Originally Posted by Vantasstic

1.5 hours...with no rudder...Show Off!!!

It wasn't hard at all, think about it- It will climb straight up to almost out of sight in about 5-6 seconds or so. And w/ the two 2200's, you can get a BUNCH of climbs! Not to mention the fact that even without a rudder, the plane really thermals well.

Bill Davenport
AMA 28141

Rare,
not many options in the build. The tail end has alot of CF and resin with a bolt on Horixontal tail. Elevator servo is mounted in the tail. I used an HS 56 servo. mostly for the side mounting lugs and since this was my fisrt hotliner, I liked the carbonite gears. it may be a bit of an overkill. Also, if you are shaving off grams, the pushrod could be a bit lighter and nylon bolts cut down a bit. but those changes really would not have helped my situation.
I found that a 35mm diameter outrunner will fit in the nose. I am not familiar with the eflite 15, but there is not much space along the sides of the motor.
There is more volume along the belly of the plane so mount the motor so the wires are pointing downward.
The plane has a light ply structure in the center of the fuse, it stiffens the fuse, but you will probably want to cut out part of it if you want to stick with a single battery pack, so you can slide it as far forward as possible. Everything forward of the wing is solid, no access hatches, so it can get a bit challenging trying to work in the front of the plane.
Badbill's time is about what I am seeing, But I only get about 2 hours at a time for flying so I usually have to land for other things besides battery time. I tend to like to climb up, power off, search around for lift and do a high speed dive, with some mild acrobatics, then blast back up again to a different part of the sky. I haven't tried continuous power on flight through a whole pack yet. With my battery set up, I am only pulling an 8-9C load at full power. If I understand the math, that should be about 7-8 minutes of full power and it only takes a few seconds to get to altitude so there is alot of climbs in that set up.

I've got the same problems with the too light outrunner (and the problems to reach the correct cg), so I put about 120g of lead in the front oft the plane, but this was not enough, so I spent the plane also a seperate 5 cell RX battery, this means the added weight is not really dead weight.
My flight battery is a 3S 2200mah lipo battery.

Wolfgang

wpnguy,

Thanks for the interesting material you and the others are sharing about the Siren. I'm getting acquainted with my new Siren slowly--using brushed motor and NiMH batteries. Do you know how much your Siren weighs with the brushless and Li-Po set up you have? Thanks again and I hope all you guys enjoyed a Happy Thanksgiving.

Cheers,
Dave in Atlanta

"Georgia 31- Georgia Tech...xC$3zzSt...you're breaking up!"

Originally Posted by wpnguy

Rare,
not many options in the build. The tail end has alot of CF and resin with a bolt on Horixontal tail. Elevator servo is mounted in the tail. I used an HS 56 servo. mostly for the side mounting lugs and since this was my fisrt hotliner, I liked the carbonite gears. it may be a bit of an overkill. Also, if you are shaving off grams, the pushrod could be a bit lighter and nylon bolts cut down a bit. but those changes really would not have helped my situation.
I found that a 35mm diameter outrunner will fit in the nose. I am not familiar with the eflite 15, but there is not much space along the sides of the motor.
There is more volume along the belly of the plane so mount the motor so the wires are pointing downward.
The plane has a light ply structure in the center of the fuse, it stiffens the fuse, but you will probably want to cut out part of it if you want to stick with a single battery pack, so you can slide it as far forward as possible. Everything forward of the wing is solid, no access hatches, so it can get a bit challenging trying to work in the front of the plane.
Badbill's time is about what I am seeing, But I only get about 2 hours at a time for flying so I usually have to land for other things besides battery time. I tend to like to climb up, power off, search around for lift and do a high speed dive, with some mild acrobatics, then blast back up again to a different part of the sky. I haven't tried continuous power on flight through a whole pack yet. With my battery set up, I am only pulling an 8-9C load at full power. If I understand the math, that should be about 7-8 minutes of full power and it only takes a few seconds to get to altitude so there is alot of climbs in that set up.

Thanks so much, wpnguy - you've been incredibly helpful. 35mm will fit, huh? The Eflite 15 should fit then, but will it be a miserable nightmare to install? From the way things sound, (2) 2100mah batts should work well - I'm liking the idea of extra flight time, so the weight doesn't bother me. I have a Multiplex Easy Glider and a Cularis on the way, so those will be my thermal birds - I'm just looking for something a bit "hotter" and playful, and the Siren is really sounding good. Check the below specs and let me know what you think - would really appreciate your insight!!

