Parramatta Radio Control Aircraft Club

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Two weeks ago, I went to take off an discovered a total lack of power from my motor. It sounded more like a sewing machine than a model aircraft motor.
I tested a couple of fresh packs and not difference.
I deduced that it was probably speedy trouble as I had been pushing the 55A Scorpion speedy. I had been using 20c 2200Mah batteries so only had 44A - well under the speedy headroom. However, about 4 flights has been on 6S (serialing two 3S packs) and when I inspected the speedy, it is labelled as rating to 4S.

Prior to this, I had noticed possible sluggish response and figured old batteries and a need to switch to 4S operations for a power/ speed boost.

I've just finished soldering up and testing a brand new Plush 60 from Rob and got similar results!!! On the amp meter, it was barely drawing 10A at full throttle.




I did recell changing the prop recently 'coz I figured that mine was starting to look a little banged up. It was the same size, pitch and manufacturer. Anyhow, I swapped back after the poor result on the plush and nearly hamstrung myself (I was standing with my feet in fromt of the slabiliser to stop the plane running away)!!! A full 46A coming from the battery and plenty of thrust.

I think I have probably hurt my scorpion speedy but the real issue might have been an unbalanced ot uncentred prop Frown. To prove this, I need to unsolder the bullet connectors and resolder them to the scorpion. Too much trouble right now but I may do it later for academic interest.

The good news is that it has proven that my motor is fine. Smile
Gday Drew

That is seriously bizarre. I can only surmise that you may have a dodgy solder join somewhere, or, a break in the wires from the motor that is causing an intermittent fault. I cannot see an unbalanced prop causing the issue. Very odd.

Cheers
Rob B
Well, after swapping in a new Plush 60, the plane flew well on the old prop until some magic smike came out of the motor. So now I'm not sure again!!!
I've just finished fitting a 35-42C with either a 11x5.5 or 9x6 (not sure yet - I'll probably start small and cautious). Unfottunately the weather this weekend hasn't been conducive to flying.

When I het Kieran's Decathlon stuck back together, I'll try the scorpion speedy in that.
Put a 35/48 on it. I'll be suprised if you can melt one of those!
(13-02-2011, 09:17 PM)kizza42 Wrote: [ -> ]Put a 35/48 on it. I'll be suprised if you can melt one of those!

+1

(although, surprised yes, but not impossible Smile )