[samste]

Yes Wayne you Flew the Pulse well, Well Done.

I managed to get in about 4 Flights with the Gee Bee and even did a outside Knife edge upon Steve L Request which i manage first Time the second time i had dumb thumbs but recovered quickly without mishap.

Normal Knife Edges I'm was Use Too , So it was good to Try something Different, Thanks Steve L.

Steve

Love the Gee Bee

   

[secant0give]

Well done Wayne !!
I'm sorry I wasn't there to see it !!

I'm looking forward too seeing it in the air soon

How did you find the pulse to fly ??

The Gee Bee is a beautie Steve !!

[Flying fisho]

How did you find the pulse to fly ??
The Gee Bee is a beautie Steve !!

Q. "How did you find the pulse to fly ??"
A. Found it in the car when I arrived
Seriously, the power train is more than ample for take off and I will experiment with take-off throttle & props to minimise torque roll. Programmed heaps of expo & toned down rates and was very stable in air at all speeds, still stable on medium rates & will try full rates to be more aerobatic in the future when I am more used to it's performance. Quite slippery in the air and I am still getting used to hot landings, to quote Gazz "A nice head wind can be a blessing... as long as it is coming from the right direction... helps slow down the quick ones." It's 3rd flight found me being gratefull for stronger winds for the first time, this little beauty will be my strong wind plane in future as it suffered so little in the turbulence over the trees & made landings easier. 1st flight I clipped a tree branch (with the landing gear) beside driveway into field L-R approach (no flight disruption or damage) & 2nd flight overshot runway R-L as battery level prevented 3rd aborted landing. Doesn't appear to tipstall and will experiment with slower turns up high to test that theory. Overall VERY happy with plane.

"The Gee Bee is a beautie Steve !!" Agree wholeheartedly with you Jason and I think Samste does as well. Handled by one of our masters, the plane is as impressive in the air as it is on the ground.

[gbanger]

Congrats on the successful flights Wayne.
Now you're in trouble mate, you have contracted the dreaded speed bug... and I'm happy to report that the only cure is... MORE SPEED !!!

[wingtipper]

panther maiden flight .
ok . the manual says C of G 70MM from leading edge , someone has crossed out that print and written in hand writing 75 mm . which would make it more tail heavy .
so i did some reading and found that a 4000mah 3s 40c battery is good for correct balance , which it did give it a CG of 75mm .
" THE MAIDEN " hand launched well , ( thanks Claudio ) . but went vertical , i had to put heaps of down trim on it , once trimmed it flew beaut right way up and inverted . after landing looking at the trim it was 20 degrees down .
i then put 28grams of lead on the front flew it again and needed the same amount of down trim to fly it level .
I'M kindve stumped here . it flys great CG IS AT 70MM . but ELEVON needs 20 degrees down .
GOT ME STUMPED .......

[Skidz]

Is the fuselage creating lift forward of CoG?

[smuzz]

... or is there an issue with the thrust-line? Or is there a negative angle of incidence on the tailplane (my money is on the latter!).

[wingtipper]

buggared if i know . look all ok . so i have added another 30 grams of lead to the nose . that makes a 4000mah battery pack + 60 grams of nose lead .
The CG IS NOW 65 MM From leading edge , batteries are on charge , tomorrow shes going up again .
book says 70mm pen in book says 75 mm . mine is now 65mm .
some people are flying these with 5000mah batteries , so tomorrow if the same charactoristics appear , then i'd say your right SMUZZ .
It ripped through the air quite nice on 3s and was very stable to fly . once the trimming was right , 20 degrees down , it flew inverted nicely and low speed and high speed changed nothing in lift .
anyhow 60grams of lead up front now , i'll have to see the results tomorrow .

Glued the wings together and the elevon a few drops to stop it moving on the corsair . MAIDEN tomorrow on that on the one 2650mah 4s battery , before i decide on battery selection for that also .

any INSIDE INFO on the PANTHER appreciated . CHEERS !!

[secant0give]

... or is there an issue with the thrust-line? Or is there a negative angle of incidence on the tailplane (my money is on the latter!).

