Drenalyn - Page 9 - RC Groups
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Aug 28, 2009, 03:06 PM
mangi's Avatar
Hy dear modell pilots! my name Dezsi from Hungary
please show my drenalyn video:
electro drenalyn fun rc airplan (2 min 2 sec)

Other videos www.rchalas.mlap.hu
Wery hapi and fun airplan. Y am love the simple modelss.
and pic:

And build the mega drenalyn
wing span: 90cm engine: os max25 3pcs normal servo. Video later.
Last edited by mangi; Aug 28, 2009 at 03:13 PM.
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Aug 28, 2009, 03:42 PM
flyin' fool
goldguy's Avatar
Thanks for posting the video. Nice to see others know a great design. It's hard to believe this design is over 10 years old now.
Last edited by goldguy; Aug 29, 2009 at 12:51 AM.
Sep 04, 2009, 06:23 PM
Registered User
Just maidened a 20" Drenalyn....what a floater and great inverted!....have to add a rudder for better hovering next....

Construction: 6mm white Depron...no reinforcing required..."I" beam fuselage to allow hiding the electronics since it has no gear...hot glue throughout

BW -1300 motor, GWS 8X4HD, 3S450 mah Hyperion 5C charge Lipo, HXT900 servos for elevons...

AUW 7.5 oz...2.75oz/sft wing loading....CG at 29% of chord

I found that this model flies a LOT better than my 24" Don't Panic (Delta shaped Drenalyn)....could be that the Depron stiffness is in play here....the DP was made with 6mm EPP with a Depron rib on each wind side to stiffen it chord wise...also, the loading on the DP was about 4 oz/sqft,but I don't think this is the issue...I think the round LE has a significant effect on the flight characteristics...

This and a BW powered, 16" Depron Duplex Delta are my curent "fly everyday" planes....the DDD in any weather....we'll see how the Drenalyn does in wind later this week...will probably have to switch to my 1100mah pack and forward CG...
Sep 04, 2009, 07:01 PM
flyin' fool
goldguy's Avatar
2.75 oz/sft, that's a winner for sure. As you've discovered, the Drenalyn's round LE and undercambered airfoil is it's strong points and yes, it loves inverted and about anything else you can throw at it.

I just maidened a FFF 19 incher and was planning on close to a loading of 3 oz but had CG issues. (too much color junk on the tail area) Had to go with a heavy Komodo, 25A ESC and 3S, so it's up to over 4 oz/sft. Flies up a storm, but lacks that light feel.

On windy days balance nose heavy. I've sloped mine numerous times, so it can fly without a motor too.
Sep 05, 2009, 06:41 PM
Registered User
Just spent an hour of flight time with my 20 incher (with added rudder)....the more I fly it, the more I love it ..this thing does anything you can think of except knife-edge....this might be my all time favorite foamie ..

just a thought on your CG issue forcing a bigger motor....why not just tack on a 2 or 3" nose box extension?...my next Drenalyn is going to be another 20" 6mm Depron one, but I want to move the servos back within a few inches of the elevons and rudder...I intend to make a nose box of 9mm EPP forward of the LE such that with the BW and ESC, I get a CG at 30% without battery...I prefer to have the battery mount over the CG so that capacity changes don't HAVE to affect CG...and this will give me an EPP crash bumper ....most of my dings to models seem always to be the firewall mount or forward fuselage....usually from low inverted

on my 16" Depron Duplex Delta I used a 6mm EPP fuse with 4.5mm Rediboard wings and it has held up very well to the many "head plants" I've done with it...

in general, what if any differences have you noticed between your Depron and all-EPP Drenalyns?....I am a bit concerned that if I went all EPP, the lack of absolute wing ridigity would affect its precision, which is very good right now...

in my DDDs, if I use EPP for the wings, it just doesn't have the speed range that a Depron wing allows...and wide wide speed range is the triple D's forte ...fun slow, but can be a bat out of h_ll when you want...

I am thinking about putting a few of my other planes into salvage now...
lets see.....
YAK55...nope....3D just too good
Super Slofly...nope....just too nice a slow flyer
Maverick....nope....smoothest fast aerobatic plane I've got
Mini Maverick...nope...same but crash resistant...its EPP
SD....maybe....elegantly simple, but not as much fun to fly
mini SD...nope....just too easy to throw in the car anytime
NB...maybe...the Drenalyn does everything and much more that NB does
DDD...never....best speed range of any plane I've built..
Sep 05, 2009, 06:51 PM
Curiouser and curiouser
Kokopeli's Avatar
Oooohhh mannnn...
Please 'splane what all the DDD NB SD mean.
Sep 05, 2009, 08:09 PM
Registered User
Originally Posted by wjbite
Oooohhh mannnn...
Please 'splane what all the DDD NB SD mean.

DDD = Depron Duplex Delta .... https://www.rcgroups.com/forums/showthread.php?t=559186

NB = Nutball...

