Tons of discussion on successful power systems in this forum (Electric Sailplanes) and also High Performance.

Call Neu (actually Castle sells them now) and tell them what you want.
..a

Originally Posted by johnnyrocco123

I don't really know much about the gear drives but I am researching them as we speak. All I know is if I drop the money, I want to make sure it will put out some serious watts so I can move the setup into a better hotliner later this summer.

Which ratio? Does it depend on kv? Where can I learn how this works?

Thanks guys

1) The bigger the ratio, the better (in general). it will allow you a bigger prop, or a higher kv motor (lower resistance), or higher voltage (better efficiency)

2) it is COMPLETELY dependent on kv! The Arcs will be happy on 3s or 4s with 4.2-4.4 gearing with a 13" prop. Any taller (3.3 etc) will cause the amp draw to sky rocket, and you'll be relegated to small, inefficient, props

3) to run the kind of power that will keep you satisfied in this or another airframe is going to need a much bigger motor then the ARC. You will be limited by the GB, as it will have a loctited pinion that will have a tendency to come off at power levels above 600W.

If I were in your place, I would get one of Hyperions new Outrunners with the 28mm nose. This should fit the Siren without a problem, and they can likely take 2kW. Also, they would fit your price range.

Kid

Appropriately sized 36mm inrunners, direct drive, also work just fine in the Siren.

Ive been running a Mega 22-30-4 on 3S spinning 14x12 folder. With that prop, the 22/30/4 runs about 600 watts on quality 3S packs and performs quite well. Ive been running 2ea 3S 2200 packs in parallel to fit better in the space.

A Neu or Hacker or Medusa or any other quality 36mm inrunner with the appropriate Kv will work great. No issues with gear boxes or wire routing or hole spacing. Also more efficient than an outrunner.

I prefer motors like the Mega or Medusa with flow trough cooling rather than a sealed can but as long as you're not pushing the motor too hard it will do fine with the cooling as is.

If your packs can handle the amps go with a slightly higher kV for more power if you want. A Mega 22/30/3 should get you into the 800 watt range. Or go with 2ea 2S packs in series with a medium kV Neu like maybe a 15152Y to get some stupid power

Originally Posted by MrE

Appropriately sized 36mm inrunners, direct drive, also work just fine in the Siren.

Ive been running a Mega 22-30-4 on 3S spinning 14x12 folder. With that prop, the 22/30/4 runs about 600 watts on quality 3S packs and performs quite well. Ive been running 2ea 3S 2200 packs in parallel to fit better in the space.

A Neu or Hacker or Medusa or any other quality 36mm inrunner with the appropriate Kv will work great. No issues with gear boxes or wire routing or hole spacing. Also more efficient than an outrunner.

I prefer motors like the Mega or Medusa with flow trough cooling rather than a sealed can but as long as you're not pushing the motor too hard it will do fine with the cooling as is.

If your packs can handle the amps go with a slightly higher kV for more power if you want. A Mega 22/30/3 should get you into the 800 watt range. Or go with 2ea 2S packs in series with a medium kV Neu like maybe a 15152Y to get some stupid power

The 1515/2Y looks like a great motor for a bigger hotliner but it won't fit in the Siren. I have been looking today at the Mega22/30/3 but I think I want more Watts.

If I could find a Direct Drive inrunner that would give me 1500 watts I would be very interested.

Doesn't exist, at least, not one that will swing a prop suitable for a model such as this.
..a

Originally Posted by Andy W

Doesn't exist, at least, not one that will swing a prop suitable for a model such as this.
..a

After talking to Castle Creations today, I think I am interested in a 10 to 11 inch prop. I am not interested in flying this plane like a Hotliner. I want to stay on the throttle more. Neu motors will do it direct drive no problem, but they wont fit in this one, I will go there with my next one that is built tough and has a bigger fuse.

For now I will play with the Turnigy 36-56 1800kv on a 8x5 sport prop (4S) and then I might go take a look at AXI motors.

