TopModel Samsara 3.2 meter glider, build thread on Aloft's Forum.

[purview]

i like to add that there are specific wing dihedral types where it is extremely tricky to sort out clean control inputs

it is also an issue that a lightweight wing with low wing loading reacts different, so here with 3.2m and your flying weight you must "program" your solution to avoid her to pitch and yaw and maneuovers independently

 

[Konrad]

That is the crux of the issue. Most control inputs effect more than one axis.
Just to be clear, other than the adverse yaw the Samsara really is well balanced in her control response.

What I'm trying to trim for are the minute but unintended pitch change. As a result of flap differential a change in aileron can cause the tail to pitch up, looking just like an indication of light lift. (AKA stick lift ?)


All the best,
Konrad

 

[Konrad]

Wow, I’m liking the Samsara more and more. This is the first time I’ve flown her since her refitting. Her weight is now down to 1.940Kg. Most of this loss is a change from the 330g 4 cell EF-1 battery to the ubiquitous 2200 4 cell at 260g battery. I also modified the programing a little bit. One of the ways I measure the performance of a glider is how well she performs against the professionals (read hawks and vultures). After all they make their living by soaring. Today the Samsara in her current trim is more efficient than the Turkey Vulture. I say this as 4 times I was working low level lift that caught the attention of the Turkey Vultures. In short order I had over a dozen birds overhead coring the thermal. At around 300 to 400 feet I had climbed above these birds and out climbed them past 900 feet. At about 1100 feet the vultures left the thermal looking for food. I switched to speed mode and followed them for .5 a kilometer. At 1000 feet, it looked like the Samsara was faster and not loosing as much height as the vultures as we covered ground.

Now while riding the thermal I noticed that the Samsara was rotating in the thermal about 1.5 times faster than the vultures. I assume this was allowing the airfoil used in the Samsara to generate lift. If I slowed down I noticed my climb rate looked slower.

The one dark spot in today's flying was that the X0-8 plus gear train is NOT up to the task as a flap servo for the Samsara. I stripped the gears twice as I failed to raise the flaps fast enough while landing. I think I’ll have to make a set of override linkages as I can’t afford $10 for every landing.

If anybody is following along you are aware that I had some concerns about flutter. Well today I flew as fast as I wanted. I performed dives, rolls, stall turns, loops, anything I could think of (no inverted work) and never got the wing or any other part of the plane to flutter. Heck, I can with the 17x9 prop fly straight and level at full throttle and not get the ship to flutter. I don't know why anyone would want to fly a glider at full power straight and level, but at the pitch speed from the 9inch pitch prop the Samsara did not flutter.

I can’t understand why the Samsara is selling for such a discount ($140 less) compared to the TopModels Element. I think that “D" tube wing really is showing its performance advantage when flown at speed. The “D" tube allows a much truer airfoil compared to the fully ribbed wing of say the Element. Each sag of the Element's covering between the ribs allows the air to develop a small span-wise vortex between the ribs. This means drag and lost lift.

With the battery change I had to re-trim all the flight modes for about 4 clicks more down. I’ll have to check where the CofG is as of now. I will say that the dive test indicated that the Samsara is very close to neutral trim. Very little pull up as the speed increased. (I actually was able to dive her for a good distance).

I’m really happy I stuck with trimming the Samsara after the initial control and flutter problems. I can’t for the life of me understand why TopModels has the recommended CofG called out at 75mm. I’m sure the 75mm point is the cause of more control issues than any other issue with the model. Being nose heavy meant that the model had to be flown far too fast to keep the nose up (read flirt with flutter)! With the CofG now aft of 95mm the Samsara is a sweet handling ship. The only complaint I now have with the model is the roll rate is rather slow. It takes me 4 to 5 seconds to roll the Samsara! The roll rate seems ok until one gets past about 115° point then you need to add a lot of rudder to get her to come around. I think this has to do with the large aileron differential I need to use for “normal” flying. If anybody has any insight as to how to get more roll authority I’d welcome the input.

All the best,
Konrad

 

[Konrad]

After learning that the gear train for the OX-8 really isn't suitable for the flaps on a 3.2 meter ship even with the output support frames. (I kind of already knew that). I decided that a set of override springs might absorb some of the shock loads should the flaps hit anything while landing. Normally I don't like override spring because at speed they can cause flutter. But as the Samsara really can't go fast (she is fast enough) this shouldn't be a problem.

