hitec minima and tundra not getting along........

[nigel fatbloke]

Got me a Hobbyking Tundra, fitted a Hitec Minima rx, all bound up and good to go. You'd think. However......all seemed to work fine , if memory serves correctly , but now, the rudder and elevator work fine , and motor control is good, the ailerons and flaps chatter violently , and then go unresponsive along with all other channels. Sometimes , I get alternate slow flashing red-blue leds on the rx,not called out in any Hitec notes that I can find. The servos are "soft" at this point , so maybe failsafe has occurred.

I have tried other Minimas, and Optimas, different servos, connecting them directly via a y lead and powered by a seperate rx pack , as well as the power supply from the li -po via the throttle channel. Result is always the same. Supected the wiring to the multipin connectors, but the direct y lead check rules this out. Could it be the power suply is marginal with 2 servos on each channel output? Can't think of owt else to try .All the components and receivers check out fine in my Radian , so this has me suspecting the Tundra or it's wiring. Only one more potential issue , the flaps and ailerons are a servo for each in either wing , 4 total. To my er, "logic" , the channel setup as I see itis the Aurora 9 shouldbe set to "one aileron , one flap servo per wing" as per system menu options. Correct or not?

Edited By nigel fatbloke on 11/04/2017 10:29:57

[Frank Skilbeck]

It might not be the power supply to two servos but the position signal strength, I have seen an occasional servo that didn't like to be on a Y lead, if you just connect up 1 aileron and 1 flap, are they OK?

It maybe that you've got a faulty servo in the wing which is then causing the rest of the system to be dragged down, we had this on another plane (well autogyro) where on connecting the Rx it worked for a second and then stopped, we changed the ESC but this didn't help, but it worked OK off a separate battery, but when we eventually found the offending servo we cured it, this one servo (one of 3 identical ones in the model) was drawing a very high current which was overloading the ESC.

[Jon H]

Hitex rx's are not interested if the voltage is too low. I would suggest that the BEC on the model is not man enough for the job.

To test see if you can lay your hands on a 6v nimh receiver battery and power it up with that. If it works, then you have the reason.

[Denis Watkins]

Definitely low on power, as the boys suggest

.

[nigel fatbloke]

Thanx for the swift responses, folks !

The servos in the wings are a bit difficult to check singly, would mean cutting into the y leadsas they're "hard" wired to the sockets and the Rx plug. Will try single servos in the offending Rx channels, and see wot 'appens. I note that whilst the spare servos were plugged in with a Hitec-supplied y-lead, that jiggling or moving the servos gave 'em the chatters like Billy-Ho. At one point I even had the BEC and a 800MAh Eneloop pack plugged in at the same time - same story. Frank ,without butchery-at this stage not an option in case of any warranty palaver- I could only narrow it down to being a dud servo on either the ailerons OR flaps. Wonder if a better , branded ESC may fare better. Hmmmmmm......much chin-stroking required, methinks. Just going to connect the ol' HPP 22 and udate everything just to be sure , then more "fun" at detecting. Keeps me off street corners , at least.

[nigel fatbloke]

Now then;

I've tried a known good 40 Amp ESC , and the result was the same-no joy. So, I have some decent quality servos for another project to hand ,so I've tried these on a y-lead and ....perfecto ! So , then there's something stinky in the quality control dept. at Hobbyking . I'm lookin' at you, servos. I'll replace all 4 ,it's a pain, and I've already dug one out so it's been tampered with so the warranty thing is kaput, not that I had much faith in HK customer service anyway ,so maybe no great loss. Now I need to get one servo to operate in the opposite sense to it's manufactured state so both flap servos push together rather than oppose as with the ailerons. Am I correct in thinking it was just a matter of swopping red and black on the servo leads as I'm sure I've done in the dim and distant past? Nice airframe- pity about the 'leccy bits.

[nigel fatbloke]

But now thinking again, Bad habit ,oughtta know better ,but, if the 2 flap and 2 aileron servos are on Y-leads, does the Tx need to "see" these as one servo per Y-lead/channel or 2 ?

[Denis Watkins]

A Y lead is one channel Nigel

With no Y led, you would use two channels

Normally you do select the type of wing in your Tx, as single or two servo

[nigel fatbloke]

Good . That's that sorted . Funny how when something like this is driving yer round the twist , you can't see wood for trees. Not me , leastways . It's me age. Oh dear......

 

Anyhoo , seems this 'ere problem with the Tundra wing servos is very widespread ,it's on Youtube  , and possibly due to the multi-pin plugs designed to aid quick assembly -HAH!!- , and therefore the product is relegated to status of a load o' cack . Pity ,it is otherwise a fine 'plane and right up my street, Contacted HK , so let's see. Not holding me breath .

