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Old Oct 10, 2009, 04:43 AM
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MIA RC TRIKE - Ultralight Microlight Nanolight (2 min 54 sec)
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Old Oct 10, 2009, 06:30 AM
flexwing addict
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thats looking nice mario,

how come you use such a narrow chord on your wings? is it just to decrease drag and increase gliding ability?
from the top view it almost looks like a 3-axis wing, seems to fly pretty good though

also do you think the weight shift approach didnt work on yours because of the lack of trike weight? or maybe the wing too stable in roll?
its just seems that the 'precision flight control system' seems to steer too quick to be truly realistic..

dont take this as crytisyzing just trying to get some feedback


EDIT:

ive just read through the other trike thread you made back in 2002 and its answered all my questions,
for the 'parkflyer' type trike you are making a nice glide and responsive handling for small areas is a 'must have'
and i would imagine the weight shift approach didnt prove affective because of the very low weight of your trike unit,
if you increased the weight and used weight-shift then it wont glide aswell and still hasnt got a very direct roll response so needs more room to fly in,

seems like youve achieved what you set out to do!
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Last edited by mark675; Oct 11, 2009 at 11:02 AM.
Old Oct 11, 2009, 02:58 PM
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another one!

this has gotta be the most realistic one yet!
not sure if the guy bought the wing or not but it looks incredible!

RC ULM Flexiwing 1/3 Scale Microlight First Flight Trial Crash (1 min 54 sec)
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Old Oct 11, 2009, 03:31 PM
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ive been thinking lately about the different ways to control the trike and i think im going to resort back to my very first idea with the springs,

i thought they were the reason the trike wasnt turning too well (maybe they were abit too long and soft) but i think the main reason was the wing was junk and the long control arms werent rigid enough and were bowing instead of transfering the force to the wing.


ive read that the trike part of the microlight doesnt offer a pendulum stabilising effect unless it is rigidly mounted to the wing (like a falling parasol) ... that why i believe the controls need to have some 'give' to make it nice and stable as you want the wing to do the stabilising not the trike!

you can see this in my last video when i removed the springs, as it turned right i turned to the left to get it straight again and it came back so fast i couldnt stop it turning it to the left and diving, maybe i over corrected and the un -washout and battened wing wasnt stable but you can definatley see at 4:26 in the video below that the trike was acting like a pendulum!

as a weight shift microlight isnt mounted to the wing in this way the springs would allow the trike to move independantly to absorb turbulance without upsetting the stability of the wing but would also let the trike do the weight shifting when you put in a control input, a added benefit is that they would save the servos in a rough landing.. the elctric ones seem to do without this but this fairly large nitro powered one is a pretty heavy plane afterall!

these springs would enable you to 'guide' the trike in the right direction as your arms do in a real one

no new videos but heres something i made cus ive just learned to used windows movie maker

http://www.youtube.com/watch?v=Am5J88y9xNE
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Old Oct 12, 2009, 04:23 PM
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take a look at the double opposed spring cushioning steerable tail wheel servo connection on Tim from Telfords Site ,that is Scale and vintage Tim of the incredibly ugly aircraft fame .
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Old Oct 14, 2009, 03:31 PM
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ive been trying to find out whether hang gliders have anhedral or dihedral built into their wings and found some useful information
its hard to tell if they have anhedral because from different angles the wing can look to be level (no dihedral or anhedral) or have loads of anhedral because of the sweepback of the leading edges, and plus the wing looks pretty much level on the ground being supported by its landing/ground wires but thats when the flying wires are slack!
it gets very complicated! lol

-----------------------------------------------------------------------

'most hang glider wings have effective anhedral. The reason being that dihedral makes weight shift harder or impossible'

'You can usually evaluate how much dihedral or anhedral a glider has by how it flies.
If it is very hard to initiate roll, but it holds a given bank angle very well, or even wants to roll level again, it has dihedral.
If it rolls into a turn easily, but the steeper you turn the more the glider wants to roll into the turn, it likely has Anhedral.'

'Dihedral is better for stability, but a glider that's too stable can't be steered via weight shift Anhedral causes roll INSTABILITY, which can be used to make a glider handle better (or at all). '

'swept wing aircraft are more effected by dihedral than non swept wings. The effect of dihedral on swept wings makes them harder to maneuver (even if they use control surfaces).'

Also, in flex wing gliders, there is some amount of polyhedral, since the leading edges flex and the sail has billow. Because both these features change during flight (symmetrically and asymmetrically) - by design - the nature of flex wing hang gliders can be pretty complicated. And then there is wing twist. That also changes (symmetrically and asymmetrically) in flight.'

'As to stiff (flex wing) gliders, . . . The stiffer the sail the more efficient the wing can be lift-wise. More efficient in creating lift = higher performance.
A looser sail = lower performance (but easier handling). Essentially, a wing that can asymmetrically change shape more easily, in reaction to pilot weight shift, is easier to maneuver. But a more elastic wing produces more drag (and/or less lift).'

