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Old Jul 27, 2012, 05:44 PM
flexwing addict
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midlands uk
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the modification was just a set of longer, softer springs and longer servo arms.

if the longer springs were put in and not the longer arms then it wouldnt turn as there isnt enough travel to overcome the springs so they would take out almost all the steering input.

the longer, softer springs allow the trike to move around much more freely to find its own hangpoint and not affect the wing angle of attack with things like trike movement from thrust,
the microlight can climb on full power now and not stall because the angle off attack can stay the same, this was why i was having climb issues before unless the springs were set absolutely smack on which isnt easy (or fun) lol

the front suspension works a treat too, its a very rough bumpy runway at that place and it handled it pretty well i thought
had a heavy crash the other day before the mod and bend the front suspension but i just took the axle out, bent it back, put back together again and it was fine!

new video is on previous page,
hoping to make a real nice video next time i get it out cus the view isnt the best on that one
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Old Jul 28, 2012, 06:55 AM
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Australia, VIC, Craigieburn
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Quote:
Originally Posted by mark675 View Post
the modification was just a set of longer, softer springs and longer servo arms.

if the longer springs were put in and not the longer arms then it wouldnt turn as there isnt enough travel to overcome the springs so they would take out almost all the steering input.

the longer, softer springs allow the trike to move around much more freely to find its own hangpoint and not affect the wing angle of attack with things like trike movement from thrust,
the microlight can climb on full power now and not stall because the angle off attack can stay the same, this was why i was having climb issues before unless the springs were set absolutely smack on which isnt easy (or fun) lol

the front suspension works a treat too, its a very rough bumpy runway at that place and it handled it pretty well i thought
had a heavy crash the other day before the mod and bend the front suspension but i just took the axle out, bent it back, put back together again and it was fine!

new video is on previous page,
hoping to make a real nice video next time i get it out cus the view isnt the best on that one
great handling and looks like the part to, love the way the head turns.
the springs that isolate the steering from the servo's is brilliant, might have a look at that as well for my build. Thanks again for sharing Mark. keep it coming.
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Last edited by ritchie_laird; Jul 28, 2012 at 07:04 AM. Reason: adding comment
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Old Jul 28, 2012, 11:44 AM
flexwing addict
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midlands uk
Joined Sep 2004
2,676 Posts
Thanks Ritchie

the steering springs are pretty essential with a model this big and using the twin servo idea,
they allow the trike to hang in the position it wants to and the wing to trim at the angle of attack it wants to,
if you restrict this movement at all it will be very unstable!
on full throttle the trike pushes forward so the bar comes back towards the pilots chest, this was the problem i had before i put the longer springs on..
the movement of the trike was restricted fore and aft so as you throttle up the trike would push forward and also tilt the wing backwards stalling it.

they also eliminate the pendulum effect of the trike because its free to pivot in all directions,
if the wing and trike were fixed you would get a swinging or rocking motion after every turn or climb etc as the trike will want to hang at the lowest point,
when it swings to the lowest point the momentum would make it swing past and then back again several times like a falling parasol.

the springs pretty much replicate how the bar would move on a full size microlight as the wing is self stabalising and can fly without the control bar being held,
but then you have the servo arms to overide the springs for control inputs.

they also have the added bonus of being servo savers in a crash and now ive got longer ones fitted they soak it up even better


ive got a new idea of making the control bar adjustable with a screw thread to adjust the dihedral and anhedral of the wing,
this effectively lengthens or shortens the side flying wires without having the adjust all 4 lengths of cable! much easier to finetune the handling or stability you want with a twist of the adjuster,
i think mine could do with a slight bit more dihedral for straight line stability,
too much though and itll be difficult or impossible to turn via weightshift as itll be too stable.

rc microlight landing crashes (6 min 59 sec)
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Old Jul 29, 2012, 06:01 PM
Foamy Season is here! MX2#1
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Elizabethtown, Kentucky
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found it
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Old Jul 30, 2012, 12:12 PM
flexwing addict
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midlands uk
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ah cool, welcome mike
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Old Jul 30, 2012, 07:58 PM
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Australia, VIC, Craigieburn
Joined Jul 2012
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pendulum effect?