I'm ashamed to admit it but I haven't wound a set of spring in close to 30 years, and it shows!

 

[Wayne]

Interesting.. We sort of did something similar for combat planes.

 

[Konrad]

Well I'm happy to report that the new override spring pushrods worked well. I made over 1/2 a dozen landings today and still have the same gear sets I had when I started flying earlier in the morning.

I don't know what the issue was with thermals today. While it was hot I couldn't catch one. And what lift I did find was weak. I know it wasn't just me as there was very little avian activity. All the hawks and vultures stayed in the trees. Some came out to see what I was doing and quickly realized I didn't know what I was doing, so they went back into the trees hoping that the thermals would grow later in the afternoon.

 

[Konrad]

Wow I just saw that Aloft has the Samsara on sale!!
Get it while you can! I see only one available! It is well worth the price just for the 1.8 meter fuselage.

TopModel Samsara

The Samsara is an excellent thermal ship that features a sleek and long carbon reinforced glass fuselage that is light yet strong with ample room for gear. A traditional built up, 3 piece balsa wing with D-tube does the heavy lifting. The full flying elev

alofthobbies.com

The override spring push rods worked so well, I thought I'd draw up in detail what they are and how they work.

All the best,
Konrad

P.S.
I wound the spring from 0.5mm music wire. Remember this is for the XO-8 servo. Larger geartrain servos might best be served with a spring made of a larger diameter wire.

 

[Konrad]

Trying to join the video revolution. Here is a quick video showing some of the vertical performance I'm getting with my Samsara. This was actually the worst day I had flying the Samsara as the winds were a bit high (12 to 16mph).

 

[Doc James Hammond]

Cool...mine is all done but not flown.

Doc.

 

[Konrad]

Well, get her in the air! ?

I will say she is my favorite flat land sailplane, and has been for about a year now. That 1.8 meter long fuse really does let you know what the air is doing around her.

All the best,
Konrad

 

[Hank GB Z]

Also is that your YouTube Chanel?


Hank

 

[Konrad]

Yes,
I was fighting the wind and a mis-rigged flap. On an earlier landing the override springs sprung. I had overloaded the spring so that the two parts of the push rod had seperated and didn't slide back together. I should always check the full motion of the controls after every landing!

Not sure you can hear it, but it looks like I push into the horizontal with the motor running. I don't, what we are noticing is the delay in the speed of sound. The ship is in the horizontal and in glide trim when we hear the motor stop and prop fold.

All the best,
Konrad

 

[Kestrel]

I was wondering if Konrad or someone else might be able to explain what's causing the fluttering issues. Konrad mentioned that he used harder/heavier sheeting in the repair, Is the balsa sheeting that they used soft, low grade or too thin? Because otherwise I'm not understanding why flutter would happen since the wing is sheeted and has a D box. Also, I was under the impression that cap strips on ribs are meant to increase torsional rigidity along with maintaining a more accurate profile which should further negate any issue with flutter. Is it the "heavy" solid ailerons that are causing this? Is the flutter induced by the ailerons and then causing the rest of the wing to flutter? Does it have to do with using servos that are underpowered? Are those KST X08H+s up to the task of moving such a large surface under load? They look awfully small even if they put out ~60oz of torque. Is there slop in the geartrain? The way the wing is designed it seems counter logical that this plane would have flutter issues. The Element, Astra, Avia, Albatros, etc... don't have a sheeted leading edge so I would expect more of an issue with flutter with these designs than the Samsara.

 

[Konrad]

All aircraft have a do not exceed velocity.

This wing as designed is NOT an issue. The flutter I got and other have seen is in trying to fly too fast. The only quality hit I'd give the wing is that it is made from what looks like a hot glue adhesive. My repair used mainly Titebond the original formulation. This was done because I could heat activate the glue when ironing on the Leading edge sheeting. A benefit is that it is a much stiffer glue than that used by Topmodel. (Ok, I see it was Elmer's carpenter glue, much the same stuff).

From a dynamics perspective any weight aft of the main torsional member (spar) will offer positive feed back to the flutter response. Weight ahead of the spar will dampen the flutter response. (Actually the mass need to be centered around the axis of rotation. Putting mass in the LE does bring the mean mass and the axis of rotation closer, lower the flutter feedback )

Cap strips do nothing for torsional stiffness. They offer lateral support of the rib. But if the covering is used properly the film will offer more than enough lateral support (Keep the rib from buckling span-wise).

