RE: TWIN FEVER !!!  
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RE: TWIN FEVER !!! - 4/25/2008 5:21:50 PM   
Max_Power



Posts: 96
Joined: 5/14/2005
From: Bloomington, MN, USA
Status: offline 		Man, That thing is so cool CP! What Great Name has been attached to this model?(Or are you waiting for the flight test?lol) Just the other day I looked and that thing was just some wood and foam! You guys got me thinking about your launcher and highstarts...And that video of The guys Launching a squirell with a skeet launcher popped into my mind.........Then I thought "HEY!, I wonder if anyone has ever tried to mod a skeet launcher to sling planes?" (maybe stretch the arm, add a "Paralell Linkage" in the plane holder to make take the arc out of the throw, etc) Hmmmm... Can't wait to hear the flight report!!. Todd

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RE: TWIN FEVER !!! - 4/25/2008 6:44:11 PM   
KidEpoxy



Posts: 3224
Joined: 10/14/2004
From: San Antonio, TX, USA
Status: online 		I wonder if a pully block on a tension mainspring would do the trick without laying out 20-30' of rubber line out in front? If you have say 8' of rail to accellerate the model, run a 4 pully block so the spring just needs to contract 1'... like from a 4' stretch to a 3' so you have decent tension thru the whole travel. Or use silicone tube to really steal from the slingshot concept.

That, or use a big cam wheel under the rails that uses the lobe to keep tension on the string up till the end... the compoundbow idea of managed tension thru the entire release by camwheel.

Anyway, it would be neat to have it be self contained unit that dont leave rubber all over the field after the shot.

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Optional MA is part of AMA history, we can go optional AGAIN if we just say so

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RE: TWIN FEVER !!! - 4/25/2008 7:06:40 PM   
Mr Cox



Posts: 336
Joined: 7/20/2007
From: Gothenburg, SWEDEN
Status: offline 		Ahhh, a giant crossbow would do the trick!

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RE: TWIN FEVER !!! - 4/25/2008 8:19:41 PM   
combatpigg



Posts: 9528
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline 		I'll bet there are simpler set ups. My main objection to this launcher is that it is too big. The rubber never releases, it stays hooked to the sliding pin that is on the middle rail. If the model proves to have plenty of power for its weight, then I'll cut the launcher down shorter. That is if the model flies. If it stuffs, then I'll not do any heroic repairs, just slice it up into bulkhead stations and make tracings for a hollow balsa version with no fiberglass, bondo, or paint.
It might be wise to wait until after the first flight to name it?

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Led Zeppelin is NOT "old fogie" music.

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RE: TWIN FEVER !!! - 4/25/2008 8:57:27 PM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline
quote:

I'll bet there are simpler set ups.


Ya think!![

When I saw the pic of the launcher my mind immediately went to the Whil E Cyote theme music. There has to be an ACME box around there somewhere. LOL

I'm waiting to hear how this thing goes. Keep up the good work.

< Message edited by vicman -- 4/25/2008 8:58:15 PM >


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       Post #: 130

RE: TWIN FEVER !!! - 4/26/2008 9:49:48 PM   
combatpigg



Posts: 9528
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline 		After firing up both engines and feeling the thrust, I've come to the conclusion that WE DUN NEE NO STEENKEEN LUNCHERZZZ.
The sound would be perfect for a B25, WOW! kind of funky sounding for a modernistic ship, but those 2.5 inch turbines are on back order for a couple of decades.
Wish me luck, I'm just going to hold it in back and give it a push. There is a 700 mah NIMH stuffed in the very back to get the CG within what I hope is flyable. Figuring CGs is iffy on a plane like this because of uncertainty with where some lines begin and where others end for doing the layout work.
If it's too nose heavy, I'll just pull it out of the ground and hack a couple of inches out of the front end and try it again. Those moles down at the field better dig deep!

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Led Zeppelin is NOT "old fogie" music.