Thanks and God bless - "Rare"


Eflite Power 15 Specs:

* Type:Brushless Outrunner Motor
* Size:15-size
* Bearings or Bushings:Ball Bearings
* Wire Gauge:16
* Recommended Prop Range:10x6–13x6.5
* Voltage:7.4 - 14.4V
* RPM/Volt (Kv):950
* Resistance (Ri):.03 ohms
* Idle Current (Io):2.00A @10V
* Continuous Current:34A
* Maximum Burst Current:42A (15 sec)
* Cells:8–12 Ni-MH/Ni-Cd or 3-4S Li-Po
* Speed Control:40-45A Brushless
* Weight:152g (5.4 oz)
* Overall Diameter:35mm (1.40 in)
* Shaft Diameter:5mm (.20 in)
* Overall Length:50mm (1.90 in)

Needed to Complete
40A - 45A Brushless ESC
8-12 Cells Ni-MH/Ni-Cd or 3-4S Li-Po
10x6 to 13x6.5 Electric Prop

http://www.horizonhobby.com/Products...odID=EFLM4015A

I've been using AXI 2826/12 with Graupner 14x9.5 folder on 4 cell 2100, 30 C Lipoly on a 100" RCM Northeast sailplanes Pike electric (not the high tech Moulded Pike).
53 amps without overheating and typical flights without thermals of over an hour.
Typical climbs are 10 seconds to 400 Ft plus (estimated 2400 ft/ min) Checked climb rates on 3S 2p 2100 was 1850 ft / min, but my LoLo logger has gone bust so I can't give precise figures for the 4s.
John O'Sullivan

Rare.
The power 15 should fit just fine. The extra weight of the motor will help with the CG as well. One note with the Eflite motors, you will have to follow the instructions that come with the motor to reverse the shaft, it is an easy process, should be no problem.

Dave,
if my scales are accurate, my Siren with a Eflite 10 and 2 3s 2100 lipos is around 43 1/2 oz

Originally Posted by wpnguy

Rare.
The power 15 should fit just fine. The extra weight of the motor will help with the CG as well. One note with the Eflite motors, you will have to follow the instructions that come with the motor to reverse the shaft, it is an easy process, should be no problem.

Dave,
if my scales are accurate, my Siren with a Eflite 10 and 2 3s 2100 lipos is around 43 1/2 oz

Thanks so much, wpnguy - you've really been helpful. I think I'll opt for the Eflite Power 15 when I go the Siren route - just wish I would have known that before I picked up my Eratix 3D plane; should be a blast, but the Siren sounds better!

I'll probably be harassing everyone here with more questions when I pick up a Siren in a bit, but for now, I'm glad to hear an outrunner will work. Thanks so much for the info!


God bless - "Rare"

One last, quick question - for now, at least!

Overkill???

Eflite Power 25
* Type:Brushless Outrunner
* Size:Replacement for 25-size glow engine
* Bearings or Bushings:Ball Bearings
* Wire Gauge:14
* Recommended Prop Range:11x8 to 14x7
* Voltage:12 - 16.8
* RPM/Volt (Kv):870
* Resistance (Ri):.03 ohms
* Idle Current (Io):2.40A @ 10V
* Continuous Current:32A
* Maximum Burst Current:44A (30 sec)
* Cells:3S-4S Li-Po or 10-14 Ni-MH/Ni-Cd
* Speed Control:40A - 45A Brushless
* Weight:190g (6.7 oz)
* Overall Diameter:35mm (1.40 in)
* Shaft Diameter:5mm (.20 in)
* Overall Length:54mm (2.10 in)

Needed to Complete

40A - 45A Brushless ESC
3S - 4S Li-Po or 10 - 14 Cell Ni-MH/Ni-Cd
11x8 to 14x7 Prop

What size spinner did everyone use? Some say a 38mm is too small and a 40mm too big?

I found a MPJET 40mm spinner would that look bad?

Whats the feedback on these AXi2826 clones for Siren usage: http://www.hobbycity.com/hobbycity/s...idProduct=4910

Spar

rare,
the early parts of this thread say the airframe is rated for 500 watts. The 25 still looks to be below that limit. So it should be no problem.
If you follow the hotliner discussions in the high performance electrics section, they generally think more power = more fun... right up until you rip the wings off

My 40mm spinner is just a hair larger than the fuse. but you have to look real close to notice

I'll be getting one of these for mine for one I think they look cool and second to help keep the motor,ESC,and battery temp under control.

Originally Posted by wpnguy

rare,
the early parts of this thread say the airframe is rated for 500 watts. The 25 still looks to be below that limit. So it should be no problem.
If you follow the hotliner discussions in the high performance electrics section, they generally think more power = more fun... right up until you rip the wings off

My 40mm spinner is just a hair larger than the fuse. but you have to look real close to notice

Thanks, wpnguy - if I go the power route, I'll try and keep the G's within limits!


God bless - "Rare"

That 40mm looks great!

Would a 205 gram (7.3 oz) motor be good for balancing?

Are you guys running with a three cell or four cell lipo?


Also if I buy a 4200mah 3S lipo would it fit in the battery compartment or is it really cramped? What was the largest battery size you fitted and is it better to go for a lower mah battery to keep the weight down?