I tend to agree with Steve, I reckon it's the incidence that's wrong.
If it passes the C of G test.
Wich is as follows :

first trim it out to fly straight and level right side up at 60-75% throttle, Then once satisfied with that, half roll over to inverted and take note of how much down elevator you need to hold her level in pitch.

If you need heaps like 1/2 down elevator stick then it's Way nose heavy
If you need just a little, say less than 1/4 stick then it's probably all right for sports flying and will likely pull out of a verticle dive automaitcaly. (positivly stable in pitch)
If it needs no stick at all to hold it level inverted then it's neutral. Good for 3D and slow areobatics.
If it needs up elevator to fly level then it's tail heavy and you'll notice that it's not so nice to fly, especially at any speed !!

If it passes the C of G test and flies nicely inverted with just a little down elevator and still has a lot of down trim on it then almost certainly its the insodence.

You might be able to fix it by packing up the wing to bring it more into the same plane as the horosontal stab or you may have to change the angle of the tailplane.

[secant0give]

I test flew the Vipers on Friday. The weather was perfect being cool and still, tho’ the sky was a little grey there was no trouble with visibility. The red white and blue colour scheme turned out to be highly visible in the air.

I’d mixed a batch of 4:1 fuel, just methanol and caster as this is what they use in competition. The engines had been run in on this mix and both operated very reliably when they were bolted to the bench. I don’t think I’ve ever had a glow engine run as nicely as the two Thunder Tiger 46s I brought for these vipers.

When I read about how people set up their pylon models I found most would say that you want very slow rates to fly around a pylon course. You don’t want any twitchiness just a nice and smooth response and you want to be able to use the full throw of the sticks as well. For this reason a lot of people use dual rates, High rates for take off and landing and low speed flying and low rates for when the throttle is open wide and the plane is going fast.

It was with more than a little trepidation that I stood behind the first of the two vipers with high rates selected. We were on the Pylon course and taking off across the strip width ways, there’s only a fairly short distance with which to build speed and get airborne.
This was it, Ian was holding her by the tail with the engine running at about ½ throttle. Before I had a chance to wind it up to full peg he let her go. I pushed the throttle wide open as it had almost covered half the width of the strip. Magically she roared into the air and accelerated rapidly away.

Now Vipers don’t have very big control surfaces and they are set up with relatively small throws even when on high rates. Turnigy 9X Radios have very fine trims, so even several clicks on the Turnigy 9X’s trim buttons makes so little difference that you’d never notice it. The viper needed a little up trim, quite expectable as they are rigged with zero incidence and zero thrust angle. She also needed a little left aileron trim. After what seemed like a disconcerting eternity of clicking trims she finally flew straight and true. It wasn’t actually that she needed a lot of trim, it’s just that with this radio and how Vipers are set up it seemed like a lot of clicking to get there!!

I switched to low rates and let her run flat out around the sky for what seemed like half an hour, but in reality was only just over 2 minuets. The ailerons were a little soft on low rates for my liking so I later upped them from 50-70% the elevator was fine on low rates and was certainly able to turn her around quite smartly so I left that as it was.

One thing I was noticing is that a Viper flies nothing like a RareBear. By comparison Vipers are rock solid in the air, more predictable and track much better. They seem more slippery and carry their way much more than a RareBear as well.
Another thing is that they don’t seem to tire three quarters of the way through a flight like a RareBear when it’s Lipos start to get low. The Viper just Keeps on powering along regardless!! The Viper being a bigger plane is much easier to see but is not nearly as nimble a flier as a rerebear. With a Rarebear if you get it out of line you can put it back pretty quickly but with the viper it seems to take more time to make an adjustment and it felt like it often got to the next pylon before any correction could be completed. It will take a bit more getting used to but that’s the fun bit !!
The first landing was interesting, I backed off, slowed her up, turned and lined up with the strip, Vipers can slow up quite a bit and still fly. She just floated on down the strip with her engine ticking away at a fast idle. I’d set my idle speed a bit high and had to fly it onto the ground cause once she hit ground effect she wasn’t going to slow up any more. Luckily the strip was 200m long!! A bit of a bounce and she was down perfectly fine and all in one piece. I adjusted the idle down a bit lower and had no such trouble after that! The test flight of Viper number two was a bit less stressfull trimming was about the same but I’d already upped the aileron throws on low rates as I did for the Viper #1 and I remembered to set the Idle down to a nice low tick over before taking off.

