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sir_clive's blog
Posted by sir_clive | Jul 27, 2014 @ 06:36 PM | 1,678 Views
Finally, I managed to find some time and to continue to work on my SBach 342.

In the meantime, I purchased a copy of DevWing - a very very nice program, although a bit unstable and "quirky" at moments. I'll be posting my wing definitions here as soon as they are finished - for the time being, I concentrate on the fuselage.

What I am pretty unsure about is whether I picked the wood (ply vs. balsa) and thickness correctly. The most will be balsa, at least that's the current plan, and it will be a 2mm balsa of a harder kind. 3 resp. 2mm ply will only be used for the motor mount, firewall and the front part of the fuselage. The turtledeck and the upper area of the fuselage front partition (say, "fore turtledeck" ) will be sheeted with 1 or 1.5mm balsa (please note, that the formers are not yet adjusted for the sheeting thickness!), and the entire fuselage will then be covered with covering film.

I hope to make a depron prototype tomorrow, just the "base" without any sheeting, to see whether all the parts fit correctly. I only have the 3mm depron, but it will be a good approximation for the 2mm parts I guess.

If somebody wants the CAD drawing, I'll be happy to provide it. A "letter / A4 paginated" PDF will be provided with the final plans.
Posted by sir_clive | May 03, 2014 @ 06:48 PM | 2,197 Views
Hi,

after a break, I'm back at building. And this time, I'm trying to produce my own plans!

I picked the gorgeous SBach-342. The model will be built from balsa, covered with film. Wing span will be approximately 1m. If you are interested in details, you might want to check this thread: http://www.rcgroups.com/forums/showthread.php?t=2159333 for further details.

I'm looking forward to reading your comments!
Posted by sir_clive | May 21, 2013 @ 10:09 AM | 3,118 Views
Finally, I had my first few flights today. The weather gods were nice to me - almost no wind, and here and there even a weak thermal. After the fifth flight, I had to pack up and go home because the motor started to sound "strangely" (maybe I should stop buying 7$ motors and hop up a class to 10-12$ a piece ).

Guppy flies really nicely! I was pretty much afraid of flying without ailerons (my first plane was a Floater Jet, and she did have ailerons), but it turned out it's quite easy. No wonder RETs are recommended for beginners. Didn't have to do much trimming either, she just flew as I built her.

Of all my planes, Guppy flies the most beautiful circles, almost without losing any height while doing so, stays in the air even when there's just the slightest of all thermals and all in all behaves just perfectly. I can't wait to try her out on a slope! For strong winds, she's surely too fragile, but when the conditions are "right", she might be the only plane in the air, while all those GFK ships are laying around in the grass and waiting for the wind to pick up.

I had 5 flights today, the on-board video is from the second flight. I had the feeling that the camera (808 #11) has reduced the gliding time quite a lot, without a camera, the plane just stayed up, with the camera, I had to use much more motor. On the other hand, maybe I was just lucky on my other flights to find some (weak) thermals, who knows.

Ultralajt, THANK YOU VERY MUCH for this gorgeous plane!

The video is just being uploaded, once it's done, you can find it here:
Guppy - First Flight (Aspern, 2013) (0 min 0 sec)

Posted by sir_clive | May 12, 2013 @ 04:57 AM | 5,905 Views
Hi,

I just finished my first balsa e-glider with built-up wings: the gorgeous GUPPY (see http://www.rcgroups.com/forums/showthread.php?t=539755), with a few minor modifications:

1. Made the fuse 6mm wider. No idea how you people manage to cram all the electronics into the original fuse!
2. Didn't make the fuse quite as nice and smooth as the original plans call for, out of the fear that covering it would be much harder. Turned out the fear was exaggerated, I think the next time, I'd make it nice and round, as shown on the plans.

The plane is wonderful, and I'm pretty happy with the result. I'm afraid it will take some time until the first test-flight: right now, the weather is not suitable and the next week-end, I'm on a trip, but I hope I'll manage to make at least a few trimming tosses.

The AUW is shy over 500g, with the 3s 1000mAh LIPO and a EMAX CF2822 motor with a 8x4.5 folding prop, which seems to be a bit of an over-kill. Maybe a 2s would also be suitable, I'll have to test it.

