Eco Piccolo Micro Indoor/Outdoor Helicopter
Upgrade n Mods (chronological order of technical discovery):
Please note: DO NOT take too much notice of the mods mentioned here as new products and technology has moved on since 2003.
Alternative Gallery plus upgrade info
motor (£50) 8T-10T pinion or G310 12T-13T pinion
Motor - Orion Elite Modified (Brushed)
Orion offers better efficiency, more power and long
life span if properly setup (blades/pinion/weight/battery). No real
maintenance just don't cook it! Don't stress the little motor too much
n fly a light setup; no heavy lifting or body kits.
Consider the following upgrade path/setup for a great little heli:
Motor and blades:
Orion - setup
Ruff guide for Orion Elite 2x1020 kokam cell powered (A.U.W. 200-240g) FP Pic (near stock Eco) with Hornet CF/GF blades. 50-75% throttle at hover out of GE:
50%, high current 'hot' dangerous motor(s), 10+T/100T, 12-25mins, ~90% cell capacity used.
75%, low current high motor rpm warm safe motor(s), 8T/100T, 8-14mins, ~60% cell capacity used.
Gearing is down to personal choice and as MS blades do seem to differ in pitch from one pair to another, u may have better success adjusting pitch. i aim for ~1550 rotor rpm, out of GE for stability.
Orion - performance (specs)
Better than my 310, ~20% more efficient, 2997rpm/v, quiet, small yet can be fragile and voltage restrictive. Brushess can burn out, over revin and heat will melt resin core.
Out doors the other day, i really gave the Orion Elite (Hor*** CFs ) on 2x1020 Kokams some stress and have to admit that climb out was a bit poor but the ship did respond eventually (4amp limit for these 7.2v nominal cells maybe?). Even with a high or low loaded Orion gear-blade setup that hovers at 80%(8T low load) or 50% (10T high load) throttle, I can see that in a few months i will be wanting more power, maybe brushless n separates. Saying that, it does fly good enough for my learning curve at the moment.
Money would have been better invested in a brushless motor, something like a Mini AC 1215-20 (49g 3000rpm/v) + Pheonix 10 + Y cable n pinion from www.e-flight.co.uk £100 + change.
Blades - MS Hornet FP
Prefer Hornet Carbon Fiber or
Glass Fiber blades (FP Pic G310 motor), as they are more stable for
the confined space hovering i do at home BUT i had to up to a 13T metal
pinion gear (i think 12T might have been a better choice) as the CF/GF
blades have less pitch than the stock Piccolo and a higher head speed
is required to hover. I saw some where that a stock Pic FP is 1400 rpm
and the Hornet is closer to 1900 rpm, 1400 * 100T/9T = 15555 motor rmp,
1900 * 100T/13T = 14615 motor rmp. Caution, i couldn't get any flight
duration out of ground effect with a G310 and 10T pinion, it's just
too under geared for the head speed required for lift off.
Longer metal screws and washers required for blade mounting, i mount mine on top of the rotor head. When mounted on the top side of the rotor head they sit very flat with a plastic washer and an appropriate screw that just beds into the existing hole. Or u could remove the divit that sticks out of the under side but i never did as i was sure i would need to use stock blades at some point but never did.
Mount on top of the rotor head
- Kokam Lithium cells (Lithium Polymer User/Safety Manual)
2x1020 kokams flying for 10+mins with light setup (210g)flying/hovering before cells at 6v minimum. Kokam 1020 weighs about 20g per cell. so 2x2x1020 (4ah!) = 85g with wires (3oz), which is lighter than my 3.2oz 8cell 700mah twicell Nimh pack and would expect 20-40mins flight times if pushed and motors not over heating.
Fly 210g with 2 kokams for 8-14mins+ but being lighter slightly increases ground effect stability and i like to fly in GE at home so sometimes prefer to use a heavier battery pack. It's a trade off between flight duration, stability and motor stress. one advantage for running a light setup is cooler running motors.
Wes-Tek Kokam charger board: had a problem when i tried to charge 2 cells in my car (12v). sometimes it would charge and other times i had to start the car up to kick the cycle it into life. ??? so it does work but may be marginal. fine for charging one cell at a time as the voltage difference is greater, takes too long tho.
no good for 3 cells even on a bit dodgy with a 13.8v 3amp mains supply. for 3 cells i use 15v 800ma AC adaptor i found laying about. of course it never charges 3x1020mah cells at more than 800ma but it gets there ~10mins later.
found that the Wes-Tek charger puts in slightly more charge if u charge individually. As this extra charging is at the end of the charge cycle, the current is very low and takes a long time to achieve. it seems that the cut off voltage is less accurate (lower cut off) when charging 3 cells in series.
initially charge all cells individually, then top up
charge all cells individually every month or so to rebalance.