Defiantly fun, fast, furious and rock solid machines! They fly a bit like a trainer except for the top speed. And the sound and smell of glow fuel thrown in certainly makes them something different.

Here's some video of Viper no1 in the air.

http://www.youtube.com/watch?v=cCxhlSvjS40

[wingtipper]

Yes Wayne you Flew the Pulse well, Well Done.

I managed to get in about 4 Flights with the Gee Bee and even did a outside Knife edge upon Steve L Request which i manage first Time the second time i had dumb thumbs but recovered quickly without mishap.

Normal Knife Edges I'm was Use Too , So it was good to Try something Different, Thanks Steve L.

Steve

Love the Gee Bee


THE PIC WAS DECEIVING IN THIS POST . seeing this in the flesh over the weekend it was nice and scale like , a big plane indeed .

---

I test flew the Vipers on Friday. The weather was perfect being cool and still, tho’ the sky was a little grey there was no trouble with visibility. The red white and blue colour scheme turned out to be highly visible in the air.

I’d mixed a batch of 4:1 fuel, just methanol and caster as this is what they use in competition. The engines had been run in on this mix and both operated very reliably when they were bolted to the bench. I don’t think I’ve ever had a glow engine run as nicely as the two Thunder Tiger 46s I brought for these vipers.

When I read about how people set up their pylon models I found most would say that you want very slow rates to fly around a pylon course. You don’t want any twitchiness just a nice and smooth response and you want to be able to use the full throw of the sticks as well. For this reason a lot of people use dual rates, High rates for take off and landing and low speed flying and low rates for when the throttle is open wide and the plane is going fast.

It was with more than a little trepidation that I stood behind the first of the two vipers with high rates selected. We were on the Pylon course and taking off across the strip width ways, there’s only a fairly short distance with which to build speed and get airborne.
This was it, Ian was holding her by the tail with the engine running at about ½ throttle. Before I had a chance to wind it up to full peg he let her go. I pushed the throttle wide open as it had almost covered half the width of the strip. Magically she roared into the air and accelerated rapidly away.

Now Vipers don’t have very big control surfaces and they are set up with relatively small throws even when on high rates. Turnigy 9X Radios have very fine trims, so even several clicks on the Turnigy 9X’s trim buttons makes so little difference that you’d never notice it. The viper needed a little up trim, quite expectable as they are rigged with zero incidence and zero thrust angle. She also needed a little left aileron trim. After what seemed like a disconcerting eternity of clicking trims she finally flew straight and true. It wasn’t actually that she needed a lot of trim, it’s just that with this radio and how Vipers are set up it seemed like a lot of clicking to get there!!

I switched to low rates and let her run flat out around the sky for what seemed like half an hour, but in reality was only just over 2 minuets. The ailerons were a little soft on low rates for my liking so I later upped them from 50-70% the elevator was fine on low rates and was certainly able to turn her around quite smartly so I left that as it was.

One thing I was noticing is that a Viper flies nothing like a RareBear. By comparison Vipers are rock solid in the air, more predictable and track much better. They seem more slippery and carry their way much more than a RareBear as well.
Another thing is that they don’t seem to tire three quarters of the way through a flight like a RareBear when it’s Lipos start to get low. The Viper just Keeps on powering along regardless!! The Viper being a bigger plane is much easier to see but is not nearly as nimble a flier as a rerebear. With a Rarebear if you get it out of line you can put it back pretty quickly but with the viper it seems to take more time to make an adjustment and it felt like it often got to the next pylon before any correction could be completed. It will take a bit more getting used to but that’s the fun bit !!
The first landing was interesting, I backed off, slowed her up, turned and lined up with the strip, Vipers can slow up quite a bit and still fly. She just floated on down the strip with her engine ticking away at a fast idle. I’d set my idle speed a bit high and had to fly it onto the ground cause once she hit ground effect she wasn’t going to slow up any more. Luckily the strip was 200m long!! A bit of a bounce and she was down perfectly fine and all in one piece. I adjusted the idle down a bit lower and had no such trouble after that! The test flight of Viper number two was a bit less stressfull trimming was about the same but I’d already upped the aileron throws on low rates as I did for the Viper #1 and I remembered to set the Idle down to a nice low tick over before taking off.