Edited By nigel fatbloke on 11/04/2017 21:05:50

[David Ovenden]

I have 300 flights with no issues on my Tundra, so they are not all cack. However, sounds like you have a "Friday afternoon" one. If you peel off the tape over the connecter block on the wing underside you can unplug the aileron and flap servos from the wing root connector block. The servos have standard plugs on them though the leads are short. This will allow you to check each servo individually via a separate ext lead direct to your receiver. Like that you should be able to isolate whether if it is a servo, a y lead, or a connector block issue.

[onetenor]

Dry joint or break under insulation possibly

[nigel fatbloke]

Dug out a flap servo last night, and found that standard servo plugs are used , so will be easy to check servos in turn to spot a dud. Did find a post on YouTube suggesting that a conductive flux used in the boards construction was causing these symptoms. When cleaned off -all was well when muttley-metered, so that'll be looked into as well. Have contacted HK , but not hopeful , having already removed the covering tape and one servo might've knacked any warranty claim. Ought not to , given the widespread occurrence of this thing. If it comes to it , I'll replace the servos and use Y-leads ,but will be cheesed off to lose the convenience factor of just plugging the wings on and no wire wrestling. Have some MPX green plugs ,might be an option . We'll see.

Edited By nigel fatbloke on 12/04/2017 13:08:43

Edited By nigel fatbloke on 12/04/2017 13:09:05

[Frank Skilbeck]

Look on the bright side, you can now plug each servo directly into the Rx and use the facilities on your radio to program in aileron differential, crow braking, coupled ailerons and flaps etc etc

[nigel fatbloke]

Good suggestion, Frank . Missed that one. Only have 6 channels on the Rx to play with , so will keep flaps as a single channel on a Y-lead ,differential for aileron would be handy,tho'. Servos check out good, have removed the multi-pin connectors and restored full function. Need more Y-leads and short extensions now. Off to Webbo's tomorrow, then . The sevo's plugs need to be absolutely shoved home into the Y-lead sockets, tho' , else connexion is flakey. Did try the cleaning of the excess flux , but only from one wing -side connector, left all the fuz ones and 't other wing one alone , so that bit is inconclusive for me. The HK multi-pin connectors are off to the landfill bin, then.Pity- good idea,rubbish execution thereof.

[Rosco]

I had the same issue with mine and it's seems to be a regular occurance.
I just used the Y lead solution.
I'd rather know that it's all going to work rather than find out when it's up in the air!
When I first plugged mine in, it all worked. The second time it didn't.

[nigel fatbloke]

Rosco,

yeah, that's JUST how mine went . Fine at first , went for a beer from the fridge, then all went to carp. Maybe it likes not ye beer ! I am thinking that alignment of various pins may be behind all this, but the conductive flux video on u-toob is pretty convincing , too.

[Rosco]

By putting the Y lead on there it also gave me an opportunity to add a servo slower in the flaps lead/s, so that I get a slow 'clean' lowering of the flaps as opposed to a dump!

[nigel fatbloke]

Well' 76 miles, a gallon of derv and 40 quid later, the Y-leads are in and rock solid. Pity the multi-plugs did'nt hack it. I reckon it's an alignment issue , will wire up some servos and check as the units were removed intact, despite the little voice in me head sayin' " smash 'em !!!" . Now all I have to do is get HK to send me the mising keepers for the linkages which were missing in action. Commercial ones I have don't quite look secure enough, the HK ones are single-sided , so get a more positive hold on the 90 degree bend than 't others. I like the Tundra, tho' it be a curate's egg for sure.

I have a servo-slow facility on my Aurora 9 Tx , but it seems  as tho' I can get flap retract as slow as I want, deploying them is almost instant. Unless I've missed summat in the  Aurora manual ,but I'm sure I have'nt .

Unless anyone knows any different , of course I'd be pleased to learn of this. Believe it or not , I've overlooked the obvious before. I claim immunity from sarcasm on age grounds.

Thanx all for input on this , seemingly random but by no means isolated caper.

Edited By nigel fatbloke on 14/04/2017 13:15:18

[Denis Watkins]

Hi Nigel

The servo speed is set in the model menu

And you can select the number of seconds for the travel time

And it is easy to assign onto the wrong servo, depending on the channel that your flap surface is plugged into

[nigel fatbloke]

Denis,

Yep . I got that . The issue is at the moment it only affects servo travel upon retraction, not extension. One thing to try when I get a chance is to move the flap control- left slider as I have it- to full flap and see if it switches the highlighted value on the screen to "L" position , rather than "H" ,or vice-versa , as a similar setup applies to other functions on the Aurora. I'm thinking those may be end point or sub trim or similar. If this IS how it's done , I'da thunk it oughtta been called out in the manual . I do have a servo-slow gizmo someplace, but it's weight saved , and more space inside if it's not required. I'd have to find it first. A task not undertaken lightly , and only then , with much trepidation...........

[nigel fatbloke]

As I suspected, then . Flap slider needs moved to opposite end of travel to program for extension speed. Now got me 10 second extend/retract cycle,5 down , 5 back up . Sweet.