Belt CP power issues?

[Lyfe]

Hi all,

As some of you may be aware, I'm having strange problems with my BeltCP. It hovers fine for couple of minutes, but will suddenly spin the tail out and I'll loose control. Cost me some blades and a feathering shaft so far, so not the end of the world... but something nasty will eventually happen.

Are any of the following normal using the stock RTF kit?

Sitting on the ground rotating the main blades at constant trottle gives stubley different head speeds - you can hear the motor winding up and down
The aircraft hovers for a few minutes but spins, typically nose to the right about 90 degrees in about 500ms, then partly stablises
This instability lasts until I put it down on the deck, wind down and give it a few seconds (5) before trying again
The instability is simular over 4 lipos, although it appears my orginal eSky 1800mah is the general best, a second 1800mah I bought at the same time is the worst and 2 2200mah later ones are in the middle
The ESC (which I suspect) is warm to the touch on the heatsink and coolish hot on the sides closest to the MOSFETs. Certainly not painfully hot.
Controller batteries are charged, the antenna wraps around the tail until the mid-boom fin and then doubles back to the front of the skids.
It appears to have behaved like this from new - obviously at the start I wouldnt have been able to see this.

I've checked linkages and can find nothing loose. I'm flying indoors, so this isnt a wind/weather issue. I'm flying within the ground affect zone - <1m altitude, but can hover for a minute+ so dont think its a terbulance issue.

My gut feeling says ESC at the moment... any other opinions?

thanks,

Lyfe

[LoBsTeR]

Check all connections are solid. It could be interference also. Is the tx aerial screwed in properly? Do you have full control apart from spinning? ie when you get it back on the deck before disconnecting the lipo, do the servos operate correctly?

[withnail]

Do the blades ever twitch when on the ground with a fully closed throttle? Try leaving it there, ready to go for about 20 minutes and see if you pick up any interference that causes the motor of servos to twitch.

Regards

Mark

[Lyfe]

Checked tx antenna, which was finger tight. I do have full control (dependant on my skill, of course ) other than the freakyness. When its back on the deck, I still have full and predicable control of the servos.

Its currently on the desk next to me, live and run at zero throttle, with the tx running on a neutral input and I'm listening very carefully for the servos to move. I'll double check connections after the batteries go flat.
-- Now completed - Ran for 15-20 minutes which is much longer than would have expected to see in flight without a problem. The servos had negligable movement, I think one clicked a single tooth about twice... nothing that would cause the problems that I am seeing...
-- Connections are secure

I'll also fly it outdoors away from any office interference sources this weekend.

I hope to be able to post a video of the problem inflight later today.

Thanks for the help both!

[withnail]

It doesn't sound like interference is your problem as you would expect it to show on the ground as well as in the air. Hope the video clip will give some of the "old hands" a clue as to what your problem is.

Best of luck

Mark

[Lyfe]

[ame]http://www.youtube.com/watch?v=R5H25mTL8j0[/ame]

Well... I managed to film the problem... I would have liked to have spent a bit more time getting a couple of examples, but I'm sure you'll get the idea.

Three comments... I'm ashamed of the instability of the aircraft in hover... under the pressure of the camera and being at an angle so you can see the controls quite seriously put me off. I'll have to post another video of normal hover.

Secondly... having watched the video, it looks like the aircraft quite dangerously span towards me... it wasnt quite like that, and there wasnt actually an real chance of it hitting my leg... it does look bad on the video although.

Finally... if you watch my controls - particularly in the slowmo, you see me react to the spin with full right rudder, put it into a spin the other way, and only start to correct that when the tail is central... plus, as I was powering down, the rear rotor didnt have the power to stablise the turn... all of this is bad and inexperienced piloting and I will improve... what I'd like you to focus on is the first 90degree turn to the left without any input into the controls to cause it.

I also know I didnt handle the cyclic well at all, but I'm not strong enough at tail-in hover to work on angled hovering and hence still use a up to move towards the far wall, rather than up to move the aircraft forward. Again, this is a practice and experience thing.

[Boggy]

that looks like glitching to me lyfe! route your ariel away from the tail tube perhaps down the u/c and use a piece of poly tube to point it out the front. failing that let it dangle across to the tail stab fin.
also try and get as much of a gap as possible between the esc and rx.

[withnail]

It does look a lot like the result of interference. At least it seems to behave in a similar way to my little Esky Lama when I was having problems. It's odd that you didn't get any glitching at all when it was sat on your desk. One thought; How close is the desk you left it sitting on to the area where you fly? Is it possible that your office is shielding the effects?

Nice flying space by the way!

Regards

Mark

[Lyfe]

Thanks all...

