The Tailwheel is the next item to install and with the Robart electric unit, it requires just a little bit of modification to the plane. The unit has the same standard vertical attachment bracket that screws into two hardwood rails attached to the former just forward of the tailwheel opening. When the gear is cycled, the locking/actuator arm bumps into the former so a notch has to be made to clear the hardware.
By forming this notch, it clears the tailwheel hardware from running into the former.
The instructions say to drill four 3/32 inch holes for the tailwheel attachment bolts and to use #4 x 1/2 inch screws to secure the unit. This is not correct. You need to drill 1/16 inch drill bit, or, #10 screws. Since I drilled the holes, I went to my spare parts box and replaced the screws with #1o x 1/2 inch pan head sheetmetal screws. I also used thin Zap CA to harden the threads in the hardwood rails.
Before installing the Tailwheel unit, you need to attach the steering cables. The instructions say to install the ball-links to the tiller arm and then loop the cables around the ball-links. This is a very good technique as it allows the cables to be replaced relatively easily by unbolting the links and, it eliminates a chaffing contact point had you looped the cable through the tiller arm holes with it sharp edges. The guide tubes for the cables are already installed in the fuselage. Be sure to use thread locker on the ball links.
Here the tailwheel unit is installed and in the extended position. I also replaced the tailwheel that came with the kit with a slightly larger (and wider) wheel with one with a rubber tire.
Here the tailwheel is in the retracted position. When the tailwheel is in the up position the steering cables go slack and the springs attached to the tiller arm center the wheel in the wheel well.
Here you see the tailwheel hardware clearing the former by passing through the notch I formed with my Dremel Moto-Tool and a grinding bit.
Now that the tailwheel and the steering cables are installed, you can setup the linkage for the servo attachment of the steering cable. Here’s the threaded couplers and the rest of the hardware.
I found that attaching the linkage to the second holes in the servo arms provided the best control travel without over straining the servo at the extreme ends of the throw.
Easy Workshop Tip
The easiest way to feed the power wire for the tailwheel through the fuselage is to do it with the help of gravity. Place a weight on the end of the wire extention ( like a clothspin!) and place the fuselage on its firewall with the tail pointing straight up.
Now feed the wire through the tailwheel door and guide the weight through the various formers in the fuselage. When the end is accessible through the wing saddle you can pull it through the rest of the way. Quick and easy! You can do this to install air lines for a pneumatic retracts as well.
Once the control linkage and the tailwheel hardware are all in place, you can install the fiberglass tailcone. It is held in place with two screws but for some additional security, I applied a little PFM adhesive to provide a solid, yet removable bond.
That’s it for now, stay tuned as we work our way forward to the engine and fuel system installations.