booke23

Hi,

I recently upgraded the stock battery pack of my honey bee FP to a 7.4v lipo pack. (its the TP 2100 Mah pack....big I know, but it only weighs 100g/3.5 oz)

However this seems to have caused me a problem with the heli.....basically as the voltage of the pack falls during use, I find the tail seems to cut out every few seconds....only for a very short time....but enough to induce significant yaw....this usually starts happening when the pack voltage gets below about 8v

Additionally if i spin up the rotor to a very low speed the motor seems to "surge".....as if full power were applied for a millisecond......it will occasionally do this even with the rotors stopped, but with enough force and speed to cause the blades to be moved in their grips.

I can't really work out what is causing this.........I have tried the old 8.4v NiMh pack and the above symptoms vanish.....so I have to think it is associated with the decreased voltage range of the lipo (I used to experience a similar loss in tail control when the Ni-Mh was almost discharged.......I used it as a cue to land and recharge).

The symptoms I describe make me think the Gyro is having problems at lower voltages....or maybe the ESC.........I don't think it's R/F interference or an RX problem, as the servos always function perfectly. Any ideas on how to solve this??......more efficient motor to lower current draw....maybe I'll have to get an 11.1v pack?

Any of you guys running the honeybee on 7.4v liop's experienced this? I'd really like to solve this....I'm getting 30-35 mins flying out of this pack!!.......but can't strand the glitchyness!!!

tanasit

Mine came with the 11.1 volt pack, so no cut off problem.

MASTER YODA

My Feedback: (10)

Im not sure, but have you ruled out the possibility of a radio glitching problem?

booke23

I can not say that it is not radio glitching/interference, but I'm pretty sure that it is not as the servos always work perfectly......the glitching only effects the speed control.

Rob_k

I have the 7.4v 1800 mah pack and notice as the voltage drops during flight, I have to keep trimming the tail to give more power to hold it steady. I found some 2/3 AAA batteries at this site's sponser and am going to make a pack with 8 batteries.

They are .27 oz each and together will weigh slightly less than my 7.4v 1800 battery which is 77 grams. But with the pack I will get
2800 MAh and 9.6v. This should be enough to hold steady and for normal flying.

The link is here: http://www.unipros.com/cbpsite/custo...sion_id=244168 and are the CBP-350. If I understand correctly, the are 350 MAh each.

racemiata

I have had over 40 flights with my 2-cell lipo with my honey bee. No problem with cutting out. Tail trimming does drift off as the battery drains but that happens to the stock 8.4V NiMh as well.

BTW, when you put 8 350mAh 2/3 AAA cells in series, you get a 9.6V 350mAh battery. You don't multiply mAh that way.

Rob_k

So is the drifting caused by the battery or the stock ESC?

booke23

If you guys are not having problems with the 7.4v packs, then maybe my ESC is failing............although when I go back to using my old 8.4v pack, the increased voltage seems to cure the problem......maybe I'll replace the FET's and see if that cures it.

disguy2k

I think what it could be, is the low voltage cutoff on the Esky gyro/ESC box. Some might have a slightly higher cutoff voltage than others. We configured the HB around using the Align 11.1 1800 mAh LiPo cells, and after a bit of tweaking found it to be alot more stable than using the 8.4 NiMh packs, as there was just so much more current available to run both motors at the same time. Although we had to decrease gain and proportion a bit to actually stop wagging, which we couldn't even achieve with the 8.4V packs.

racemiata

If it's because of low-voltage cutout, you should see the red light at least momentarily.

booke23

Is the low voltage cutoff adjustable on the esky 3-in-1?

racemiata

Don't think so. Just my guess.

My experience of low-voltage cutout is more gradual than what you described and will only revert when I lower throttle til the red light goes out. Also, it cuts main motor directly while tail motor cuts out only when gyro senses the reduced torque from the reduced power to the main motor. The only time I got quick momentary cutout on the tail is either because of a failing tail motor or radio glitches or after I adjust the proportiional trim without unplug/replug the battery.