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General control line discussion => Open Forum => Topic started by: Dane Martin on July 05, 2018, 01:38:05 PM

Title: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 01:38:05 PM
Dumb sounding question, sure. The inboard wing is warped on Daviny's plane. Should a trim tab still go on the outboard wing? The wing feel's too stiff to "fix".
Title: Re: Trim tab, inboard or outboard
Post by: Tim Wescott on July 05, 2018, 01:59:43 PM
I'd put it on the warped wing.  But if it's for stunt, I'd get the warp out or rip the wing off trying (well, unless it's my only plane -- but even then, I'd consider putting the thing under the knife to get the wing straight).

What plane?  What covering?  If it's not a D-tube and covered in Monocoat, I know you can fix it.  I'm pretty sure you still can even if it's D-tube with silkspan & dope, although in that case I believe that (A) I'd use the boiling water and a towel trick, and (B) I'd consult with the experts here before I started.
Title: Re: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 02:30:41 PM
I don't know how much she'll be stunting, but she does want to do loops. Kinda hard as is.
It is silk and dope. So that does make it more difficult. I don't know how willing I am to perform surgery. Same ol excuses. Busy, working a lot. You know.
Title: Re: Trim tab, inboard or outboard
Post by: Dave_Trible on July 05, 2018, 02:40:32 PM
Dane get some towels in a big pot boiling on the stove.  Rig blocks, books, whatever on a table so that the airplane can be laid down and the wing twisted the opposite direction about the same as the warp.  Carefully wrap or lay the hot towels on the wing and set down on the table, again with the wing twisted the opposite way.  Let set till cool.  The wing should be close to straight.  Repeat as you need to.

Dave
Title: Re: Trim tab, inboard or outboard
Post by: Tim Wescott on July 05, 2018, 02:48:58 PM
Dane get some towels in a big pot boiling on the stove.  Rig blocks, books, whatever on a table so that the airplane can be laid down and the wing twisted the opposite direction about the same as the warp.  Carefully wrap or lay the hot towels on the wing and set down on the table, again with the wing twisted the opposite way.  Let set till cool.  The wing should be close to straight.  Repeat as you need to.

Dave

I trust Dave, and he's giving the same advice that I've seen over and over from other guys I trust.  The wing's torsional position is set by the covering, so you should be able to move it a lot.  You'll probably spend less time getting it done right than you will messing with a tab.
Title: Re: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 03:03:02 PM
In process.
Title: Re: Trim tab, inboard or outboard
Post by: john e. holliday on July 05, 2018, 03:30:27 PM
Do as Dave and Tim stated.   I had one plane that you could not see a warp, but it flew with the out board wing up in level flight.   Not once did it come into the circle but it looked strange and scary.   Finally put a coke can tab on it to get the wing level both ways.    Use a tab only if you can't get the warp out.    At different speeds the tab will work different than other speeds.  Onc done don't forget the video. H^^
Title: Re: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 03:36:10 PM
Wow, after just one shot, it made a noticeable difference.
It'll take a couple attempts, but it looks possible.
Thank you thank you.
Title: Re: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 03:56:46 PM
Looks substantially better. Needs a little more lovin but it's working! Daviny just got this plane, but so far it might be her favorite so I want to be sure it flys well for her.
Title: Re: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 04:18:24 PM
After that last tweak, I'm gonna say it's down to a flight test!
Thanks again Dave for the how to.
Title: Re: Trim tab, inboard or outboard
Post by: Dave_Trible on July 05, 2018, 04:48:36 PM
Keep an eye on it.  It may creep back in.  What you can never be quite sure of is did it come from the finish or internal structural stresses that were relieved when the wood was wetted with dope.  It may fight with you for a while but that Magician is a fine flying airplane and worth the effort.  Eventually it should stabilize.  That silk can only shrink so (not very) far. 

Dave
Title: Re: Trim tab, inboard or outboard
Post by: Dane Martin on July 05, 2018, 05:11:05 PM
I'm hoping it was from sitting in a garage, untouched for many many years Dave. But I'll definitely keep an eye on it.

Here's Dav's first flight of this plane. She wouldn't let me go. She said there's a problem. Lol. Her muffler came loose and you could feel it in the lines.

https://youtu.be/A5xoomtRqDw
Title: Re: Trim tab, inboard or outboard
Post by: john e. holliday on July 06, 2018, 09:40:39 AM
Looking good and a little fast.   Hope she gets a lot of flights on it.   If the wing stays stable now you might think of a trim tab if the wing is not level.   Looking at pictures the little warp is right direction for up right flight learning take off. level laps, climbs dives and landing. H^^