Eco Piccolo Micro Indoor/Outdoor Helicopter

TIPs

Below 2ft the stock Pic is a pain and skates around wildly! hold heli 4ft+ high by the frame n tail boom join, spin up and CAREFULLY try momentary hand launches, good for identifying trim setup issues out of GE without crashing. try not to hit u'r self or u'r own TX aerial or accidentally tip TX over enabling full throttle etc.

If you don't have 'dual rate' control and suffers from over correction during indoor hovering/learning. Try moving servo links to the inner most servo horn holes and/or experiment by forcing stock paddles up the flybar 15mm. results in a dumb/stable indoor machine and may help avoid over compensation syndrome.

By the time i learned to hover i was modifying the heli to get it more stability. Ball in swash mod, low pitch blades, higher head speed etc.. i reckon that whilst the stock setup's low head speed reduces crash damage, it makes for a quite unstable, awkward to fly heli. a nasty little floating slug that skates n twitches like a mad man in ground effect. i hear people do fly them stock but it never looks very pretty. Maybe i missed the point and that's just part of the fun.

Trim in the air: i always fine trim by holding at the tail/frame joint. spool up n momentary let off's and adjust trim to suit. takes a bit of getting used to but find it very useful. again, keep the rotor disk off eye level and/or use safety specs, be careful that a paddle doesn't fly off at ya! also whilst u are operating the radio with one hand u'r more likely to have a mishap. just use u'r loaf. u should have already checked u'r heli's centre of gravity by holding with two fingers at the flybar. i'v never got on with trimming on the ground but many do, whatever works i guess.

Ground Effect Skate: if u increase rotor speed and add some mass (steel flybar) u can almost eliminate GE skating, 1500+ rpm 1 inch high is stable enough.

How does the heli steer - Stick - Cyclic - Control paddle - Blade pitch
one way to look at it. on a stock Piccolo, if u tilt the swash plate forward (rear up, front down),... rotating paddles pitch back n forth in the air... the flybar at right angles roll and rock the rotor head during rotation... the result causes pitch to decrease for blades that pass the front of the rotor disk and increase pitch for blades as they pass the rear of the disk... the heli pitches forward. Now some of the downward thrust component is to the rear, so the heli starts to move off in a forward direction. (that's complete BOLLOX actually! but u live n learn) it doesn't matter too much, so long as it fly's.

Altitude control: on my cheap radio i added tape under the friction ratchet so now i have no a click friction throttle... but it makes very little difference to the 'yo yo effect'. i put it down to not having enough discrete steps somewhere in the radio/receiver/Pic+board ESC's combo and just live with it. Requires a little extra cranial work load poking the throttle up n down a tad for altitude (+compensate tail control).

If u have a more expensive radio (mine isn't) u can add some throttle mix to compensate battery voltage changes form inputs when u move a servo or that tail.

Outdoors the 'yo yo' is much more noticeable but for a different reason, much more to worry about, especially when hover/flying a small FP heli in a gusting breeze. The inherent characteristics of a small low head speed FP heli, trying to hovering at a fixed altitude being very dependent on any air movement changes and turbulence effects.

Cut Blades: i never liked cut blades very much (many do) but once u can hover and require some FF, anything has to be better than stock blades. Warning, if you cut the trailing edge of Tuning blades, don't cut too much as at the time i wasn't able to gear up the G-310 enough to achieve hover. start with a trailing edge cut of 5mm at the root to 2mm at tip, instead of the recommended 8mm root to 3mm tip cut.

Blade Tracking, Balancing and Vibration - a real pain. Or try this 'Rotor Blade Instructions.pdf'

Correct blade tracking is easy to observed by looking across the rotor disk profile whilst hovering. you should see that both blades follow the same smooth rotational track. if you see a split or oscillation between the blades then they are said to be out of track.
Bad blade tracking may give rise to unwanted vibrations and is an inefficient rotor disk.
Bad balancing will shake u'r heli to bits and normally shows up at certain rpm ranges or resonant zones.

1. Main shaft: check main shaft isn't bent or warped. to check, remove and roll along a flat surface. with carbon shafts, apply slight twist to check for cracks under load at each end.
Assemble heli without the rotor head connected. Spin up motor slowly and watch the swash plate to see if it oscillates. Don't over rev u'r motor without a load, it may damage some motor's internal windings.

