Read: 3G Servo Bus Concern

[MrMel]

Ok,

Yes, I dont say the servos your using isnt up for it, I just say that why previous person didnt experience it could be a number of reasons.
(Like Spektrum shutdown very easy compared to Futaba RX)

Baseline, just because it works in a simular setup on one heli, doesnt mean it will for the next person

[CeeveeSiN]

Originally Posted by MrMel

Ok,

Yes, I dont say the servos your using isnt up for it, I just say that why previous person didnt experience it could be a number of reasons.
(Like Spektrum shutdown very easy compared to Futaba RX)

Baseline, just because it works in a simular setup on one heli, doesnt mean it will for the next person

yeh I just dont understand why the HV system worked and my 6.6 didnt..
very strange. and very frustrating and confusing...

[Ultraviolet]

Originally Posted by MrMel

Ok,

Yes, I dont say the servos your using isnt up for it, I just say that why previous person didnt experience it could be a number of reasons.
(Like Spektrum shutdown very easy compared to Futaba RX)
(

I do not think the Spektrum / Futaba comparison is accurate. The power bus of the Spektrum was never an issue. People who had issues were primarily running off there ESC's linear Bec, and / or drawing more power than was available.

Align's issue appears to be design related. They did not spend a whole lot of time calculating voltage drops. This seems odd given the nature of a flybarless system ( power hungry ). You would think the correct way to design it would be with 14awg wire for the power input with a correspondingly robust internal circuit.

[MrMel]

I do not think the Spektrum / Futaba comparison is accurate. The power bus of the Spektrum was never an issue. People who had issues were primarily running off there ESC's linear Bec, and / or drawing more power than was available.

I know for a fact its accurate, Spektrum shuts down at a a lot higher voltage then Futaba.
Big plank guys doesnt fly Spektrum anymore, the share load of the servos put the RX in Failsafe mode, even if the power-supply is up for it.

Not an issue on our helis though, since we dont put load that long on our servos like big planks.

Still, lower the voltage slowly and you can test.

(I fly Spektrum regardless, without a single failure so far)

[Ultraviolet]

Originally Posted by CeeveeSiN

yeh I just dont understand why the HV system worked and my 6.6 didnt..
very strange. and very frustrating and confusing...

With HV the resultant voltage drop does not result in a brown out, merely reduced performance. At lower input voltages you end up with more voltage sag causing a brownout.

[Ultraviolet]

Originally Posted by MrMel

I know for a fact its accurate, Spektrum shuts down at a a lot higher voltage then Futaba.

Yeah like under 3.5v or so. It does not change the root cause which is inadequate supply.

[CeeveeSiN]

The only thing I can think to do is similar to Gixxum.
maybe put these systems on my 450s and then wait for the TotalG and put it on the 700Ns..

very disappointed in this I dont feel I can trust these units in the 700Ns
maybe I'll try one in the Vel50..but doubt the servos in that thing are up to the task.

This really sucks... the Corpus Fun Fly is next week and I'm down both my 700s

[MrMel]

Yeah like under 3.5v or so. It does not change the root cause which is inadequate supply.

Wrong,
a friend lost a huge plane (this was whenSpektum came out and how we found out)
He had a triple redundant system, 20 amp each, into the "super high current RX, is it the 9100 I think the name is)

It still browned out because the powerbus INSIDE the RX failed (caused too much drop)
The power supply didnt even registered any voltage drop.

[CeeveeSiN]

Originally Posted by Ultraviolet

With HV the resultant voltage drop does not result in a brown out, merely reduced performance. At lower input voltages you end up with more voltage sag causing a brownout.

Oh I see.. even if its not enough to reboot the RX's themselves it is enough to brownout and shutout the 3G.

becasue the RX's are staying lit solid.
so its not rebooting them.

but upon inspection of the crash the G3s were not sending out gyro signals but were passing through control via sticks.

[Ultraviolet]

Originally Posted by MrMel

Wrong,
a friend lost a huge plane (this was whenSpektum came out and how we found out)
He had a triple redundant system, 20 amp each, into the "super high current RX, is it the 9100 I think the name is)

It still browned out because the powerbus INSIDE the RX failed (caused too much drop)
The power supply didnt even registered any voltage drop.

