Freakazoid

My Feedback: (1)

Hi all,

I want a to replace my sp300 motor with a brushless motor.
Its for a small pylon plane.
Size: 27.5" (70cm)
Weight: 4.5oz. (125gr.) without motor, ESC and battery.

I wish to fly atleast 10 minutes. (Id rather go 10 minutes perty fast then 2 minutes at brainblistering speed)
Also, it has to be mounted like a sp300, so no outrunners.

Can someone help me pick a nice power system?
I need a motor, ESC and some lipoly. My budget has a roof of somewhere around 175 dollars.


Cheers,
Sven

FLYBOY

My Feedback: (11)

You might get better answers in the electric forums. They would know more about the electrics there and may not see it here in the questions forum.

Freakazoid

My Feedback: (1)

Ok thanks, ill ask for a move.

exeter_acres

My Feedback: (2)

it might be a bit larger, but maybe something like a Mega 1615 motor.....

I use one in my Zagi.. with a 5.5 x 4.5 prop and it really moves...


Heck... with the weight of yours...that may be a bit much...

but at least your question gets a bump

Freakazoid

My Feedback: (1)

With that motor the flight time will become an issue aswell. You might have to cram it full of lipo to get a propper time on it.

theHarpmanDan

Hello,
I bet the model motors mini ac would make it do what you want. Better yet try one of those e-flight (made by Hacker) brushless motors. The price is around 50$ and they have very similar numbers. I would run moto calc to figure out which prop will give you the flight times vs speed. E-flight has brushless speed controllers for much cheaper as well. I hope to get one soon, to try them out. The price is right, and they are nearly as powerful as a 480. Also they are close to the same weight as a 280. My Mini Ac weighs only 1.7 oz.! I bet the Eflight is the same weight, I would have to look again.

as far as a battery goes...you definately need lipo power to get the most out of it. Get a 3cell HIGH Discharge Battery. That way if you decide to pull the most out of your motor prop wise, then will have a battery that can handle the amp loads. I am able to get 25 amp bursts out of one of these suckers! By the way, do not hold the hammer down for very long if you start pulling that many amps through it. It would fry an egg. I would guess at least a second gen. Kokam or thunder power would be the ticket. Or newer polyquest. I personally would get at least a 1500mah in order to have more options later. And definately get at least an 18amp esc.

here it is...E-flight brushless, E-flight esc, Kokam 1500mah 3s1p, and a 4x3-5x3 prop. I ran moto calc, and found on a 4.3x4 prop my mini ac produces 112mph prop speed, and nearly 13 oz. thrust! Drop by my house so we can try my system in your pylon racer! I bet it would be too fast

theharpmandan

Freakazoid

My Feedback: (1)

As powerfull as a 480, yet as light as 280? Blimey! That would make this thing shoot straight up. 112mph with nearly 13 oz. thrust, thats just so wrong. :P Whats the estimated flight time it gave up on 1500mAh? Im not sure the 1500mAh stuff will fit the sleek and tiny fuse though.

Matt Kirsch

My Feedback: (21)

According to P-Calc, the Speed 300 brushed has a Kv of ~4800, so we're looking for a brushless with a similar, or slightly higher Kv rating and roughly the same physical size, for a drop-in replacement.

Himaxx's 2015-4100 and 2015-5400, also the Eflite Park 370-4100 and Park 370-5400, come to mind. The -4100s will be a little slower so you might have to run a bigger/higher-pitched prop. The -5400s will be a little faster, so you should be able to run the same prop, but you might have to drop back a little.

Freakazoid

My Feedback: (1)

Im not looking to get the same power as a s300, im looking for something that consumes asmuch as one, fits in the same space (same size or smaller), but does a lot more with it. Its a chassis origionally made for a S300 and 7 AAAcells. But I want to have enough power onboard to be able to do somewhat unlimited verticle and a nice cruising speed. but dont forget, Its a small plane, so TO fast is also possible, and any excess speed is wasted power.

What setup would give me atleast 10 minutes of limitless flight (a.k.a. impossible to stall with full throttle)?

All I would like is to hold the plane, slam the throttle, and freak out in a verticle barrelroll untill barely visible, then do some nice fast dives.


EDIT:
I just chucked my piggybank, ive got 157 bucks to spend. Is that enough for a Prop, Motor, ESC, and 2 batterypacks?
Im gonna have a hard time spending all that hardearned cash, but I bet the fun will be well worth it.

theHarpmanDan

hey freakazoid,

If a 1500 wont fit, get one that will, and has 15-20c discharge...I think the kokam 750?

yes, the Model Motors mini ac1215/16 will put out as much or more than a 480, granted heat becomes an issue. Its power to weight potential is huge. here is a link.

http://www.hobby-lobby.com/model_motors.htm

Are you able to put a gearbox on this plane, that would definatly help your needs flight performance wise. Since you want thrust more than speed, adding a gearbox is the solution. You gain more thrust, use less amps, gain flight times, and yes...slow your pylon RACER down.

theharpman

Freakazoid

My Feedback: (1)

Well I cant fly a green blip, But I can fly a rather fast green airplane. This thing is way to small to get up to speed in long sprints, because youll simply lose track of it. Id much rather go for something nippy with an awesome acceleration to slam around corners. I could build it for pure speed, but howlong of a run would it take to get the maximum out of that? 500 yards? I think it ll be invisible by the time it reaches the topspeed it could be built for. If its ever entering any races, it ll be laps with pylons no further then 200yards apart. Its gonna be nothing like those bigass 2mtr gassers whizzing around a square mile lap.

Also, I just like a very steep climbrate, because I think having to circle your way up sucks. Think of it as sitting in a rollercoaster that chugs around in big inclining circles at a walking speed for 10 minutes before it reaches the 3 minute drop and loop part of the track. Id rather get hauled up at as close to 90' up as possible.

I could build it with a gearbox I guess, but only with one thats inline with the motor, because the mount is just a big hole with no room to go to the side of it without having to cut it open and have the prop axle stick out of the fuse allignment. Is that possible, and will it take a huge amount of length? Because im not sure the battery will like the motor sticking out so far back.

theHarpmanDan

hey,

Like I said before, there is more than one way to skin a cat.. you might be better off with an outrunner type E-flight motor. You could swing a bigger prop without a gearbox. Giving you unlimited vertical with fewer amps. that way you can use a smaller lipo. I recommend you run some numbers yourself to decide such a complex question.

here is what I use... Motocalc, P-calc, and this one...er....a...here is the link.

http://www.tdmsoftware.com/TDMmodels/TDMmtrcalc.asp

if the motor is not listed simply manual put in the Kv, and no load amps. It will give you a close idea of what is going on...Prop/gb/motor/esc wise.

Like matt said, try motocalc free for 30days....

I went a step past that...lol...my wife now has a free trial on her computer I do plan on buying a watt meter, but untill then...these software preditions work fine...so far.

theharpmandan

theHarpmanDan

Freakazoid,

I see you are on this page...we should use some type of instant messanger...way easier.

[email protected] is mine..if you have the msn instant messager,,then let's chat about this.

If not, I will keep trying to catch up with your questions...I am running the numbers on motocalc now..

[email protected]

Freakazoid

My Feedback: (1)

That site is wasted on me. I dont even know half of those numbers. I dont know the wing area because its home built by someone else, and I know nothing about prop things. And even if I did know al that, it would probably give me a number that doesnt mean anything to me, because I dont know what a plane does with it. If you tell me it gives me 11oz of static thrust and what powerlanding I get, I have no clue what to make of that.

Im just a simpleton trying to ask the big guys what to do. [sm=stupid.gif]