2. Balance paddles: Assemble rotor head with flybar only (no blades). measure head to paddles to make sure everything is symmetrical n square. spin up and down going through the rev ranges and look for any oscillations or large vibration. if u have a vibration, add a 1/2 inch square piece of sticky tape to one paddle. if it gets worst then try the other paddle.

3. Blade Track: spin up until u see a blade spit. the carefully lower a felt pen down to just mark the highest blade tip. this is the blade with the most pitch of the two. sandwich a small piece of insulation tape between the blade mount, in front of the mount on the leading edge side. this should reduce pitch and lift for this blade, just by a little to match the other blade. go through this cycle a few times to get it perfect.

Note that paddle alignment must be correct (horizontal and square) or else it will cause tracking problems. u can use this to your advantage by strategic paddle alignment. The highest pitched blade can precede a slightly positive pitched paddle thus reducing the blades pitch during rotation. i don't like this method although it is a valid approach.

(Hornet CF tracking issue's with head stiffener installed (soft plastic head warps). I made some washers with insulation tape glued to one half, they can be rotated to adjust pitch on both blades until they match. Other than that, they are great blades, fly well, robust, buzz nicely.)

4. Blade Balancing: if the main shaft is true and the paddles are balanced but u still have bad vibrations at certain rev ranges then it may be the blades. add a 2x1 inch piece of sticky tape to the underside tip of one blade. if it gets worst then try the same on other blade.

Still got vibration problems? normally it's blade tracking n balancing, main shaft warp/cracked, balance paddles n flybar etc. can be most noticeable on hard surfaces spooling up slowly. any slight difference in lift on each blade as u spin up.
check: motor pinions, main gear, Cf shaft, steel shaft, rotor hubs, paddles, flybars, swash plates, blades, frame, head bearings etc. still at a loss... give up!

Tail Rotor Strike: i had a mild landing that unseated the rotor head causing main blades to fly off. not normally a problem but this time they sheared off the tail rotor. STRIKE! oh well, at least it wasn't another boom strike.
CA glued the tail rotor back together. last time i broke one i used match wood for splints, works great but looked a bit rough. This time (different set) i cut out small black news paper segments to fit. saturated the repair area and put the paper in place to soak up the glue. dries rock hard and so far so good.

Use steel main shaft as it will last longer than the CFs i'v twisted up so far.. i'v had 2 carbon shafts crack or warp. now use a solid steel with a bit of a weight penalty.

Flybar length and rotating Mass: a longer flybar means the paddles are further out and travel more distance each rotation, so cutting through the air faster, increasing cyclic response.
if u'r flybar is made out of steel and longer, the heavier flybar will increase the amount of rotating mass and will have more resistance to movement, feeling slightly more stable. replacing the CF flybar with a steel flybar (2mm x 175mm?) had a similar effect. less twitchy for indoor hovering but more sluggish outdoor handling. so try a standard length steel flybar. depends what sort of setup u'r aiming for. either a stead dumb down hovering indoor ship (ie. short flybar... etc.) or an agile stunt copter (raise rotor rpm/longer flybar/lager paddles/further servo horn holes/full Tx rates etc.)

Loss off lift and flight duration, check: slipping main pinion, battery voltages loaded and unloaded, charging ok, no negative pitch on paddle alignment any unwanted friction or drag, gear mesh should be loose, not binding, use light weight training gear, try different pinions 8/9/10T

Worn rotor head, may cause boom strikes: to help avoid boom strikes, u might try tightening up the rotor head setting on the head bearings. as the head gets worn it becomes loose and in a moderately hard landing, particularly if u'r tail hits the ground first u'r likely to get a strike. one method is to apply CA glue carefully in strategic locations, to tighten up the fit of the head bearings in the rotor head.

Head Stiffener: if u'r still having a lot of 'pitch up' problems in Forward Flight, try some kind of home made head stiffener to flatten out the blade profile under load. tape cassette case plastic is a bit thing but with raised spacers can be a quick n easy prototype in few mins.

Dead Tail Motors: try using a dead stock tail motor and bodge in some heavier duty brushes (from an old RC car servo motor). not easy but that's my current method for long lasting tail motors on 3x1020 Kokams (12v - 9v operational). 3 hard months now and still going strong...
As for the Piccolo's ever lasting tail motor solution... use a high frequency tail ESC (Schulze 105E) and/or a tail motor with carbon brushes, like the Pro tail motor with a grey end bell. but they are more thirsty on current (duration will suffer) and as they are heavier u may find it difficult to balance the centre of gravity, particularly if u fly 2 cell Kokam packs.