when I built the smaller unit with a standard kite I had 1 servo for left and right, climbing was by thrust. I had string from both sides of the kite connected to the servo, but didn't notice the pendulum effect. mind you this was a 1.5meter kite with balsa undercarriage. I think with the 2.5 meter unit I am building this will become evident so I will have to do similar.
I still haven't decided whether to use aluminium rod for the wing or look at 2 $120 pieces of carbon fiber for the build, I have excluded the use of fiber glass due to the weight.
powered up the trike the other day and found that the c3526 had a small shaft curve, its ok at slow speed but at high speed there is a violent shake of the trike so, I have ordered a 35-36 1400kv Brushless Motor for the task.
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Old Jul 31, 2012, 10:59 AM
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midlands uk
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yeah you wont notice the pendulum effect on smaller lighter trikes,
also i would go towards carbon or fibreglass for the wing frame as aluminium will bend and not return to its original shape (like real ones after a crash)
and also be quite abit heavier.

I used fibreglass for mine off a cheap 5 kite and it takes everything i can throw at it (or throw it at more like )
the tips are bent inwards slightly and then attached to the sail,
the tips then try to pull straight and apply tension to the trailing edge of the wing pulling it flat until the air pressure lifts the tips in flight to form the stabalising 'washout' (wing twist towards tips)
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Old Aug 03, 2012, 06:42 PM
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Australia, VIC, Craigieburn
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Quote:
Originally Posted by mark675 View Post
yeah you wont notice the pendulum effect on smaller lighter trikes,
also i would go towards carbon or fibreglass for the wing frame as aluminium will bend and not return to its original shape (like real ones after a crash)
and also be quite abit heavier.

I used fibreglass for mine off a cheap 5 kite and it takes everything i can throw at it (or throw it at more like )
the tips are bent inwards slightly and then attached to the sail,
the tips then try to pull straight and apply tension to the trailing edge of the wing pulling it flat until the air pressure lifts the tips in flight to form the stabalising 'washout' (wing twist towards tips)
the problem I have found is getting the lengths I need most carbon fiber comes in about 1 meter lengths, I have calculated I need about 1.5 meter lengths. looking on the web for this length is darn expensive, a 3 meter length of aluminium will cost me $10au which is 10mm diameter with a wall thickness of 1mm. total width I need from wing tip to wing tip is 2.5 meters.
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Old Aug 04, 2012, 03:21 AM
flexwing addict
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midlands uk
Joined Sep 2004
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what you could do is use some kite ferrules (i think theyre called) which is a short bit of plastic or alloy tube which joins the two bits together,
these could act as abit of a stress riser at that point but the carbon is so flexible it shouldnt be a problem,
also if you snap part of the leading edge you only have to replace a section and not the whole lot
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Old Aug 04, 2012, 05:54 AM
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midlands uk
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bought this little beauty off ebay the other day
its a ripmax discoverer which comes with a cheap futaba radio,
wasnt expecting much tbh but ive got an addiction to aircraft that are different to the run of the mill planes
ive had one of the 'bat microlights' before which have two motors side by side,
one slowing down to yaw it either way and it was total cr@p lol

this one though it a different kettle of fish and flies like a dream!
its fully proportional and throttle for climb and left and right obviously to steer, pitch is fixed in place.

i chucked it off a hill by my house with a fair old wind blowing and it just sat there into wind hovering like a heli

it turns on command and once sat into wind is more stable than any small aircraft ive ever seen

shame these are rare now cus they really look cool and a doddle for a beginner,
not really scale but im looking at making a more scale trike out of some depron sheets ive got in the garage
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Last edited by mark675; Aug 04, 2012 at 06:01 AM.
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Old Aug 05, 2012, 01:37 AM
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midlands uk
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had a lovely fly with both the microlights last night
was a dead calm night which wasnt expected so the mods i was making to my trike had to wait which is the reason it looks so tatty at the moment

the discoverer was flying lovely! everyone had a go with it and were all raving at how easy it was to fly and how slow and stable it is,
it would even glide with the motor off no problem at all.

