size previously and printed that. I'm going to try 3/4 dihedral which is about three times what the 3-View shows.

Caley Embarrassed
Logged

What's stall speed?  Undecided
Sky9pilot
Titanium Member
*******

Kudos: 50
Offline Offline

United States United States

Posts: 2,769


WWW

Ignore
« Reply #153 on: October 12, 2010, 05:46:03 PM »

That ought to work ok as a catajet Smiley. Just project the wing LE and TE to the fuz centerline to maintain the span. The stab looks close to 25% as is, but u could increase it a bit and the fin/rudder looks a bit small.

What size are u going for?

I've come to the conclusion that catajets UNDER 10" wingspan do NOT work too well. They CAN be made to fly decently, but require a huge amount of work. Most of my stuff has "grown" to 10-12", which has made trimming much easier.

Caley.... good looking choice. I think it has real potential.

I must agree with Pete.... 10-12 inches span will be the minimum for me in the future. They are much easier to trim and a whole lot easier to see off the catapult.

Tom
Logged

Best Regards,
Sky9pilot
    "If God is your Co-pilot, consider switching seats!" 
http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl
http://freeflightarchive.com/index.php/homepage-2
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #154 on: October 12, 2010, 06:29:40 PM »

I've got everything sanded. Well, I may sand the fuselage a tiny bit to give it a slightly curvy shape.

I think I'm going to do some computer work and do the graphics on tissue and cover. I know that adds weight, but I'm just trying to see if it'll even fly. let alone fly like the way, say Pete gets his to. I'm not really sure what the overall colour is. All there are online for pics are the black and white kind. I think it was just a prototype in basic aluminum colour, so I will probably do it in light gray.

Getting the stab and fin slot had to be done by slitting from the fin LE back. I'll fill in ahead of the stab once I get things glued correctly. I'll also be putting in micro pieces of wood below the stab along the fin to give some grip/support since I'm using 1/20 wood in those locations.

Note the flying surfaces (all) have sub fins and rudders, or whatever they are called. Getting those perfectly aligned is going to be a real pain. The scale model I mentioned earlier did not have these attached. I am wondering if there are several versions of this, those with these little sub thingies and those without. I might just leave them off, as they probably will create a tremendous headache trimming the model, which I am lousy at.

Pete, I did leave the fin the same size, but if the thing is getting a dutch roll or whatever you get with a small fin, I can always add a little with cardstock til I get it right, and then make another stab/fin of appropriate sizing.

I'm stil dubious about it actually being able to fly since it has such a short tail moment. This could be another flop like my U-2 which also had a shorter tail moment than I usually see in CLG's

Well, back to work.

Caley
Logged

What's stall speed?  Undecided
FAAMAN
Silver Member
****

Kudos: 3
Offline Offline

Australia Australia

Posts: 144


Even bumble bees can fly !!!!



Ignore
« Reply #155 on: October 12, 2010, 07:29:29 PM »

Caley, had a look through my library on the He176, as far as all my refs and the web says, there is only 1 b&w image of the plane at Peenemunde, and debate rages over the actual scheme, there were no discernible markings as you've probably noticed. The popular scheme is aluminium (polished) fuselage with lt. grey wings, horizontal and vertical tail along with the landing gear, just have a look see the model pics I've found. I hope this helps with your project.

Neil
Attached files Thumbnail(s):
Re: CATAJETS: Design and Development
Re: CATAJETS: Design and Development
Logged
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #156 on: October 12, 2010, 08:00:50 PM »

Neil, I figured the colour was aluminum/silvery. I sure would like to do all that landing gear stuff, but that would be some kind of drag and make trimming a super problem. Wonder what those cages on the wingtips and stab accomplish? Landing stability? I've got some silvery enamel paint I could use, though, if my memory serves me the stuff looks terrible unless the surface is perfectly smooth. I don't have the patience for that. Light gray will have to do all over with panel lines.

