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Old May 27, 2012, 12:55 AM
Hey Ya'll!! Watch THIS!!
Michael Paxton's Avatar
Nashville TN.
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Quote:
Originally Posted by Extreme_RC View Post
Artistic licence its just a guide, we could make it as big as is needed for sure.
Ah! Understood.
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Old May 27, 2012, 01:06 AM
Extreme CNC Alloy EDF
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Australia
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Here, a cleaned up "van gough" version seeing as it just got lost on the last page.
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Old May 27, 2012, 01:08 AM
Hey Ya'll!! Watch THIS!!
Michael Paxton's Avatar
Nashville TN.
Joined Mar 2006
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Quote:
Originally Posted by Extreme_RC View Post
Here, a cleaned up "van gough" version seeing as it just got lost on the last page.
Wow. Hope it works. Cause it sure is ugly!!
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Old May 27, 2012, 01:14 AM
Extreme CNC Alloy EDF
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Australia
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Personally I think the original sniper tail was an ugly pos, dunno why they stuck with the shape even in the first 90mm version. swept tail with even elevators would be nice, I am just trying to work with the original setup with servo in the centre.
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Old May 27, 2012, 01:25 AM
Hey Ya'll!! Watch THIS!!
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I agree it's not pretty. But any way I change it only seems to make it worse.
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Old May 27, 2012, 01:40 AM
Extreme CNC Alloy EDF
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Australia
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Could cut the stab tips right off, block them in, and then extend the elevators to each end, with their ends angled back in a little, that would make it look neater. This would also make it much easier to rework the stab and not upset its finish or look, no tips to deal with.
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Last edited by Extreme_RC; May 27, 2012 at 01:46 AM.
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Old May 27, 2012, 01:56 AM
Lee Liddle
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Carrollton, Tx
Joined Dec 2006
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Well there`s no way to keep the original stab, and keep the overall original shape, and have the elevators taper smaller from root to tip. Mods will have to be made to the stab to get it right.
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Old May 27, 2012, 01:59 AM
Extreme CNC Alloy EDF
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Australia
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The above pic only requires slicing the stab tips off, then filling the gap with wood, done neatly it would not even affect the paint finish. The elevator I was thinking about cutting it from one sheet of 3mm ply, then laminating it either side with balsa, tapering and shaping, wire rod to stiffen, and then cover in white film.
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Old May 27, 2012, 02:10 AM
Lee Liddle
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Carrollton, Tx
Joined Dec 2006
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Low freqency howl

This is Vics first XL demo video. Listen carefuly to the pass at 2:05, you can hear a low freq vibe that sounds like it is resonating through the fuselage causing what I would describe as a low howl. It`s my opinion that this is very likely the elevator trying to flutter. It`s being controled by a tight linkage, a good servo and properly installed ca hinges. Still, it sounds like the elevator is buzzing. You can hear it the best after the jet passes the camera.

If so, that would explain the eventual failure of the elevator hinges on this particular airframe. The sound is there on all of the fast passes, but is easiest to hear at 2:05 because the anouncer isn`t gabbing.

This is a lot of speculation, but given the rate of failure, it is very probable that Vic`s first XL was lost to the same basic problem.

Sometimes a camera mic can pick up things that you don`t hear when you are there in person.

Sniper XL90 HD.wmv (3 min 21 sec)
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Last edited by Knife Liddle; May 27, 2012 at 02:19 AM.
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Old May 27, 2012, 02:22 AM
deltas are cool
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Tehachapi ,CA.
Joined Apr 2006
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Knife i believe that is the HET inlet duct noise ...herd that on some of there planes ...i think Brent F-20 has that howl too.
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Old May 27, 2012, 02:24 AM
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I made the same mod as Xtreme but with two servos in the centre of the stab; hope it will work...
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Old May 27, 2012, 02:26 AM
Lee Liddle
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Carrollton, Tx
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Quote:
Originally Posted by AIR SALLY View Post
Knife i believe that is the HET inlet duct noise ...herd that on some of there planes ...i think Brent F-20 has that howl too.

Yep it could be. I remember the L-39 had it bad.
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Old May 27, 2012, 02:49 AM
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San Jose, CA
Joined Jun 2006
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The elevator should be done as Mark, Brian, Lee and few other had suggested.
Even with one servo is not any issue. The dump elevator design to save cost from HET is constant flutter at the tip. Even how beefy you had that elevator rig up. At some point it will fail.
Did I repeat this again?
Vic,
You should listen and learn from expert that had much more experience and been this much longer and built over 100 of high performance jets.
I never wrong and know what goes to happen with this design and just most other had the experience like I do.
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Old May 27, 2012, 08:04 AM
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United States, NY, New York
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Quote:
Originally Posted by Extreme_RC View Post
Could cut the stab tips right off, block them in, and then extend the elevators to each end, with their ends angled back in a little, that would make it look neater. This would also make it much easier to rework the stab and not upset its finish or look, no tips to deal with.
I really don't like the look of this mod (Extreme_RC's).. I think it changes the outline too much. Lets be honest, it's a mini Bandit replica, & the swept design is all part of the look/success. I'll repost this drawing I did many pages back, & I remember seeing another like it. Het could make it longer at the root if desired, airfoil won't change.
1. maintains current look/profile
2. utilizes the existing stab/elevator
3. existing airfoil profile will remain 100% the same
4. flight characteristics unchanged
5. HET can utilize existing plugs/pieces to form the new one
6. easy to do at home if you don't feel like waiting on HET
7. Same BASIC design utilized by the (super successful) BVM Bandit.
"NOT TO SCALE"
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Last edited by Brickyard; May 27, 2012 at 08:11 AM.
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Old May 27, 2012, 10:05 AM
Hey Ya'll!! Watch THIS!!
Michael Paxton's Avatar
Nashville TN.
Joined Mar 2006
2,555 Posts
Quote:
Originally Posted by Brickyard View Post
I really don't like the look of this mod (Extreme_RC's).. I think it changes the outline too much. Lets be honest, it's a mini Bandit replica, & the swept design is all part of the look/success. I'll repost this drawing I did many pages back, & I remember seeing another like it. Het could make it longer at the root if desired, airfoil won't change.
1. maintains current look/profile
2. utilizes the existing stab/elevator
3. existing airfoil profile will remain 100% the same
4. flight characteristics unchanged
5. HET can utilize existing plugs/pieces to form the new one
6. easy to do at home if you don't feel like waiting on HET
7. Same BASIC design utilized by the (super successful) BVM Bandit.
"NOT TO SCALE"
I like the look of this one the best. A bit more work than the others....But comes out looking like it is supposed to. Good job Brickyard!
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