Official Voltage Regulator/BEC Thread - Page 20 - RC Groups
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Apr 27, 2012, 11:37 PM
Registered User
Lenny970's Avatar
Originally Posted by vespa
No, that was my point. The 809 and 802 are repackaged versions of the same servo. All are identical to one another other than ratios and shapes.
That is an interesting comparison, but at the end of the day I would still use a DS-11 or 94809 in applications that I would not trust a DS-09 or 94802.

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Apr 28, 2012, 01:31 AM
Detail Freak
target's Avatar
Me too!

Apr 28, 2012, 03:31 AM
Needs to do 52 legs !!
jjmouris's Avatar
So Lenny, does that then mean you think we should tell Sergey to thicken the wing an extra mm so we can have the MKS 6100 over the DS09 / 428 ?!

Apr 28, 2012, 05:42 AM
Registered User
Hi all,

I never understood the comparison (which I did read about in the past) between the 94809 and the ds09amd, I always had difficulty believing they were the same servo. Surely the wider case makes the gearing larger / more robust. Also the electronics have differences, as the hyperion is programmable, the ATX is not. So they may share some parts, but there are differences.

Back on topic, I did not have the castle link to change the voltage at the time, so it was still set to the default 5.1V, ruling out over voltage. I am still loving this little unit, so am browsing this thread for any future feedback. I only use it as a separate bec for my electric versions of my gliders, still 'old school' with my high discharge 4.8v nimh's on the gliders.

I still put it down to bad luck with the electronics of the 09amd, as I am still at the start of the bathtub curve of the electronics on this glider (it was my maiden flight after some heavy bench testing). I did find them a bit suspicous, as their travel was never smooth (none of the three I have). Smooth, slow stick movement resulted in visible incremental movements. I reckoned it was normal for those servo's, since they all did it. I have heard of other recent failures of the 09amd, so perhaps a bad batch. Regardless, I have lost my trust in them, but that is more personal than anything else.
Apr 28, 2012, 11:21 AM
Registered User
Lenny970's Avatar
Originally Posted by jjmouris
So Lenny, does that then mean you think we should tell Sergey to thicken the wing an extra mm so we can have the MKS 6100 over the DS09 / 428 ?!

No, I'll leave those choices up to Sergey.

It seems that there may have been a bad batch of the DS-09's out last year with numerous reports of failures.
I had a couple of loose servos that were DOA. I'm sure some from that batch, unfortunately, could have gotten molded into wings/fins also.
Other than the ones from that time period, I've been very happy with them. Hopefully those troubles are behind us now.

Apr 28, 2012, 01:49 PM
Needs to do 52 legs !!
jjmouris's Avatar
Lenny, tell me about it.

Unfortionately my B09.5 did not live to tell the tail and i am once again planeless.

Apr 30, 2012, 03:53 AM
UAS Test Pilot
SpeedMaster's Avatar
Beware of the CC 10A BEC in combination with MKS servos, we had several receiver reboots during this weekends F3F comp. All Futaba or Spektrum with CC bec and all MKS servos. Those flying with less powerhungry Sanwa servos seemed to be fine...
Apr 30, 2012, 06:04 AM
Registered User

CC Bec

This is not the first time I hear about this. I can only assume that a full house mks (or similar powerhungry servo ship) paired with high loads can produce situations where the CCBEC (or potentially other switching regulators), can simply not keep up with the fast transients mentioned by Vespa in post 223.

For my use (F5J) I still reckon I don't give it such a hard time as for example F3F or F3J/B launches. My 'Butterfly' is only flaps/elevator comp, so the agressive big movements are limited to three servo's. I am still going to lay it on the grass and do some prolonged stick 'flicking' and will let you guys know the results.
Apr 30, 2012, 08:30 AM
Ricky Windsock
aussief3b's Avatar
Just another quick update re my issues. I don't have any issues!
Another full day of flying the same model with a 4 cell NiMh pack with zero issues with the JR 2.4 radio. I echo Speedmaster's sentiments above. All my issues came from full house MKS servo setup combined with LiFe and CC reg.
Don't use a CC reg with 6 MKS servos.
Apr 30, 2012, 08:57 AM
Registered User
+1 to that
May 07, 2012, 05:38 PM
Registered User

Voltron Regulator Question

Just dodged a bullet this past weekend with my new Shadow. The radio set up is a 5 cell 1500 mah NiMh Elite battery, a Voltron regulator, a Sombra Labs 72 MHz RX, DS 368 and 3421 servos for rudder and elevator, and 4 MKS 6125 mini servos for flaps and ailerons. No ON-OFF switch, just disconnected and reconnected the input lead from the battery to the regulator for each flight.