Pinion's: changing main motor pinions don't effect an FP's hover head speed but can effect max head speed, motor loading n efficiency. on u'r fixed pitch heli, if weight and pitch remains constant, the cut blade's required rpm to achieve hover is constant. by changing the gearing u are changing the work load u'r motor has to do. weight vs. pitch/rpm vs. voltage vs. current draw vs. efficiency n temperature curves. overall hover head speed will ONLY change if u alter blade pitch or change the heli's AUW (weight).

When ever u change the motor, the voltage, the blade pitch (head speed at hover) or the overall weight then u will probably have to recalculate the pinion gearing for efficiency, duration and heat reduction (current loading).

Basically, what ever u modify ther will be some thing to consider some where. The trick is to come to some sort of compromise and build u'r ship for a purpose. that is, setup for indoor hovering (Orion on 2 cells, 20 mins durations, gearing and blades) or outside flying (G310 on 3 cells, 20 mins duration, with tail motor sorted).

Hot Motor Temp: (eg. Orion on STOCK blades)
- reduce overall weight (lighter cells, reduces power required hover)
- reduce blade pitch (increase rotor and motor rpm at hover)
- reduce voltage (not really an option for 6v Orion)
- reduce pinion size (reduces current draw)

Not Enough Lift: (e.g Orion on CUT blades)
- reduce overall weight (lighter cells, reduces power required hover)
- increase blade pitch (increases current draw, lower rotor and motor rpm at hover)
- increase voltage (not really an option for 6v Orion, cells may not have good load voltage, check)
- increase pinion size (increases current draw, "with height auth tail motor" can cells deliver?)

Problems operating at 12v: Stock tail motors last anywhere between 6mins-6months. stock tail motors are quite fragile and the brushless don't like high voltage pulsed at low frequency from a Pic+ board ESC. either switch to a high frequency ESC and/or upgrade to a heavier high authority tail motor (some thing with carbon brushes). i fly 10.8v using a home made 'modified brushed' stock motor.

9v-12.6v, 3x1020 Kokam cell setup issuse:
I'v been running a Pic+ board, G310 with 3x1024mah Kokam cells (9-12v operational) for 5 months without any problems other than the motor get red hot when static hovering for more than a few mins. I don't think the board
is spec'd to run any higher than 9.6v and there are some other issues like the BEC 5v servo n Rx supply may not be to happy either... but lots of flyer's out there have not reported any board problems yet.

Another problem with 3 cells packs is that the Pic+ board uses low frequency speed controllers. This means that if you use a 12v pack the ESC pulses 12v to drive u'r 7.2v tail motor and they can suffer brush burn out in minutes.
To get around this you have to:
- bodge in some heavy duty brushes (what i did, see web page 'Upgrades')
- use a power hungry, hard to balance High Authority Tail motor/Pro carbon brushed (can draw 2 amps so duration could suffer)
- use a separate high frequency tail ESC (£35 for a Schules 105E)

it is very hard to get a Pic on 2 cells to escape GE at 6v loaded. that's the principle most use for detecting when it's time to recharge. 3v per cell minimum under load is the general safe margin for u'r cells without causing damage. some flyers go as low as 2.5v but it's not very practical/useful to do so.

when i run a 3 cell setup i'm able to gear so that i'm also in GE at 9v and the power noticeably falls away. not sure how easy this would be using an efficient brushless motor tho.

How to learn to fly a micro heli outdoors: here


In the early days and bad idea's:

Once you have a good setup! (temporary short lived idea): Suspend your piccolo from the roof by it's rotor blades!!! I have been advised to use a training undercarriage frame but in restricted space I came up with a new idea. Well I haven't seen it on any of the bulletin boards yet. I mounted a fishing rod from the far end of my attic, wedging it between two chairs, hooking the top of the rod to the apex (highest point 7 ft) in the middle of the attic. Then I suspended the Piccolo 2ft+ above the floor (to escape ground effect problems). I used a spinner joint to stop the fishing line from winding up when the blades spin up and simply threaded some line through the center of the rotor head under the fly bar. Add a 1/4oz (small) weight to the rod line by the real to pull in slack line once the helicopter rises. The advantage of this system is that it helps you learn to hover out of ground effect and without crashing when things go wrong. When you loose control, dump the throttle and the helicopter just gentle spin down, restrained from hitting the surrounds by the fishing line. Remember that you are supporting the aircraft by the rotor blades and in some situations it is possible to unclip the blades, plunging the rest of the body to the ground. If you lay a thick quilt down then most of the time you will only need to realign the blades and fly bar setup.

