Simple tail steering.

by alibopo | December 12, 2013 | (22) Posted in Tips

Simple tail steering.

After a few attempts at this I finally came up with a winning system for my foam board builds. It’s super-simple, cheap and easy – best of all, it seems to stay put.

It’s been so successful I now use it on all my builds.

You need;

About a 120mm(6 inch) length of control rod wire - 1.2mm dia. (18SWG) or thereabouts.

A cotton bud.

A wheel – or not, if you just want a skid. One less thing to drop off!

Long nose pliers to bend the wire.

Some way to cut the wire (long nose pliers?)

Hot glue to stick the final assembly to your plane.

Here’s a mock-up of the back of your typical foam board build. A short length of tube from the cotton bud will become the hinge for the steering. You’ll be fitting the tube on the opposite side to your bevel – this keeps the hinge point of the rudder and the steering as close to each other as possible. If your bevel is on this side (as you look at my mock-up) you’ll need to think it through and reverse all the bends so that you can fit the assembly on the other side of the rudder.

Cut a length of tube so that when it lines up with the bottom of the fuselage, the top won’t interfere with the elevator or overlap the elevator cut-out in the rudder.

The wheels I use have quite large axle holes, but the cotton bud tube is also a good fit as a sleeve to reduce the size of the hole.

Leave enough wire sticking out for a screw collet, glue blob, CA and washer, or whatever fitting you intend to hold the wheel in place with.

First bend is a right angle.

Not essential, but you can snake the wire over the top of the wheel with two shallow bends.

Here’s a quick test fit. You’ll see the next bend will need to turn the wire so that it runs up the back of the fuselage.

That’s the bend made…

…and you can then slip the tube over the wire.

Here’s the end view. You now make another right angle bend at the top of the tube…

…and this traps the tube. Note the bend is not in line with the rudder but will appear to make the wire stick out sideways from the fuselage – that’s OK!

View from above.

Now we want to bring that wire around so that we can fix it to the rudder. Put your pliers here and make a small bend.

Move the pliers along the wire and make a series of these shallow bends, each time about the width of the jaws - this creates a rough curve.

Eventually you’ll have a little loop, and the wire will now be pointing out the other side of the fuselage. Almost there!

Last bend. Turn the wire through a right angle until it points to the back of the plane and is in line with the wheel’s direction of travel.

Here’s the test fit. The loop is needed to stop the wire binding against the rudder and restricting its motion. Without the loop the rudder would stick and the mechanism wouldn’t allow the plane to turn.

Cut the wire so that you have a reasonable length of lever to act on your wheel. Now cut a little length of cotton bud tube to fit over the wire. One of the VERY important things about this system is that the steering/tiller wire is quite a sloppy fit in the tube. Without a little play, the system will seize up. UPDATE - I've discovered some cotton buds have smaller diameter holes, which works well as the hinge tube but not as the steering/tiller tube. If this is the case either stretch the tube or find a slightly larger tube (ink reservoir tube in a ball point pen). Once the hinge tube is in place a little final adjustment is usually needed to get the last straight section of the wire to sit in line with the rudder (as in the picture above). You want a good ‘rattly’ fit. The steering tube should be kept about 6mm (1/4 inch) away from the loop. When the rudder moves the wire actually slides in and out of this tube – just a couple of mm’s, but it needs that movement.

When you come to fitting the steering it’s good to get the wire to slide up the hinge tube (second picture) so that the weight of the plane is taken by the tube resting against the wire and not by the lever resting against the rudder.

Glue the hinge tube onto the back of the fuselage. If space is a bit tight near the rudder hinge, you can run a skewer down the end of the foamboard to help bed in the hinge tube. It’s important to make sure the glue doesn’t bind or restrict the rudder, but it’s also important that the steering hinge is close to the rudder hinge – you just have to be careful!

I
’ve found hot glue works well enough on both tubes, with a little smearing to get good contact up the sides of the tube. I’ve also just taped the little steering tube onto the rudder.