The majaority of issues were still supply related. You do not here about Spektrum brown outs anymore because the user has become more knowledgeable regarding external BEC's , as well as the advent of internal switching BEC's. I am sure drawing a lot of amps with a "huge model " could still cause issues with many rx's.

The issues remains that given the experiences of other companies with stable power requirements, Align still made a choice to under design the 3G power bus.

[MrMel]

The issues remains that given the experiences of other companies with stable power requirements, Align still made a choice to under design the 3G power bus.

Yup, competition FBL units even use built in capacitors in the FBL unit, that way even if you get a brownout that put's the RX into failsafe, the gyro still work..

[gixxum]

Originally Posted by CeeveeSiN

The only thing I can think to do is similar to Gixxum.
maybe put these systems on my 450s and then wait for the TotalG and put it on the 700Ns..

very disappointed in this I dont feel I can trust these units in the 700Ns
maybe I'll try one in the Vel50..but doubt the servos in that thing are up to the task.

This really sucks... the Corpus Fun Fly is next week and I'm down both my 700s

OFF TOPIC:
oh man you just opened a whole other can by saying vel 50..which i was first in line for like an idiot...talk about fail...my god that thing had every issue known to man...throw the 3g on that and you might as well just throw some gas on the whole mess and light it.. i have resigned the velocity to be the counter queen because i got sick of them sending me "updated parts" for parts that failed...like the one way..only issue was they kept sending me the same crappy parts...not updated versions so of course i kept crashing the bastard. /end rant

BACK ON TOPIC:

ready heli has the vbar in stock if its a crisis situation (throw one or both of the 3g's up for sale).. which is my next step because i got the align funfly in march here..so it could not have been worse timing..fofr both of us.


it just seems wrong to me to put this 3g on the 450 when, it cost more (the 700 3g kit) than the whole heli with all the electronics...but ill give it a go...

[panzlflyer]

Big plank guys doesnt fly Spektrum anymore, the share load of the servos put the RX in Failsafe mode, even if the power-supply is up for it.

Last year I had 3 35% planks with Spektrums, flew it since it came out..never had an issue, around here 90-95% fly JR 2.4.

This is an issue with the 3g and it wil happen with any reciever, what I dont understand is the other FBL manufacturers felt a need to beef up the supply lines but Align knows better?????

[MrMel]

This is an issue with the 3g and it wil happen with any reciever, what I dont understand is the other FBL manufacturers felt a need to beef up the supply lines but Align knows better?????

Is rushed out to the market letting users beta test a valid guess?


(as for Spektrum vs Futaba voltage, anyone want to discuss that we can start a new thread or take it via PM, as panziflyer says, I agreee, this is another issue)

[panzlflyer]

Yeh I feel like I just got burned by this, although Im pretty sure my mess of added wiring will take care of it.
I was hoping for a clean install!!!
On the upside it did perform pretty much like my old Skookum

[gixxum]

if this 3g isnt going to work right soon...ill just wait for mr. youngbloods contribution to the party =) ************** has a little write up today





*****dejavu: i remember saying the same thing about the 3g********

[UPSDOC]

I just did panzlflyer's servo extension mod using a 6' Hitec extension. Works great. Pins fit Hitec connectors perfectly.

[gixxum]

i just did a gy611 mod

[ShuNut]

If you guys make a new thread discussing the futaba vs Spekrum low volt cut off issue plz pm me the link. I'd like to know were spekrum misleading with the vid showing they both cut off at the same voltage ?

youtube.c om/watch?v=PwnM9pBH9QM (added space in link to not show vid)

Back on topic theres some very interesting info concerning the 3G & amp draw using 3 servos with RX only vs RX & 3G, amp are nearly double. A must see i think.
http://www.archeli.com.au/forums/sho...131857&page=14
See whole page as more graphs etc further down.

Peace

[panzlflyer]

okay these are per a request. its tough to get a good picture.

The 1st one is if you just want to inject power to the servo using a spare port on the reciever.
The last one adds 2 power wires, (red and brown or white) to the plug from the 3g labeled pitch/elevator etc if you dont have a spare slot.
The male plug on the Right in the last picture goes to the reciever, female end to servo, signal from reciever goes to the 3g as it was.
Signalfrom the 3g to servo goes into servo via female connector.
No soldering required and it is pretty much the same as the drawings done earlier and much like Mikados advice on how to power servos direct.