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Building Tips and technical articles. => Building techniques => Topic started by: Jim Roselle on January 19, 2014, 04:14:19 PM
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What is the building process for models where the elevator passes through the vertical stabiliser? Is the elevator assembled onto the horizontal stab after the finish is applied? How are the elevator halves joined?
Jim
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I always attach moveable surfaces after its finished. Its the last thing I do.
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I always attach moveable surfaces after its finished. Its the last thing I do.
So how do you join the elevator halves?
Jim
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So how do you join the elevator halves?
Jim
Elevator horn (wire)
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What is the building process for models where the elevator passes through the vertical stabiliser? Is the elevator assembled onto the horizontal stab after the finish is applied? How are the elevator halves joined?
To expand, you use a u-shaped wire joiner, and attach it (with a brass tube bearing) to the fixed part of the stabilizer, usually with some sort of glue and cloth. You make a pocket in the elevators for the ends of the "u" to go into. You mock up the entire stab/elevator/control horn and hinges, get it all working the way it should, then remove the elevators and install the stab. Usually, you want to paint the model before attaching the surfaces, so about the last thing you do is is put in the hinges and elevator. Most are permanently installed, others use a single hinge pin and don't glue the horn into the elevator, so you can take the elevators off later.
If you want to use cloth hinges, you can probably permanently attach them before you install the stab, or not. I would probably put it all together before putting in the stab.
Brett
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Ok, thanks. I've only built 1/2a until now and they always have a ply joiner instead of a wire horn. My local hobby shop is getting a twister in for me this week and I want to step up me finish/assembly skills on it.
Jim.
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The Twister kit includes all the necessary horns, and has detailed directions on how to make it all work (and, you can always ask us!).
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The Twister kit includes all the necessary horns, and has detailed directions on how to make it all work (and, you can always ask us!).
Oh trust me I'll have questions.
Jim
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Hi Jim, the twister is a good choice for a first larger ship, BUT, you may want to consider starting with a non-flapped ship first. Depending on experience and your building skills flaps on a first ship can be a little daunting. I know from experience. If you stay with the twister consider ball links on the flaps and elevator. They have much more wiggle room built in than hard soldered connections. Their adjustability is a big plus. Also when installing the wire control horns in the elevator and the flaps be very careful to drill straight holes, it's very easy to go through the side of the wood. A clamp and drill press is the best way, but I for one don't have one. If you do this will be a big plus. I am building a Francherized twister right now. I think you'll find the directions from Sig very easy to follow. One more point make sure the flaps are the same hardness and weight. My kit came with one very light and one very hard and heavy, had to make two new ones from fresh balsa. Have fun.
Rich
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Hi Jim, the twister is a good choice for a first larger ship, BUT, you may want to consider starting with a non-flapped ship first. Depending on experience and your building skills flaps on a first ship can be a little daunting. I know from experience. If you stay with the twister consider ball links on the flaps and elevator. They have much more wiggle room built in than hard soldered connections. Their adjustability is a big plus. Also when installing the wire control horns in the elevator and the flaps be very careful to drill straight holes, it's very easy to go through the side of the wood. A clamp and drill press is the best way, but I for one don't have one. If you do this will be a big plus. I am building a Francherized twister right now. I think you'll find the directions from Sig very easy to follow. One more point make sure the flaps are the same hardness and weight. My kit came with one very light and one very hard and heavy, had to make two new ones from fresh balsa. Have fun.
Rich
This is what I've been using for links on my 1/2a builds. I was hoping to stay with the same setup, in the appropriate size of course. (http://i.imgur.com/DdWXk3o.jpg)
Jim
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Hey Jim -- I think those links are just an invitation for something to slip in flight. They'd have to be HUGE to really hold effectively on a big ship. Control linkages on control line ships just seem to take a beating: it's not an area to skimp.
Ball links are just as easy to install, and if you're going to have to buy new stuff anyway, why not get what's been proven by hundreds of people to work well?
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Those links are good on sport 1/2A planes or for throttle on RC planes. I would never use them on any thing bigger than 1/2A. In fact I have gotten away from the 2/56 thread hardware on my new planes.
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Where do I get ball links? Do they require a special control horn?
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Hi Jim,
Du-bro ball links are available from tower hobbies and I think Brodak may also sell them. I use the supplied control horns by Sig just enlarge the hole. The string for connecting the elev. to the stab has to be replaced with either plastic hinges which are preferred or the cloth supplied by Sig. As the other guys said don't use your 1/2 A pushrod set up on a large ship. Like I said before you might want to consider a Brodak kit for your first big project. They come with a booklet put Together by John Brodak with step by step directions for building your model. It kind of goof proofs your build.
