HK AXM Floater "jet" glider

[jolfstn74]

Wanting something that flew like the UMX Radian I killed,but more substantial, with a brushless motor,less than half the cost of the full size radian, actually cheaper than the UMX,but with Airleons,the AXM seemed to fit the bill.my first pusher prop,the upswept wings make this not unlike gyro flight stabilized models. After the fast assembly,I drove to my field,unable to shake the feeling I forgot something important.i have 2 basic intentions for this model, teaching my friend to fly, instead of the squirrely clipped wing cub I was teaching him on,that bugger loves to stall & death spin out of spite. My other plan for the AXN, Since she's got a pusher prop,the nose is free,so as a radian-like, gentle slow flyer,I intend this to be my new fpv platform.
There's 4 couples with their dogs at one end of the field,I've got an audience for this maiden! I plug in, control surfaces check, everything seems cromulent,what was that one thing?no matter.
Throttle up to about 3/4, if you've never flown a pusher, they're bloody LOUD! power plant in the middle of the body makes all that motor vibration resonate. The AXN in particular is considered a screamer.if one of my tractor planes made a noise like that,it would mean something was wrong. Nose ever so slightly up,firm toss,back on the elevator,
& CRASH!!!
Oh yeah! My elevator channel was reversed! That's what I forgot! Actually split the seam about 1/4 down the fuselage,I'll have to reglue that. I reversed the elevator throw on my tx, put the battery back in the hatch, checked control surfaces again, this time everything is going in the right direction. Throttle up:
Twitch,twitch twitch!
One of the esc wires fell out in the impact! It's a fiddly mess to get at the ESC, can't do it at the field, besides,the sun was setting. The seam rip was fortuitous, as by augmenting it a bit that was my means of getting to the ESC to plug it back in, afterwards I glued it all back together check surfaces and throttle again everything's good to go for my maiden tomorrow morning.

 

[daxian]

had mine for 12 months as a wall decoration ...scared to fly as i was newbie pilot !!! first flight was totally perfect !!!
was amazed how well it flew at 1/3 throttle ....1/2 throttle and it rippppppps the sky a new one !!

 

[quorneng]

jolfstn74
Just remember the control check is not just that they move but do so in the correct sense. "Stick to the right, right aileron up, left aileron down" etc. Do the check like your life depended on it, which in full size it does.

 

[jolfstn74]

jolfstn74
Just remember the control check is not just that they move but do so in the correct sense. "Stick to the right, right aileron up, left aileron down" etc. Do the check like your life depended on it, which in full size it does.

You're absolutely right! As flippant, obtuse & forgetful as people can be, it's a wonder there aren't more accidents in full scale flight than there are! As keen as I am to paramotor, it's truly frightening how easily one small forgotten thing can and does easily snowball to end your life,or others, or cause injury,or damage expensive equipment.

 

[jolfstn74]

My maiden this afternoon went very well! She can be a speed demon,or come to a damn near full stop before she thinks about stalling. Graceful,fast,obedient,predictable,this plane exceeded my expectations concerning performance. The hatch is a bit fiddly & prone to flying off in flight,I've added hook & loop strips along the edge next to the front notch & rear magnet. The split along the center seam I caused with my initial crash yesterday reopened a little,so I glued that more agressively,but overall I couldn't be more pleased with my acquisition.i highly recommend the Hobbyking AXN Floater Jet pnp, I can confidently say it's well worth the money, it has a wide flight envelope, the pusher prop design saves propellers, & frees the nose for FPV, and she would make a fantastic first plane for a novice, especially I like the complete lack of gyroscopic technology based flight assistance, which, based on my experience, I liken to a dangerous narcotic. It gets you high fast,but you quickly find you're not much of a pilot without it! I had to relearn flying when I realized I couldn't without SAFE or equivalent. I say, learn completely without it first,then use it when you get in trouble only, at least that's the way I wish I had done it, and the way I intend to proceed.

 

[quorneng]

jolfstn74
Glad you liked it. It is a very popular layout.
The only criticism can be the fact the prop is high mounted, well above the centre of gravity and the centre of drag, so applying full thrust particularly at slow speed tends to force the nose down. The more you 'up rate' the power in such a configuration the worse the effect becomes.

