DS650 servos and Li-Fe packs

[J-S-Q]

Just sold my reg and lipo in favour of going LiFe

My only concern is that the voltage holds consistantly at 6.6v, as if the voltage fluctuates the servo speed will be inconsistant.

Do you mean consistently when placed under load or do you mean consistently as in will it be the same on flight 1 as it is in flight 2, 3 and 4? If you mean under load, I'm not really sure how consistent the voltage is with most (or any?) regulators when placed under load.

I know that the Align 2-in-1 regulator drops substantially under load (according to my Spektrum telemetry). I tried two different 2-in-1's and they dropped from the spec'ed 5.8v to as low as 4v if you move the collective stick very rapidly. Pushing down firmly on the swash showed a minimum voltage in the low 5's (which I reckon is probably a good replication of what happens in flight. In flight I was registering minimum voltages in the low 5's if I remember rightly). I also emailed a pretty well respected reg manufacturer to ask if their regulators behaved similarly and the reply was that they would show up to 0.5v drop under load.

I just tried a quick bench test on my 700N. Li-fe standing voltage is at 6.5v (pack not fully charged). Very rapid collective stick movement shows a minimum voltage on the telemetry of 5.7v. Pushing firmly down on the swash plate shows a minimum of 6.2v.

So I would say in terms of holding voltage under load, the Li-Fe is as good as or probably better than a regulated setup. I'm not an expert in electronics but I'm still struggling to find a reason why a Li-Fe setup is not obviously better than the regulated setup. It performs similarly, is cheaper, weighs about the same and is less prone to failure.

[sacko]

I meant when the servos are underload how much does the voltage drop.The 2in1 isnt the greatest reg in the world, so wouldnt compare anything to that :SThe flightech reg (spektrum telemtry) showed a 0.2v drop under heavy load, and wouldnt want to see anymore tbh.

[trillian]

I'm not an expert in electronics but I'm still struggling to find a reason why a Li-Fe setup is not obviously better than the regulated setup. It performs similarly, is cheaper, weighs about the same and is less prone to failure.

What tail servo are you using on the 700? I have a 9254 on the Ely.Q now but I could put a DS650 or 620 on there. The other advantage of going direct with a LiFe pack
is it can deliver a lot more amps than most regs, which is probably why the voltage doesn't drop as much under normal loads.

[J-S-Q]

I meant when the servos are underload how much does the voltage drop.The 2in1 isnt the greatest reg in the world, so wouldnt compare anything to that :SThe flightech reg (spektrum telemtry) showed a 0.2v drop under heavy load, and wouldnt want to see anymore tbh.

Well as I said, I did get an email from a quite well regarded manufacturer saying that I should expect a 0.5v drop. I won't name them simply because I'm not slagging of their products, my guess was that most regs acted like that. (from one of your previous posts though, this reg may have been on your shopping list. lol).

Incidentally, when you saw the 0.2v drop, did you try moving the collective up and down very fast because I'm definitely getting the biggest drop when I do that.

[J-S-Q]

What tail servo are you using on the 700? I have a 9254 on the Ely.Q now but I could put a DS650 or 620 on there. The other advantage of going direct with a LiFe pack
is it can deliver a lot more amps than most regs, which is probably why the voltage doesn't drop as much under normal loads.

I have a DS650 on tail and throttle, with DS610's on cyclic.

[trillian]

I have a DS650 on tail and throttle, with DS610's on cyclic.

Doh! 'Just realised that's in the very first post and in the title of the thread!

[sacko]

Yup, full collective movement as well as aileron.Im using BLS351's, DS610 on Throttle and Outrage BL9088 on the tail.

[J-S-Q]

Well I haven't actually flown my Li-Fe setup yet due to some other technical hitches but might get out later this week so I'll report the telemetry info in this thread.

[trillian]

Well I haven't actually flown my Li-Fe setup yet due to some other technical hitches but might get out later this week so I'll report the telemetry info in this thread.

Let me know if you're going over to Kempton, I haven't been over there in ages. (I will try to make the AGM as well on the 17th)

[J-S-Q]

Let me know if you're going over to Kempton, I haven't been over there in ages. (I will try to make the AGM as well on the 17th)

I'm planning on going down on Friday, subject to the weather which is looking pretty good at the moment.

[sacko]

Got the Hyperion LiFe 3000mah pack in the post yesterday, and looks pretty good.

Cant believe how short the wires are on it though!.. Just over an inch :S

[J-S-Q]

Got the Hyperion LiFe 3000mah pack in the post yesterday, and looks pretty good.

Cant believe how short the wires are on it though!.. Just over an inch :S

You're not running a DX8 with telemetry by any chance? If so, I'd be interested to see how much voltage drop you get in flight with this battery.

[sacko]

I will be unfortunately...

[J-S-Q]

I will be unfortunately...

I find flying with the DX8 really adds a nice adrenalin hit. It just takes heli flying to the next level.