The covering film is from HobbyKing, turned out to be just GREAT, at a laughable fraction of the price some other, well-known films. As I said, my first covering job, and I had no problems at all.

I know, some parts could still use some care and finish. ...Continue Reading
Posted by sir_clive | May 12, 2013 @ 04:47 AM | 5,515 Views
Finally, a ground-based video of my OSG! The conditions were pretty bad (for soaring), but it was the first flight of the season, so I was enjoying it anyway.

First flight of the season 2013 - "Pimped OSG" on Stettner Berg (7 min 33 sec)

Posted by sir_clive | Jul 23, 2012 @ 06:16 PM | 4,029 Views
It's been 3 months and 1 week since my "looking for slope glider plans" post. Today, finally, my "Pimped OSG" is Almost Ready To Fly! Tomorrow the weather could just be good enough for a few tosses... fingers crossed that all the hard work actually pays out!

I was aiming at a slope glider somewhere between 1000 and 1500g of weight. As I put it on the scale today, I was surprised to see AUW 920g! Wow! For a 1.8m wing span, depron / balsa / plywood combination all covered in GFK, I was pretty happy with the result.

Unfortunately, the plane is SO tail heavy, that I had to stuck 140g of ballast into the nose to get the CG right. That brought me to 1060g - still nice, but I'm kind of disappointed I have to carry dead weight around.

Anyway, I'm proud of the result, over 1kg or not.

Tomorrow I just need to think of a way to secure the battery in the compartment, measure the motor current (it's an rctimer A2830/8 with a 9x4 folding prop on a 3S lipo), close that fuselage gap behind the TE of the wing, and I'm ready to go. I'll think of some nice covering for the wing servos later, if the plane proves to be airworthy. (Update: measured current was 19A, exactly as specified for the motor; and yes, she IS airworthy, you might want to check the first in-flight video here, it's being uploaded right now, if you are not reading this the moment I am writing it, it should already be there
"One Sheet Glider" pimped for the slope (5 min 4 sec)
)

...Continue Reading
Posted by sir_clive | Jun 24, 2012 @ 03:09 PM | 3,731 Views
Ok, here we go again... Wing #3! But this one is going to FLY! One way or another.

As it turned out, carbon spar, as I put it, is not an ideal way to enforce the wing. I was also way to sloppy while cutting, the blocks I cut the cores from were useless as a help for balsa sheeting.

Besides, I forgot to cut in a washout. Silly me, I *knew* it existed, but didn't think of it until Don asked me.

So - in the dumpster it goes. Well, not in the dumpster yet, have to salvage those carbon rods first.

Armed with the wire-cutting knowledge of the previous wings and this time taking VERY much time to get it as well as I possibly could, this is the result.

The cores still look rather bad near the TE, but I don't think one can actually do this job much better without better tools. Once covered with 1mm balsa, the TE ugliness disappears anyway.

The wing I was aiming at was S6063 (7%). What I ended with, and I *really* tried hard, is something resembling S6063, but not the S6063 itself, due to building inadequacies. GIven the similarity of profiles out there, I'm sure my wing now is a kind of a Frankenstein's Monster, flicked together from different profiles, scattered randomly all over the place.

At least it LOOKS nice and smooth, as far as I can tell; if I didn't know how important the utmost precision is when building a wing strictly to a given profile, I'd say it's perfect, except for the too thin TE, which doesn't look nice, but which is not so much thinner than the original...Continue Reading
Posted by sir_clive | May 20, 2012 @ 04:16 PM | 3,939 Views
Things are moving...

I ditched the previous wing (it took me some tears to rip that spar out of the EPS) and made a new one, this time painfully taking care that the wire of my hot-wire cutter is as straight as possible.

I'm very happy with the result - good that I got rid of the old wing!

In the mean time, the laminating epoxy is ordered (Hobby King sells stuff from BSI, it should be very good), 48g GFK too, now I can only wait. There is enough to do anyway, I won't be bored.