Defiantly fun, fast, furious and rock solid machines! They fly a bit like a trainer except for the top speed. And the sound and smell of glow fuel thrown in certainly makes them something different.

Here's some video of Viper no1 in the air.

http://www.youtube.com/watch?v=cCxhlSvjS40

nice writeup JASON and great vid to boot . let us know if there are any differences between these 2 birds . they look very stble in the air , and remind me of long legged race cars with high diff ratios .

[smuzz]

Yes, that was an interesting read Jason - thanks for putting it together.

[Flying fisho]

Great review Jason, sounds like you had loads od fun. Any idea of top speed (my topic of interest at the moment )

[secant0give]

Great review Jason, sounds like you had loads od fun. Any idea of top speed (my topic of interest at the moment )

G’day Wayne,
I do have a pretty good idea of the speed they were doing, from the fastest pass I videoed, it’s around 154 kph.
My engines are running a bit rich, being still new, I didn’t want to risk them running too lean and overheating. There was no point in pushing them to absolutely flank speed for a bit of practice, I will save that for race day. : D

Because your interested in how fast models go (caught the speed bug ay ??  )

I should mention how I arrived at these numbers.

This is how the speed was measured. It’s the most reliable and accurate method I can find. Even tho’ it gives lower numbers than the GPS method I’m much more inclined to believe the results.

The speed was measured buy analysing the Doppler shift in the sound of the prop blades from a video/audio recording of the plane flying a low, close in, pass.
It should be a very accurate method of measuring the speed as it relies on the frequency difference between the plane approaching and departing. Any recording error that shifts one frequency should also shift the other the same amount and not affect the difference between the two in any way. The difference is what is used to measure the speed.

There is a small error tho’. The error one might expect is a cosine error but it’s very small and will always make the measurement on the lower side of what the speed actually is. How much error there is depends on how close the pass is and the straightness of the path that the model flies during the recording. If the model flies in a reasonably straight line for at least 50m approaching and departing the recording point and passes the recording point no further than 10 yards away then. The error should be less than 2% and that will mean a measured speed of at least 98% of the actual speed.


If you maintain the 50m straight line approach and departure and fly with in 15 meters of the recording point then. The error should be less than 5% and that will mean that the measured speed will be at least 95% of the actual speed.

You can do a little cross check of any measured speed by calculating the pitch-speed of your prop and multiplying it by 0.8 to allow for slippage. For a good prop will grip only about 0.8 of it’s pitch speed and a not so good one about 0.65
These numbers are affected by the drag of the air frame and allow some latitude either way. But for a quick cross check they are not too bad.

If I look at the frequency of the prop noise divide by two (two for two blades) you get the engine speed. Not suprisingly this is the same number as the frequency of the engines exaust note. around 335 Hz.

If we multiply this frequency by 60 to get Hz into RPM (cycles per second) into (Revs per minuet) we get around 20,000 RPM which is about right, considering when the plane is in the air the engine unloads a bit and revs harder than it does static running, on the ground.

A 10X6 prop reving at 20,000 rpm = 120,000 inches per minuet

120,000 X .0254 = 3048 meters per min

3048 X 60 / 1000 = 182 Kph



182 Kph X 0.8 = 146.304 (Pretty close to the measured 154 Kph)

[gbanger]

I would put a GPS in the sucker and get a proper top speed reading over 100 meters or more... that would save a shit load of muckin around... don't you think!

[Claudius]

I would put a GPS in the sucker and get a proper top speed reading over 100 meters or more... that would save a shit load of muckin around... don't you think!

It is a bit of stuffing around, but an accurate doppler reading should easily beat a cheapie GPS for speed accuracy on short runs... and he's also getting the RPM to boot.

Thinking about it for a sec, most of the stuffing around has to do with downloading files, putting them into Audacity, etc. Would be a heck of a lot easier if you just had an app on your phone that did that for you on the flight line Jason...

Turns out there is one: http://www.rcspeedo.info/ Think there's a free cut-down version too if you wanted to check accuracy first.