The Drela airfoil used the LE sheeting rather far aft to control the airfoil shape in the critical areas. The aft part of the airfoil is not so critical, so we can loose some fidelity to the design with an open light structure. Cap strips are counter productive to this idea. That is they add next to nothing as far as holding the airfoil shape but add mass aft.

So, I'd think it would be wise of Topmodel to stop cap stripping the rear of the rib. It adds nothing to maintaining the airfoil and it adds weight aft of the spar. Use the labor saving from the omission of the cap strips to build a multi piece (hollow) aileron and flap. Again to minimize the positive feed back we see in the flutter mode.

A function of camber (lift) is that it puts a torsional load on the structure. When I want to go fast I put the TE in reflex this removes most of the camber putting a lot less torsional load on the wing as I gain speed looking for lift.

The control surfaces are not going into flutter (mine never have). The X08 are more than enough servo as far as torque. I've flown this size and speed model on half as much torque! Yes one needs to have good hinges and linkage. I strongly recommend the servo trays with external servo output support. The only issue with the X08 is that the gears are small and don't take kindly to impacts. That is why I'm now using over-ride springs on my flap servos. I'm also using the X08+ on the flaps incase I do something stupid and deploy the flaps in an over speed condition.

The two or three outing that I've had flutter was because I was going too fast and had the ship mis-rigged. You might have notice that I dropped way down on the pitch speed. I think I dropped from a 13" to a 9" pitch on the prop. In the videos I think you can see the climb is more than one would want and in the other video the horizontal speed looks great, before I rotate into the climb. Note that was into a 12mph head wind! my airspeed is what you see plus about 12 mph.

The other design you mention have far too heavy a spar structure with those carbon tubes close to the center of the wing thickness. They need that heavy carbon tube to stay together. The Samsara has a little bit of carbon just under the sheeting. This is to aid in the bending moment with those nice long thin wings.

I love how the Samsara flies! But it is not a beginners ship! That is you can't be stupid in how you fly her. But if you respect her, she will reward you with hours of great flying.

That 1.8 meter fuselage is fantastic at telling you what the air around her is doing! Set the CofG at 95mm or so, and sit back and enjoy the conversation with her.

Did I mis anything?

All the best,
Konrad

 

[Kestrel]

I think you covered most of it, however...

I'm somewhat confused now by what you wrote in some of your other posts. You had mentioned that "Flutter was always near at hand, you could not power up unless the nose was pointed up." and "...the wing tips just started to flutter having only covered about 50 feet. This is a real problem with this model." The first instance appears to be a power/speed related issue, the second it's less clear, for testing CG 4 degrees seems pretty shallow to me so at 50 feet that doesn't sound like it would be flying that fast. "The issue as I see it is that the wing goes into flutter at a bit under twice the stall speed." this doesn't sound very fast to me. You also wrote, "The big question was did the wings go into flutter? And the answer is no!!!." I'm not sure what to make of this when again you wrote, "The issue as I see it is that the wing goes into flutter at a bit under twice the stall speed." I'm assuming that when you did the CG test you weren't running the motor, so then what was the source for flutter when flying 4 degrees in a dive for 50 feet? This makes it sound like the aircraft has a very narrow operating speed range. Then after the repair you wrote, "Well today I flew as fast as I wanted. I performed dives, rolls, stall turns, loops, anything I could think of (no inverted work) and never got the wing or any other part of the plane to flutter. Heck, I can with the 17x9 prop fly straight and level at full throttle and not get the ship to flutter." So was it the glue, heavier sheeting, CG change, prop pitch change, all of the above or something else that made the difference? If I'm not mistaken, the cap strips were still on the wing after you repaired it so the weight behind the spar was still there and the plane was even heavier than before. It's great that you were able to get it to where it doesn't flutter but maybe I'm missing something here because it's not clear what the solution was. Before the accident you were able to induce flutter with and without power but now it's gone, why? Somehow glue alone doesn't seem to be the answer. Is the glue they used that elastic? I've never used hot glue on any plane that I've built, I would have thought Topmodel would know better. I hope you can understand my confusion.