I also ordered the servos from Giant Cod (now Giant Shark): Tower Pro MG90, cheap ones getting pretty good reviews, they should be here until the end of the week.

I was contemplating for a long time whether to put that polyhedral or whether to go with a flat wing. Finally, for practical reasons (position of ailerons / flaperons), I opted for a flat wing. Unfortunately, my main spar was already cut to 90cm flat wing segment of a (planned) polyhedral wing and glued in, so now I have to think of a way to connect it to the outer panels. This hobby seems to be a never ending series of bad decisions...

One thing bothers me a bit: the S6063 profile thins out into virtually NOTHING. The TE is so thin, the hot wire cutter melded way into the EPS, destroying some last 2-3cm. Even if it didn't, the last approx. 2cm would be thinner than the two 1mm balsa skin sheets. I decided to cut off the trailing (and badly cut) EPS part, glue a 3mm depron sheet instead and sand it down as thin as...Continue Reading
Posted by sir_clive | May 13, 2012 @ 05:47 PM | 4,304 Views
Looking for a slope soarer, I was pointed to this wonderful and easy to build plane designed by Springer: http://www.rcgroups.com/forums/showthread.php?t=1138106

This plane was designed to be a gentle soarer with motor to help her gain height, and as a such she performs beautifully!

However, the requirements on a sloper are a bit different. What I learned from talking to Springer, davereap and Don Stackhouse from DJAerotech (check http://www.djaerotech.com/, there is a GREAT information section in "Ask J & D", these guys build beautiful planes), there are a few important design considerations to follow when building for a slope. THANK YOU VERY MUCH guys, I learned (and am still learning) a lot from you!

The most important points are:

1. Stress / Load:

- Hang gliding in stronger winds impose rather high loads on the structure. Build the plane accordingly.
- Landing without a motor also sometimes turns out to be a pretty hard one. Make sure the fuse will survive it.

2. Visibility. On the slope, you can get pretty far in search for thermals. Interestingly, it's mainly the chord length and not that much the wing span which aids the visibility of a plane!

3. Wing thickness. Don't go over 7-8% of the chord length, that will induce high drag. I experienced it myself, sloping in some 30-40km/h winds with my Floater Jet - where other planes (real, dedicated slopers) were penetrating the wind as if it were nothing, my poor FJ hovered in place...Continue Reading
Posted by sir_clive | Apr 15, 2012 @ 12:43 PM | 4,267 Views
Finally, my Pitts is Ready-To-Fly!

I rushed the final few steps a bit, I admit, but I'm very happy with the build.

She came out just shy of 700g (24.7 oz) AUW, with a 1300 3s LIPO - a real fatso compared to the 18-19oz advertised by Tony! Don't know how that happened, but I hope the good side of it will be that it will handle the wind better. Always look on the bright side of the life!

On the second thought, maybe the advertised weight was without LIPO, which accounts by itself for 122g (4.3 oz). That alone would bring me down far enough to a more acceptable weight.i

Servos: 4 x EMAX 9g (analog)
Motor: EMAX CF2215 (25A max, 1200kv, 59g)
ESC: HK BlueSeries, 30A / 3A BEC
Prop: "APC-like" 9x6E
Power (with the above setup): a bit over 20A / 250W - resulting in 166W per lb, which should be more than enough. She surely wanted to fly out of the hand during the static test, I had to hold her very firmly.

I had some troubles trimming the connector wires between the lower and the upper wing to the correct size. At the end, I resorted to a Z-bend, which made the things not exactly simple, but at least possible.

Looking forward to a maiden flight next weekend!

BTW, I really don't understand why the corresponding thread is not 1000+ pages long - this is a very nice plane and only a moderately complex build, what more can one expect?...Continue Reading
Posted by sir_clive | Mar 06, 2012 @ 05:02 PM | 4,352 Views
After a short break (and a middle depression due to the premature death of my BluBaby 42" - may she rest in pieces until I find some time to repair her), I managed to continue with my Pitts.

I must say, I like that kfm2 airfoil really much! The LE looks just beautifull, it's easy to build, and many people say it flies very nice. But enough words - see for yourself!