-----------------------------------------------------------------------

im designing my wing with adjustable side flying wires so the anhedral can be adjusted to get the mix of handling and stability as i want it-
apparently a very small adjustment in the side wires can have a pretty big effect on handling and stability.

theres is also going to be a plate on the pullback chord (bit that pulls back the cross bar and tensions the wing) with key hole shapes in a row so the sail tension/leading edge angle can be adjusted for different handling and stabilty just by using a different 'keyhole' over the locating peg.

the hangpoint is going to be easily adjustable aswell just by undoing 2 clamps and sliding the hangbracket backwards or forwards so i can adjust the trim speed and the c of g.

ive been fitting the flying wires to my wing today and im really happy with the way it is looking! the 'a frame' is very rigid to the wing and its all looking pretty realistic
will post more pics soon when i get abit more done
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Last edited by mark675; Oct 24, 2009 at 01:27 AM.
Old Oct 16, 2009, 12:24 PM
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heres what i meant about the springs taking up turbulance,
when the trike/wing gets kicked around it doesnt affect the direction its flying in much, the springs will pretty much act like the pilots arms.. loose enough so the trike can do its own thing but you still have the servos to put in a control input,
if the trike and wing is mounted solid then the pendulum effect would make it overcorrect itself and may gain a swinging momentum?
this is the theory anyway.. we'll have to see what happpens in the tests

started the 'a' frame/ kingpost mount today that clamps onto the keel,
will finish it off tomorrow and then make the leading edge/crossbar mounts


http://www.youtube.com/watch?v=uR4zvmc7hio
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Old Oct 17, 2009, 07:29 AM
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finished the 'a' frame and king post mount this morning,
its made out of titanium and is very light and strong!

its got a clamping part on the bottom to clamp it to the keel and the 'a' frame mounts can be adjusted to change the angle of attack available on the wing
the front strut acts as a limiter to how far the 'a' frame can move forwards,
my old wing obviusly didnt have this which is why the prop could hit the keel and maybe why it stalled so easily

ive also started on the leading edge/cross bar mount so should have that finished today or tomorrow,

things are starting to move on again...finally!
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Old Oct 20, 2009, 02:03 PM
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very nearly finished the wing frame work now,
ive finished the leading edge/cross bar connectors and am cutting out the washout strut holders tomorrow,

i am using a very tightly coiled extension spring to join the cross bar in the middle so it can pivot up and down and backwards and forwards but cant go too far from the keel because it has a strap over the top.

the wing is looking really promising and even folds up into a thin tube shape when u push the crossbar forwards exactly like the real thing!

have just thought up an idea using ripstop repair tape or duct tape to make pockets for the battens so they can be removable to fold the wing up!
might just tape them to the wing for now though until ive got it flying properly.

should be testing the wing very soon so will have pics and videos of that



i found a video on youtube today that has got a perfect view of the floating crossbar moving when the hanglider turns, also shows the billow shift to the inside wing and watch it shift to the opposite wing to cancel the turn, looks really cool!

skip to 1:56 to see it

Starting Hang Gliding - Learn to Fly a Hangglider (2 min 54 sec)
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Last edited by mark675; Oct 20, 2009 at 02:11 PM.
Old Oct 28, 2009, 02:37 PM
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Combo Trike and Autogyro

Nice to see the interest in RC trikes has picked up since my very first thread about them here in RCG several years ago. Great progress Kneeboy!

MIA ROTO-TRIKE-PLANE Awesome!!! RC Autogyro- RC Trike Ultralight Microlight Nanolight Hanglider (4 min 5 sec)
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Old Oct 29, 2009, 02:03 PM
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thanks mario

yeah it seems they are slowly getting more popular,

i was like you.. couldnt find a realistic looking or flying microlight so had no choice but to build my own

always more fun and rewarding that way though

nice video, that autogyro is awesome!

cheers,mark
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Old Jan 02, 2010, 04:48 AM
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hi guys, ive been working on my microlight abit more lately between working, family stuff and my other rc models!! lol

ive done a bit more since the pics below were taken though,
ive made the fin abit lower, made a plastic ring that screws into the centre batten to clear the kingpost and allow the sail to shift (the ring will be fixed to the sail)
put heat shrink over the spring at the middle of the crossbar so it can flex but still hold the two halfs of the crossbar together.
attached the side flying wires and side landing wires
and a few cosmetic mods like painting the prop black with white tips and making a new balsa part for under the trike (painted black too) so the side skirts can be attached to them eventually
filled the pilots helmet with filler so its alot lighter now, just needs painting
also now ive moved the big servos i can make the throttle arm alot less complicated, before it wasnt at the right angle to get full throttle and even had the possibility of jammimg at full throttle without using some type of bellcrank type setup, but now the arm comes from a servo mounted to the area above the fuel tank so can easily get to the throttle arm on the engine, saves weight and hides the throttle servo.. much better!

ill get some updated pics on next week the ones below are about a month old but it just shows how the a frame and other parts are fitted

happy new year everyone!
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Last edited by mark675; Jan 02, 2010 at 04:59 AM.
Old Jan 02, 2010, 08:53 AM
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Nice work kneeboy! I'll be attempting to build an ultralite in the future but I've got 4 ARFs to take care of first (I'm halfway thru the first). Hope you can get some video of your project when you've finished.
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Old Jan 02, 2010, 11:03 AM
flexwing addict
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midlands uk
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Thanks mate,

i know the feeling about having other things to do!
ive got a hpi savage x 4.6 quad and a savage .25
3x thunder tiger electric bikes
4x nitro bikes
a OTO 1/8th scale bike and a venom gpv-1
a team associated t4 truggy
a eflite mcx and two align 450 helicopters!!

so i know exactly what u mean
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Old Jan 02, 2010, 12:07 PM
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:I watched your video of trial and error at post #109 and I've concluded that the 'hang glider' type wings ultralite is very difficult to get to fly right. Many variables there that have to be just right. Mine will be an ultra light with more of a conventional airplane wing.
I think my little ultralite is at the front of this thread....I've not messed with it as of late...it's the wind bag type. Extremely hard to deal with, especially takeoff and landing. It was introduced in the early 80's and my guess is no on could get it to fly properly so the discontinued it. There was no improved version after that so it's now history.

Just checked...it's post #7. The Barbie doll quit and walked off the job after the last of many crashes...she just couldn't take it any more. lol
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Last edited by Mr. Angry Eyes; Jan 02, 2010 at 12:12 PM.
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