Doesn't appear to do RPM at a quick glance though, but if this approach proves to be useful you might just know someone you might be able to talk into writing up a custom app

[Skidz]

I am pretty sure there is an RPM app for the iphone. I have seen heli guys using it some time ago.

[secant0give]

An app that gives the RPM and speed would be very handy and give a quick result,
but I do like having the video to look at as well, It just adds some extra information when you have the picture too. You know what plane it is and where it was taken and you also get an idea of the distance that the plane passed by the camera. You can see how straight the approach and departure were so you have a bit of a handle for the accuracy of the measurement. When you pick a pass out of a bunch of video you can pick the best one to analyse, You can pick a video of a pass when there was little background noise from wind or other models or talking on the flight line.

Thanks for the link to that app Claudio, I’ll have a look at it when I get a chance.

The GPS option at first glance looks good but you only get a peak reading and the GPS probably only updates every 10th of a second if it’s a very fast one. A lot of cheap ones only update every 5th of a second. The positional accuracy of a GPS is not that great so when you want an accurate speed measurement over a short distance your going to get errors. Because a cheap GPS reader only remembers the top speed recorded then it’s just going to keep the largest error.

You’ve got to remember that the GPS is using satellites that are a very great distance form the model and the fact that the model is moving also adds in timing errors. It would probably not be so bad if the model travelled for a km in a straight line or if the unit recorded the average speed or recorded all the points and you did some other analysis of that data later on.

I am pretty sure there is an RPM app for the iphone. I have seen heli guys using it some time ago.

I'll have a look for that as well but you need to do some averaging of the aproach and departing frequencies to get the RPM of a motor that it moving at speed through the air. Staticly it would be OK. It's nice to look at the spectrum and see which is the frequency you want to use tho', There are quite a few harmonics which can be ruled out by comon scence.

[Stuka]

Hi Jason, really enjoyed seeing those two planes fly so well.

What intrigued me most was actually where you were flying them. Oodles of space where one can express oneself a little more than what one is accustomed to at McCoy.

[Flying fisho]

I like the GPS option for it's simplicity, and if it is inacurate all the better, I can tell people my 176kph result from the Pulse was potentially 190kph

[gbanger]

Timing errors eh Jas?
The GPS looks ok to me.
Looking at the huge variation in the data you have taken and the mathematical equations used that still give you a varience of over 30kph, I would be more than happy to accept the GPS data as close enough!
Afte rall... we don't want to find out we are going to slowly!

[secant0give]

Timing errors eh Jas?
The GPS looks ok to me.
Looking at the huge variation in the data you have taken and the mathematical equations used that still give you a varience of over 30kph, I would be more than happy to accept the GPS data as close enough!
Afte rall... we don't want to find out we are going to slowly!

Your right Gazz there is a certain sence of dissapointment when you find out that your not going as fast as you hoped you might be. Let me tell you I don't like it one bit !!!

The trouble is that because of the various class rules, you can only change certain things to make a difference and those differences are only small, being only small differences it's hard to measure them unless you have an accurate method of measurement.

If you can go just a small amount faster, then if everything else is equal you will allways win. So it is a worthwhile trade off, if your after the last little tiny bit of performance to demoralised by the bare and naked truths occasionally.

[dwils]

It took a while but its sold

[BenR]

Maiden flight report

Plane: Eflite UMX Beast 3D (with AS3X)
Location: Unofficial airfield (double fields in out of the way area, with a plane under 100grams)
Date: 28/11/12
Conditions: Overcast, no to very light winds.

I have been wanting to get a plane that I can fly in my lunch break. I knew that it would have to be under 100 grams to be exempt from flying regulations. I had originally planned the Carbon Cub, but ended up with the Beast as there were huge delays in getting Carbon Cubs.

The plane looks very nice - if you havent seen one its a modified Pitts 12 biplane done in red and black, and about a foot long. Site is http://www.e-fliterc.com/Products/Defaul...D=EFLU4080

I got the plane a while ago, but had to send it back under warranty. The servos were attached to a control board, and in the first plane that board was not glued in, and the board moved with application of rudder or elevator, making both controls move at the application of a control.

