If you are tired of the same old boring food, then it’s time to get out the cookbook and spice things up! Here is a simple recipe to turn that boring old flat-bottom wing trainer plane into a hot new tow plane. Follow these simple steps to make your own homemade tow release mechanism and transform that old trainer into a delicious new dish that your entire club will enjoy. The following ingredients can commonly be found in most any R/C workshop.
- Length of 2-56 size pushrod wire (about 6-8 inches)
- Length of 1/16” music wire (about 6-8 inches)
- Length of 1/8” O.D. nylon tubing (about 2 inches)
- Plywood plate (at least 1/2” thick)
- Thin CA glue
- Gorilla Glue
- Sandpaper (fine to medium grit)
- Servo (heavy duty servo with metal gears recommended)
- Servo connector of your choice
- Small vise
- 1/4 x 20 bolt
- Wire cutters
- 1/16” drill bit
- 5/64” drill bit
- 1/8” drill bit
- Anchor the 1/4 x 20 bolt in the vise.
- Bend the 2-56 pushrod wire around the bolt to make a “U” shape.
- Use the pliers to squeeze the wire tight around the bolt.
- Remove the bolt from the vise and insert the U-shaped piece. Allow the U to stick up out of the vise about 1/2 of an inch.
- Use the hammer to bend the “U” over making a 90 degree bend.
- Remove the wire from the vise and bend as needed for symmetry. Cut the “legs” of the U to about 1-1/4 inches in length and scuff them with the sandpaper.
- Install the plywood plate in the top of the fuselage just aft of the wing. Mark the centerline of the fuselage on the plywood plate. Using the “U” as a guide, drill two 5/64” holes straddling the centerline and insert the U (but do not glue it in yet) allowing it to stick up about 1/4 of an inch.
- The U should have the open side facing toward the front of the plane. Drill a 1/16” hole down through the hardwood just inside the U. The 1/16” music wire pushrod will extend upward through this hole. Remove the U and enlarge the 1/16” hole you just made to 1/8” diameter. Insert the 1/8″ O.D. nylon tubing into this hole and glue it in using thin CA (we find that scuffing the nylon tube with sandpaper makes for a better CA bond). Once the CA cures, cut the nylon tubing flush with the outside surface.
- Install your servo in the plane and adjust the servo linkage and/or travel so that the 1/16” music wire pushrod extends upward just slightly above the U to capture the towline and then retracts fully down below the surface so as to release the towline.
- Remove the U and apply covering (if plane is not already covered). Scuff the “legs” of the U with sandpaper and reinstall the U with Gorilla Glue to anchor it in place.
Congratulations! You are now ready to tow your first Easy Glider.
For larger tow planes, this same recipe can be used substituting 4-40 wire in place of the 2-56 size wire.
We used the 2-56 size wire to make the tow release mechanism for our Telemaster 40 tow plane, but we used 4-40 wire to make the tow release for our more powerful 2M Pilatus Porter tow plane. Both of these tow release mechanisms have proven themselves over many, many uses.