Rich
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Thanks Rich,
So which one of these of I want, the 2-56 or the 2-56/4-40?
http://www3.towerhobbies.com/cgi-bin/wti0095p?FVPROFIL=&FVSEARCH=Dubro+ball+link&search=Go
If I understand correctly the hard wear bolts through the bellcrank/control horn where the wire pushrod would normally go through?
Thank you,
Jim
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http://brodak.com/catalogsearch/result/index/?limit=40&q=ball+links&x=9&y=10 Try this link, I dont think tower carries the 4-40 threaded couplings you will also need. You want -40 dubro ball links they are tower number lxd-610. they are farther down on the page you posted. The push rod sig sends is 3/32 dia. the 4-40 connectors brodak sells will work with these rods. Yes the connector and ball link go on the end of the pushrod the hardware bolt goes through the control horn.
Hope this helps Rich
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4-40 sized, definitely. The Twister has you using RC-style control horns and wire couplers between surfaces. The horns have holes too small for anything but clevis ends. You want to be very careful enlarging the holes in the horns -- ideally you would make sure that you don't lose any material on the thin side of the hole, which means offsetting the center of your new hole.
If it wasn't your first big plane I'd tell you to just order control line style horns from Brodak or Sig -- but we're already asking you to change a lot of stuff around.
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If it wasn't your first big plane I'd tell you to just order control line style horns from Brodak or Sig -- but we're already asking you to change a lot of stuff around.
Don't mind changing/ordering more stuff if it makes a better plane and I learn something along the way. I should have the kit in hand by the end of the week and will asses what I need then so I can order it all in one shot.
Thanks for all the help,
Jim
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For your Twister scroll down to Vendors Corner to Tom's building service. If you want a ball link system contact Tom Morris, Yes there expensive compared to standard control systems but he will Custom make it for your Twister. This is a professional set up that you'll never have to worry about !!! or buy the items individually and make it up yourself.
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BTW there's a link to his catalog on the top post on his Vendors link. you can click on the control systems and see for yourself.
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Hey there...
I'm almost done with my build of a Fancherized Twister. It is not my first plane, though. I wanted something to build and fly, that had already been well-engineered. The mods were not difficult, and I did opt for the ball links on carbon fiber tube pushrods. Ultracote on the wing and tail-fabric Coverite on the fuselage, that will be painted.
Sorry, I just had to butt-in here, and comment on my thing, since I saw somebody else was working on a Twister, too. I'm expecting a good-flying airplane, when it's done.
Good luck with yours!
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Hey there...
I'm almost done with my build of a Fancherized Twister. It is not my first plane, though. I wanted something to build and fly, that had already been well-engineered. The mods were not difficult, and I did opt for the ball links on carbon fiber tube pushrods. Ultracote on the wing and tail-fabric Coverite on the fuselage, that will be painted.
Sorry, I just had to butt-in here, and comment on my thing, since I saw somebody else was working on a Twister, too. I'm expecting a good-flying airplane, when it's done.
Good luck with yours!
Thanks for the input, much appreciated. Could you post photos of your control setup?
Jim
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If you go with the 4-40 hardware for the ball links, do not drill thru the horns for the bolt. I use a 4-40 tap to put threads in the horns. Also a nylock nut to help hold the bolt in place.
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Don't mind changing/ordering more stuff if it makes a better plane and I learn something along the way. I should have the kit in hand by the end of the week and will asses what I need then so I can order it all in one shot.
You may find this thread helpful. Keep in mind when you're reading what I said there that I was still in the middle of Intermediate, and now I'm in the middle of Advanced -- so I'm not an expert by any means, just some slob who likes to document what he builds.
I build up my own control hardware. I'm not sure if seeing me do it will lead you down the Path of Unrighteousness, but just keep in mind that (a) I have a welding bench so it's convenient for me, (b) I get beaten regularly by people who buy their parts from Brodak or Sig, so it must not confer any special advantage, and (c), messing around with control hardware isn't flying airplanes, so you shouldn't spend too much time on it.
http://stunthanger.com/smf/index.php?topic=27915.msg283855#msg283855 (http://stunthanger.com/smf/index.php?topic=27915.msg283855#msg283855)
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Tim,
I just went through the thread you linked to. Lots of great info in there, thanks.
Jim
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I just went through the thread you linked to. Lots of great info in there, thanks.
You can learn a lot from going through the build threads here. Sometimes it's enough to make you get overwhelmed and stall out trying to decide what's the absolute best way of doing things, even though standing still in indecision is generally far from any sort of best. But there's generally some goodness in there some place to file away for later.