Steerable tail gear recipe
So, after destroying the dragger assembly on the first taxi in testing, I went to the mancave to build up a solution. The first iteration was a learning experience. The DTFB wheel wobbled and the left over light wire from the build was too weak to support the wheel with even just the weight of the plane. This assembly moved the CG rearward about 1/4" or so. Easily corrected with the battery placement.
Here is my answer:
- Du-Bro 100MW 1" foam wheel
- .047 music wire
- Leftover paint stick section from kit build
- hobby saw or small japanese pull saw for cutting paint stick.
- hobby knife for shaping paint stick mount
- sand paper for finishing shaping
- Wire cutters and pliers
- Drill
First, cut a 5/8" wide by about 4 1/2" piece of paint stick out with the saw.
Second, I cut that piece into 3 smaller pieces, a 1 1/4 bottom, a 1 5/8" middle and, a 1 1/2" top.
Third, whittled down the leading edge of all three sections and rounded slightly to give a bit of a start to the shape. Always cut away from yourself.
Fourth, I glued the the pieces together. Glued the middle piece to the top with 1/2" of overhang to aft.
Fifth, glued the bottom piece to the middle piece, squareing up the aft edges.
Sixth, cut a piece of the wire off to use as a drill bit and layed it against the top piece and drilled down through the lower two. In hind sight I would have drilled it off center to line up better with the hinge line of the vert stab.
Seventh, shape the leading edge of the paint stick mount carefully with the hobby knife and sand paper. Always cut away from yourself.
Eighth, bent the wire 90 deg 3" from one end. This is where the wood takes the load off the wire from the wheel. This prevents the stab from taking much shock or abuse.
Ninth, 1/4" from that 90 I bent about a 45deg down then at about 1/4", 30deg perpendicular to the previous bend. This allowed clearance for the wheel whidth. Then 3/8" later another 30deg to get back to parallel with the side of the wheel. Another 1/2" and I gave it a final 90deg to form the axle. I fit a wheel and cut off any extra length and made a glue wheel collar.
Tenth, inserted the wire up through the drilled hole in the mount and carefully bent the wire over in line with the wheel, locking it in to the mount. Then 2 1/2" from the last 90 I bent the wire up at a 90 to be inserted into rudder. I cut the wire about an inch from the last 90.
Eleventh, I dry fit the mount and pushed the wire into the rudder till flush. then glued the mount to the tail, lining up the hinge line of the rudder with the wire as it passed throught the mount.
I hope this gives you a starting point to improving your ground handling. Thank you FT!
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I have used the more expensive similar store bought solutions with one difference. On the last 90° bend used to insert the steering wire into the rudder I instead glue a small tube (straw, coffee stirrer, plastic sucker straw, small carbon fiber tube , aluminum tube, etc.) along the bottom of the rudder (1"-2"). Then, without the 90° bend, I insert the steering portion of the wire into the tube. This allows just a little play (front to back) and helps if the center line of the steering wheel does not match the rudder hinge line perfectly. If the plastic tube is a good fit it won't allow any side to side play. It also spreads the stress of the steering force along this short tube area on the rudder.
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IOT keep the top of the wire from moving forward due to the leverage from the tail wheel coming up, I've used plastic (clamshell leftovers or gift cards) inserted vertically (from the bottom) of the rudder to keep tailwheel wires from coming loose. I use zipties to really hold them in place. Hotglue doesn't last. I did not bend the wire horizontally to go into the tail until the wire is about 1 inch above the bottom of the tail. Once the plastic is inserted as a rudder reinforcement, drill a hole for the ziptie and wrap it around the wire at the front of the rudder.
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Came down like a maple seedling! When I was adding the paint sticks at the center
line I realized later that it was no dihedral brace I had ever seen before. I will re-build
the Storch but this time with a different wing joiner. Should make a big difference.
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