Espritmodel.com Telemetry Radio
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Old Dec 08, 2007, 05:26 PM
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Brimfield, MA
Joined Jul 2002
194 Posts
Thanks - I will avoid ground impact at all costs!

Simple is good, just like me.

Jim
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Old Dec 09, 2007, 06:19 AM
RIP Ric
Andy W's Avatar
Marietta, GA
Joined Jun 1999
43,312 Posts
Not flaperons, but spoilerons. Watch the video to see how they assist in landing approaches.
..a
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Old Dec 09, 2007, 10:58 AM
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Brimfield, MA
Joined Jul 2002
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Andy,

Thanks, I had forgotten about the video. Answered all my questions. I 'think' I can do reverse differential with my 9C, will have to check later. I'm not sure if I want to put the throttle on a switch, I'm still a little leery about the torque on launch when the throttle hits full. I'll play around with it a bit when I'm close to getting it ready to fly.

Not exactly the best of flying weather here in MA right now!

I've got an AXI outrunner and will probably go with either 3S1P or 3S2P when completed.

Merry Christmas,

Jim

Jim
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Old Dec 09, 2007, 11:08 AM
RIP Ric
Andy W's Avatar
Marietta, GA
Joined Jun 1999
43,312 Posts
I did reverse differential when I had an 8U, I am certain you'll be able to with the 9C. There is no torque on launch at these power levels - I'm flying 800W and it launches straight and level. Even if there were, such as with really powerful systems, all you do is hit power before you release the model, so your hand absorbs the torque. The siren, however, can be thrown straight ahead and glide for a couple of hundred yards! Hitting power at any point will allow you to climb out safely..
..a
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Old Dec 09, 2007, 11:18 AM
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Brimfield, MA
Joined Jul 2002
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Thanks for the advice, I really appreciate it!

One question. I'm back into the hobby after a lot of years out. I just can't get my arms around gooping the servos in the wing and want to at least glue a few locating blocks along the side of the servo. Am I just being old fashioned? In the 'old days' I would have used two sided servo tape but I don't see that being used much anymore.

I've read the issues concerning the elevator servo mounting so I will addressthat one with screws of some type.

Thanks,

Jim
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Old Dec 10, 2007, 12:25 PM
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Peter Mar's Avatar
Toronto, Ontario
Joined Oct 1999
363 Posts
Panzer: It is probably easier to fly than your 40 trainer, especially if you don't dive it with the motor off to gain speed. Leaving the motor on at idle really slows it down, especially with a big 14" or 15" prop. However, you want the blades folded back to glide fast and flat.

The only thing really different will be the lack of self righting capability. If you put it on a 30 degree roll to one side it won't come back to neutral in a few seconds. It'll just dive if left alone.

Mine doesn't noticeably climb at power on. With the cg back at 80mm, the elevator is set so it neither climbs or dives at high speed.

Jim-KK1W: You want spoilerons for sure. Flaperons at slow speed could cause a vicious snap stall at the wrong time (landing low and slow).

I do not like landing without spoilers as the glide is really flat and too fast. That paper thin fuse can only take so much abuse before you get cracks. Just remember that you will have to trial and error the spoileron and down elevator mix til it sinks the exact way you want it to. The spoilers need to go up as far as you can get them, anything less than 30 degrees and it won't noticeably slow it down. Mine are at about 45 - 50 degrees with about 6% - 8% down elevator mixed in. I fly it in on the landing (riding the elevator) as opposed to letting it float on its own.

I don't like the throttle on a switch. If I need to go around on a landing 100% throttle is not my preference. I launch at 1/4 to 1/2 throttle. It reduces the muscle needed for the javelin throw. I no longer like to run with the Siren as it is too easy to trip and eat it.

I tried servo tape and one of the servos broke loose. Today's servos seem to leak way too much gear grease. Make sure you clean and tape the servo well before gluing.

The blocks are a good idea. I also suggest cleaning the balsa and especially the carbon fin before gluing the servos in. There is a lot of dust that the glue attaches to and then simply pulls loose. I used tape to "pull" off as much dust as possible. In the fin I filleted the servo with glue after it was initially set.

3s1p or 3s2p might depend on your AXI weight. With the big AXI (2826) you may get away with one pack (it will take a beating though at 30-50 amps). The other issue is wire routing. My motor is like a 2814 and there is almost no room for wires. Longer motors will need you to hang em outside.

As for batteries sizes, 35mm is really the max width and about 26mm the max depth. Bigger than that may pose problems with wiring and connectors and ESC location. I leave about 10mm on the side to route the wires and Deans plugs.
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Old Dec 10, 2007, 10:27 PM
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Brimfield, MA
Joined Jul 2002
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Peter,

That is all great information, detailed and specific! Now all I have to do is finish the darn thing and hope for some good weather to fly it in. We're in a little mini-ice storm with more on the way later this week. Maybe in the January thaw...

Jim
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Old Dec 11, 2007, 03:04 AM
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Germany
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@jim

Hello Jim,

I use the parts from here to mount the servos safely, with this parts you could glue (or better use epoxy) the mounting frame for the servo in the wing, If a servo fails, its very easy to swap it out or change the servo. Maybe theres also a solution like the servorahmen available in the US, or perhaps you can order them from here in Germany.

rgds
Wolfgang
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Old Dec 13, 2007, 03:56 PM
YardGoat lives with mama
Joined Feb 2007
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AMAZING. Simply amazing. I maidened the Siren yesterday at Hodges. I flew my freebird earlier in the morning to get my mind in the glider/hotliner mindset. There was a break in the wind and no one was flying. I grab JStone to toss the plane for me, and off she went. Verticle + more. There is no doubt this thing could climb out of sight in mere seconds.