I'm going to search for a large crafts shop that might carry the gel pens I've been waiting to get for doing panel lines while in Perris tomorrow. I would imagine a Staples outlet might have them. This CATAJET is kinda fun stuff.  Smiley

Caley
Logged

What's stall speed?  Undecided
Sky9pilot
Titanium Member
*******

Kudos: 50
Offline Offline

United States United States

Posts: 2,769


WWW

Ignore
« Reply #157 on: October 13, 2010, 12:57:08 AM »

Caley

Look forward to seeing your bird come to life. For black panel lines I'd use the fine and medium point Sharpie Permanent pens. For the dark background scheme that need a light line I use the white gel pen the Michael's Craft Store has in their scrapbook section. Be careful with the gel pens they will smear till they dry.

Neil...you're a resource library all on your own Grin Wink

Tom
Logged

Best Regards,
Sky9pilot
    "If God is your Co-pilot, consider switching seats!" 
http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl
http://freeflightarchive.com/index.php/homepage-2
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #158 on: October 13, 2010, 07:15:22 AM »

Tom, Thanks for the tip. I'll keep an eye out for a Michael's while in Hemet. Parts sit as was described until I gather these pens. I'm also going to look for paint that matches what Neil showed.

Caley
Logged

What's stall speed?  Undecided
Sky9pilot
Titanium Member
*******

Kudos: 50
Offline Offline

United States United States

Posts: 2,769


WWW

Ignore
« Reply #159 on: October 14, 2010, 01:47:56 AM »

Caley,

While surfing the net found this site with your Heinkle 176 didn't know if you'd seen it.

http://ww2drawings.jexiste.fr/Files/2-Airplanes/Axis/1-Germany/01-Fighters/He-176/He-176.htm

Hope this post works for you fairly nice three view of the He-176, but I'd still use the colors recommended by Neil.

Tom
Logged

Best Regards,
Sky9pilot
    "If God is your Co-pilot, consider switching seats!" 
http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl
http://freeflightarchive.com/index.php/homepage-2
Pit
Palladium Member
********

Kudos: 130
Offline Offline

Germany Germany

Posts: 5,515


Topic starter
aka staubkorb


WWW

Ignore
« Reply #160 on: October 14, 2010, 09:20:15 AM »

Just to add a bit of salt to the soup regarding the He-176, the info I've seen regarding all WW II German aircraft has indicated that NONE were ever tested, or even rolled out of the workshop, without a coat of paint - usually the grey. There was too much risk with a polished alu scheme, blinking away in the sun, during the war.
Logged

A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)

Comparing Spammers to a pile of organic waste is an insult to the organic waste!
FAAMAN
Silver Member
****

Kudos: 3
Offline Offline

Australia Australia

Posts: 144


Even bumble bees can fly !!!!



Ignore
« Reply #161 on: October 14, 2010, 10:07:11 AM »

Just a quick note on the HP.115, backyard test flights went well yesterday morning and this morning, so well that I bit the bullet and took the Fi103R and the HP to the park for some "aviating" even though there was a 5+knot breeze from the WNW.

The Fi103R is STILL frustrating Angry

The HP had some good results from some low power launches, so continuing to adjust the trim I got up the nerve to do a full power launch across the wind at 70-80deg, Whoo Hoo did it go Shocked Cool!!! Up approx 40-50 foot rolled right way up and flew 50m approx, quick and a bit "twitchy" but good. So I did approx 15 flights with ok results, so I came away reasonably happy. I still have to finish the trimming but I'm happy that I'm on the right path.

I'll try to capture some pics and video during test flights tomorrow so that over the weekend I can finish the detailing (..... and repairs Embarrassed) and then paint.

Did I say this was going to be a quick note ........... Huh

Cheers all

Neil
Logged
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #162 on: October 14, 2010, 10:07:37 AM »

Tom, I don't think I came across this site, but did see the pics in my picture browser. Not sure why I didn't follow the pics. Guess I was looking for a pic of the real thing.

Seems I may've picked the correct paint colour based on these new drawings. I picked out, or should I say, a very nice lady picked out Folkart Acrylic Metallic Aluminum. It's pretty close, though maybe a bit bright like Pete mentioned about bare metal.

I also picked up some gel pens and those pens that mark white on dark background. Thanks for the Michaels tip. They had one in Hemet, California.