I notice a slight power/voltage drop off over the first 30secs of use and sometimes nudge tail/rudder trim a click(s) to compensate. The cells then discharge pretty close to what the documentation says. At the end of a discharge, power falls away quite suddenly (over 20sec) as load voltage drops off 6.5v...6.0v.
Please read the Lithium Polymer User/Safety Manual
Before tweaking pitch, WD40 on bearings and gearing I could achieve 12 mins out of GE then 3 mins in GE. Now accurately timed 4x5 min hovers and one 4 min weak hover until unable to climb out of GE, with 5-10min rest periods between flights (for me and the Orion). Total of 24 mins and 16 secs.
Moving up a gear (Orion with 10T) and adjusting pitch with tape under mounts I can completely utilize the 2x1020 kokam pack until 5-6v (under load) in GE. This causes my Orion to get quite warm after 5 mins of hard 3ft hover at ~1/2 throttle with a head speed of ~1500-1600 rpm. At which point I chicken out and let the motor cool (40-80 deg.C, hot to the touch but not as hot as a fresh cup of tea), tail motor is fine tho. 2 cell kokam pack supplies 1 amp for 60 mins so 60mins / 24 mins = 2.5amps average hover current (assuming the cell is drained).
There's no hard fast rules, it's very dependent on personal setup, blade/pitch/motor/pinion/heat stress/weight etc. to get maximum efficiency. 12 mins of safe flying may be cheaper and more desirable in the long run.
Flight Characteristics (see also Flying)
I've managed to hover quite well n solidly in calm air
by dumbing down the Pic responses, using 'dual rate' set very low, increasing
rotor speed (low pitch blades, higher stability) and smaller control
paddles (Hornet, Pic paddles are too responsive). whoops, almost forgot
plate ball insert mod. All help to enable very small precise
inputs n corrections without over compensation. confident hovering in
confined 4 ft square areas even in ground effect as low as 4 inches.
but in confined spaces with high surrounding I'm not so happy due to
increasing back washing turbulence.
With current setup I noticed 4 still blades, at 10"
in ground effect, under what i think was a 50Hz strip light (UK 240v
Piccolo FP (165g/5.8oz no batts), Orion Elite motor 8T/10T pinion or G310 12T/13T pinion, Hornet GF/CF Blades & paddles, Swash Plate ball insert(www.helinut.com), Ali hub(www.helinut.com), Skysports 6, 2 x 1020mAh Kokams(45g/1.58oz).
Pushing the G310 on 3 cells (10.8v nominal)
3x1020 Kokams (original type) 2 up front
and 1 under main gear centre (plug n play).
MIA landing gear, Ball
in Swash mod
Looking at the numbers,
i can't see how my heavily mod'd FP Pic+ G310 and 12v supply can duration
hover cool, without killing any performance gains? i just expect a trade
off, that there is going to be a heat management problem that i can
live with (land every 5 mins if hovering at room temp) for the given
Using a metal flybar does add some slight stability as u will have more mass rotating and swash plate inputs take a little long to respond.
For good FF for a FP u want a flat blade profile (no cone angle) and the faster the head speed the better. try stiff low pitch carbon fiber blades and head stiffener mod (eg. FP H**rnet 080 with correct gearing).
For bodging the stock tail motor brushes i use the heat of a soldering iron to force fit bigger brushes into the plastic end bell. the hard bit is bending the new brush leaves to get a similar angle of com contact to the original brushes. getting it wrong effects the timing or may spin backwards or just short circuit. so make a quick sketch of the originals and test with a single cell direct. to begin with the tail motor did run slightly rougher than stock but now i don't notice it.
If only we had some decent weather in the UK... anyway last time i was outside i reckon at ~1600rpm i was able to get ~30mph in still air. where as stock blades at 1100rpm should get nearer 20mph.
i don't know how to work out all the theoretical maths
involved. it has something to do with stable lift remaining on the retreating
blade. somat like 1/3 of speed at wing tips.
51cm wing span 1100rpm Piccolo = ~20mph forward flight
Near full throttle on a full charge
of 3 cells my 310 can pull ~2000, so at best i might reach 35mph...
Alternative head speed tacho, look through the rotor disk at a flashing light source of known frequency to observe still blade patterns.
50Hz TV screen or 50Hz UK fluorescent light
60Hz US fluorescent light
70Hz monitor screen
Approximate rotor rpm u can work out motor rpm, 96T/9T * 2100rpm = 22,400 motor rpm
Kokam 3x1200mah HDs (5C or 6 amp peak discharge)
I'm not sure what the life span of the old 1020 cells is supposed to be. I bought 3 cells 11 months ago. The performance was ok with 12-16 mins of good power and the remaining 8-12 mins ok for hovering about. It's hard to say how many cycles the cells have had, estimate 200+. Not always a discharged before charging.
