Interesting fact about GemFan

[OneStopRC]

So, long story short. I bought some 10" Gemfans for my 450 (Direct replacements), they seem to work pretty good, but at the same time added some led lighting all around my arms.

I thought something was odd, as my flight times reduced from 14 minutes running nothing but the 450, Naza and a Nano-Tech 2650mAh on the DJI 10" props. Getting concerned about the DJI props, I went over to these 10" GemFans. With the Gemfans on, I get 8 minutes flight time, move back to the DJI props, I am getting 10 minutes running all my LED lamps.

Without the lights on board and running, I think I would be back to 14 minutes again. These GemFans are going to be replaced with the New DJI 10" props, until one day I can afford the Graupners.

Just thought you would all like to know my findings on the Gemfan 10" Direct replacement props. I guess for $2 a prop, you can't really complain, and you really do get what you pay for.....

 

[Dewster]

Hmmm... I thought I was upgrading my props from APC to Gemfan. I could not comment on flight times because my flight lasted less than five minutes when one of the carbon fiber props cracked at the hub.

 

[OneStopRC]

Gemfan cracked or the APC?

I have not seen the Gemfans crack, although I am or was on my second set, due to a topple on my skids. :livid:

 

[OneStopRC]

Maybe I was a bit quick to jump on this.... I stripped my Quad down to what is was, no lights or anything. I used to get 14 minutes, but I stated the above was wrong, I am now getting only 10 minutes with my DJI 10", but still only just over 8 with my Gemfans 10".

The only change I made, was to buy a charger. The last charger I had before this, took many hours to charge my 2650 3S LiPos, I bought a Turnigy Accucell 6, so I am if I want to, put a full 2.6 amps into the battery. I do not normally do that, so I am unsure why my flight times are down.

 

[rexbirk]

Could your lipos be wearing out? Maybe discharge them to see what their capacity is? I have 6 Accucell6 Chargers and have had no issues with them. I charge everything with them. I use 4 cell Nano Tech's 3000 Mah. I usually charge them at 1.5 amps. Never been a fan of high charge rates.

 

[OneStopRC]

I was wondering that myself, not sure how that could of happened mind you. I did find my charger was a little out of calibration, but not enough to do much damage. The highest charge rate I have fed into my batteries is 2.5 amp, which is a little under maximum for my 2650's. Weird thing is, I am getting the same flight time out of my 2200 compared to the 2650.

Now when I used to charge my 2650's, I used to notice them only taking some 1400 or so mAh, now for some reason they are taking almost 2600.... I do not understand that, seeing as I am not going below 10.3 volts under load on a 3S. This only seemed to have started when I bought this Accucel6. Might try again with my other slow charger and see the results.

All cells balance out to a healthy voltage before shutting down to 12.6 volts 4.20 volts per cell.

So you think run it down on a discharge and see how many mAh it sucks out of them?