Tail Wheel Strut vs Stooge question

[Steve Fitton]

I do not recall seeing this question ever come up, mabe because its a dumb one, but...: Has anyone ever had trouble stooging a piped 60 plane that uses 1/16th wire for the tail wheel strut?  I was looking at an old Bill Rich plane the other day and noticed he used much heavier wire, like 3/32nd for the strut.

Will 1/16th be strong enough?  I am already terrified of stooging, although I will have to master it to gain enough practice time.  Both my current planes have 1/16th tail wheel struts, and I was under the impression that 1/16 was way more strength than needed, until I saw Bill's and a few other planes with heavier struts.

[Doug Moon]

I use 3/32" wire.

The 1/16" maybe enough to hold it but it will flex under loan more and tear the bottom block around the back side. The 3/32 wire doesnt flex as much and I get alot less damage to the bottom block.  I also relieve the area behind the block further and further on each model to make sure it wont touch the block under loan.  I am slowly getting there.  But it seems some wires flex more than others.

Are you using a bolt in tail wheel wire?

[Tim Wescott]

1/16 music wire, by itself, should be more than enough to restrain the plane, but it may not make you happy.

But that just means that when your stooge fails it won't be because the tail wheel strut fails in tension.  Either it'll pull out of the fuselage and the stooge will fail, or the thrust on the engine will be enough to bend the wire and mess up your strut adjustment and/or fuselage.  The former event, of course, lends far more excitement to your day.

I try to arrange all of my tail wheel struts so that if the glue failed completely the strut would still retain the plane in the stooge, at least for one flying session.  This means either inserting the strut into the fuselage angled backwards, then bending it at the fuselage for proper wheel location, or it means bending a hook on the end of the strut and gluing a cross-piece in the fuselage.  The "bend a hook" method pretty much insures that the whole bottom rear of your fuselage needs to be ripped apart to get the strut out.

[Balsa Butcher]

Another trick is to make the stooge hook part of the actual T/W strut. Bend, wrap, and solder on a 90 degree piece of wire to use as the axle. Many do it the other way with the hook being the soldered piece. The hook is going to take a lot more stress than the T/W axle so it makes sense to make it the stronger part.

[Dave_Trible]

Hi Steve.  My first question is how is the wire anchored in the fuse?  I sew the wire AND a separate launch cable (from lead out wire .027) to a plywood plate which is epoxied into the fuselage sides. The cable and wire exit the same spot but are independent.  I have also in the past bent in a loop in the tail wire.  The wire itself should have enough tensile strength but its more about how it's mounted.  I do all my flying with the stooge so it has to stay put forever.

Dave

[RandySmith]

I  can tell you for fact that there have been several 1/16 in wire stooge hooks that have failed, that is why Bill went to the 3.32.  Many people use a separate piece of loop wire  at the rear instead of soldering it to the tail wheel..... all up to you !

Randy

[Richard Koehler]

The worst accident I ever had was a 1/16 wire coming apart allowing the plane, a Fox-35 powered Sterling Navion to get me in the leg.  Had I not had on heavy bluejeans my leg would have been much worse than it was.  Needless to say my hooks are 3/32 wire specifically anchored in the fuse, and I get behind the plane before I let go of it.

[Joseph Lijoi]

Aside from the mounting to the plane, it will surprise you how much load a 1/16 music wire will take under tension.  Your weak point is really the bend or solder joint.  Mine failed at the bend.  Too sharp of a bend or too much heat or questionable wire can cause problems.  My solution is a line clip between the 90 degree bend and the tailwheel.  This is clipped on not soldered so it floats and will minimize vibration fatigue.  Of course the tailwheel is securely attached.  3/32 wire is probably not a bad idea.

[Steve Fitton]

Hey Doug, neither is of the removable tailwheel block type.  The next one will be.  Derek had showed me how it looked as well as some pictures Gene had sent of the removable settup, but it never occured to me to 3/32 wire till I saw the pictures of yours and noticed the wire on Bill's plane.

[RandySmith]

My Ships use  3/32  tail wheel wires, I have used a stooge on ocassions with them but try not to if possible

Randy

[Gene Martine]

   
  Steve:
 Never had a problem with .078.
 Gene
 

[Russell Bond]

This is how I do mine.
The 3/32 wire is solid all the way with the bend for the stooge.
This way you are not relying on the soldered wire to hold the plane.

The 1/16th flat wire can be even thinner as it carries no load.

[Bob Hudak]

 Academy of Model Aviation has a good online article of a control line stooge that holds the plane by the stabilizer. It shows how to make it or you can buy it from the author(Don Ogren) of the article. Here's the link to it.... http://www.modelaviation.com/clstooge I built one and will never use a tail wire stooge again. It also works on trike gear planes.

[Russell Shaffer]

Wow, Russell.  I thought that I had invented that, but great minds think alike.  Note our names.  On the same subject, has anyone else thought that a very nice stunter with wing mounted gear and wheel pants looks strange with a wimpy little wire sticking way down for the tail wheel?  I think Steve has a very good point here.  Whatever the stooge hooks to has to be very well mounted to a part of the airplane that will absolutely not detach.  I always try to give a little pull test to my stooge hookup and just a couple of days ago, I broke the fancy cable hookup between the airplane and stooge.  No biggee because the engine wasn't running.  We give a lot of thought to the stooge and its securement and then hook it to one of the weakest parts of our airplanes.