It's still (for a large part) a dry-fit, I need the paint job done before all the glueing begins. Oh, yes, and the electronics, of course. But it already looks like a plane! And a beautiful one!
Posted by sir_clive | Feb 26, 2012 @ 08:34 AM | 4,440 Views
The farther I come, the more I love this plane! Great design, not too hard to build (even for a beginner builder like I am), and it already looks as if wanted to take off and roar the skies.

Here the most recent photos.

As it seems, if one builds exactly according to the plans, the rear section doesn't quite work. I looked for how other people solved the problem - I found a few pictures showing that others had the same issue, but didn't find any photos detailed enough to help me out.

This is how I solved it....Continue Reading
Posted by sir_clive | Feb 22, 2012 @ 04:40 PM | 5,075 Views
Here I am, starting with a new plane: the wonderful Pitts Challenger, designed and given to us by Tony 65x55. You can find the thread with plans and a lot of information on http://www.rcgroups.com/forums/showthread.php?t=774178

I started out with the Monobloc. This time I opted not to go EPS, but to try out that blue foam: Roofmate. Don't know whether it's the same one other US-based guys are using for e.g. BluBaby, but I think it's at least pretty close.

I also DXF-ized the plans (originally only available as PDF), so if you need it, here it is:

pitts-vectorized.zip

Here the first pictures, more to follow!
Posted by sir_clive | Feb 14, 2012 @ 03:49 PM | 4,614 Views
Finally, the second part of my blog.

Except for, maybe, covering the wings with packing tape and for placing a few decals, the Baby is finished. And she looks GREAT!

Of course, there are some points that I would do differently now, but that's what it's all about: learning.

Here a few of the most important experiences I made:
  • Always TAKE YOUR TIME. Measure 3 times, cut only once. Don't hurry things. There is nothing worse than spoiling a great job with a small but irreversible mistake done because one was not patient enough
  • Watch out while painting your plane. As you can see, I managed to do my paint job less than perfect, although I took quite some time to mask the wing. See point one.
  • Always use your glue as it was designed to! I had to throw away my first fuse (presented in the first part of this blog) and to completely redo it because I applied UHU Por badly. I just poured it generously over the EPS and connected the parts before waiting for the glue to dry up a bit. The result: at first, the connection seemed OK, but than the glue ate its' way through the EPS and the bond was destroyed!
  • Watch out for your cats (if you have any) not to develop too much of an interest in your plane. Luckily, I cought my cats chowing on the scrap EPS parts laying around, but it also could have been the wing!
  • Clark Y wing inclination recommendation: 3 deg positive.
  • Take your time when thinking about the placement of push rods. Also make sure the push rod is not fixed too near the
...Continue Reading
Posted by sir_clive | Jan 16, 2012 @ 03:25 PM | 5,016 Views
As much as I love my AXN Floater Jet, I felt the urge for getting *more* involved in this hobby - by building my own plane.

After some reading on the principles of airplane design, I decided to take the easier route and to start out with a ready-made plans. A short research revealed this wonderful "BluBaby" plane, designed by Tony65x55. Basically, I stuck with the plans, except for the wing, which I wanted to look more like a "real" one.

Being too coward to make a dihedral, I opted for a flat wing with winglets on it.

The materials I use are simple EPS (5cm block for the ribs, 1cm sheet for the fuse), and 3 resp. 6mm depron for wing coating, stabilizer, rudder and winglets.

The plane already starts to look like a plane, so I decided to share some pics and some experience with you....Continue Reading
Posted by sir_clive | Nov 13, 2011 @ 04:11 PM | 6,302 Views
This is a mini blog of my Wing Retention System for the AXN Floater Jet / Clouds Fly.

I read a lot suggestions about the retention system, but I somehow didn't like any of them. So I set out to make an Ultimate Wing Retention System! I think I did quite well... those wings ain't going ANYWHERE I don't want them to go!

Basically, I re-enforced the wings with pieces of wood, drilled a hole, put a carbon rod through it, stick a piece of steel wire, bent it, took another piece of wire, bent it into a clamp, and that's it.

Here the details. Just remember to work as precise as you can, and the result will be really nice to look at AND it will do the job perfectly....Continue Reading