SD = Simple Delta....
Sep 05, 2009, 08:11 PM
flyin' fool
goldguy's Avatar
Ya gotta learn to walk the walk and talk the talk .
Sep 05, 2009, 08:36 PM
flyin' fool
goldguy's Avatar
This thread is now over two years old and it's nice to see a few have discovered how great the Drenalyn really is. It's my all time favorite for indoor and out door. NutBalls are silly fun, but your can get a bit more serious with the Drenalyn. It's solves all the problems of other low aspect ratio flattie wing platforms.

Building one in EPP works great. It's important where you place the CF to get the bend at the LE and the reflex, although the reflex can be tuned in with the elevons. The airfoil shape adds to the rigidity of the floppy EPP.

I flew the heck out of my 19" the other night and it was a blast, even being porky. I even left my NutBall at home and got the gears from my FB's. There were lots of others there to make up for it though.

I've got an EPP 16 incher at under 4 oz. RTF for indoor and it's absolutely the best foamy yet that I've build for confined flying, and I've built lots of different designs. Indoor is just around the corner and I'm going for a target of 4 oz. for a 17 incher to take it up a notch.

I brought you guys the Dart and NutBall, so you can trust me on this one too. Give the Drenalyn a try and you'll realize the name is appropriate.
Guaranteed or double your money back.
Last edited by goldguy; Sep 05, 2009 at 08:43 PM.
Sep 06, 2009, 04:47 AM
D'oh.. Dumb Left Thumb
dekan's Avatar
Frank, the curved wing is too much effort in Epp for the average NB builder , and on top of that the Gpw Fan club aint bitting....
Sep 06, 2009, 05:10 AM
RIP Azarr - "Old age is not for sissies"
Azarr's Avatar
I built one from the plans on David's site years ago before we had the equipment we do now. It may be time to revisit the Drenalyn. I have a 17g motor without a home at the moment so when I finish up a couple of thiings I'm working on I may build a 17" version.

Sep 06, 2009, 05:12 AM
flyin' fool
goldguy's Avatar
For the extra effort to build, which isn't really that much, the Drenalyn is well worth it since it out performs most. Why would anyone not want that?
Sep 06, 2009, 09:45 PM
Registered User

Drenalyn on steriods

Labor day weekend....might as well build another foamie...
target was a small version out of 6mm EPP for a 10g motor with ultra light landing gear for living room flying ...

off to the foam bin, found a big scrap, but a 14.75" WS was all that could be had...no problem, should work fine with 5g servos elevon only and 10g motor on a 3S small battery...

mark, and start to cut and realize that instead of a 1.3# 6mm sheet, it was a 9mm 1.9# scrap...oh h#$@ ...well, lets see what develops...

what developed was a 2.5oz airframe, one a gorilla could sit on , but heavy...by the time the 10g motor and gear was added, it could barely fly with a 2S at 5oz.....okay,but mushy on 3S and the motor was getting hot....

what the heck, rather than scrap it, I changed the 10g for a high KV BW and a 2S450mah battery....6.5oz AUW...4.3 oz/sft...

boy is this thing fun!...not floaty like my <3oz/sft 20" Depron version, but still harriers, slow flys (@ a fast walk), and prop hangs great(notice the extended nose moment)..with its CG at 30% it flies inverted hands off...and its a rocket when called for...

plus its nearly indestructible..its built like a mac truck...I planted it full power from 5 ft several times horsing around with it and no damage ...just bounce

plus its very small...toss in the front seat easily..

sorry mini SD, you've been replaced as my toss and go plane...love these Drenalyns!
Don't be afraid of 4+oz/sqft loadings, these things still fly great at 4-5oz/sft..
Sep 07, 2009, 12:20 AM
Registered User
I might give the Drenalyn a go this fall, but miss nice easy to print BW sized plans. I will need something esle if I ever get tired of my Bullseye deltas as I haven't flown anything else since them. I still haven't gotten to the joystick or the xp-39 either which have been haunting me for months along with a foamie gyro from one of them other RCG forums. The skycart looks interesting. I keep watching this thread hoping for some decent printable PDF plans in American measurements that don't require too much thinking. I am rather patient...
Sep 07, 2009, 10:22 AM
Registered User
Originally Posted by tymbrewolf
I might give the Drenalyn a go this fall, but miss nice easy to print BW sized plans. ...sic... I I keep watching this thread hoping for some decent printable PDF plans in American measurements that don't require too much thinking. I am rather patient...

how about these?...just knocked them out this AM....not 100% exactly what was drawn on page 7, but its what I built, is very close to Golds plans, and flies well...

oh, and if you have Excel...here is a little scalable spreadsheet with major dimensions that scales to any WS you wish( WARNING this is NOT a TXT file...change file extension to XLS before using...the site won't allow me to uplaod a file with XLS extension)...

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