Orion & Lithiums WOW

I fitted an Orion motor over the weekend (couldn't believe how small they are) and put my cut blades back on (I had Ikarus Tuning blades fitted). The Piccolo now flys great on the two lithium cells and I get around 20 minutes of flight. I may even get more but my brain is addled after 20. The lithiums are out of two old (less than 12 months) Nokia cell phones, 6210 I think anyway they work great for me and as we've updated phones at work and Orange don't want the old ones back I've got a good supply. I'm going to be experimenting with lots of battery combinations and I may even try playing with pinion and main drive wheel sizes. I'll keep you all posted on my findings. I've also noticed that with the Orion fitted I have the rotors spinning for ages after I power down. It's almost like I've got a one way bearing fitted. I have now got another problem in that the Picoboard won't supply enough power to the tail rotor. I have the mixing pot right on it's end stop and it's not enough. It was set a a whisker back from the end on the 310 motor. Any suggestions? I've just got a new JR XP662 tranny so I might try turning the PB mixing off and mix on the TX. Will this work? The Pic hovers now at just less than 1/2 throttle would cutting the blades in length get me a higher head speed and therefore more throttle and so help the mix problem or would it get worse. I await your comments eagerly.

Andy

Andy

[Pokey]

could you let me know how you modified the Lithiums to use with the pic. I have a lot of the nokia 6210 batteries and would like to know the best way of using them.

[Luap]

I don't have a heli radio so can't comment on that.
The only way I got the tail motor to keep up with the Orion was cut the tips by 10mm (from no cut tips so will probably work with less) and adding the HH to PB+.
Some people get it to work without HH on cut blades but I'm still trying to get that to work. Maybe using Jostalli's direct drive motor?
Did you put the LiPoly where the regular batteries usually go using a rubbe band?

Hi Guys, that was quick. I 'modified' the Nokia cells by removing them from the plastic case and de-soldering the circuit board at the top. I put a meter on the two tabs to determine + and - and soldered two cells together. I use a camlink charger I got from Cleanswing (www.cleanswing.com) and I've not had any problems. I've been flying these cells in my GWS Tiger Moth & Pico Stik for a couple of months.

The lithiums are mounted where my nicads used to go and I hold them on with a rubber band.

Andy

I forgot to mention that the Nokia cells have a +ve outer case so you have to ensure the two metal cases don't touch at all. I shrink wrapped one of the cells, soldered it to another unwrapped cell and then shrink wrapped the pair together. I know it adds a little weight but it's safer.

Andy

Andy - this may be a dumb suggestion - but what about extending your tail boom an inch or 2 to add leverage to the tails efforts??

I think my tail boom is slightly longer than stock already. I broke my stock boom very earlt on and couldn't find any 5mm carbon tube. The Ikarus part was way too expensive, so I found a kite supplier, Mullins, and got some 5.5mm tube. It's much thicker than the standard part (I guarantee it will never break in a Piccolo). I drilled out the frame and the tail rotor mount to 5.5 and it's been like that ever since. As I couldn't measure the old one (it really smashed big style) I guessed the length and I'm sure it's too long. I might try with an even longer piece though. The new boom is just a friction fit so apart from threading the tail power cables it should be an easy swap. Thanks for the suggestion. By the way the CF tube I got was about £3.00 a metre.

Andy

Andy - do you know how heavy the batteries are - r they heavier than std 7 or 8 cell nicads/nimh's?
20 minutes is phenomenal - makes me wonder if id finally be able to get my bell 222 flying for a decent time

Ozzie,

I'll bring my 1500mA Li-Ion pack to Watford on Tuesday. Note that this pack doesn't actually work (or hasn't yet) but that seems to be due to it not being able to deliever the current rather than being too heavy. It weighs about 93 grammes, which is pretty much the same as a 7 cell NiMH pack.

The Nokia lithiums are lighter than my 7 cell nicad pack. But 7 cells gives 8.4V and the lithiums are 7.2V. I would guess that a 6 cell nicad pack would weigh around the same as the lithiums. I don't know what actual capacity they are Nokia's web site is sparse on detail. I saw one data sheet that said 900mAH and this seems about right. I'm being careful about discharge as the BEC won't cut off until the lithiums have gone past their point of no return low end voltage (which I think is around 3V (x 2 = 6V and the BEC cuts off at around 5V, I think). As far a carrying weight goes I'm not sure. I think I'm very close to the maximum current I can draw before the cells 'shut down' and the weight of a scale fuse may tip the balance. I do know that there is good news on the horizon in the shape of the Kokam cells that should be available soon. One of those is 1500mAH and they are said to be good for more than 5C i.e 7.5A.

Andy