Mavrik!

My Turbine F16 has or I should say had 67 flights. The last 2 flights Temora Jets Australia September 2010 I changed to the Aroura 9. Set up as follows;

20 amp regulator fed by 2 x 2200 ma 2S lipos, Hitec aroura 9 ch rx with Y lead to the 2 elevator servos JR 8711 25 kg individual channels so the Y lead was fed power by the 2 power leads that exit the regulator. So I was effectively feeding power direct to the 2 most hungry servos 8711. 2 x Hitec 5955 TG on ailerons and small servo for steering and rudder. 6 servos in total and EV5U valve to control retracts and gear doors.

2nd flight with Hitec system and I go a bit harder than first flight, but not any harder than the prior JR system using the power safe 9 ch rx JR.

Seems elevator servo fail for some reason? Jet Spun after exit vertical accent zero control, then barrel roll fast rate vertical nose first to ground. Impact 200 km plus nose in, fire nothing left. Did it overload the rx more than 15 amps??? Somehwere in my Hitec set up there is a failure or could be servo failure, however ironic it fails just after 2 flights with Hitec set up? 65 flights JR no problems. Did my regulator fail for some reason? Can the rx truly cope with 15 amps?

Not saying this is Hitec fault, however strange fail just after 2 Hitec flights?

$6k total loss.

Any input pelase.

Cheers,

Mav

Vincent

My Feedback: (61)

Other than normal manitenance there is no way i am removing anything after 67 dialed in flights. BTW why did you remove the JR equipment??
V..

smaze17

My Feedback: (60)

Yes, Vincent beat me to it...just curious as to why you would feel the need to change out your JR equipment? After all, it is #1 among jet guys for a reason. Personally speaking, there is no way
I would EVER change out equipment after 67 successful flights!!


-Spence

gruntled

I hope this isn't a case of buying into the "sky is falling" mentality surrounding the JR/Spektrum threads here on RCU. If so, that was an unfortunate and costly error.

cavandish

easy to be wise after the event, but why fly a 6k plus model without a redundant power source going all the way to the RX ? (1 reg)

gooseF22

likely you had an issue with the 8711s on a Y cord with weak signal not with power.

Peter A

My Feedback: (34)

Are you sure the structure did not fail on your elevators and not the servo? On my HAWK,both elevators ripped outofthe fuselage due to structural failure. Both broke in the same place at the same time in straight and level flight at half power.

AndyAndrews

Single regs with dual imputs are not uncommon. This is the setup I have with 3 jets I've been flying with hundreds of flights. The "Y" servo lead to to 8711's now that gives me pause. I wouldn't do that for anything. I fly the exact same jet with over 100 flights on it so I doubt very seriously it was any structural failure.

Mavrik!

This is the MPI regulator I used 20 amp max 10 amp continuous and has 2 inputs for batt and 2 outputs for RX. I was running 2 batts and yes only 1 regulator. Have done this for years also?

Link;

http://www.maxxprod.com/mpi/mpi-21.html

Rider-60

My Feedback: (17)

Sorry for your loss.
I would never trust an Y lead to powerfull servos especially on main flight controls, doing this is limiting the amps to the servos and hence their power.
Did you have the same electrical set up for the previous 65 flights?

olnico

Is it the 1/5,5 FEJ F-16 ?
Did you fly on a Y lead feeding both 8711 as well before ?

There are two possible causes for this crash:
1. Y lead melting somewhere due to the high amps ( quite unlikely if you chose correct quality wires )
2. Elevator structural failure

olnico

Was there any video shoot of this mishap ?

Vincent

My Feedback: (61)

Going by the size of the motor the guy is holding it looks like a 1/8th scale F-16. I had one of the early model FEJ F-16`s and the elev set up was not very good. We had to mod those clamps so they would bite better on the elev pivot shaft. I would say (2) 8711`s was over kill for that size jet but doubt it was an over amp situation with a Y lead.
V..

GrayUK

Not according to the last poll, FASST came out on top.

UK jet meets i have attended are also FASST dominated.

Paul

Mavrik!

No the JR set up did not require Y leads as it was the 9 ch power safe rx. Hitec rep Mike Mayberry recommends the Y lead to the most power hungry servos. this was the only way to power the rx as all the inputs were used being 9 servo leads!

Note did not Y lead the servos only Y lead to feed power to the rx.

Mav

Mavrik!

1/8 FEJ F16 using Merlin 90k turbine. I was able to diagnose not a mechanical fault as the tail was the only part left per the pic!

I agree the linkage system was not great, however was adequite.

Mav

mk1spitfire

like sheep!! lol

AndyAndrews

That regulator can handle more amps than the wires attached to it. I use the Smartfly super reg and it uses Deans connectors with heavy ga wire. that then goes to a power expander and then you can use the standard servo wire ga to the RX because its regulated voltage and amps from that point on. I think the small ga of wire combined with the "y" harness is a bad mix. I woldn't do that for future jets.

Hitec told you to use a "y" harness for the most power hungry servos? Its not a good practice to double the load on a single wire. The best approach is to have regulated voltage through a power box or power expander equally divided into two separate connections. Plus those "y" harnesses have been covered extensively here on RCU regarding NOT using them at all.

smaze17

My Feedback: (60)

That's news to me Paul but if you say so. Personally I fly a Spektrum DX-7 and have never even had a glitch!!

Cheers

Spence

gunradd

My Feedback: (9)

Well after lossing 4 planes I want to wipe my $$$ with my Dx7. Its on the way back to horizon for its second repair now. It is a POS.

AndyAndrews

I fly JR, but there is no way I would trust a $200 Spektrum DX-7 with a jet. Foamies yes but never a turbine jet.

john josey

Was it just a normal 'Y' lead ? If so how did you get the elevator halfs going the same way ?

1/ Reversed servo from JR or 'pick up point' from the 'bottom' of the servo on one side ?

2/ 'Y' lead with reverser ? (personally i wouldn`t trust these in a jet)

Airplanes400

My Feedback: (349)

It's all speculation as to what happened to your jet.

All I can tell you is this theory, "A chain is only as strong as its weakest link." With that in mind, even if you are using a heavy guaged "Y" harness, a thinner guage extension wire could have been the culprit. Don't know if the radio could have been at fault or the powerbox, so I'm not going to speculate on that. I'm just making a comment about the wiring.

I use the heaviest guage wires available for "Y" harnesses and extentions. I also use a Futaba FASST radio. Never had the problem you did.

Vincent

My Feedback: (61)

I have run a pair of 8611`s many times thru a single match box on elev with no issues, i would say that is the same as a Y lead??
V..

gunradd

My Feedback: (9)