my scratch build was also flying great, the climb rate now is pretty amazing and you can use full throttle with no worries about stalling or looping
got up to some pretty high altitudes with it aswell,

wish id of got some video of them both but forgot my camera.
got some shots of the scratch build though with a dogcamsport wide camera that i just bought,
im quite pleased with the views but the 'turning head cam' was pointing too far up so ill try that again next time

new video below

rc microlight - dogcamsport wide test (4 min 53 sec)
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Old Aug 06, 2012, 11:40 AM
flexwing addict
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midlands uk
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had another fly with microlight last night before the rain came in and am enjoying it more than ever now!
it climbs when you want it to and is so easy to fly thats it almost relaxing lol
i also hand launched it which is something i havent done before!
always had trouble finding somewhere safe to hold it by without getting cutup by the prop! (yeah it did get me before lol)
i leave the motor off until ive thrown it now and then when its gliding just apply the power,
didnt really have the confidence to try this with the earlier version as it didnt glide nearly as well as this version.


Today ive done a few more modifications to the trike..
ive been milling slots in some sections of the frame that arent under much stress,
id drilled holes before but i like the slots far better as it doesnt make it look like a slice of swiss cheese
this should have lost a fair bit more weight and ive done it mostly in the places that wont be seen to keep it looking scale (pics below)

this even gave me the idea of using two alloy plates seperated by spacers every so often for stength.. but maybe an idea for the future.


im also making some new sideskirts out of fabric instead of foam as it will have a more realistic look and be lighter, also itll be easy to pull them down to get battery and reciever access as the foam always cracks and breaks

Ive been working abit more on my new trike aswell which is looking abit posh compared to my prototype lol
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Old Aug 07, 2012, 11:23 AM
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The hangpoint has been getting abit of slop lately which im not suprised about,
its only a m4 bolt that passes through the hangpoint bracket and frame upright,

the hangbracket is fine but the bolt has slowly been wearing this alloy frame away and making it abit of a loose fit (cheap alloy)
ive made a 6mm dia titanium bush that ive pressed into the holes ive opened up,
its completely slop free now and should be much more resistant to wear,
especially as im crashing alot less now

ive got a new video on the way with some very different views so ill post that as soon as the 'little blue suited dude' can get airbourne again.
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Old Aug 07, 2012, 04:41 PM
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managed to get to the field again tonight,
there was rain about and a little windy but i had a new view i was desperate to try out!
i was a little unsure how it was going to fly with a long carbon rod and a bullet camera stuck on the end,
even though the camera isnt too heavy it was quite a long way from the trike so was making the front wheel hang slightly lower than the back ones!
i knew i was going to be catching it so wasnt too worried about that.

i shouldnt have worried at all cus it didnt affect the way it flew one bit! lol
was a pretty funny sight seing the long pole sticking out the front of it!
if i crashed it would of been like a javelin!!

only dodgy part was on landing cus you dont want that pole hitting you anywhere whilst trying to catch it

rc weightshift microlight (new view) (2 min 53 sec)
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Old Aug 08, 2012, 03:42 PM
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midlands uk
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flew again tonight! im being spoilt! lol

without meaning to sound like m#rio.. we managed to do the worlds first FPV from a rc weightshift microlight

it was much easier to fly than it looks in the video but if we did it again i would mount the camera further back or maybe remove the pod,
my gopro camera would be a bonus too for the wider lens and better quality

its not the best video but didnt want to leave the field with no evidence of having done it.
thanks to my mate Dave for lending me his gear

rc weightshift microlight FPV!! (0 min 25 sec)


cant forget the first Loop aswell

RC flexwing microlight Loop! (0 min 28 sec)
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Last edited by mark675; Aug 08, 2012 at 04:48 PM.
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