One of the earliest design decisions for the R54 was that it had to have retracts. Right about
that same time, Robart introduced their 500-Series for jets. The retract units are smaller and lighter than their popular
600-Series, but are made with rugged, aircraft-quality materials. Believe me, I have put these units to the test and they passed
with flying colors! The units come equipped with 3/16" wire struts bent specifically for the R54. Wire struts were chosen to keep
it simple and less expensive.
Now Robart offers these retracts with electric actuators instead of air cylinders. No more air tanks, hoses, valves, pressure gauges,
compressors, or worries about leaks. Just bolt these units in the model, run the wires to the controller, plug the controller into the gear
channel on your receiver and you are done! The wires coming out of the actuators are custom lengths to fit the R54. Also included is a hardware
pack with everything you need, down to the last nut and bolt, to install retracts in your R54. Even if this is your first retract installation,
this complete package takes all the guesswork out of what can be a daunting task.
ROBART RETRACTS AND STRUTS 1 Robart #563 Nose Wheel 100° Retract Unit 2 Robart #530 Main Wheel 90° Retract Units 1 Set 3/16" Wire Struts (1 nose wheel, 1 left main, 1 right main)
ROBART ELECTRONICS 1 Robart Electric Retract Controller 2 12" Retract Wire Extensions (with proprietary locking connectors) 1 12" Extension (to connect the controller to your receiver)
NOSE WHEEL STEERING LINKAGE 1 48" nylon-Coated Steel Cable (for nose wheel steering - cut into two 24" pieces) 2 Du-Bro 2-56 x 1/2" Swivel Ball Links (for nose wheel steering; includes hardware) 2 Du-Bro 2-56 Rigging Couplers (for nose wheel steering; use to adjust cable tension) 4 Steel Crimping Sleeves (for steering cables; loop cable through twice then crimp) 2 .130 o.d. x 6" Nylon Tubes (for steering cables) 4 1/4" x 1/2" x 3/4" Grooved Hardwood Tube Retainers (for mounting nylon tubes)
RETRACT MOUNTING HARDWARE 8 4-40 x 3/8" Socket-Head Cap Screws (for mounting nose wheel retract) 4 4-40 Blind Nuts (for nose wheel retract, install in F-2 for front flanges) 4 4-40 Hex Nuts (for nose wheel retract, use to mount top flanges to receiver shelf) 4 4-40 Flat Washers (for nose wheel retract, use under hex nuts) 8 6-32 x 1/2" Socket-Head Cap Screws (for mounting main wheel retracts, use 4 on each unit) 8 6-32 Blind Nuts (for main wheel retracts, install in wing)
1 Instruction Sheet with Installation Tips
Main Landing Gear Retract Unit
Here's an up-close view of one retract with the electric actuator. When the actuator is energized, it drives a jackscrew
to raise or lower the gear. If it encounters an obstacle, the motor will stop automatically, avoiding a high current
drain. Still, you want to keep your fingers out of there! The wires coming out of the actuators are custom lengths to fit the R54.
Robart Electronic Controller
You could call this the heart of the system, but it's more like the brain. All three retract units plug into this box.
Another wire attaches the box to your receiver. Power for the retracts can come from your radio battery, or you can
power them with an auxilliary battery. The system requires 4.8V to 9.0V, and retract speed varies with voltage.
Mount it in your plane so you can see the green status light easily.
Main Landing Gear Mount and Wheel Well
This is the R54 left-hand wing panel, viewed from above. As you can see, the landing gear mount
is carefully designed to spread the loads to the surrounding ribs, spars, and sheeting. The thick wing allows for deep
wheel wells. Keep in mind that the R54 is designed to accept these Robart retracts - other brands may require some
minor modifications to the structure.
Main Wheel Retract Installed
The main wheel units simply bolt to the plywood landing gear mounts. Just outside the view of this photo is a small
hatch in the bottom wing sheeting that makes it simple to route the air lines (and servo leads). The wire struts all
feature a shock absorbing loop to reduce the strain on the retract units.
Nose Wheel Retract Installed
An interesting feature of the nose wheel unit is that it has two sets of flanges to allow mounting to a bulkhead (firewall
mount) or to a flat plate (belly mount). The R54 takes advantage of this by incorporating both a bulkhead and a
flat plate for extra strong mounting. There's no need for the complexity of gear doors in a sport model like this - save
those headaches for that ultra-scale model on your "to-do" list.