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Nov 26, 2010, 03:48 PM
Detail Freak
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Build Log

Extasy F3B from www.soaringusa.com


I have a new toy. Since I am starting to fly some F3B when time allows, I decided to get one of these babies.
I wanted a plane that would be light unballasted, so that I would be able to make the duration task without as much trouble as a heavier plane.
And, I have to use my less than "world class" thermal skills to do it.
I believe that the Extasy will be easier in this regard than my Cyril was. I can also use this plane as a windy condition TD plane, the way I did with my NAN Tracer.

Anyway, a little bit about the plane:

It's a little over 3 meters in span. It comes with the wings setup with RDS, and the frames are pre-installed. This, in my opinion makes for a "starter" RDS plane. The factory has already done the measuring, taking the head-scratching and guess work out of the build. While I had no problem with installing the RDS in the Cyril, and it came out great, I did spend a lot of time "looking" at the servo install in the wings, and gluing the frames in is a "leap of faith".... So, the Extasy is more of a "plug and play" plane in that regard.

The fuse is more of a standard setup, that requires the builder to cut out the shelf on the sub-nose for their own servo arrangement. This is a bit more work than where there is a pre-cut, specific servo arrangement. I like options for the gear layout in the fuselage, and I will likely add a ballast tube in the fuse.
Last edited by target; Jun 10, 2011 at 01:20 AM.
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Dec 01, 2010, 05:56 AM
Always looking for lift...
sky_surfer_fra's Avatar
Looks very nice Target! I look forward to reading your build log ! Cheers, Tom
Dec 03, 2010, 05:13 PM
Detail Freak
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Hi, Tom-

I should have posted the pics that I took last weekend of the wing servo install.
Once I "prepped" the parts for a smooth fit, slapping the servos and wiper rods into the pre-glued frames happens in a matter of minutes for each servo, it is that easy.

I like what the European builders are doing in this regard, but it assumes that you are going along with their program on throw for the flaps and ailerons. Most of the RDS setups if built stock, could use a bit more bend in the flap wiper rod, which is what I did with my Cyril (added 10* to the 45* bend to make it 55*). That gave me much more flap travel, trading off a little torque in exchange.

I'll have to see how the Extasy works out. The pockets in my plane are a bit narrow, and I suspect that I wouldn't be able to get away with a steeper bend without making the wiper rod really short because of it.
Nice thing is, it's real easy to dismount any of the pieces for removal/modification/replacement.

I'd like to see a setup more like Dr Drela's Supra setup in one of these planes from the European builders. Also, with the RDS arrangement, we can get by with some fatter servos than the JR378's, especially for the flap servos.

I'll post more when I get back on land.... If ever!
:-(
R,
Target
Dec 28, 2010, 04:53 PM
Detail Freak
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As promised some time ago, the wing servo pics have now been added.
It only takes about an hour to plug in the parts in the wing, once you know how they go and any prep/fitting you might do to the parts, as I did.
Pretty slick.

R,
Target
Dec 29, 2010, 01:29 AM
Detail Freak
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Added the fuse layout. Might be over-engineered, but it works, adds strength, and is serviceable to all components.

R,
Target
Dec 29, 2010, 02:32 AM
Always looking for lift...
sky_surfer_fra's Avatar

servo tray


Hi Target,
very nice idea how you implemented the servo tray!
Before Christmas I started to overwork my Tracer.
Try to do a similar implementation to move the whole equipment more forward to the nose to save some lead.

Cheers, Tom
Dec 29, 2010, 11:06 AM
F3B and F3K
RetoF3X's Avatar
Hi Target

Don't forget to make really short servo arms for the V-tail. The arms on the tail are quite small. Else you will end up with slop and poor accuracy.

The austrian used this set up on the Evolution V and now also on the Extasy:

http://www.rc-network.de/forum/attac...1&d=1292321656

I did the same on the Evolution V and still needed only 30% of the servo travel.

Keep up the nice work!

Reto
Latest blog entry: Pull-pull: back to the roots
Dec 29, 2010, 11:10 AM
Detail Freak
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Wow, Reto, those ARE some short arms!
I did notice last night that the tail links look to be short, but I haven't started on them yet.
I'll keep that in mind, thank you for the tip.

R,
Target
Dec 31, 2010, 12:37 AM
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Added more pics.
It's almost done. Rough balanced it tonight and weighed it. At 100mm, it weighs 67.8oz, and I had to use 3 oz of lead in the nose. Used shot/epoxy in a bag, pushed up in there.

R,
Target
Jan 28, 2011, 08:27 PM
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Ok, so some of you know that I had a set back with my RDS in the wings.... I wanted to use the new MKS 6125 mini digi servos, and I also wanted to have more travel than the stock setup would give me on the flaps.
In order to get more than about 50-55* down travel and 10* up travel, really the RDS should either telescope in and out, or the shaft needs to flext up and down a bit at the hinge line. Telescoping seems better yet more complicated to me....

Enter Walt Dimick's special Generation 2 RDS set up. It has a hex at the servo coupler that slips in and out as needed. Seemed like just the thing for 80* of flap travel....