Neil, Somehow I missed your creation, a delta wing!. Glad to hear it is showing good signs. Everyone beware! The skies will soon be filled with CATAJETS and CATAPROPS. Grin

Caley
Logged

What's stall speed?  Undecided
FAAMAN
Silver Member
****

Kudos: 3
Offline Offline

Australia Australia

Posts: 144


Even bumble bees can fly !!!!



Ignore
« Reply #163 on: October 14, 2010, 10:19:00 AM »

Just a note on the He176, her first flight was in March 1939 with the first official flight 20June 1939, this being before the war taken in context with the only pic, I would think it was safe to say that alley fuse and grey everything else is correct for it's finish. I got this from the Luft 46 site page ...... http://www.luft46.com/prototyp/he176.html

I just love digging for info Wink

Cheers all!!

Neil
Logged
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #164 on: October 14, 2010, 10:53:44 AM »

Neil, You're a lot more dedicated than me. I just build. Grin This airplane, well, rocket, sure was an advanced design for the year they were doing it. I guess the Germans had a lot of people who thought outside the box. Just glad the people in charge didn't go along and use these designs.

Caley
Logged

What's stall speed?  Undecided
Sky9pilot
Titanium Member
*******

Kudos: 50
Offline Offline

United States United States

Posts: 2,769


WWW

Ignore
« Reply #165 on: October 16, 2010, 03:54:59 AM »

Neil,

Ran across this F102 solution to your delta leading edge. Its a conical camber leading edge made from a solid balsa stick 5/16 X 3/8 as long as your leading edge. The conical under camber is carved from root to tip with the root being a flat 1/16 then rolls down to 5/16 at the tip.

Here's a picture that explains it better. Remember its looking at the delta from the rear.

Tom
Attached files Thumbnail(s):
Re: CATAJETS: Design and Development
Logged

Best Regards,
Sky9pilot
    "If God is your Co-pilot, consider switching seats!" 
http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl
http://freeflightarchive.com/index.php/homepage-2
pubguy
Bronze Member
***

Kudos: 3
Offline Offline

United States United States

Posts: 55




Ignore
« Reply #166 on: October 16, 2010, 02:48:21 PM »

Hey everyone, I've been reading a lot of the posts on making the gliders from 3 view drawings but I'm not sure how you figure out where to place the center of gravity. The few gliders I've built F9F and F84 showed the c/g. Not sure how to do this if I try to make plane from the 3 views. Looking for any help I can get. Good flying to all.

Brian
Logged
Pit
Palladium Member
********

Kudos: 130
Offline Offline

Germany Germany

Posts: 5,515


Topic starter
aka staubkorb


WWW

Ignore
« Reply #167 on: October 16, 2010, 03:37:55 PM »

The way I've done it is to use regular catapult glider numbers. That is, decalage ~0.5° and balance point around 50-55% root chord. Hand glide tests should show a marked glide slope - NOT floaty across the yard and NO dive. THEN try a catalaunch with about 25% pull and see what the model does for starters. I start adjusting glide turn on the building board, sanding in camber on the outside (RIGHT side for left glide) of the fin/rudder. If it shows need for more turn , I add a bit of weight to the inside wing tip. If the transition is poor, I try a bit more rudder offset (or a temporary Gurney flap) near the base of the rudder.

Jets, with the generally short tail moment (short coupled) is not quite so "easy" as a purpose built endurance glider and a flat plate airfoil (as on my present F9F Cougar) present even more willies - a new "proper" airfoiled wing is in the works as is the straight winged Panther.

The whole thing is "cut and try" (and don't tell anyone about the failures Roll Eyes).

One thing I just did, as a result of the still occasional spin-in with the Cougar, was to trim the fin/rudder to almost scale size. I haven't had a chance to test the mod yet (weather uncooperative/rain). The next decent day will be devoted to catagliders/jets for the various Postals, so I'll let everyone know the outcome - this coming Wednesday looks promising.
Logged

A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)

Comparing Spammers to a pile of organic waste is an insult to the organic waste!
Sky9pilot
Titanium Member
*******

Kudos: 50
Offline Offline

United States United States

Posts: 2,769


WWW

Ignore
« Reply #168 on: October 16, 2010, 09:34:17 PM »

I agree with Pit...