Note that these photo's also shows my make shift rotor head stiffening brace using a cut n drilled clear plastic CD case edge ;) This modification is not required for Piccolo suspension training harness.

To take off you can hold the landing skids and slowly spin up to rotor hover speed. Initially I used a platform to take off from (Piccolo box + 8 inches), until I got a little more confident and got fed up with taking off, panicking, aborting and crashing the blades into the platform.

Safety: It might be worth colouring the blade tips so you can see where they are. Make sure your control blades a on tight as you done want one flying off when the Piccolo is at head height and 2ft from you face! Be careful, I did put my hands in the blades at full speed (by mistake of course) and it hurts. I only suffered a cut finger and think I got off quite lightly (that time). I take no responsibility for any injuries you incur from this procedure, it's at your own risk!!!

Then after I was a little more confident I built a training frame. Constructed out of box tube plastic sheet cut down strips and fishing line ;}

Now able to sustain unstable hover for 30+ seconds.

Breakage's to to date:

-Rotor hub plastic bearing pin wrecked and glued many times.
-Intermittent gyro fault, gyro stops working due to bad board soldering
-Swash plate lower stabilizer spike broke twice
-Chipped main rotor blades after high throttle chair impact
-Split carbon ski struts
-Tail carbon fiber thin ski snapped twice

...couple of months pass, now able to fly many packs without every crashing until you try to learn something new.


RealFlight G2 Simulator:

Sadly no good Pic models are simulated. but what i call a Piccolo might not be what u would recognise and modelling a stock Piccolo isn't the greatest heli in the world to fly out doors, if u know what i mean (blades!).

u can fly any of the heli range supported, they are very good or u can modify many parameters to emulate u'r own Pic's characteristics. although u'll probably end up with a gas powered CP machine that is greatly over powered compared to a stock Piccolo, again u can modify it to suit. the larger heli's are relatively easy to fly, so i scale everything down to result in a twitchy little thing that can test my reflexes, coordination and orientation skills.
the general fly skills required to control any of the simulated heli's will help u a lot, particularly if u'r looking to increase u'r flying abilities from hovering tail-in to nose-in and out door forward flight, circuits and onward to more complex 3D aerobatics. what ever, it's generally good fun, educational and a whole lot cheaper when u crash n trash u'r heli.

Trying to simulate a Piccolo tail behaviour.
A gas simulated heli, even with no tail fins seems to tail vain very easily. this make flying about considerably easier as which ever way the heli moves, very quickly the nose comes round automatically. this makes flying circuits and fig8's quite easy. compared with flying a Piccolo (even with tail fins) where u have to feed the tail round all the time at speeds below 15 mph. To work around this i found if i wound up the Piezo gyro setting i could simulate tail behaviour better.

i would fly the 'Electric Wot Not' heli but i haven't managed to reduce the extreme 'pitch up' it exhibits. also the model seems to fly itself. my slightly modified Piccolo no longer suffers from 'pitch up' so i don't want to simulate it.

Anyway, here's my basic sim setup for close(ish) modelling of my current Piccolo (HCF blades) flight characteristics. Of course this may be a world away from any one else's setup.

Heli - edited Dolphin (.46 heli) set to 0.5 scale
Misc- Inertia % 55 55 88
Tail Fins - No Horizontal Tail Fin and as little a Vertical Fin as allowed
Fuselage - Weight 3bls
Gyro - Piezo 60% 100 100 (tail will jump about/wag but stays put without much weather vain)

Using a s/w radio
Joystick - Cyclic
Mouse - Throttle (50% would out power my Piccolo)
Keyboard - Rudder (redefined 1 - 9 or Q - T)
Soften up heli response with exponential/dual rate settings etc.

Options->Miscellaneous Physic Resolution 200% Time Multiplier 150%


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