ADDING RADIO CONTROL TO ACCUCRAFT's RUBY



WHAT IS RADIO CONTROL?

Radio Control allows you to control your engine from a distance. This includes starting, stopping, even reversing. My setup is fully self contained and does not need a follower car or tender to carry any part of it.

NOTICE:

This is only a description of what I chose to do to my own RUBY engine. It in no way is meant to encourage others to make this or any other modifications to their equipment. This is a major modification and is difficult to undo. Exert EXTREME CARE and remember to MEASURE TWICE / CUT ONCE! Again, this is what I did and how I did it. It worked for me but NO guarantees are expressed nor implied that this is the way any sane person would accomplish this task.

Radio Control Materials List*
Part #
Description
TX-8 8 Function TX Handset
RF-RX Stabdard RF Receiver
SD-2 Two Servo 8 Function Decoder
HS-55 HITEC Sub-Micro Servo
HS-81 HITEC Micro-Servo
(Radio Shack) Battery Holder
(Hobby Shop) Misc wire, switch, connectors, etc.
(Hobby Shop) 2mm Rod, Threaded one end.

Here are a few pictures and a 'brief' description what I did:

It is recommended that you first layout and test fit the various mounts using a sheet of cardboard or poster board.

Any Hobby Shop carrying Radio Control planes or boats will do to get the rod and swivel connectors. You may be able to find an appropriate battery box and switch there too, or go to your local Radio Shack. The servos you choose may affect the size and cut-outs for the mounts. Please make a mock-up first to verify the fit.

Remove the original Johnson Bar and linkage. (Save in case you need to undo this modification.) Using fairly stiff Brass sheet, cut out the Johnson Bar Servo Mount. Bend up the side pieces to form a 3 sided box and braze the joints. Fit the servo you plan to use and mark the mounting holes for it. Also fit in the cab and mark the location of the original J-Bar mounting holes from underneath. Drill the appropriate sized holes. Screw the mount to the cab floor using the bolts from the original J-Bar. Place the servo in the unit and attach. After making sure the threaded rod screws into the directional valve OK, cut a length of it a few inches longer than the engine. Start bending it to fit around the boiler mounting stud and to the control arm of the servo. Once you have it made, cut off the excess length. Take everything back out.

Looking in the rear of the cab, remove the left side bolt at the rear that attaches the floor to the frame. Build the throttle servo mount, bending and braising as before. Hold the mount in the correct position and mark the location of the bolt hole. Drill this to the appropriate size. Bend a left-over piece of the control rod to form a linkage to the throttle from the servo arm. You may also want to bend a thin piece of brass to form a 'Heat Shield' around his servo. After my first run I had a slight SAG in the plastic housing of the servo unit.

Mount the receiver and antenna under the cab roof. You can detach the receiver from the decoder via the connecting cable to remove the cab. I took two of the dual AAA holders and made a quad AAA battery holder and fitted it to sit the center chassis frame under the cab floor as a faux firebox. It is bolted through the floor to hold it in place, with some doubled up boiler insulation between the batteries and the cab floor to help keep them from over-heating. An option is to use two dual AA or AAA battery holders and mount to each side under the cab floor as 'tool boxes'. I drilled a hole up through the floor to bring the battery cable up to the decoder board. Be sure you round the edges of this hole so you wont cut these wires. (Radio Shack had some vinyl grommets I used to protect the wires.)

My decoder mounts vertically. Originally I used double-sided tape, but it did not hold out long. I ended up making a clamp that holds the decoder in place. To make this, start with a length of tubing and a rod that will snugly but freely fit inside. Thread a small length of this rod to accept a nut. Bend two arms from more of this rod and notch the very ends about half-way through and as wide as the decoder base is thick. Braise one set of arms to the rod, and the other to the tube. Make sure the notches face inward. When done, and everything works well, braise the tube to the back of the tall wall of the J-Bar Servo mount. (You may have to notch the Servo Mount to accept the arms.) Slide the rod in the tube, put a washer & nut, and place the decoder in its grasp. Tighten the nut to draw it tight, but do not over tighten. BE SURE THE DECOER CIRCUIT BOARD DOES NOT TOUCH THE MOUNT - YOU WILL SHORT IT OUT IF IT DOES! I placed a little piece of insulating material behind it just to make sure it does not connect to anything. If you have a pressure gauge, you may have to bend the siphon out of the way a bit to make it fit around the decoder.

From the 'DO AS I SAY NOT AS I DO' Department: There is NO SUBSTITUTE for the RIGHT TOOLS. If you should decide to attempt a similar conversion, I recommend having a Dremel or similar tool with cutting and grinding bits, a drill (Drill Press preferred) with an assortment of small metal bits, small metal files, TUBE BENDERs of the appropriate size, a good hot torch, and all SAFETY EQUIPMENT! Nothing is worth an eye or a hand!


PICTURES OF MY RCS RADIO CONTROL MODIFICATION
Direction Servo Mount Throttle Servo Mount
Johnson Bar Servo Mount
Throttle Servo Mount
Decoder Clamp
R/C Decoder Clamp
Installation from Rear Installation from Rear
Installation from Rear
Installation from Rear, looking up
Decoder Clamp Mount
Decoder Clamp


*I buy the majority of my supplies from Sulphur Springs Steam Models and supply the part numbers as a convenience. I am in no way related to the company other than as a satisfied customer.