I sometimes start the CG at about 30% of the wing chord on straight wings.... I just experiment with swept wings. Because these catajet aren't competition its just try to get the best glide out in the front yard before heading for the park.

Pit...any results on the F111?  Sure getting the itch to try that swing wing bird.

Regards,
Tom
Logged

Best Regards,
Sky9pilot
    "If God is your Co-pilot, consider switching seats!" 
http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl
http://freeflightarchive.com/index.php/homepage-2
Pit
Palladium Member
********

Kudos: 130
Offline Offline

Germany Germany

Posts: 5,515


Topic starter
aka staubkorb


WWW

Ignore
« Reply #169 on: October 16, 2010, 09:55:51 PM »

>SNIP<
Pit...any results on the F111? Sure getting the itch to try that swing wing bird.

Not heard from Marty (Copbat) yet. He's been laying low since the Geneseo party.
Logged

A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)

Comparing Spammers to a pile of organic waste is an insult to the organic waste!
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #170 on: October 19, 2010, 10:17:55 PM »

Gents, The glider Heinkel He176 is almost done. Needless to say, detailing isn't one of my talents. The gel pen did more scoring of the wood than marking. Lines therefore got a bit icky. I didn't put the wheels on, but may make them for display setting. Colour is acrylic silver aluminum on the fuse. I couldn't figure out how to get a clear effect, so I painted it enamel silver on canopy and nose to simulate the glass. Not even close. Wings are painted again with acrylic with a mixture of medium gray, white and elm green mixed. Again, not even close to the photo example, but what the heck, maybe a fantasy version. I might size a bond paper pilot on the canopy to give it a driver.

Haven't CG'd it, but from what I think someone was saying, starting around 50 percent probably is a good start. It won't take a lot of nose ballast because of the long nose. Anyone have a good suggestion for a near invisible catahook? If nothing else, it may be a good five second chuck glider.

As you can see, the Allies have already winged it on the right wingtip. Not sure how that happened

Caley
Attached files Thumbnail(s):
Re: CATAJETS: Design and Development
Logged

What's stall speed?  Undecided
FAAMAN
Silver Member
****

Kudos: 3
Offline Offline

Australia Australia

Posts: 144


Even bumble bees can fly !!!!



Ignore
« Reply #171 on: October 20, 2010, 07:36:56 AM »

Cool beastie Caley!! Cool Looks fine to me. Must've been winged by some marauding RAF Typhoons while on the ground, sneaky sods!!! Grin

Happy trimming and lite breezes,

Neil
Logged
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #172 on: October 20, 2010, 10:40:18 AM »

Neil, Like I said, not very well decorated, but the best I've done so far. I had to add 1.3 grams of nose weight to balance. Test glides onto the bed are promising. May have to take a tad of the ballast off. When it slows, it noses downward. No testing outdoors until the rain quits, and the ground dries out.

Caley
Logged

What's stall speed?  Undecided
Alvaro Sala
Silver Member
****

Kudos: 16
Offline Offline

Brazil Brazil

Posts: 185


Long live google translator!



Ignore
« Reply #173 on: October 20, 2010, 11:20:31 AM »

Caley
The bird looks very good. For an invisible hook I use acrylic.

May have to take a tad of the ballast off. When it slows, it noses downward.

What you describe sounds like stall. I would't take ballast, perhaps add some more...
Attached files Thumbnail(s):
Re: CATAJETS: Design and Development
Logged

Brazil: Where the nuts come from.
crashcaley
Palladium Member
********

Kudos: 243
Offline Offline

United States United States

Posts: 5,321




Ignore
« Reply #174 on: October 20, 2010, 11:36:37 AM »

Alvaro, Thanks. I decided to place the hook where the nose gear strut is shown on the three view. That solved that problem. If I decide to add the wheels, the strut is available for the nose wheel.

I did another test glide with the catahook on and it continued this time without dropping its nose. As for the nose in during first glides, it was a flat glide, and when speed bled off, it dropped its nose.

Caley
Logged

What's stall speed?  Undecided
Pages: 1 2 3 4 5 6 [7] 8 9 10 11 12 13 14 ... 31   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!