I've followed Boggys advise and rerouted the antenna along eSkys offical suggestion rather than my wrap-around method. I've flown it outside (for the first time) in Milton Keynes yesterday and dealing with wind is quite a lot different than office flying!
I've run a battery and dont appear to have had any issues, so it looks like it could be that! Woohoo! The problem with wind, however, was fighting it all the time made it hard to stabley hover, so its not yet conclusive until Ive tested it indoors, but fingers crossed! Its looking like we can narrow it down to interference in the office or bad antenna layout.

Yeah - I'm pretty lucky Withnail! I have a choice of 3 empty floors to fly on - one more open than that, but with a lower ceiling and another worse one. Security owe me a favour or two so its time to claim

[Lyfe]

Doh. New blades and feathering shaft.

Problem definately still exists.

Some new shafts arrive tomorrow, so I'll take it to my old warehouse and give it a try there - should rule out interference from the office conclusively. If the problem persists there, its looking like the helis fault... can anyone recommend where to go from there?

[Bennie]

Same Problem!! Help!!

Good evening hope you are all good and well It seems I've got exactly the same problem with my belt cp and I can't see anything wrong (I'm only a beginer however I know this isn't right!!) I likewise have checked all connections and my arial is nicely unwrapped and through the straw thing on the skie's . I'm totally lost all I wanted to do is learn to fly and enjoy my belt but all that keeps happening is this crazy flip out stuff and likewise it's nearly hit me a few times lol , also have gone through 2 sets of blades dentend my tail boom and broke a blade clamp :-( not good :-( , I'm starting to think it's got something to do with the radio gear as I can't find any mechanical things wrong . If anyone is aware of any such probs with these belt cp's or have heard anything please advise I'm in a desperate state as I'm fed up of repairing and not getting to the problem , all I wanna do is fly :-(

Any replies will be so much appreciated thanks :-)

Lyfe dude if you've solved the problem please mail me and help I'd be over the moon if you could help , take care all and thanks for reading

Ben

[Lyfe]

Hi Bennie,
Its horrible when you know its not working but dont know how to fix, isnt it? Lost alot of enthusiasum for the hobby, and now personal cercumstances have made me nearly give it up
I may have solved my personal issue. i've flown it twice outside now, with none of the freakiness, so its increasly looking like interference even although I'd tested for it, but dry run and changing crystals to a set that a collegue successfully runs. Since only flown about twice in the last 4 weeks, its not conclusive.

Things to try...
Several different antenna runs - ideally keeping as far away as possible from the ESC.
Keep the receiver and the ESC at opposite ends of the aircraft
Put a ferrite ring betweent the ESC and receiver
Try a different controller channel (crystal)
Check all your servos are in good condition - ideally swapping them and looking for different behavour
Fly in several different locations, ideally miles apart

This one is speculative, but ESC temperture... its flown well outside, but unpredicably in a warm office...

Other last ditch things are replacing ESC and receiver/transmitter (ideally borrowing them from someone else), checking same behavour on multiple batteries. Looking for alignment issues and loose connections. Finally - try flying it in a different orination...

Hope some of this sheds some light. Shame your so far away from the sunny, single-mum-capital, primark-tracksuit-loving oasis that is Slough!

Lyfe

[robgt]

crazy flip out stuff

Can you describe this more?
Is it spinning around madly, or are the servos jittering, or??

I may be recalling this wrong, but doesn't the BeltCP Transmitter take AA cells - if so, are they fresh batteries?

Cheers,
Rob

[Bennie]

belt cp

Hi all thanks so much for your help and Lyfe cheers for getting back so quick much appreciated dude I will start checking all of the things you have suggested I also put it down to some sort of interferance so the first thing I will check is the radio gear and I will keep going till I work out what the fault is as this is one hobby I'm not about to give up with lol as soon as I ruite out the problem I will post it on here have a nice holiday Lyfe Oz is fab and have spent a year out myself hehe

Hiya Robgt hope your good and well my transmiter does take AA bats but they are full up so guess thats not it , I'm starting to think it's somewhere in the radio gear itself either the ESC or receiver ?? the thing flies okay for a minute or so but then suddenly will do weird things like sudden tail flip spin's or the whole thing will suddenly pull up and back (weird) it's definatelly servo or radio gear but not sure till I start my checks
, Anyways thanks all if anyone has the answer please don't hesitate to post a helping thread it'd be much apreciated by me indeed take care all and thanks

[Lyfe]

From the description, it sounds exactly like the problem I was facing.

I'd recommend trying another location.

Oz will be awesome. Got my residency during the summer, so this is a research trip.

Lyfe