I climbed up, cut the throttle and trimmed it out. Once I felt it was good, I climbed higher, turned her over, cut the throttle and zoomed down the field. I almost got into a midair with the static ultralight windsock.

I have not been this nervous since I flew my first plane. After the first flight, I saw Badbill there (I did not want him to see the crash, if it did crash) and decided to fly it again with him out there. He recommended the plane and I am excited he did. Truely a blast to fly.

Now I need a new car to transport the wing.
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Old Dec 13, 2007, 04:18 PM
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Brimfield, MA
Joined Jul 2002
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Quote:
Originally Posted by fwolf15
@jim

Hello Jim,

I use the parts from here to mount the servos safely, with this parts you could glue (or better use epoxy) the mounting frame for the servo in the wing, If a servo fails, its very easy to swap it out or change the servo. Maybe theres also a solution like the servorahmen available in the US, or perhaps you can order them from here in Germany.

rgds
Wolfgang
Those are really neat, I would order from Germany but they don't appear to have any for HS65's. Thanks for the link, I had not seen these before.

Jim
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Old Dec 15, 2007, 05:02 AM
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Germany
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Quote:
Originally Posted by Jim-KK1W
Those are really neat, I would order from Germany but they don't appear to have any for HS65's. Thanks for the link, I had not seen these before.

Jim
I use the HS 81MG, they fit perfect in the part for the HS85, and its cheaper than a HS65MG (here in germany)

Wolfgang
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Old Dec 24, 2007, 09:54 AM
WHEN IN DOUBT FLOOR IT!!!
G-unit's Avatar
AZ
Joined May 2006
4,701 Posts
Hi,where is the best place to get parts for the siren in the US.
THANKS G
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Old Dec 24, 2007, 10:46 AM
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Germany
Joined Jan 2007
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Quote:
Originally Posted by G-unit
Hi,where is the best place to get parts for the siren in the US.
THANKS G
I think at omnimodels.com or Towerhobbies.com you can get it.
At Towerhobbies you can get a rebate of 15$ if place a order >150 $
maybe there is a different about the shipping costs, but for me I have to pay shipping cost from bove.

rgds from germany

Wolfgang
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Old Dec 25, 2007, 11:21 PM
WHEN IN DOUBT FLOOR IT!!!
G-unit's Avatar
AZ
Joined May 2006
4,701 Posts
Quote:
Originally Posted by fwolf15
I think at omnimodels.com or Towerhobbies.com you can get it.
At Towerhobbies you can get a rebate of 15$ if place a order >150 $
maybe there is a different about the shipping costs, but for me I have to pay shipping cost from bove.

rgds from germany

Wolfgang
THANX
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Old Dec 31, 2007, 02:17 PM
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Peter Mar's Avatar
Toronto, Ontario
Joined Oct 1999
363 Posts
aglbcl
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Join Date: Aug 2006
Posts: 8 Siren motor

--------------------------------------------------------------------------------

Hi Peter. Your post indicated that you fly your Siren with the cg at 80mm back of leading edge. Would it be possible to use the same United Hobbies motor with a cg further forward for a less experienced flier?


Putting the CG further forward will just require heavier batteries pushed further forward.

I recently tried the Loong Max 3s 2250 25C batts (UH / HC) and they are heavy enuf if you have two end to end in 3s2p format. Yes they will touch the motor so you have to secure them somehow. I just rely a friction fit and from time to time they fall forward or back 5 to 10 mm. It does throw the trim out a bit but I am accustomed to it. If I donít launch too hard and do not do too many hammerhead type reversals, spins, etc., the batts will stay put the whole flight. But what fun would that be...?

The 35-36 1000kv is very light but not very efficient. In fact, I think it is awful. Using a 12x6 I get about 33A drawn but the climb is not more than 45 degrees (if you want to maintain good airspeed). Did I mention it was cheap?

Back to the CG question:
Any CG less than 80mm, with correct elevator trim, will cause the bird to pull out on dives. This is not a bad thing for newbies. The Siren instruction's CG is so nose heavy that you need a ton of up trim to allow it to fly anything like level. Then you put it into a dive to do a loop or flyby and the Siren does an auto pull out as the velocity increases.

I should point out that I have three programmed trim settings:

1. Landing: Max Spoilers and down elevator
2. Diving / Climbing: Neutral elevator (both right side up and inverted dives)
3. Floating / Thermalling: Up elevator about 5-10% depending upon turbulence.

You cannot fly hands off in position 2 as the Siren will sooner or later head for the ground. Moving the CG between 80mm and 100mm might allow dive and float trim to be close. Since I fly inverted dives I have set the elevator and CG to allow for no trim changes no matter which side up I am diving and pulling out from.

I have found THE Siren thread and someone had recommended 100mm back. I have flown it that far back and if trimmed flat in dives it will actually pull up in inverted dives. These are 45 to 75 degree dive angles from about 100m to 200m up and pulling out at 2m or 3m (need to have some margin...).
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