Anyway, over time the cells began to fade more quickly,
that is even after hovering for just a few mins the cells would be noticeably
soft on power and no reserve power for climbing etc. bringing the cells
to this point and watching a volt meter i could see the voltage was
dropping to 9v prematurely and unable to supply the current required.
Assuming the Westek and supply is charging and working properly. i now
have a new pack of 3x1200HDs.
Had to cut my front retro fit landing gear mount back
and managed to hang the cells from on the heli in the conventional manor,
like u would with an original NiCd pack. with a beat up canopy just
fitting around them, for good CofG (with stock like tail motor).
Direct Drive tail
After chatting to Hogster i ordered one from e-flight
uk for £9.50 and fitted using two 1 inch pieces of TV coax cable
cover, one to slip over the tail boom and the other cut open to hold
the motor and joined by glue to the other. Then painted it all black
with white blade tips (couldn't stand the orange).
I'm not sure whether the DD tail draws more current
over old my geared stock tail. after i got the prop the right way round
(all opposite), i had to reduce the mix on the Pic+ board quite a bit,
so it should be drawing less juice in hover, right?
First indoor impressions... i'm getting used to it... i always thought the geared tail blades looked way too big, had got used to them, now the tail looks way too small. makes a buzzing noise now but the tail response is very sharp, quick to respond and solid.
Hover 1550 rpm. Outdoor average 1700 rpm. Max throttle
briefly 2100 rpm
The Next Step
Current brushed motor:
Moving up to a brushless main motor plus additional ESCs costs £££?
Hacker B20-41S 40g, 2195 rpm/V - F/P Piccolo
Separates Fixed Pitch wiring diagram here
Brushless Collective Pitch wiring diagram here
Piccolo component reference for Rx's, Gyros,
ESCs, Mods etc. here
CD ROM brushless motors DIY here
Himax 2015 2800rpm/v (48g) + Phoenix 10 $100 combo April 2004
The good news is that I will soon have my hands on a budget brushless Himax 2015 2800rpm/v (48g) + Phoenix 10 $100 combo... www.toddsmodels.com in the post. I've heard some bad reports about Himax motor's efficiency from private individuals on the other RC groups but decided that those results may not be that accurate. A $50 motor may not be as light and efficient as some of the competition but at that price I'll live with it :). Also a 2 mm shaft will save money by using my old pinions. The G310 has had a hard life at 11.2v and I hope a smoother motor will help achieve slightly better altitude control in hover.
I'm so locking forward to road testing it. my soldering
iron is on standby whilst I wait for the post to arrive (tax man 'get
ya hands off!'). respect is due to the old G-310 holding up so well
beyond spec. other than the axel bush clogging up with carbon particles
(removed with a WD40 wash), it's lasted well.
Himax 2800 brushless vs G-310 in an FP modified
Himax 2015 2800 rpm/v + Phoenix 10 combo - $100
Ripped it all out the bag, slapped on a 2 mm 8 tooth pinion, made a 4 mm riser motor mount, soldered up. disable ESC brake and cutoffs, ready to roll.
One tip for the 'Y' cableless, extract the signal pin from the Phoenix servo connector, take a normal sowing pin and push it through the signal connector and piggy back it onto the throttle signal pin from the Pic board to the Rx. an easy bodge that is working so well and secure, I'll probably leave it that way.
Real RPM: I did a quick max blade rpm test using a microphone to sample the blades at 44100 Hz, then counted the samples taken between 2 peaks (one revolution). eg. for my current ~310g Airwolf FP setup's hover rpm: 44100 samples per second / 1506 samples per rev = 29.28 per sec. 29.28 X 60 = ~1756 rpm. In the process I had a little scare as I managed to hit the mic with the blade tips ;)
I should have the patients to wire up a multimeter and measure the Amps so here's the only comparison I can currently give:
Both setups hover around 60-70%.
G-310 10T/96T on pic+ board, 11.2v
Himax 2800 8T/96T on Phoenix 11.2v (standard timing,
auto calibrate throttle range or fixed range)
200 rpm (+9.6%) doesn't sound like much but it makes quite a bit of difference when you need to climb out in a hurry. the amount of extra energy required probably increases by the square of the blade velocity increase.... mmm yea, some one might find the numbers useful?
using the correct gearing?
good news for anyone out there who accidentally switches off their Tx before powering down the Pic board, now it doesn't go full throttle n wiz off, the brushless ESC shuts down.
Feels like an Orion with more grunt on demand and a
bit smoother. Don't yet know about duration and efficiency and still
gets quite hot inside and Airwolf kit. So far so good.