You do end up using less wire than I say at the beginning, but it’s always handy having a little extra sticking out when you need to apply pressure for bending.

Any small wheel will do, but these are from Hobby-King - $1.95 for 5.

Small Wheel (Diam: 20mm Width: 10mm) (5pc/Bag) - PRODUCT ID: OR006-01003

If you’re just doing a skid version, first turn the end of the wire into a tight loop to make a ‘safe end’ - that gets rid of the sharp point. Allow about 30mm for the skid and then work forward from the first mock-up picture of the tail.

I hope that’s of use. Cheers, alibopo.

COMMENTS

Christopher14 on December 12, 2013
Very cool!
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madaquif on December 12, 2013
awsome trick ....is it possible for you to make a video.......specially for slow learners like me
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clough42 on December 12, 2013
I like this. I've been looking for an easy way to do this without a tail wheel bracket. The two tubes at 90 degree angles are a great way to go, and they take the focused load off the endpoint of the hinge. Thanks.
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rockets4kids on December 12, 2013
Nice!

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ankit dhama on December 13, 2013
hi i see your all post you do great jobs i also making plane can you tell me how much lenght and which type wings i make for plane made by form i have 1100kv moter 250gm and esc 20c and battery 2200 mah 250 gm can you help me how types of wings which give max lift thank you
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alibopo on December 13, 2013
Hi ankit dhama, I don't know if I can help too much here. Let's start with the motor. You may know this already but to be sure - the KV value of the motor only tells you how FAST it turns - NOT how powerful it is. I'm also not sure if you are saying the motor can make 250gms of thrust - or if the motor is advised for planes between a lower weight and 250gms maximum weight. If that is the top weight of plane advised for that motor you have a problem. The battery on its own weighs 250gms - you have no power left over to lift the weight of the plane. Do you have the AMPS for the motor? - it might be easier to work from that. If this is a first build I would go for the FT Flyer or the Nutball - those are very simple and quick to build designs. The suggested motor for them (Blue Wonder) is around 8 amps. With the 3S battery that means they produce about 80-90 watts. The heaviest plane for that motor would be about 600 gms, but the Flyer weighs much less than that - which gives it good performance. The FT flyer is a great plane for a beginner. Sorry I can't be more help. Do search through the Flite Test site - there is a lot of good information to be found. All the best, alibopo.
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ankit dhama on December 13, 2013
thanks you it help me sorry i give less information the moter give 1.5 kg thrust and my plane weight is 700 gm and wings span is 1 m and angle of attack is 6 can it be good to lift my plane ?
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alibopo on December 13, 2013
Hi ankit - WOW! Sounds like you've got plenty of power. Unlimited 3D potential. I've only been involved in this RC flying lark for a year. There's a lot of more experienced hands in this Flite Test community who can offer advice on this kind of setup. The only plane I've got that's near to your wingspan is in this article; Morphocoupe Mk II and the brownout blues.
My plane is a fair bit heavier than yours (940grams) and has a wing chord of 185mm. The motor on it produces a lot less power than yours and it flies fine, but not 3D. I suggest you post a few pictures of your plane in an article and see what reactions you get. Cheers.
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ankit dhama on December 14, 2013
hiii thanks you are really great in your work good and thanks for the planes i look for them and i will post my plane pics
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alibopo on December 14, 2013
Looking forward to seeing your plane. All the best.
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ankit dhama on December 15, 2013
Hiii hey friend help me plane crash again I try everything I don't know what wrong can you tell me how much dimension I use for my moter thrust 1.5 kg and weight with battery is 500 Gm send me dimension if you know any
Thanks
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alibopo on December 16, 2013
Hi Ankit - I need to see you flying the plane to give a sensible answer. There are too many possible reasons why your plane is crashing. If you are learning to fly you need a plane that is good for a beginner. It will be a plane that can fly very easily. Maybe there is nothing wrong with your plane, it might be too hard to fly for your beginner skills? Without knowing your skill level or the design of the plane there is no way for me to offer an answer. Sorry I can't be more help.