 

[jolfstn74]

I've noticed that, partially on taking off, unaware upon my first few flights,had a hard time climbing,now that I know to account for it,it just becomes part of flying this model. This morning,my plumber was coming in half hour,just enough time for a quick test flight as I'm trying out a new propeller,so of course I got it stuck in a tree,at least 12 meters up! 4 hours later I got it down, zero damage! I may have met my match with this plane,I have done my subconscious best to kill this bird,yet she survives,nay,thrives regardless! I love it!

 

[jolfstn74]

My axn was decapitated this morning! I had a cartwheel landing,& the fuselage just forward of the tail servos, basically just the battery compartment was ripped clean off! Attached only by the battery cable. I used a generous quantity of epoxy and she's back in one piece. Also coated the bottom as it's getting a bit soft, plus I keep seeing videos wherein people are able to launch from the ground,but mine either won't move or spins out,so felt a smooth coating of epoxy might do the trick. NOPE! Still hand launch, though I noticed one of the bixlers does have Landing gear, I bet I could put some landing gear on this thing if I wanted to, also I am tempted to put in my 4s 2200 but don't want to blow the esc. Still very happy with my plane,it's a bit too fast and squirrely to use to instruct my friend or to use for FPV, but it is improving my own skills nicely, learning some basic aerobatics with it now.

 

[quorneng]

jolfstn74
Try really wet grass for a slide take off. It about halves the coefficient of friction. Grass with frost on it is even better.

 

[jolfstn74]

Very quick flight today, 20knt winds gusting to 50! She held her own but was scared she'd crash so cut it short. Aerobatics are coming along,really wanted to try for a roll today,but when the winds die down I'll give it a go. Really thinking about landing gear, trying to come up with a configuration wherein I need not puncture the fuselage, something temporary that can be braced on, and not too heavy.

 

[jolfstn74]

My poor plane! There were paramotorists on the east side of the field,and as the wind increased, my plane began drifting to where it would be in their way, I tried to land it fast,and I did. Snapped the fuselage in half,and decapitated it again! I came up with a novel repair for the fuselage after joining it with epoxy, I had some heat shrink wrap that generally is used for packs of batteries, and I put that around it to hold everything in place and it did a beautiful job realigning the plane; the tail and the wings are perfectly aligned! The front decapitation was forward of the previous one so that patch job was successful; I did a similar one. she's ugly as sin now, but has regained her general silhouette, and I believe she's still air-worthy. this morning I had far more luck, I was there very early I had the whole field to myself, and I completed two rolls which were my very first ever! I was having a hard time initially because of the dihedral wings, it fights a roll, but discovered if I include some rudder, I was able to do it. I don't know how much longer she'll last but she's been serving me very well and I still strongly recommend the axn floater jet from HobbyKing.

 

[quorneng]

Apart from having the novelty of taking off my suggestion would be to avoid an undercarriage on a thing like the Floater Jet. The problem is the undercarriage not only adds weight and drag but is very likely to make any landing but a perfect one even more damaging to the plane. Belly landing was after all what it was intended to do.
Apart from scale planes that have a fixed undercarriage even my most delicate foam planes hand launch and belly land successfully on quite rough grass with no damage - most of the time.

 

[jolfstn74]

Today I had a successful post surgery flight,I was worried the constant drift to the right was an imperceptible misalignment that occurred upon reattaching the tail section following detachment caused by a particularly percussive unintentional rapid landing, I sanded off most of the epoxy on the front,and noticed just aft of the nose, that the fuselage widened significantly at a vulnerable crumple zone. Unable to reshape it safely,I used a heat gun to soften the foam an make it more malleable. i was more or less able to return it's original,intended shape, though heating the foam caused it to pixelate & harden, making me feel it's probably somewhat brittle now. THEN I added a 3 blade prop, approximately 5.5 x 6, it's made a world of difference! Top speed is dramatically faster, vertical climb is unlimited at just over 1/2 throttle! The reason the prop measurements are approximate is because I purchased it yesterday at HobbyTown and is sold as a spare tail prop for the E-flite Convergence! If you have an AXN Floater Jet from HobbyKing,or a ranger from Voltanex, or a Bixler,or ANY pusher style glider of approximate dimensions, get one of these 3 blade props! Like me,when you fly it the first time, you're likely to exclaim "JESUS CHRIST & HIS ALL GIRL ORCHESTRA*! Why are these not sold in this configuration!?!"
* Your own exclamation may vary.