If cap strips are useless to our models, then you're correct we shouldn't use them and so I don't understand why designers are adding them. If I'm not mistaken, the decrease in sag between the ribs aft of the spar wouldn't be an issue as that's past the boundary layer separation region so there would be no benefit with that and the added benefit of surface adhesion for the covering isn't worth the extra weight... so I don't get it. Don't any of these people know about this? All I remember is that, back in the day of building Wanders, Gnomes, etc..., it was really easy to twist the wings to add washout when there weren't any cap strips. The wings with cap strips were harder to twist but I guess that has nothing to do with torsional rigidity. I even recall some designs placing the ribs in an X pattern but again this wouldn't seem to make any difference for the same reason, since it's behind the spar.

Also, it wasn't clear what the issue was concerning your lack of directional control causing the crash, "Much to my horror I had no directional control...". Was this due to a "brown out", flutter issue, did a servo fail, etc...? It's obvious that you were having programming issues sorting out differential and roll control but again it's not clear exactly why that would be. If it was flying so fast as to induce flutter, one would think that you would have roll control until the flutter occurred. Again this sounds counter intuitive to me.

"Being nose heavy meant that the model had to be flown far too fast to keep the nose up (read flirt with flutter)!" How does this work? I thought that a nose heavy aircraft has a tendency to drop the nose, therefore you would pull up, as in slow down, to keep the nose up. How does one fly too fast while keeping the nose up? Generally when you drop the nose you pick up speed so I'm trying to visualize this but I'm not getting it.

Again, thanks for your time in sharing your experiences with us and taking the time to answer my questions, I plan on purchasing a Samsara in the near future and so I don't see any point in "reinventing the wheel" if someone else has worked out the bugs.

 

[Konrad]

Ok, I think you are confusing the maiden test flight with the subsequent flights and their rigging.

The maiden was poorly set up. With the improper balance point in the manual 75mm for the CofG. This meant that to keep the nose up the minimum speed (stall speed/trim speed) was a lot higher than if the CofG was placed at 92mm to 95mm. This is because I need airspeed over the stabilizer to keep the nose level (up). If I allowed the model to fly too slowly the nose would drop as the model tried to reach steady state (trim state).

Note; I reference my top speed as a function of stall speed. So with the CofG aft if the stall speed dropped to half and the flutter speed stayed the same. This means that my original statement, that I can now go 4 times as fast as the stall speed is correct. I did not say I could now go 4 times faster.

As originally rigged the model did have a very narrow speed range, stall and flutter speed are very close. I blame much of this to improper data in the manual. Mainly having the CofG set at 75mm, far too far nose heavy!

During the test flights I had far too much pitch speed from the prop. With the 13" pitch and the power I get from the 4 cell battery and Hacker motor it was easy to drive the plane into flutter from level flight, heck even in a moderate climb I could get the wings to flutter. In the vertical with the wings at a lower Cl (less pitching moment putting a torsional load on the wings) I could go to full power and NOT flutter the wings. To harness the power of my motor set up I dropped the pitch speed using a 9" prop to keep the level velocity below the flutter point. the resulting climb would have been horrible if I kept with the 15" diameter prop. To regain the power lost by dropping to a 9" pitch I went with a 17" diameter prop. Both props are driving the plane with close to 600 watts of power.

You are correct that flutter is highly dependent of air speed. The do not exceed velocity is still close to the same speed before and after the repair. (This is with the TE in profile). What has changed from the maiden is the stall speed has dropped a lot. Not only is the CofG placed a lot close to the neutral point lowering the trim speed. I've also been able to loose a lot of weight not needing the nose weight in the form of oversized batteries to get to manual CofG of 75mm. My Samsara is well below 2Kg in mass.

I also had the flaps mis-programed as ailerons. This is why I had no directional control from the wings in all but "crow" during the maiden flights. I had the flaps inducing a lot of adverse yaw being that they were rigged to give more down than up when acting as ailerons. Subsequent reprograming of the flap to aileron mix solved this control issue. The flaps now move an equal amount up and down as ailerons.(Maybe a bit more up than down). I can now roll the Samsara.

There has also been some work with the TE programing. With the TE in reflex there is a lot less torsional load on the wing. This allows for a much higher top speed before the wing goes into flutter.

I never notice the old gas bags being more difficult to twist with the addition of cap strips. I still don't see how adding cap strips adds any rigidity to the wing unless the ribs were flexing laterally. So an uncovered wing where the ribs are flexing it would appear to be stiffer in torsion with the addition of cap strips. But if you tested a covered wing with the covering attached to the uncapped ribs you are more likely to find the covered uncapped wing to be just as stiff as a covered wing with rear cap strips on the ribs. The geodesic structures (X) was for torsional stiffness it offers nothing to the maintaining of the profile shape.