Soooo, I ordered the HD shaft setups from IFR machine works, and worked on some other stuff.
They arrived as ordered. I took the stock wiper rods out of the stock Extasy aluminum couplers, and tinned them with silver solder. Then I trimmed the 6" long shafts down to size that Walt sent me, and did some mock up installs. I also read Harley's PDF on using the G2 couplers with the brass hex, and how they may need to be lightly reduced in size to slip into the plastic couplers smoothly. I did this, and they became very low friction sliding, without slop.

To get the larger flap travel, I would have to increase the angle of the shaft to the hinge line to about 55 degrees from the stock 70 degrees. To do this, I ground out the stock 378 servo mount (and I wanted to use the mounts for the MKS 6125 mini's), and planned to install the servo flipped over, with the output shaft inboard. This allowed the shaft to end up in the stock pocket, but the wiper needed to be bent to be pointing at the original angle... So I bent the wipers an additional 15*, the difference between the 70* shaft angle and the 55* angle I wanted it to be at....
This caused the shaft to not be in line with the stock bearing in the drag spar. Out she came with a pair of needlenose pliers and a little clean up with a Dremal Tool.

Ultimately, I knew that to have a slop free system, I would need to put the bearing back in somehow. A piece of .065 G-10 plate, drilled on an 55* angle worked well, but getting it perfectly placed would be damn near impossible, I figured.... And, I didn't want a metal-to-glass, or metal-to-metal rub if I could help it....

I found some plastic tube that was perfect diameter in my shop. So I made the hole in the G-10 a bit sloppy to allow the plastic bearing to float in there, until the linkage was installed, and then I would glue it in. And it worked perfectly!

I will poste pics later, but suffice to say that I have some slop free servos, with slop free linkages in my Extasy. And the servos are very quiet, as a bonus.

I an REALLY looking forward to this plane, it just looks like it will fly very well, and you know what they say, "If it looks right, it'll fly right". And, it's very light, should thermal really well.

R,
Target
Feb 06, 2011, 07:16 PM
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Finally maidened the plane-

I knew it would fly great, it just looks like it should be excellent!
And, it was. The plane seems very tame. Even when I was slowing it way more than I should of, it wouldn't drop a tip at all; I couldn't make it stall really.

I did add 1/2oz to the nose after the first time up the winch. It needed a measurable amount of down trim in all flight phases, and I thought I had set the CG empty at 98mm (recommended is 100mm).
Not sure where it is with the 1/2oz, but it was a little nose heavy, as the plane wanted to "pull out" when on a down line before a speed run trial. I will get that sorted and report back....

The plane is very docile up the line on mono, and my mono was (gasp) stored on the winch for 6 months, stretched out on the spool... So not much bang in the line.
The plane seemed to pull hard at 14 degrees camber and the tow hook at 127mm back from the nose cone edge (recommended 13 degrees and 128mm, so I might try that, its so close anyway.

The plane indicated active air very well, it was very easy to thermal, even though I never gave it much effort.

The plane seems very fast even unballasted, and maybe the factory supplied ballast will be plenty.

More later, but I really like the plane. It doesn't feel edgy at all, very predictable indeed.

R,
Target
Feb 27, 2011, 08:42 PM
Detail Freak
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Got to finally fly the Extasy on the slope today.

Flew her at Fermin in 10-12MPH SW, and man, all I can say is that the plane is named right!
It is smooth as silk, and reminded me of the Cyril they way it accelerated out of the turns, and how rock solid it was.
But, slowed down, she is also quite the pussycat.... I never felt really comfortable with the Cyril flying slowly, although part of it could have been my setup.

I used the same setup that JiTum recommends, but had the ailerons and elevator low-rated at 70% of the recommended throw, and added a tiny amount of rudder mix to the speed setting.
Was flying with 40% ballast aboard, so AUW @ 86 oz (2436g).

I think that I can take a pinch of nose weight out of it and drop a few more percent elevator.

Overall, I'm very happy with the model, and also think it's really a great looking plane.

R,
Target
Mar 15, 2011, 12:17 AM
Registered User
Hello Target, I picked up an Extasy from Bob today and I am ng to start build. This is my first RDS build and I noticed that there are two types of RDS rods. One pair is longer with more bend but not attached yet to base. I assume longer is for flaps and shorter for airelons. What did you use to attach wiper to shaft and how to line up bend for proper length? Thanks for help in advance, Robert.
Mar 15, 2011, 12:53 AM
Detail Freak
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Hi-
Mine were pre-bonded, but unbonded is really better.
If you watch the Baudis RDS videos on YouTube, it will give you a good idea how to do it.
Yours is slightly different, but the plan is the same:
Do a dry mock up first, have your radio setup or servo tester ready, and use some slow
epoxy or JB weld, working the flaps up and down. The wiper will find its happy place on its
own. Make sure if your servos are centered, that the flaps are down about 30*...
Dry runs are critical, and then you take the leap of faith!
Ailerons are much less critical with the shallow bend in the wiper.
G/L!

R,
Target
Mar 16, 2011, 12:38 AM
Registered User
Thanks Target, I appreciate the help, Robert.


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