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       Post #: 131

RE: TWIN FEVER !!! - 4/27/2008 3:07:17 AM   
combatpigg



Posts: 9528
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline 		Well, so much for my figuring CGs. I figured flyable would be 20%.
First launch the plane did about a 10 foot diameter loop and landed flat on its belly.
So I moved the battery up front and gave it another toss. This time the loop was bigger and it did a nice figure 9, so back to the shop for a nose job and some lead in the nose.
Next launch it flew beautifully out of my hand and showed signs of being a touch tail heavy and prone to being snap happy from being so heavy. I was able to fly it for a couple of minutes, but it was one of those flights where the plane could veto whatever command you gave it with little warning and I eventually stuffed it. At least the nose saved those props.
My overall impression is that it needs to have more wing area at the same weight its at. My hat is off to anyone who has success flying more realistic versions, especially in this size range.
I'll patch it up again and move the battery further forward just to see it fly decently. As you would expect, it is great to hear the harmony of those engines. They fire right up and there is no need to play with them..they are set to run about 16,000 with 7x3 props.


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Led Zeppelin is NOT "old fogie" music.

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       Post #: 132

RE: TWIN FEVER !!! - 4/27/2008 3:12:50 AM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		Sorry to hear your woes.
I would think this gives you a firm endorsement that the chine is creating a good bit of lift on a bird like this.
We look forward to another flight report tomorrow.

How many moles gave their life in your persuit of flight?


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RE: TWIN FEVER !!! - 4/27/2008 3:23:08 AM   
combatpigg



Posts: 9528
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline 		Yep, I didn't think so but the forward area does factor into the wing area. I'll give it another try tomorrow, but this plane needs a proper burial.
A better use of these engines would be a stick built WWII bomber, made as light as possible. They have that great cyclic humm where they take turns hitting the high note.
Well it was a fun day of tinkering and doing a little bit of learning.

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Led Zeppelin is NOT "old fogie" music.

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RE: TWIN FEVER !!! - 4/27/2008 4:16:02 AM   
KidEpoxy



Posts: 3224
Joined: 10/14/2004
From: San Antonio, TX, USA
Status: online 		awww man....

But hey, at least you looped it right out the door
What a showman... and you even left the crowd wanting more.

_____________________________

Optional MA is part of AMA history, we can go optional AGAIN if we just say so

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       Post #: 135

RE: TWIN FEVER !!! - 4/27/2008 4:30:34 AM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		KE,
Looping out of the hand is a normal deal for Chuck. I learned a whole new way of trimming by watching him get one to go straight. Craziest thing I've seen to maiden a bird.


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Bigger Badder Meaner Faster!
Revver Brotherhood & NMPRA #41

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       Post #: 136

RE: TWIN FEVER !!! - 4/27/2008 4:56:26 AM   
combatpigg



Posts: 9528
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline 		Looping right after take off will get you DQd in C/L combat and make it difficult to find the pit crew next time you're up. [)]
Let's burn barrel this flying toilet seat and start talking about a BOMBER!!

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Led Zeppelin is NOT "old fogie" music.

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RE: TWIN FEVER !!! - 4/28/2008 3:10:59 AM   
Johnny C!



Posts: 361
Joined: 3/24/2003
From: Pisgah Forest, NC, USA
Status: offline 		Sorry pig!

You had a great looking bird. Maybe you could salvage
the main wing & engine structure by adding a tail boom.
Twins are incredible fun, but 1/2a twins are even better.

I had to add 9 oz's of lead to my 1/2a Warthog.
Since it was a conventional set up (i.e. main wing
to the front, etc.), it was real straight forward to
get the CG correct. It seemed real heavy overall,
but it flies great with a good stout, straight toss.

I really enjoy these smaller projects. It doesn't take so
long to complete them, but they are just as much fun.

I built a 48" ws B-25 form some reduced plans. I was going
to use 2 .074's, but opted for 2 .10 TT's. I thought it was too
heavy, so I've never flown it.

Keep it up & Good Luck!

Johnny C!

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"...and once man has tasted flight, he will walk the earth
with his eyes turned skyward... L. DaVinci.

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RE: TWIN FEVER !!! - 4/28/2008 3:40:59 AM   
combatpigg



Posts: 9528
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline 		Thanks JohnnyC!
I moved the 700 mah pack all the way up to the nose in front of the canopy. The CG ends up at about 15%. Now the plane handles great! It has enough thrust to maintain a vertical line for about 150 feet and it is a fairly agile flyer.
One problem is that it doesn't look like any more of a Blackbird at 300 feet out than it does at 5 feet....it just looks like a flying wing with a skinny neck sticking out front. I think it actually looks better up close, in the air it loo