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checker on December 13, 2013
Advice is only as good as the source : Any 20-30 inch wing would work. I've only been building /flying for a year now but that set up would work good with the F-T Versa Wing http://flitetest.com/articles/ft-versa-wing-build. I started flying with a similar set -up and I learned the bigger your battery the heavier the plane, the larger the wing has to be or the faster you have to fly (weight vs lift) Soo I went to using smaller batteries ( all 3 cell's) , 750 mah is very small and light and works great on any slow-fly plane and keeps it small and portable. I also use 1000 and 1300 mha and use them in parallel PAIRS(matching batteries that have the same charge level) if I want more weight (for CG balance) or fly time. EX: 2 1300 mha 3s batteries wired parallel=2600 mha's at 12.6v If you wire them in series you get a 1300 mha 6 cell witch would be 25v. you can see my vers-wing on the forum site http://forum.flitetest.com/showthread.php?6264-FT-Versa-Wing-Build Basically the bigger the payload (battery in this case) the bigger the wing a good example of this is the cinder-block video http://flitetest.com/articles/flying-cinder-block Hope this helps ;)
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madaquif on December 13, 2013
can i use this ona ft nutball??????????
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alibopo on December 13, 2013
Hi madaquif, ....hmmmm... there's a challenge! I'd extend the keel on the existing foam skid to take it almost to the hinge point of the elevator - then make up a steering gear assembly with a very long hinge tube. Carefully poke it through the wing right behind the rudder hinge on the vertical stabiliser and glue it in place to the side of the vertical stabiliser above the wing, and to the keel extension below the wing. Fit the steering/tiller part of the assembly to the side of the rudder as in the instructions. Yes, it could be done - but surely that plane is never on the ground long enough to need steering??? :)
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Shorty1953RCK on December 14, 2013
Great job!
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broadsholders on January 4, 2014
Here's an even simpler method:
After the angle bend continue bending the remainder of the wire to curve with the rudder bottom.
Indent the foam of the rudder bottom down the center and hot glue it in place.
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alibopo on January 4, 2014
Yep - in principal I can see that working with rudders that start above the elevator. If I'm visualising this correctly, you'd still need to poke the wire through the elevator to get the tiller/steering wire to connect with the rudder. However I do see a big problem with 'hard' fixing the tiller wire to the rudder. For your steering to work the hinge point for the rudder needs to be exactly the same as the hinge point for the steering. If there's any separation, one of the hinges (rudder or steering) would need to twist out of place to allow rudder movement. I think the paper rudder hinge would give first. I did something similar to your suggestion with my original baby blender. First I created a little keel that stuck down below the rudder and then fixed the steering hinge tube to that. The tiller wire then went through a tiny wire eye I mounted on a piece of skewer that was glued to the underside of the rudder. Because I couldn't line up the hinge points I knew I still needed that slack fit of the wire going through the eye to stop the system binding. The steering lasted for a bit until the little keel tore off the bottom of the plane during a rough landing. Goodbye tail wheel! :) The steering version in this article is a vast improvement on that as it allows for a much bigger hinge (more glue contact = tougher) and also tucks the hinge out of the way making it less vulnerable. Another big problem with a firm fixing is it will transmit any shocks from the tail wheel or skid directly into the rudder as a sheering force along the length of the hinge - which over time could result in failure of the paper hinge or even lift the whole tail off the fuselage. One of the key features of my system is that it transfers the shocks and loading from the tail wheel directly into the fuselage, and places minimal stress on the rudder - probably no greater than any force applied when the plane is in flight. I do think your suggestion would work if you glued or taped a 'sloppy fit' tube onto the underside of the rudder, with the wire running into the tube. It's not precision steering you're after, just the ability to manoeuvre and taxi on the ground. And your suggestion would be a lot less obvious - so there's a plus. Keep the ideas coming - I've sparked a few solutions to build problems from these discussion threads.
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Simple tail steering.