Cap strips were used in the old days to smooth out the ribs from the die crush edges. With today's laser cut parts there is no need or rational to use cap strips on ribs.

My repaired wing was close to the same weight as it was before the maiden. I was hoping that I would be using heaver (stiffer) wood than what Topmodel used. But this wasn't the case. My sheeting was close to the same as Top model's wood. The weight gain was with the addition of carbon and glass to repair the fuselage. I did save some weight in the wing by replacing the solid glass wing joiner with hollow carbon joiners.

There are only two or three issues with the Samsara. The biggest is the manual where it states to place the CofG at 75mm. The rest are minor and can be dealt with during the build. I point out all the gotchas' I found in this thread.

To be clear I can get the Samsara and just about any other airplane into flutter! The question we should be asking Is how far above the stall speed does flutter occur?

Based on your questions I have to ask what is your skill level with high performance sailplanes? Knowing where you are coming from might help me in answering your questions.

All the best,
Konrad

 

[Konrad]

That post was getting a bit long.

The "Hot Glue” might be a bit flexible, but my main complaint with it is that it is heavy. This is particularly true when it is used a bit too liberally when building the wings. There was like 8 grams of weight I was able to pick off of my wings when I recovered the wings.

You can see that in other Topmodel designs they know how worthless the cap strips are.

Topmodel CZ - Element 3,5m (uncovered kit - ready to cover)

TOPMODEL CZ, Production of airplane models first-class quality.

www.topmodelcz.cz

To show that the wing structure is fault tolerant the wing in those video was flown with a broken trailing edge spar. Earlier I was messing around and clipped a wing tip, this broke the trailing edge spar in compression. You can see this in the TE sheeting. (Note; Anytime you find a new wrinkle in the covering try to find out why).

Based on the fact that with my 9” prop not driving the wing into flutter I assume that my flutter speed is somewhere above 40mph. This is more than fast enough for any rational flying with a thermal duration ship (gas bag).

The Samsara is NOT a “Hot Liner”! She might not even be a good all around sailplane. What she is is a good thermal hunter. She is great at covering ground and signaling when she has found lift. She also cores the thermal well when riding that lift.

If looking for a more tolerant general propose 3 meter sailplane the Thermik Dream is a good all around sailplane with a much higher top speed.

Top Model Thermik Dream

Top Model, Thermik Dream, 3 meters of electric fun!

alofthobbies.com

All the best,
Konrad

 

[Konrad]

Just to clarify things and try to answer some questions (responses in RED)

I think you covered most of it, however...

I'm somewhat confused now by what you wrote in some of your other posts. You had mentioned that "Flutter was always near at hand, you could not power up unless the nose was pointed up." and "...the wing tips just started to flutter having only covered about 50 feet. This is a real problem with this model." The first instance appears to be a power/speed related issue, the second it's less clear, for testing CG 4 degrees seems pretty shallow to me so at 50 feet that doesn't sound like it would be flying that fast. (Flutter is a function of speed not power) "The issue as I see it is that the wing goes into flutter at a bit under twice the stall speed." this doesn't sound very fast to me. (With the way forward CofG it was a lot faster than one would think!) You also wrote, "The big question was did the wings go into flutter? And the answer is no!!!." I'm not sure what to make of this when again you wrote, "The issue as I see it is that the wing goes into flutter at a bit under twice the stall speed." I'm assuming that when you did the CG test you weren't running the motor, so then what was the source for flutter when flying 4 degrees in a dive for 50 feet? (Yep, Motor off. Too much air speed was the source of the flutter) This makes it sound like the aircraft has a very narrow operating speed range. (If setup per the manual it does) Then after the repair you wrote, "Well today I flew as fast as I wanted. I performed dives, rolls, stall turns, loops, anything I could think of (no inverted work) and never got the wing or any other part of the plane to flutter. Heck, I can with the 17x9 prop fly straight and level at full throttle and not get the ship to flutter." So was it the glue, heavier sheeting, CG change, prop pitch change, all of the above or something else that made the difference? (The CofG change was the key. And for safety I dropped the pitch from 13" to 9" should I do something stupid and add power in level flight.)If I'm not mistaken, the cap strips were still on the wing after you repaired it so the weight behind the spar was still there and the plane was even heavier than before. (Yes, the ribs were cut for cap strips so I left them when I recovered the wings. You will note that as I made further changes from the maiden setup I've been removing weight aft of the spar with changes to the size of the servos in the wing) It's great that you were able to get it to where it doesn't flutter but maybe I'm missing something here because it's not clear what the solution was. (She will flutter! All ships will flutter! It is now that she won't flutter in a reasonable flight envelope) Before the accident you were able to induce flutter with and without power but now it's gone, why? (The flutter speed has gone up both as measured by a multiple of the stall speed and in actual velocity because of trim changes and the reduction of weight) Somehow glue alone doesn't seem to be the answer. Is the glue they used that elastic? ( Maybe, I've never liked hot glue used as a structural glue) I've never used hot glue on any plane that I've built, I would have thought Topmodel would know better. (It is a production issue. Topmodels wants to get the structure out of the fixtures as fast as possible) I hope you can understand my confusion. (I hope I'm clearing up somethings)

