Originally Posted by Adrian_M

( 8 or 10 s with the Scorpion S-4020-16) on 6s sure but not 8 or 10s


http://www.scorpionsystem.com/catalo...s40/S-4020-16/

S4035-460kv is the motor you want for 8 or 10s 12 x 10 prop

http://www.scorpionsystem.com/catalo...40/S-4035-460/

Hey now, while I agree the 4035 is the motor for top speed, it does not fit the criteria he defined as 110mph and 7-8 minutes of flight.

Originally Posted by mattyhawk

Hey now, while I agree the 4035 is the motor for top speed, it does not fit the criteria he defined as 110mph and 7-8 minutes of flight.

I know that matty but Scorpion recomends no more than 6s on that motor, i think 8 or 10 s is pushing the 4020 motors

What am I missing Matty?

For heat and motor life, volts don't matter, amps do. Volts only matter when considering the amount of work being done by those amps (in watts). Manufacturer rated volts of a motor for airplanes are simply a function of their application potential. That is why you don't run 1200kv motors on 8S on the sundowner, but you can take that same motor and put it in an EDF and does beautifully over voltage.

When looking at motors, look at amps you are going to draw to meet your goals. If you want to do 137mph on 10s like many here, then do what Adrian said with the 4035. It is the best motor for the job, it has been proven over and over. Just remeber, your flights are measured in the 3-4 minute range. If you want to meet the goals of your original question, consider what I posted a few posts back. Just remember, if you ever want to go faster on the 4020, you will have to sell it and get the 4035. The 4020 doesn't have the handling power to get to the 100A range the 4035's are known for.

Originally Posted by jculottaiii

Hahahaha! Thanks......however, I am going to do the 8 or 10s setup mentioned above. Is it better to do twin packs or one pack? Wasnt sure if the battery area could fit the longer 8 or 10s packs, or if you needed a fatter set up with twin 4s or 5s packs...

I haven't seen anyone put full 8s or 10s packs in their SD-50s, but doesnt mean it can be done. Most people run twin packs in series because chargers that are capable of 8s and 10s are too expensive, at least that's my reason.

Oh, and turnigy motors (rebranded XYH) are great motors, but you have to know their limits. Scorpions / Hyperions will spank the pants off 95% of turnigys, and the other 5% Scorpions / Hyperions are still better, but only marginally better.

I guess then Scorpion and Hyperion don't know what they are talking about I just recently spoke to Scorpion technical people (they built my 8000watts motor for the NXT) and they told me you could go over their recommended cell count by one cell(3.7 volts but its not recommended
It's not my plane or my motor so jculottaiii can do what he wants really
I was just passing on the advice that I was given by the motor manufacturer
Cheers

Sounds good. Can't go wrong with staying within spec.

I may try this motor on 8s in my SD50
http://www.hobbyking.com/hobbyking/s...ize_heli_.html

Brushless,

That looks really good! Nice find, that motor looks identical to the T600 series I use in my SD-50, but a nice lower KV out of the box. On 8S, its gonna pull high amps, but it should do nicely.

Oh, that's beautiful! 480kv motor too!

http://www.hobbyking.com/hobbyking/s...ize_heli_.html

Very useable alternative to a $200 scorpion 4035 on 10S. If it is anything like my T600 (which I believe it is), the T700 is good to 3600W on 10S with a 12x12 APC at 92A peak. If the advertised numbers can be believed, they are identical to my T600 880kv reterminated to 460kv.

Does anyone know if the stock wing tube needs to be so thick? I've seen where guys are using CF replacements but I have a spare aluminum that has a much thinner wall thickness. Saves an ounce of weight but after seeing how thick the stock one is I'm worried the thin one wont be strong enough. FYI, the replacement tube came out of a Seagull Models Edge 540.

Originally Posted by ACKopter

Does anyone know if the stock wing tube needs to be so thick? I've seen where guys are using CF replacements but I have a spare aluminum that has a much thinner wall thickness. Saves an ounce of weight but after seeing how thick the stock one is I'm worried the thin one wont be strong enough. FYI, the replacement tube came out of a Seagull Models Edge 540.

Which Edge 540 out of curiousity? the 69" WS one?

I wouldn't go thinner, but this is just speculation. I have yet to hear of anyone bending a spar in the sundowner, and with the speeds we have been reaching with this thing, I would think it would bend if it was too weak. I used to have the Seagull 540 69" and I bent 2 stock tubes, one in a crash and one while flying.

Maybe someone else has some insight.

I personally wouldn't mess with it. Is the little bit of weight savings worth the "what if" feeling every flight?

On a side note....does anyone have a moto calc or similar program with a Aeolian 6364 370KV motor in it? I've looked at a few other calculators around and none of them have that KV motor in the list. I'm trying to get an idea whether 10s or 12s is the way to go. Its in the Seagull Mew Gull....don't have the ESC yet...it should be here end of the week (its a 100A). I would like to get the most speed out of it if possible

Specs are Rotational Speed: 400 (kv) RPM/V
Continuous Current: 100A
Max. Current: 120A
Input Voltage: 14.8 - 37V
Max. Efficiency: 98%
No Load Current: 7.5A
Internal Resistance: 110(Omega)
Power: 2725W
Motor Weight : 860g
Motor Dimensions (Diameter x Length): 63mm x 61mm
Propeller Dimensions: 18.5" x 12"/19" x 10"/20" x 8 "
Input Battery Types: NiCd/ Nimh/ Li-po Battery
Recommend Model: Airplane


Should be able to actually try out the black Sundowner this coming Sunday....haven't flown it yet. Going to try it with the Turnigy SK3 50-55 430KV on 8s and a 12X13 prop. Check the datalogging and see if I can go to a 12X14. Hope it goes respectably fast for the budget it was on.

Originally Posted by mattyhawk

Which Edge 540 out of curiousity? the 69" WS one?

I wouldn't go thinner, but this is just speculation. I have yet to hear of anyone bending a spar in the sundowner, and with the speeds we have been reaching with this thing, I would think it would bend if it was too weak. I used to have the Seagull 540 69" and I bent 2 stock tubes, one in a crash and one while flying.

Maybe someone else has some insight.

No its the smaller one, I think they called it a 46 size. It is longer in length than the one that comes with the Sundowner, it also survived the crash that totaled the Edge.

planebldr is probably right and a little piece of mind goes a long way. Best to just stick with the stock.

Originally Posted by planebldr

Going to try it with the Turnigy SK3 50-55 430KV on 8s and a 12X13 prop. Check the datalogging and see if I can go to a 12X14. Hope it goes respectably fast for the budget it was on.

Are you going to use glow prop or is there 12x13 electric prop?