Anyway I got the warranty one back eventually (after AusPost took 2 weeks to deliver it from Newcastle.......) and took it for a fly today. Control surface tests all performed well on the ground and throttle check was ok too. Set up dual rates giving myself only light control and reasonable expo, but left the top settings available for if I needed it. I also got and used an extra battery which had higher mAh, and its extra weight was 99% likely the reason that things went the way they did.

Taking it up in the air I was struck by how much it wanted to sink to the ground and land (from a hand launch) (hint - it was probably battery weight). After fighting it a bit, I cut the throttle and landed it in rough grass while keeping the wings level. This took off one of the wheel covers. (which didnt greatly concern me).

Tried to see what it was, and figured that the way to fix it would be to adjust the control surfaces, and gave myself higher rates (which wasnt the best move). Second flight was ok, still a little tendancy to sink, but the landing was hard. Cut the throttle higher up trying to see how well it would glide in, touched the ailerons trying to level it a bit and flipped the plane. That was followed by a unpowered meeting of the earth, where some of the foam tabs making the battery cover hold on broke, and some foam crumpling. One of the connectors that hold the upper wing also came unstuck, but that looks a case of regluing.

How was it while it was in the air? I only have a T-28 to compare it to, and it was definately a much faster machine and a hell of a lot more nimble. That flip before the crash happened was done in the blink of an eye, and it had enough speed for me to be very cautious of the throttle, only opening it up when I had it level and the space for it, and even then just to verify. I knew before I got it that there was definately the chance it was too advanced for me to handle, and that proved to be true. It has reinforced that even with some sim time, I need to get the T-28 up a lot more before I get back to this one. But I am still happy to have had a brief taste of what lies in store for me when I get more proficient.

[Raptorfly]

Maiden flight report

Hi Ben
I know these little Bi-planes are not the easiest to fly. But if this the UMX beast it should have been more stable than your description!!
Bring it down to the field for someone to have a look, fly it and check if it's set up correctly or this it self has a bad flying tendancy.

[BenR]

But if this the UMX beast it should have been more stable than your description!!
Bring it down to the field for someone to have a look, fly it and check if it's set up correctly or this it self has a bad flying tendancy.

Ok, I may have made it sound worse then it is.

The plane definately wanted to sink on me. Stock it is suggested that you use a Eflite 2S 180mAh battery. The additional battery I bought was a nanotech one at 260mAh (and a bit thicker and heavier). It definately made it want to sink - not go nosedown or nose up, just a level sinking that needed countering with elevator. It was the same (but much more extreme) with a plane I tried to fly with a USB camera on top, where the weight made it want to sink. Once repaired and ready for re-launch, it will get the stock battery first.

As for the rest... well I asked for "turn" followed quickly by "Oooh not that much!".... or words to that effect anyway.

[Claudius]

The plane definately wanted to sink on me. Stock it is suggested that you use a Eflite 2S 180mAh battery. The additional battery I bought was a nanotech one at 260mAh (and a bit thicker and heavier).

Hard to pin the problem here... wouldn't be too quick to blame the extra battery weight (perhaps position though), with only 3g difference between that nanotech and the stock Eflite.

FWIW, my (pre-ASX) Beast UMX flew out of the hand on its maiden with maybe a click or two of trim (aileron, iirc). I've flown it on 2S/120mAh and 2S/180mAh without noticeable difference. I keep the smaller battery a bit further forward, as the 2S/180mAh does need to be quite deep.

Did you push the battery in as far as it will go? When you up'ed the rates, what exactly were they set to? Don't know about the ASX version, but the original is pretty twitchy - at high speed with full rates it'll snap roll twice in a blink!

[BenR]

The plane definately wanted to sink on me. Stock it is suggested that you use a Eflite 2S 180mAh battery. The additional battery I bought was a nanotech one at 260mAh (and a bit thicker and heavier).

Hard to pin the problem here... wouldn't be too quick to blame the extra battery weight (perhaps position though), with only 3g difference between that nanotech and the stock Eflite.

FWIW, my (pre-ASX) Beast UMX flew out of the hand on its maiden with maybe a click or two of trim (aileron, iirc). I've flown it on 2S/120mAh and 2S/180mAh without noticeable difference. I keep the smaller battery a bit further forward, as the 2S/180mAh does need to be quite deep.

