15-01-2011, 10:19 PM
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 . 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.
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 . 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.
Drew
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Built-up
Balsa: Commercial: Depron:
Great Planes PT-20 (modified) HK Hawk 80 Index 3
Indoor Thingy Skyartec Cessna 182
Katana X lite (in construction) UM SU-26 12"WS Shoestring (Plantraco)
HK Extra 260
and a Fox chuck glider converted to RC
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