I hacked out the battery bay finally. I can get a 4S 2650mah in there now.

The problem with direct drive is efficiency, or more importantly internal resistance. There has been a few suggestions, so we'll run through them, and throw in my Medusa just for fun

1) Mega 22/30/4: On 3S with a 14x12 it was only 60% efficient :O and weighs 7.7 oz

2) NEU 1515/2Y: Weighs 12oz :O and turns a 13x11 at something around 1000W, but is only 77% efficient. Not to mention the cost

3) Scorpion 3032-8: weighs 7.5oz, puts out ~800W with a 13x11 (dont completely remember whether that was the prop or not) and is 76% efficient. But it is much cheaper (86 dollars!)

4) Medusa 28-56-2800 geared 4.28: weighs ~6oz with GB, will happily put out 1400W on 4s with a 13x11 at 90% efficiency! And, you'll be able to find a geared inrunner pretty cheap from time to time on the forums

This is because the outrunner and geared inrunner have much lower resistance by weight because of their design. They have a much higher torque advantage over the DD inrunner.

Guys... I now have a TURNIGY arodrive xp B3656-1200.

Will this work with this plane?

(Please say yes)

Originally Posted by Red5

Guys... I now have a TURNIGY arodrive xp B3656-1200.

Will this work with this plane?

(Please say yes)

Im not seeing it on the HC site, could you post a link? It sounds promising, but its hard to say without seeing the specs

Originally Posted by Red5

Guys... I now have a TURNIGY arodrive xp B3656-1200.

Will this work with this plane?

(Please say yes)

It will work. It's good for about 50 amps WOT. 3S or 4S depending on what prop you want on it.

I have the 3656 1800kv, just put it in the Siren with a 8x4 apc and a 4S 2200.

I ran it for 60 sec WOT and it didn''t burn up, Good enough for rock n roll. I haven't checked the watts yet but I am anticipating around 700 which should be a little better.

I will try it out this evening or tomorrow. Unfortunately because of where the battery leads are located on Turnigy/Rhino Lipos, I can't fit the 4S 2650 or 3300. I am trying to get another 4S lipo where the leads come out the top of the battery

Originally Posted by johnnyrocco123

It will work. It's good for about 50 amps WOT. 3S or 4S depending on what prop you want on it.

I have the 3656 1800kv, just put it in the Siren with a 8x4 apc and a 4S 2200.

I ran it for 60 sec WOT and it didn''t burn up, Good enough for rock n roll. I haven't checked the watts yet but I am anticipating around 700 which should be a little better.

I will try it out this evening or tomorrow. Unfortunately because of where the battery leads are located on Turnigy/Rhino Lipos, I can't fit the 4S 2650 or 3300. I am trying to get another 4S lipo where the leads come out the top of the battery

Thank You.


Question.. The control arm for the rear servo.. How short of a throw does yours have?

Originally Posted by Red5

Thank You.


Question.. The control arm for the rear servo.. How short of a throw does yours have?

Considering my Siren is extremely slow, I need more throw. But I think I started with the recommended plus 3mm. T

Originally Posted by Red5

Guys... I now have a TURNIGY arodrive xp B3656-1200.

Will this work with this plane?

(Please say yes)

With an 11x10 it should be around 700W on 3S. Your efficiency will be in the low 70%, which isn't entirely terrible. That prop is a little on the small side though

Originally Posted by Red5

Guys... I now have a TURNIGY arodrive xp B3656-1200.

Will this work with this plane?

(Please say yes)

Seems allot of guys are on a tight budget,so you try to find a cheap alternative to power.After 2 or 3 attempts at finding the right motor combo,you are probably into it alot more than if you were to just buy a tried and true setup..
Here is a motor alot of guys have tried with good results..I RUN THIS MOTOR WITH THE 4.4:1..http://cgi.ebay.com/Multiplex-BL-480...item3cac6840a1

Keep checking the rc groups FS/W section..A Multiplex 480 4g w/gb sold for 30.00