Tail Wheel Mount

I would appreciate clever ideas on how to attach tail wheels and stooge restraint devices to stunt planes. I have been permanently gluing 1/16" music wire struts into the aft fuselage. This works, except that it makes the airplane hard to fit in a jig, it makes the airplane hard to finish, it lets oil into the airplane, it makes an ugly place at the fuselage exit, and it eventually breaks, jeopardizing some of my favorite body parts.

Howard Rush

I just use the tailwheel strut itself.
I use a ply mount that goes from top to bottom of the fuse sides, at about a 30 degree angle with the wire strut bound to it with thick wire and a little epoxy over the thing to keep it quiet and vibration free.

When I am done finishing the model I attach the tailwheel and leave no other provision for a stooge holder except the 90 in the wire for the tailwheel "tire". There I slip a line connector and use that as the stooge connection. I figure it is really simple, no solder joints to fail when adding a hook or something, and it only leaves one hole for the oil to get into the fuse.

I've seen guys at the field let go of their models kneeling right in front of it on a stooge! I feel this is foolhardy, and would ask everyone to use the same caution, or maybe a lot more, than they do when someone is holding the model. I never trust anyone when I'm in front of it, and stand up and adjust the needle when standing over the model from behind.

Good question.

Chris...

One of the neatest installations I've seen is a small piece of 3/32" ply inset into the bottom of the fuselage, with two 3-48 blind nuts already installed. The tailwire has a long "paper-clip" U-shape which goes under the 3-48 screws and washers, and then bends down for the strut. Its sturdy, neat, and the strut is easily replaceable when desired.

I use the strut for the stooge loop, and wrap and solder the tail wheel axle to that. Any plane bigger than a .35 gets a 3/32" wire stooge loop, just for my peace-of-mind. With this setup, you could have two tail struts; one for the wheel and one for a stooge. Just mount whichever you're using that day.

I like the interchangeable hook and wheel. I practice mostly on grass, so the tailwheel doesn't do much except to snag my stooge line. One could recess the untidy bolts and wire and cover them with a thin carbon hatch.

Howard Rush

I use two sheets of 1/16 ply in the bottom of the fuse about 2" long. On the bottom, or outside sheet, I cut a 1/16" slot for the tail wheel wire, and then glue the two sheets of ply together. At the front of the ply pieces, I glue a piece of spruce across the fuse and drill a 1/16" hole to accept the tail wheel wire. The tail wheel wire is then bent to follow the bottom of the fuse in the groove, and then bent verticle to go in the hole drilled in the spruce. About an 1/8" from the back of the groove, I bend the tail gear down in a gradual bend to the desired angle. The wire is then held in the groove with one #2 sheet metal screw and washer about the middle of the groove. I either use a short piece of leadout wire on the tail gear with the ends made up, or use a line connector as was mentioned above. Either way, the tail wire is easly removable, and can be replaced with just a stooge wire with a loop in the end.

Howard,

I do much the same thing. I mount a small piece of maple with 2 4-40 blind nuts installed. I bend a "U" shape in the tail wheel wire and bolt it down with the two screws. I solder a piece of wire onto the tail wheel strut that extends aft of the wheel and has a loop spun into it to catch the stooge release. The wire is copper wrapped onto the tail wheel strut then soldered.

It's all pretty solid.

This point has been made before, but it's worth repeating. For safety's sake, the loop that engages your stooge pin should be bent in the primary tailwheel strut; the tailwheel axle should be a separate piece bound and soldered to the strut. All bends in the primary strut should have a radius equal to or greater than the wire diameter. Don't be afraid to use 5/64 wire for the primary strut on aircraft with engine displacement over .25 ci. Consider a backup safety wire from the stooge loop to a separate hardpoint- not the tailwheel strut mount.

Derek

Thin Carbon hatch... You must be retired.

I sandwich the U shaped tailwheel between two pieces of ply. One is routered out to accept the tailwheel loop. The bottom piece (closest to the grass) has a fuselage shaped block with a small hole to access the 4/40bolt. The result is strong, fuel resistant and blends nicely with replacement tailwheel strut options.

Or you could create a Carbon hatch with miniature dzus fasteners...

B

Yes, of course. My mind defaults to carbon as material of choice. It therefore screens out more sensible options. Similarly, when I first got a router, I would think up some elaborate way to use a router to do any operation that came up. Also, microwave oven instructions tell you how to do all sorts of cooking the hard way by using the microwave.

Howard Rush

Howard --

Your concern about a stooge attachment surprised me.

I thought when you got to be as rich and famous as Howard Rush, you would simply choose among the attractive female groupies that follow you around, and give one the honor of launching your plane.

Larry Fulwider

I tried that, but I can't keep 'em out of the circle long enough to get in a pattern.

Howard Rush

Howard,

Here is a suggestion for your consideration. This is the tail wheel on a Southwick "Skylark". It meets your requirement of being removable for painting, and also allows experimenting with various lengths struts.

[photo not recovered: 22172.jpg]


I don't use a stooge, but if the base is adequately strong, the bolts properly sized, and most importantly, Loctite on the threads, you would be fine.

[photo not recovered: 22171.jpg]


Couple of suggestions:

Bend the loop that gets soldered, first. That way you can trim the loop to fit properly.

Determine the spacing for your mounting bolts AFTER bending both loops.

For appearance, the mounting bolts are offset to the side to put the strut in the center of the fuselage.

And DON'T forget the Loctite.

