Rubber Band Man Marty.

[Tim Mackey]

Yesterday at the PSSA meet, my mate Marty handed me the box to land his Ripmax Mustang. He had launched and flown it on his own for while, as I was flying my own model. I took the Tx and had a little fly around, but the lift conditions were definitely "variable" with sudden drops to almost nothing. I wanted to do a nice loop over the estuary and then bring her onto finals, but the lift had dropped off badly, so I pushed the throttle stick forward. Nothing much appeared to happen. I closed the throttle, and scratched around to gain some height.

trying the throttle again, I shouted to Marty

"you do have a fully charged battery in this don't ya mate?"

"yes he replies...why ?? " 

"cos the throttle doesn't appear to be working" - says I.

Its then that he announces he has left the strong rubber band on holding the folding prop blades against the cowl for transporting!

Oh crikey ( or similar words ) I shout, the ESC has probably fried then

Just as I uttered the words, a large plume of white smoke trail started billowing from the model. I entered a landing circuit immediately, and still had R/C, but unfortunately this only lasted long enough to get onto base leg ( behind the farmers field and wall ) and then the lot died.

The model obviously then crashed and ended up in a sorry state.

The smell of burning electrics could be sensed several hundred yards away down wind.

As spectacular and realistic as it was -  appearing for all the world to replicate having being gunned down by the lone ME109which was in the display, it was not a final happy ending.

I estimate I had held the throttle open for only 4 or 5 seconds each time, but this was obviously enough to fry the ESC, and cabling. Obviously the BEC section of the ESC lasted a few seconds longer, but as can be seen from the pictures, it was completely destroyed soon after.

Battery is goosed too.

The model is rebuildable, with most of the damage confined to one wing panel, and the frontal area of the fus.

I told him not to use that nose art

Edited By Tim Mackey - Administrator on 03/10/2010 10:39:48

[Pete B]

Shame about the model but isn't it about time we had an emoticon for 'spluttering mirth'?

 

Pete

[Former Member]

[This posting has been removed]

[iawnski]

hmmmmmmmmmm

[Chris Card]

That's a real shame, looked like a lovely model - however is it permissible to giggle a bit at yet another silly way to have an RC crash?  

[GONZO]

Tim, oh dear, you and Martys planes. A combination that always(?) ends in disaster for one reason or another. I hope he took it well and we dont find you on the flying site face down with Harley Davidson tyre tracks up your back.

[Marty Ball]

Right, now the real story ..... lol

I 'spose I should change my avitar ..... maybe not, it will remain as a nostalgic reminder of how it was before I joined Tim's happy band! .

Being a new member of the PSSA I (mistakenly) thought that I was joining the "purists" (only kidding and not a slight of the 99% (excluding Tim) of my new PSSA mates who fly awsome models using only the wind generated lift).

As we / I was sloping I thought that power was a No - No! I was gonna take the folding prop off but being lazy I scrounged a band (a blue one mind, to match the nose cowl), I didn't want to run the risk of dinging the prop on landing!  So the end result was I saved a few quid coz the prop was about the only thing to survive so the band DID work

I was kinda taken by surprise when Tim (The Thumb) asked me if I'd charged the batteries  Of course I had charged the (insert rude word here) batteries! , Why, I asked myself, would he be asking about the battery state? I had only been in the air for about 15 minutes or so ........

Any way, the model trailing smoke while still fying was truely brilliant! But it was the only part of the day when there wasn't a camera anywhere to be seen! Typical .

Having said all of the above, I'd like to thank Tim because he has been my mentor with almost inexhaustable patience with my idiocy and has always been there to get me out of scrapes I get myself into. When I asked him if he'd land the Mustang (which against Tim's warning I had named "Grim Reaper" after a real plane) he stepped up and took over without so much as a tut! Thanks for that Mate.

I had asked Tim to land it because as already mentioned, the lift was sporadic and I didn't want to dink the model! (20/20 hindsight is a wonderful thing!).

But a lesson to take away would be for good communication between parties who might share flying and I never even thought to tell Tim I had a band on, I did have it in the back of my mind that if I did touch the throttle the band wound just ride off, well, they don't so beware.

So where do we go from here? I'm gong to attempt a repair without adding too much weight. I'll get the electrics (whats left of them) checked, Tim is a wiz with that sort of thing .... but I think all thats required is a new Battery and ESC.

The last word - No one was hurt!

 

 

[Marty Ball]

Posted by GONZO on 03/10/2010 12:13:18:

Tim, oh dear, you and Martys planes. A combination that always(?) ends in disaster for one reason or another. I hope he took it well and we dont find you on the flying site face down with Harley Davidson tyre tracks up your back.

 Lol

[Biggles' Elder Brother - Moderator]

When I read the title of this thread I thought - "OMG - Tim's gone completely eco-friendly, he's even abandoned the electrics and gone over to rubber power. Pass the green wellies!"

 

Having read it I can see how far from the truth I was - in actuality he's developed the first "hybrid" electric/rubber model. All he has to do now is get the two working towards the same goal - instead of against each other

 

Keep at it Timbo - I think you got something there - not quite sure exactly what it is - but its definately something!

 

BEB

[Tim Mackey]

I cant go out today as my mum says the swelling on my black eye should be kept dry

I was a little surprised that the ESC didnt just simply shut down open circuit when prevented with the overload - excessive current / thermal protection seemed non existent.

 

Whilst we are still friends ( just  ) I better re-pay Marty's compliment and add that in all sincerity - what a jolly good sport he is. Due to mechanical failure of one sort or another - I have managed to re-kit two of his models to date - and his laughing can be heard for miles around. He has had more than his fair share of problems since joining this crazy gang of ours, and always takes the problems on the chin, with a great bravado and smashing sense of humour.  Many a man would have packed it all in a while go, but not Marty - I'm proud to have him as a friend.

 

PS yes we do need a new icon for spluttering mirth. 

Edited By Tim Mackey - Administrator on 03/10/2010 18:23:49

[David Ashby - Moderator]

A good tale and it just goes to show there's an infinite number of ways in which a model can die - as you say Tim,  it does look repairable though   

[Myron Beaumont]

Timbo

I thought that " Quote"-"Mechanical failure" was restricted to smelly geasy oily IC powered machines 

PS  You'll never convert me (well not completely)

[Marty Ball]

I reacon Tim means the failures were Motor-neuro

[Tim Mackey]

I guess the biggest failure was communication

[Erfolg]

I had not realised that a major issue could occur if the prop cannot rotate, I have from time to time had a prop bouncing back and forwards as the prop could not rotate fully. I have been quite relaxed. Thinking, ah electrics are so safe. Not realising I was seconds from melt down.

[Myron Beaumont]

Ervfolg

You're not biased in favour of proper engines by any chance ?  If so,join the dark side club that can afford loads of dodgy power supplies . No smoke without fire they say

[Chris Bott - Moderator]

Hi Tim/Marty, I think you "got away with" that one!  I don't like the look of the charring on that battery. Don't forget I've seen one of those go up!

 

What make/type of ESC was it? I would have assumed first over current and then over temp cut outs to operate on virtually all ESC's these days. Shows how wrong assuming can be! 

 

Is the motor OK? That would have taken the full overcurrent too. I guess you won't know until you actually try it with a new ESC.

 

PS - I agree, more laughter emoticons wouldn't go amis

 

 

 

[Tim Mackey]

I have already advised Marty to ditch the battery and given him a replacement  

it looks like the burning ESC actually caused the damage to the pack, but nonetheless I wouldnt risk it in anything.

I think the ESC was an Etronix - it was a cheapy unit from GC I seem to recall.