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RE: Yet another Sig Something Extra Build - 2/21/2008 1:30:37 AM   
N1EDM



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From: Brockton, MA, USA
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Hmmm, an alternate wing, huh? Have you considered something with a 1.5M undercambered wingspan? A motor glider with a short tail moment???

Yes on the Twist. I was working on the design this evening. I may be joining the Profile Brotherhood. I have an old SSE tail section that's been hanging in my shop, and the original Twist wing is OK, so I just need the fuse. I was playing with that just a little while ago. Now all I need is the time to build it.

I like everything that you've been doing here. I can hardly wait to see it fly..

Bob

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An expert is someone who has been doing it for 15 minutes longer than you.

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RE: Yet another Sig Something Extra Build - 2/21/2008 4:30:24 AM   
iron eagel



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quote:

ORIGINAL: N1EDM

Hmmm, an alternate wing, huh? Have you considered something with a 1.5M undercambered wingspan? A motor glider with a short tail moment???

Bob


I think you might have already seen one of my alternative wing ideas, the root size almost matches the SE fuse.

I can not wait until I can get started on the carbon fiber lay up. I am pleased with the way the horizontal stabilizer came out with the sheathing, it came out weighing 1.6 ounces, and I have not even started to shape the leading edge yet. Got one elevator cut up and glued ran out of balsa of the size I need. Then I have to add the carbon fiber to the trailing edge and shape them prior to putting the sheathing on. I put on some pictures of the elevators tomorrow night, I had to notch all of the wood to get a good strong framework, it will be going down to only 1/16 thick on the trailing edge. Then add to that it is over an inch longer in cord than the stock version...

< Message edited by iron eagel -- 2/21/2008 4:51:21 AM >


_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

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       Post #: 127

RE: Yet another Sig Something Extra Build - 2/21/2008 5:11:33 PM   
vmsguy


 

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From: Woodville, WI, USA
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Your build is coming along very nicely. I've had an SSE on my wishlist for a while now. First I was going to build a kit, but I was at an auction a couple weeks back and I couldn't pass up an a good condition ARF for $70.00.

Can I ask you a for a couple favors???

I need some information.

First, I need all the info on control surface throws, and engine thrust angles.

Second, I need airfoil measurements.

I fly electric, and need to get drag numbers to plug into MotoCalc. These numbers help me determine what type of motor to use. I enclosed a screenshot of the program, if you could take the measurements off the plans and PM me, or post them here, it'd be great.

TIA

Lyndon

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“It is possible to fly without motors, but not without knowledge and skill." - Wilbur Wright

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       Post #: 128

RE: Yet another Sig Something Extra Build - 2/22/2008 1:56:22 AM   
iron eagel



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From: Middleboro, MA, USA
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Lyndon, no problem glad to help!

The control surface throws are as follows:

Low rate:

ailerons 1 inch up 1 inch down
elevator 1 1/4 inch up 1 1/4 inch down
rudder 1 7/8 inch left 1 7/8 right

High rate:

ailerons 2 inch up 2 inch down
elevator 2 inch up 2 inch down
rudder 2 1/4 inch left 2 1/4 right

Measurements were taken as follows:
Aileron at inboard trailing edge.
Elevator at widest inboard trailing edge
Rudder at the widest lower trailing edge

This is an aerobatic plane the thrust angles are all at zero to the datum.

Edit to add.
As far as the airfoil it is symmetrical and does not have camber I have scans of the original ones near the start of the post. It is 2 11/32 at the thickest point and is offset 5/32 of an inch above the datum line. The cord at the root is 15 3/8 inches and at the tip the cord is 12 5/8 the wingtip, so the UH at the root is 1 3/32 and the lh&ch would be -1 1/4 inch (?) with le and te height being zero or there abouts....

As far as E power

A far easier way to size you motor is using wattage vs weight, for an aerobatic airplane a good rule of thumb is 150 to 200 watts of power per lb with 150 watts/lb being the sport/aerobatic end, and 200 watts the aerobatic/3 d end of the spectrum. So if you were to say you have a RTF weight of 5 lbs you would want 750 to 1000 watts of engine power to the prop. Personally I would use an Axi 4120 with a 60 amp controller fueled by around 20 volts of a123 cells they have a high discharge rate and can take the type of current drain that a 40 sizes airplane requires and can supply the type of power you need. The Axi 4120/18 (If I recall the one I used) is similar in power to a .60 size glow. The reason for the larger motor and high current is, that at normal cruise speeds you could get upwards of 20 min of flight time, longer if you are not beating on it. The left stick is the final arbiter here as far as flight time or power use, the less you beat on it, the less you will shorten your battery life. I used a similar setup for my wifes LT-40, and that is what I would use in my SE if it were electric.

