Having problems with lil' skeeter

[all_fly_all_day]

A few days ago i built another skeeter (my 3rd) from memory (just proving to my mom that cleaning out your room can be a bad thing, especially when you accidentally* throw away a good set of plans:rolleyes: :mad: ) anyway, after i look at my wood i realized it might be lighter to carve the skeeter out of a brick:rolleyes: . I finished it all and weighed in close to 40g with 3 ni-cads. Im getting pretty good flights. it doesnt seem to be "dragging" at all. I can even loop it with a little dive. But i read these 50 mah ni-cads were suppost to give you almost 5 minute flights. Im getting somewhere around 1-2 minutes. It was the same situation with all my other skeeters, and they were all under an ounce. So im wondering if i have to do something with these cells so they will give me their full capacity? I have overcharges them once or twice a little bit but that was still after my first 2 skeeters. Maybe ill just buy 150mah NIMH cells instead...

[Mike Taylor]

One 140 mah LiPoly will fly a Skeeter for about 10 minutes. They take a long time to charge, so extra, replacable batteries are a good idea. They also only weigh 3 1/2 grams, so you save weight.;)

[flyinhigh]

Hey All Fly All Day
Im thinking that these lil cells take a lil longer to fully cycle then the bigger cells.How many charges do you have on them?What kinda charger you using?They may just need a couple more cycles?My supernova usaully charges new cells way under the rated capacity then all of a sudden will increase.On my 270mah packs its throwing in around 350mah now,and the packs performance and power increase is great!
This may not be the problem though and if not let us know
Good Luck
MIKE :)

[all_fly_all_day]

Thanks Mike T. and Mike,

Yeah, still saving for those Li-Polys! I might be buying a tigermoth first, I dont know. I am using a power supply unit. I usually charge them at about 4.2v and they seem to get warm in about 30 minutes. Another thing that might have done it was my not so good soldering job on them. Maybe I overheated them witht eh soldering iron? Another question that I have, would that gearbox and blue prop from Bob Selman give me longer flight times? or just increased thrust? Thanks again guys

Brandon

[Mike Taylor]

I use a charger I got from WildRC.com. It has jumpers to select from 1, 2 or 3 cells in series, and another jumper for selecting from 100 to 1000 ma. It takes close to an hour for a full charge (sometimes more for run-flat 240s charging at 200 ma), but nothing ever gets very warm. You may be over charging those batteries if they are geting hot in a half hour. Maybe you could find some one in your area with a dedicated LiPoly charger and check your batteries to see if you are geting a full charge or not...

[all_fly_all_day]

I think you might have misunderstood me. Im using the Ni-Cads. Not the Li-Polys. How bout that motor gearbox and blue prop bob sleman sells? will that work better? what kind of results will it give? More run time? more power? I woudl be using it on the lil skeeter.
thanks guys

[Mike Taylor]

Sorry. My bad. I didn't read close enough.
I don't have any experience with the blue props. Sorry I can't be of any help...

[dhurd]

Brandon,
I suspect that your short flight times may be due to the fact that your Skeeter is VERY heavy. 40 grams is WELL over an ounce (28.6 grams or so) so once the nicads come off the initial "hotness" of the charge you may not have enough power left to keep the Skeeter in the air. I would try and lighten it up a bit by building it with contest grade balsa and see if you don't get better flight times.

Dan

[Mike Taylor]

My Skeeter is ~3/4 ounce (20-22 grams), and it is still fairly quick. Of course, that is with a single LiPoly cell (under 4 grams).
At twice that weight, yours would really have to scoot to stay up... If you don't want to make the leap to LiPolys, could you get NiMh cells in that size? They should be lighter than NiCds, and you could use the same charging system. Maybe you could shave some weight that way... Otherwise you might want to scale it up just a bit and/or use lighter wood.
Also, there seems to be a quiet price war on LiPolys going on. They are MUCH cheaper than they were 3 or 4 months ago... I got over 18 minutes on 1 230 mah LP cell in a Lightning, AUW 34 grams...

[all_fly_all_day]

Dan

The weight is problably contributing to the shortened run time of the skeeter. But I have built lighter skeeters that were at an ounce and i still got these short run times. These Ni-Cads are alright if i want to charge them real quick to get outside flying, but other than that they dont offer much.

Mike

I have been to several sites that sell 150mah NIMH cells at 4g, but you have to buy at least ten of then ($0.96 each) plus the least expensive shipping method was $26.00! That turns out to be pretty expensive batteries. I was thinking about buying those 120mah 1/3AAA NIMH cells from cloud9, but i dont get why they are rated at only 1.1v? That would just decrease my power, which is what im trying to gain here.

[Mike Taylor]

Ouch! $26 shipping on a $10 order?!?!? Well, LiPolys are definately cheaper then!
If the batteries you have gave you acceptable performance before, maybe they just need a deep cycling or two...