 

[quorneng]

jolfstn
Glad you found a better prop, however you should take care before assuming the solution was entirely down the the fact it had 3 blades.

Any prop has 3 major variable, its diameter, its pitch and the number of blades.
Have you considered how quickly this new high performance is draining the battery?

If there are no other limitations a 2 blade prop is the most efficient at converting the motor power into performance. More blades reduces the prop efficiency.
If of course the design of the plane limits the maximum size of the prop then a 3 (or more) blade prop may be the only way to utilise all the available motor power but the pitch of the prop still plays an important part in determining the planes overall performance.

There is unlikely to be a single 'ideal' prop but there will be one that best suits how you want to fly.

 

[jolfstn74]

Excellent points, all, Quorneg, & yes, the clearance of the motor over the back of the fuselage limits the prop length to about just shy of 6", the width of each blade on my new triple blade prop is substantial, as well as having an agressive pitch. Flight times have decreased,if I run the motor constantly, I now get about 14 minutes as opposed to the 18-19 minutes I used to get with the original prop, though I notice the ESC stays a lot cooler under similar usage circumstances. Since I often use the motor to get to altitude then glide down, the time has not been affected as I've had 45 minute mostly glide flights, using the motor only intermittently. Overall, the motor/ESC combo on this airframe is a tad anemic according to pilots far more experienced than I, but the 3 blade Convergence tail prop seems to make the most of the available power & I'm very pleased with the results,as I suspect most AXN owners would be,excepting those who require the longest possible powered flights possible,in which case, the original prop or one with thinner blades at a less acute angle would serve their purposes at somewhat slower speeds.
Another advantage of my new prop, it's a whole lot quieter too! Pusher configurations are notably louder than their tractor counterparts, with the motor mounted in the middle of the airframe, all that vibration really resonates loudly through the body, but this prop, perhaps, is more balanced than the original, and for that or another reason, is much quieter.

 

[jolfstn74]

Much has happened to my beloved plane,not the least of which is having determined the fuselage has become too brittle,I coated it with thinned epoxy, fine, lightweight cotton fabric and more epoxy,essentially 'fiberglassing' the abused foam,painted the whole thing black except control surfaces,green for starboard aierlons & elevator, orange for port,then a few coats of polyurethane over the whole thing. My first attempt to fly was very sad, it went straight to the ground, and I thought I made the whole mess too heavy! Then realized I put the pusher prop on backwards! in the process of discovering this the plane took some very hard dives and my fiberglassing work held up beautifully. Since discovering my mistake, I've corrected it, but have been unable to do subsequent test flights because it's raining like mad

 

[jolfstn74]

The AXN is deceased.1 too many repairs & it just never flew right after. A bit sad,I'm concentrating now on my FT Simple Stick that was giving me problems, it would fly hi alpha all squirrely,then dive and shatter propellers.ive heat shrink coated the wings, polyurethane + starch coated, then sanded, painted the fuselage, given him a new rx and addressed the angle of attack,given the motor a slight down/starboard affect,letting her dry and re-maidening if the rain ever quits. The wonky flying I initially attributed to being tail heavy, but after putting four AA batteries in the nose it was still doing the same thing, another person in the forum suggested it was angle of attack if that wasn't it, so, we shall see. Conscendo is still flying, I've killed so many planes,so much blood on my hands! Well, not blood, so much hot glue on my hands, those wings haunt my dreams! I'm an involuntary plane serial killer, or more accurately Lenny from Of Mice & Men,I love my planes until I smash them to the ground.

 

[jolfstn74]

Removed the prop,rubber banded the wing and inserted but not conned the battery,I gave my now truely butt ugly elephantitis deformed one truely deserving of the name fUgly-stick...a glide test. It flew straight, at a downward angle at which I released it, then landed ok, if the rain holds up maiden today!
Behold: fUgly stick
Photo to follow

 

[jolfstn74]