Good luck now off to my build now...
Paul

< Message edited by iron eagel -- 2/22/2008 6:43:48 AM >


_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to vmsguy)
       Post #: 129

RE: Yet another Sig Something Extra Build - 2/22/2008 6:39:04 AM   
iron eagel



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Last night I promised a picture...

Here is one half of the stock elevator, next to my modified one, that I took this morning.

I managed to build the second one tonight but its late and did not feel like dragging the camera back to take a shot after I finished it.

Next comes bonding the 1/16 inch carbon fiber rod to the trailing edge that will serve both the trailing edge, and a guide for shaping the elevator frame taper front to rear.

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< Message edited by iron eagel -- 2/22/2008 7:04:06 AM >


_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to iron eagel)
       Post #: 130

RE: Yet another Sig Something Extra Build - 2/22/2008 11:45:13 PM   
reincarnate



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From: Columbia City, IN, USA
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quote:

ORIGINAL: iron eagel

reincarnate,
Nice job on your SSE, hope my finish comes out half as nice as yours.

The Du-Bro gear I got was number CAT 789, they are an inch higher, and a lot wider 14 1/2 inches. There also is a nice set that you can get from TNT of metal.

Hey iron eagle! Your SE is looking great. Can't wait to hear how it performs.

With your advice from above, I ordered a set of the TNT gear. It finally arrived today, and I got it installed tonight. (needed a break from the Shoestring!) It raised the front end 1 3/4" (plus being 1 1/2" wider) allowing me the adequate clearance to to swing the 12.25 APC. Thanks for the help and good luck. I'll keep watching.

_____________________________

Are the wheels supposed to fall off when you land? No? How about the engine?

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       Post #: 131

RE: Yet another Sig Something Extra Build - 2/23/2008 12:33:49 AM   
iron eagel



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Thanks,
And you are welcome...

I am going to order a set of either the TNT or Bolly carbon fiber gear, the Dubro is a bit heavier than I want to use on this plane. I had to order some CF for the elevator joiner my LHS did not have anything the size I wanted in stock. I want to use a carbon fiber tube rather than the bent wire to join the elevator pieces together, should be a bit more rigid that way.
Hopefully tonight I can get the fin and rudder done after shoveling some snow....



< Message edited by iron eagel -- 2/23/2008 1:07:24 AM >


_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to reincarnate)
       Post #: 132

RE: Yet another Sig Something Extra Build - 2/26/2008 2:15:35 AM   
iron eagel



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Here is a view of the finished elevator frames with the carbon fiber trailing edge installed and shaped. The two halves came out at 1 oz without the sheathing applied, not bad as the originals weighed in at .8 oz and these are larger. If you look at the side view you can see how they were tapered using the trailing edge as a guide.

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_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to iron eagel)
       Post #: 133

RE: Yet another Sig Something Extra Build - 2/27/2008 5:12:59 AM   
iron eagel



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Finally got the vertical fin and rudder are framed up tonight. The fin has the carbon fiber stiffeners installed and is ready to be shaped before sheathing.
The rudder is also framed up but needs some trimming before the carbon fiber trailing edge is installed, it then will also be ready for sheathing.
The first picture shows my modified fin and rudder glued up and drying. The second picture is the stock fin next to the modified fin. The third picture is the stock rudder and the modified one.
So the next step is to install the carbon fiber on the edges and then shape the fin and rudder, before sheathing is applied.


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_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to iron eagel)
       Post #: 134

RE: Yet another Sig Something Extra Build - 2/27/2008 5:25:53 AM   
alex7403


 

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looks good, it will add much stability to the tail.


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measure twice cut once, again i cant believe i didnt learn it yet....

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       Post #: 135

RE: Yet another Sig Something Extra Build - 2/27/2008 5:40:59 AM   
iron eagel



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Actually Alex the larger rudder is for better knife edge control, and to make up for the side area that has been added. Hopefully the enlarged rudder, along with the increase of the side area ahead of the COG provided by the cowling and cooling duct should improve its performance in knife edge. The major portion of the modification was to incorporated airfoil shape in the stab/elevator and fin/rudder, and beef up the structure, so I would be able to eliminate the tail braces, all this to reduce drag, and if possible to make it lighter.

_____________________________

The Wrights never crashed, they only had hard landings. I 've had some hard landings myself. AMA EAA AOPA revver #185

(in reply to alex7403)
       Post #: 136

RE: Yet another Sig Something Extra Build - 2/28/2008 12:47:23 AM   
N1EDM



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Y'know, now that you've built the stock and the modified tail surfaces, all you need is a wing and then build a profile fuse... then you'd have TWO SSE's !

Bob

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An expert is someone who has been doing it for 15 minutes longer than you.

(in reply to iron eagel)
       Post #: 137