With the exception of the battery and regulator and the addition of a switch this exact setup has 250 flights on my #2 Shadow.

On the 20th launch with the new Shadow the radio went completely dead as soon as the airplane was released. A gentle yaw to the right continued until the flight path was parallel to the ground about 50 ft high. My buddy got off the winch and the airplane flew off the line in about a 60 deg right bank. A death spiral developed and as the airplane circled, gaining speed and losing altitude, I frantically stirred the sticks while mentally preparing to write another big check to SUSA.

At about 20 ft altitude I suddenly regained full control. I got the airplane on the ground as quickly as I safely could. Post-flight range check showed absolutely normal operation and no loss of range.

At home I began inspecting and disassembling the R/C installation looking for anything out of the ordinary. The first thing I noticed was small bubbles of melted plastic on both halves of the connector I was using for a switch. Removing the battery and regulator and looking at the undersides of the connectors showed more evidence of melting and even burnthrough of the connector shell. I tested the battery voltage and found normal load and no load voltages. A power test of the regulator showed it was regulating properly, but moving the input connector would cause the regulator to intermittently fail. The output lead and connector of the regulator appear perfectly normal, so the failure was in the input power connector.

Now I know why I lost control, but I'm puzzled by the cause. Is there some characteristic of the regulator like a large inrush current that could overheat the connector, if it was used as a switch. I know, for example, that care has to be taken connecting ESC's to batteries to avoid arcing. I don't like to use a servo connector as a switch, but I know plenty of folks that do and have no problem. Or maybe it's just a bad voltage regulator.

Thoughts anyone???

Thanks for taking the time to read this far,

May 07, 2012, 06:15 PM
Detail Freak
target's Avatar
I would check the draw of each wing servo individually in the launch position.
If all is normal there, then possibly look towards a short that could be happening anywhere there is melting once there is launch force on the plane.
Might be time to switch back to a 4 cell pack w/o regulator, and start over on the wiring.
Use a quality connector if you use in lieu of a switch. Not a servo connector.

Good luck, which you have at least had once.

May 07, 2012, 06:26 PM
Team Hello Kitty
SoaringDude's Avatar

Glad you got your plane down okay. And good points from Target.

From what you described it sounds like one of the input connector pins was flaky and caused a point of high resistance. That in turn would cause power to be dissipated at that poor connection point. If bad enough it could cause the much of your input (battery) voltage to drop across the bad connector pin/socket connection. That would also explain the melted plastic.

I know many who use servo connectors as power switches but I think you'll find more who say--at least long term--it's a bad idea. I personally looked at the datasheets last year for several different types of servo connector pins/sockets and discovered not all are created equal. Some are good for thousands of insertions while others not. The problem is you probably won't know what you have unless you order your own discrete pin sets and make your own cables.

Chris B.
May 07, 2012, 07:14 PM
vespa's Avatar
That's pretty crazy! I'm guessing this was a standard servo connector? I strongly advocate switches and PnP wing wiring and every means necessary to avoid touching any wires at any time (other than charging), but still your melted connector is surprising. Could you have wiring somewhere else that shorted?
May 07, 2012, 07:52 PM
Magicsmoke maker
Inflexo's Avatar
+1 to not using servo connectors for the main power delivery to the RX. I've seen quite a few distorted units from overheating. More amusing is seeing people use 24 or even 28AWG for a plane with 3 or more 20g+ servos, amazing they don't crash more often (agreeably this was in the days before 2.4GHz gear, so the RXs would at least recapture the signal within a frame or two after each brown out).

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