Cheers,

Warren Wagner

Attachment #1, (jpg file)
Attachment #2, (jpg file)

Howard,
Here is one I learned from one of the Russians. Bend the gear as shown and solder on the loop for the stooge. The box that holds the gear is made of ply with the core the same thickness as the diameter of the wire. With a simple squeeze of the wire at the bottom the gear is inserted through a small slot in the bottom of the fuse and the gear then clips into place. The pull of the plane when mounted on the stooge pulls the gear tighter in the retaining box. I used this system on several of my ST60 powered Firecrackers and never had any kind of problem.
Alan


[photo not recovered: 22173.jpg]

Attachment #1, (jpg file)

Alan,

That is very cool. It would be hard to resist the urge to fill the slot with epoxy.

Howard Rush

>Alan,
>
>That is very cool. It would be hard to resist the urge to
>fill the slot with epoxy.
>
>Howard Rush


Howard,
I hope you are not thinking of sabatoging Alan's airplanes.

Alan,
Thats what I use too - stolen the idea from the Ukrainians. A couple of advantages: It is easy to make completely fuel/oil proof, just paint the inside with thinned epoxy, and most important for safety, it is very easily inspected and replaceable.

Warren,

That's mighty pretty soldering.

Howard Rush

Great idea Warren, I just made one up for my current project, thanks......John
P.S. I didn't forget the Loctite.

I spent the morning making a wire bender so I can make nice 180-degree bends like that.

Howard Rush

Almost all my flying is from a stooge.

Except for scale, I don't see the purpose of a tailwheel. I bend a loop in the music wire.

I'll try to describe how I do my removeable TW.

I use a ply floor just like you would use if it was fixed.

To that, at the fwd end, I attach a small vertical bulkhead about 3/4" high. I wire a pc of 1/16" ID brass toubing to this vertical on center and penetrate the floor so it forms a vertical socket for the TW wire.

About 1" aft of the socket, and of center just enough to clear the centerline, I install a 2-56 blind nut on the top of the TW floor.

The tail wheel wire is formed just as usual except at the fwd end, it has a 90 deg vertical bend in it to engage the brass socket. It then runs along the floor in conventional position and right next to the 2-56 scre with a small clip that captures the wire. The floor takes all of the vertical load, the socket takes the drag load and the screw just retains the wire in position.

It is very light and has worked well on my SV series ships. I always make up an extra TW assembly and keep it ready to go.

The fuse bottom only has a 1/8" wide slot about 1-1/4 long and a slight "deadbolt" detour at the end for access to the screw. I put a piece of flap seal over the whole thing and it stays very clean. I do seal all of the edges with epoxy tho.

I usually heat bend the wire and then re-harden and temper. Havent had one break yet but it helps when working on the plane and transporting to pull the TW and gear, prop, etc.

If you need a pic or sketch, I can do that.

Curt

PS. PLEASE don't use a stooge on a full size stunter that depends on the 1/16" TW to hold the plane!!

Here is a much safer, IMHO stooge design I copied

[photo not recovered: 22188.jpg]


[photo not recovered: 22189.jpg]


[photo not recovered: 22190.jpg]

Attachment #1, (jpg file)
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Thanks, Cap'n. You described it well.

Does the stooge ever lift the stab while it's retreating? I only have a micron of prop clearance.

I forgot to mention that I have the luxury of access to the bracketry from inside the airplane. It's a take-apart, and the tail comes off.

Many of you have wondered if Curt is any relation to Mojo Nixon. I asked him; he's not.


Howard Rush

Howard,

Aren't you supposed to be working on a new plane?

Yes, I forgot the tailwheel mount. Since I had to whack the whole bottom off, I get a second chance.

Howard Rush

>Thanks, Cap'n. You described it well.
>
>Does the stooge ever lift the stab while it's retreating? I
>only have a micron of prop clearance.


Not that I have noticed. But I fly mostly from grass and I didn't use alot of the gravity shielding paint on the back end of the plane..

The uprights are very light and move very freely. I can't even detect any marks in the oil or similar micro scratching from the contact.

You could always use a coil spring to make the uprights drop faster than the plane could leave.

I have perhaps 300 launches on the prototype and it has not failed once nor caused a prop strike.



>
>I forgot to mention that I have the luxury of access to the
>bracketry from inside the airplane. It's a take-apart, and
>the tail comes off.
>
>Many of you have wondered if Curt is any relation to Mojo
>Nixon. I asked him; he's not.

While I DO command some serious MOJO, I am not related.


>
>
>Howard Rush

>>Thanks, Cap'n. You described it well.
>>
>>Does the stooge ever lift the stab while it's retreating?
>I
>>only have a micron of prop clearance.
>
>
>Not that I have noticed. But I fly mostly from grass and I
>didn't use alot of the gravity shielding paint on the back end
>of the plane..
>
>The uprights are very light and move very freely. I can't
>even detect any marks in the oil or similar micro scratching
>from the contact.
>
>You could always use a coil spring to make the uprights drop
>faster than the plane could leave.
>
>I have perhaps 300 launches on the prototype and it has not
>failed once nor caused a prop strike.
>
>
>
>>
>>I forgot to mention that I have the luxury of access to
>the
>>bracketry from inside the airplane. It's a take-apart,
>and
>>the tail comes off.
>>
>>Many of you have wondered if Curt is any relation to Mojo
>>Nixon. I asked him; he's not.
>
>While I DO command some serious MOJO, I am not related.
>
>
>>
>>
>>Howard Rush
>


David Eyskens

Hey Howard ask Bobby Keyes, I saw a trick tail wheel hook up on his one and only model the "tongue" "Jumping Jack Flash" rock'n roll one..grin..just having fun, I am bored.

Are you really building a new model?
see you david

David,

Howard's been working on a new Impact for, uh, well, for awhile.

Your valentine is in the mail, Randy.

Howard Rush

Bobby's band came to town recently, but tickets cost more than the GDP of many tropical countries, so I didn't see him this time. You can't always get what you want.

Howard Rush