Did you push the battery in as far as it will go? When you up'ed the rates, what exactly were they set to? Don't know about the ASX version, but the original is pretty twitchy - at high speed with full rates it'll snap roll twice in a blink!

The battery was a reasonable way in. It may have been possible to go further, but at the time it seemed to be sitting in line with the wings, which I would have taken as the correct position. Once repairs are done, I will review that part again.

As for twitchy, that was the second crash. I tried to give it a touch of roll and was rewarded with a 180 faster then I have ever seen before. (I honestly cannot recall seeing it in a stage between almost level, needing a minor correction, and inverted 180 degrees past where I meant to start.) Crash immediately followed. And that was all under nil throttle. Hence my regretting putting the rates up after the first flight.

[Steven]

Durafly Monocoupe

Wingspan: 1100mm

Format: 4 ch/4 servo Highwing monoplane with fixed gear and steerable tail wheel

Equipment used (not supplied): Spektrun DX6i and AR6210 receiver with satellite, Nanotech 3S 2200 battery, low voltage buzzer.

Source: Hobbyking

Location: Southern Fun Fliers lot, Tasmania

Condition: westerly wind, less that 5 kn. Partially cloudy (on the day of the maiden. Really weird puffy gusts and overcast on the 2nd day of flying)


Assembly: Went by the book, with no nasty surprises relating to fit or missing items, but with two notable points: Firstly, the factory installed ESC was not properly plugged into the motor, and the esthetic flying wires for the tail plane proved just too fiddly, trying to knot a thin rubber cord around tiny expansion spring that does not have closed eyes. After about an hour trying to get one knot tied, they were discarded.

With the recommended battery, the model CG'ed fine (unlike most other HK planes that I have personally encountered), but the included prop is heavy, thick plastic and has a noticeable effect on static CG. Extra weighting would be required if it was swapped out for an APC or MA unit. There is ample room for this, along with a low voltage alarm in the battery compartment.


Maiden: With all control surfaces mechanically trimmed straight during assembly, the first flight was a pleasant experience. Rolling up to 2/3rds throttle saw a cilivised accent, with only a mild amount of elevator required to set the model's intent.

When airborne, the Monocoupe flew dead level without further trimming. It appeared to sitting tail low, until I realised it was an optical illusion created by the concave curve of the fuse's profile.

The model is happy to cruise at 2/3rds to 3/4 throttle. Any more and there's no noticeable increase in speed, it just gets louder. Which, I should mention, is not a bad thing. Probably due to the reasonable density of the foam, this plane emits a pleasant deep throbby noise, kind of like an electrical foam model impersonation of what you'd expect of the original racer. It will fly happily down to about 1/3rd stick, but you have to be much more active on the controls to maintain a level altitude at this point, you are very much sliding off the envelope.

However, at the mid or above throttle point, the Monocoupe loves long turns, banked well up. I found that most of the time little to no elevator was needed to maintain altitude during these long banked turns. However, on occasions a jab of up was required to keep things level, which I attributed to strange little puffs of wind that we were experiencing that day, as this would occur as the plane was crossing the direction of the breeze (although I am no expert on the matter, just a hunch). This did not inspire me to try any silliness, even though HK promote this model as an entry to aerobatics. I will note, on a later flight on another (less than perfect) day, I had a gust catch the plane and near flip it out of the bank and turn it 90 degrees into the wind in a split second. Uninvited, but not disastrous.

Landings were consistently not bad at all. Even with the envelope tapering off higher than I am used to with my beginner models, I still managed to line up and settle down safely. On one occasion, wind was driving my landing leg too far to a side I didn't want to be on, so I chopped and dropped from about a meter, rather than a foot to get it down quickly. The semi suspended main gear just soaked it up, a bit of a rebound and all was fine. It seems quite robust in this area. A good thing.


All in all, I think I described the experience as "Flying an EK Holden", and not in a bad way. The Monocoupe certainly feels how it looks, and from someone who likes things scale, I has a happy and I'm looking forward to taking it up again.

[smuzz]

Nice report Steve - a great read!
Look forward to seeing this one at McCoy some time.