CP - Marginal power ???

I got a CP Piccolo from my father to convert it to brushless for him. Being curious, I first tried it with the recommended G310, then with a G295 with BBs. Battery was 8x250 NiCd as recommended.

With both motors, it has marginal power. Hovers at around 1500 to 1600, but when I increase pitch, head speed drops noticeably, and it climbs very slowly. I get only 2 mins or so out of GE. Max. Pitch is around 12 or 14 °. Neither the battery nor the motor gets hot. The battery is fully charged (~ 270 mAh).

I don't worry too much because it'll soon be brushless anyway. But still I'm wondering whether this is typical for the CP Piccolo.

Does anybody get good climbs and acceptable flight times from the G310 or G295 on 8 NiCds?

I should mention that this Piccolo is all standard, everything moves freely, the G310 was run in over night at 2V, and the G295 used is a trusted motor transplanted from my FP Piccolo which flies well. 9 tooth pinion on both.

I would never expect a brushed motor to perform well in a helicopter, but it should be a little better than this...

[pgoelz]

I can not help you since I have always flown my Pitch Piccolo as brushless. However, I find it a bit odd that you have poor performance because my flight time increased noticably when I went from cut blades and fixed pitch to collective pitch. I take that to indicate that the power required to hover is slightly lower on the Pitch Piccolo.

When you climb, are you at 100% throttle?

Paul,

yes, I am close to 100% in hover and at 100% when climbing.

I have tried putting the throttle on a seperate channel (slider). Even with the throttle at 100% all the time, it's the same thing - approx. 1700 at zero pitch, going down to 1500-1600 in hover and further down to 1400 or so after a minute or two.

I can fly, did a couple of circuits and pirouttes, but not too much fun this way.

Anyway, the Graupner XN12 / Hacker / Schulze 18he / JMP HF9 combo should do the trick. I'm even tempted to put in a GY401 and try a few loops and rolls and inverted before I return it...

[aymenpicc]

suzzane, i have a height problem of my own with the 7 cell, i tried an 8 cell once, but it didn't work, anyway it was nimh.
thanks

I am trying to get my CP pic setup and am having similar problems. I am all stock with picoboard and berg rvr with hs 50s. Part of my problem is that I am still using 7 cell 250mah. I have about 1600rpm@80% but it drops off big time when i try to hover.Even at 100% there is a big drop in rpms when i try to hover. I have an 8 cell nimh that i could build,but then i will be burning up the tail motors. i was not too optimistic before i converted it,so i am not too disappointed.keith

[pgoelz]

I guess all I can add is that your problems will go away with brushless! If I ever applied anywhere near full throttle at zero pitch, my AF010 would probably ge the rotor far past 2000 RPM with a 10 tooth pinion. I over and fly at about 1700 RPM for the first couple minutes, and it drops to about 1600 RPM near the end of the flight (8 minutes). At that point I still have throttle left for a climbout. And on 8 700 mAH NiMh I can fly for 8 minutes with nearly zero performance drop. After the 8 minute mark, I can fly to about 11 minutes before I cannot get out of ground effect.

Has anyone flown on a brushed motor and measured the head speed during the flight?

[ 04 March 2002, 00:52: Message edited by: pgoelz ]

Suzanne, that's the same problem I had when I switched to CP. As the pitch increases, the motor wears down. At full throttle, I was having a hard time staying out of GE. Also with the decreased head speed, it becomes so unstable it's dangerous!

I switched back to FP, now I'm flying my ECO16 brushless and CP.

I'm flying the CP with a 295 with bb's
Flight time 5min , with 8 x 250 sanyo nicd's
The same with FP flew for 6min .
Flight time was much less at high RPM .
Now I'm running (was running , broke the head last WE) at a much lower headspeed with much longer fligts.
Response is still pretty good .
setting the piccoboard with a good curve on the TX takes a Long time !!
going brushless will give you plenty of power
but flighttime will not be that much extended .
Due to a higher efficienty , you'll gain something , but the ideal RPM for a given power will have to be determined .

best regards

Koen VG [img]images/icons/tongue.gif[/img]

Hello Suzanne,

I had one of the first CP kits (November? ), and since
then have helped 2 other people set theirs up after
they experienced poor power- as did I.
When I bought it I had to wait a few days for some nicads
to make up an 8-cell pack, and I found nimh just didn't
provide enough voltage/rpm( I have since got 7mins with
new 700 sanyo's but power is poor, and is less than the
10mins+ I get FP brushed).
7 nicads( sanyo 250 ) cannot even maintain rpm as you increase pitch to lift off.
But when I made up 3 packs of 8-sanyo 250's it was
almost too powerful. I use the recommended G310 and
9 tooth pinion, flight time was only 2mins at first but
most of that time was spent at nearly full throttle
and full pitch. Using a flat pitch curve with all available
positive travel I set about the throttle curve so as to
hover at a lower stick position, I found that the throttle
curve ( brushed )needs to be S shaped
ie.almost flat between 0+25% and 75+100% and the hover point controlledonly by the 50% stick point , my curve is
0-10-48-88-100 and a straight living room hover gives me
4mins+, with 4.45 my best in a large hall.
This gives good power for 3min+ at 60-70% throttle, and
I dont enter the 75-100 throttle position until the end of flight.

I have swapped my piccolo bits around nearly everyday
as I like to have both FP and CP available to fly, and
I have had to play with my throttle curve everytime
to get duration AND power back. The basic formula
with brushed seems to be to use the power when it's
available, to lift at the lowest sensible pitch, whilst
not allowing the head to race when on the ground and in GE.
My setups brushed are always between
0-10-48-88-100
and
0-10-65-95-100
depending where I stick the servo.
My pitch travel is flat from -5degrees to the maximum
afforded by the pitch slider.

I think the std CP is very good as I get 4mins brushed
using batteries that charge in 12mins, a 7 cell nicad would give
me only 3mins maximum.
After all that though the brushless setup is something
else with 12mins+ almost regardless of headspeed.
In fact, I've sometimes nearly nodded off as I hover
in front of the TV when using Nimh.

Phew, Allan

[Max]

Hi Suzanne,

I have no experience of a FP Piccolo as I built mine as a CP heli right from the start. My Piccolo has no mods and I'm using the stock 295 motor. After about 40 flights I'm getting the following flight times,

700MaH Sanyo NiMh Twicell:
6 Mins continuous hovering + a further 2 mins in GE
7 Mins flying continuous left/right circuits + a further 2 mins in GE

250MaH Sanyo Nicad:
4 Mins hovering
4.5 Mins flying continuous left/right circuits

The Nicads give a much better climb-out rate than the NiMh cells. The rates aren't amazing, but my only comparisons are my glow-powered models, and these as you would expect have impressive rates.

Having said the above, I'm quite happy with my Piccolo's performance with respect to flying circuits although I would imagine loops and rolls would suffer. I need to pluck up some courage and try these - may be out side this summer...

I'm also looking forward to upgrading to a brushless set-up. I promised my self that I wouldn't do this until my 295 started to wear out. I already spent far too much money on helicopters!

Max