If cap strips are useless to our models, then you're correct we shouldn't use them and so I don't understand why designers are adding them. If I'm not mistaken, the decrease in sag between the ribs aft of the spar wouldn't be an issue as that's past the boundary layer separation region so there would be no benefit with that and the added benefit of surface adhesion for the covering isn't worth the extra weight... so I don't get it. Don't any of these people know about this? (All I can say is I think this is a design habit) All I remember is that, back in the day of building Wanders, Gnomes, etc..., it was really easy to twist the wings to add washout when there weren't any cap strips. The wings with cap strips were harder to twist but I guess that has nothing to do with torsional rigidity. (This is not my experience) I even recall some designs placing the ribs in an X pattern but again this wouldn't seem to make any difference for the same reason, since it's behind the spar. (Not to profile fidelity, but it adds a lot of torsional stiffness)

Also, it wasn't clear what the issue was concerning your lack of directional control causing the crash, "Much to my horror I had no directional control...". Was this due to a "brown out", flutter issue, did a servo fail, etc...? It's obvious that you were having programming issues sorting out differential and roll control but again it's not clear exactly why that would be. (It was adverse yaw from improperly set up flaps/ailerons) If it was flying so fast as to induce flutter, one would think that you would have roll control until the flutter occurred. Again this sounds counter intuitive to me. (Can't say as I follow what you are thinking here)

"Being nose heavy meant that the model had to be flown far too fast to keep the nose up (read flirt with flutter)!" How does this work? I thought that a nose heavy aircraft has a tendency to drop the nose, therefore you would pull up, as in slow down, to keep the nose up. (To keep the nose up for level flight one needs more speed if nose heavy) How does one fly too fast while keeping the nose up? (By having too much nose weight keeping the nose down) Generally when you drop the nose you pick up speed so I'm trying to visualize this but I'm not getting it. (I think you are confusing trim state with flying technique)

Again, thanks for your time in sharing your experiences with us and taking the time to answer my questions, I plan on purchasing a Samsara in the near future and so I don't see any point in "reinventing the wheel" if someone else has worked out the bugs. (The only real "BUG" is in the manual! set the CofG at 92mm and go from there)

All the best,
Konrad

 

[Konrad]

I’ve been reading where the Top Model Samsara has been getting a lot of bad press with claims that she goes into flutter far too early. I fear that my maiden flight might be contributing to these reports. Now it is true that all aircraft do have a VNE (Velocity to Never Exceed) and one can fly the Samsara into flutter. The flutter speed is rather high as measured as a function of stall speed. My Samsara was driven into flutter on its maiden by the poor documentation in the manual! There isn’t anything inherently wrong with the structure of the model. Heck in both video my Samsara has a broken trailing edge spar! You might notice that there is no sign of flutter doing the loops and roll!

If you set the center of gravity at around 95mm it is easy to perform aerobatics and stay out of flutter! The issue with the Samsara is in the documentation NOT the airframe itself! Do NOT set the CofG at 75mm it will be far too nose heavy making it hard to fly properly.

Today I was flying with a very low fog ceiling. This meant that I was spending most of my time sport flying the Samsara rather than hunting for thermals.

Please note that the roll is usually a bit crisper but as I was climbing, the airspeed was dropping resulting in the roll rate slowing down towards the end. In level flight the roll rate is pretty constant, much like we see coming out of the loop.

All the best,
Konrad

 

[Konrad]

Is there a way to upload video to U-Tube maintaining the high resolution of the original video?