[M Spencer]

a loop of 1/8 in chord , from a few feet , so its a foot loop , under tailplane & over in front of fin .
One end secured to the deck , the other released . Will have to tear of the fin or tailplane instead .

 

[Steve Helmick]

a loop of 1/8 in chord , from a few feet , so its a foot loop , under tailplane & over in front of fin .
One end secured to the deck , the other released . Will have to tear of the fin or tailplane instead .

 

Said loop of cord can also jam between the elevator and elevator root fillets (if there are any), preventing release. Don't ask how I found that out.  Steve

[Mike Griffin]

Academy of Model Aviation has a good online article of a control line stooge that holds the plane by the stabilizer. It shows how to make it or you can buy it from the author(Don Ogren) of the article. Here's the link to it.... http://www.modelaviation.com/clstooge I built one and will never use a tail wire stooge again. It also works on trike gear planes.

I havent flown in a while for health reasons but I never did trust a tailwheel wire.  I built on like Bob referenced years ago and it works great. 

Mike

[Russell Bond]

I always make the tailwheel mount strong as I hang my planes up (in the house) by the tailwheel strut.

[Joseph Lijoi]

Really the stooge wire is the least of your problems.  Any of the solutions mentioned could fail.  I have pulled on the stooge release, no release.  Crossed the stooge/flying wires upon launch, and tangled my feet in the stooge line while flying.  These things, while learning experiences and happened to me only once, could happen with any stooge configuration.

I read that Al Rabe got a rag caught in his spinning prop, causing the nose to break off the ship.  I'm sure there are lots of stories out there.

[Larry Fruits]

 After having had two tail wheel wires fail, I now use a stooge similar to the one Don Ogren uses. It holds the plane by the leading edge of the stabilizer.
 The wire was 1/16 diameter in a .65 powered plane. Each time I was lucky in that the wire was missing after landing, with just a stub sticking out the bottom of the plane. It did not pull out of the fuselage, but the wire itself failed.
 After thinking about it for a bit, it made no sense to me to be trying to hold the plane in the stooge by the tail wheel wire, since it had fatigued twice. Like I said, I was lucky when the failure occurred. I was not going to push my luck a third time.
 3/32 diameter wire may be OK, but is still subject to fatigue and puts a lot of stress on the mount in the plane. I believe holding the plane by the stab, is much safer with less stress on the plane.

 Larry

 

[Steve Helmick]

On the other hand, if you build your stabalizer strong enough to repeatedly abuse in such a way, your plane is probably tailheavy. I would suggest an anchor eye about midway between the flap TE and stab LE, then clip a cable or nylon cord onto that when you need to use a stooge. If you're using a trike LG, you might want to move the attachment farther forward, perhaps near the flap hingeline. I'll let Tim run the numbers and finger (sic) it out for me.  Steve

[GGeezer]

The problem is not the 1/16" wire but how it is mounted. 1/16" piano wire will start to elongate at a tension load of around 600 lbs and break at about 900 lbs.

Orv.

[john e. holliday]

I  too have went to heavier wire for the tail wheel/skid of my planes.    I have several in which the 1/16 wire has left the plane right at the fuselage juncture.  This is after taking off using a stooge and flying.   3/32 wire for me with a loop.   Now I have the article printed off so I can make a stooge for my new Ringmaster Twin.

[Larry Fruits]

On the other hand, if you build your stabalizer strong enough to repeatedly abuse in such a way, your plane is probably tailheavy. I would suggest an anchor eye about midway between the flap TE and stab LE, then clip a cable or nylon cord onto that when you need to use a stooge. If you're using a trike LG, you might want to move the attachment farther forward, perhaps near the flap hingeline. I'll let Tim run the numbers and finger (sic) it out for me.  Steve

  Steve, I politely disagree. I really don't think restraining a model by the leading edge of the stabilizer, puts as much abuse or stress on the tail as restraining by a tail wheel wire, whether it be 1/16 or 3/32 in diameter. The stress is spread out by a much larger area in the stab / fuselage joint than it is with a wire and it's attachment.
 My stabs are built up with a molded leading edge with ribs and full sheeting. All material is 1/16 balsa including the rear spar. Small balsa plugs are inserted where the hinges are located. It is essentially a small torque box, very light and stiff. No other reinforcement is used.
 After several hundred launches, using a leading edge type stooge, I have seen no signs of damage, to the leading edges of the stab or in the fillet area. My stooge is padded where it contacts the model. Also, I generally need to add tail weight to my models.
 When you think about it, how much abuse does a tail get when it is held by a person when launched? Seems about the same amount as a leading edge stooge and no one questions it.
 Not trying to pick a fight, just trying to explain my reasoning.

 Safe and happy launching;
         Larry


     

[Guy B Jr]

I like the idea of the stooge with the vertical arms holding the stab. This eliminates the worry for every plane as to what tail wheel mount to use. One size fits all is great. Gonna build one.

[Rafael Gonzalez]

I use a lead out 1"" long eyelet through the bottom of the fuse at the rudder/ fuse joint where both fuse sides/halves come together. If it is a thick area, I use 2 eyelets, one on each side. I loop a length of lead-out wire through it and use a line thimble (lead eyelet) to close the loop with a crimp. The whole unit weighs nothing and is double fail safe. Always check before use.