roundhouse HBK18 Katie R/C Fittings Only Kit User manual

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Modular Locomotive System
HBK18 Katie R/C Fittings
Only Kit
Instruction Manual
Roundhouse Engineering Co. Ltd.
Units 6-9 Churchill Business Park. Churchill Road,
Wheatley. Doncaster. DN1 2TF. England.
Tel. [phone]
Fax. [phone]
Email. [e-mail]
Note:- this kit contains the parts to enable radio control
equipment to be fitted to a ‘Katie’ locomotive. No radio control
equipment is included with this kit.
www.roundhouse-eng.com
ONLINE

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HBK18 Katie R/C Fittings Kit
Introduction
These instructions cover the fitting of radio control to the
HBK15/16/17 ‘Katie’ 0-4-0 locomotive kit.
It contains all necessary brackets, fixings etc. to enable the
builder to fit his or her own radio equipment.
Roundhouse ‘Katie’ locomotives are fitted as standard with
2.4 GHz two-channel radio control equipment and all fixings
and brackets are designed for this. If using different
equipment, ensure that it is of similar specification or
problems could be encountered.
2.4 GHz radio control equipment should be used as this gives
fine control with the minimum of interference.
Before starting assembly, check contents against the list and
read through the instructions fully, referring to diagrams where
necessary, so that you identify all parts and understand where
each is fitted.
You will need to supply
A 2.4 GHz two-channel radio control set complete with
transmitter, receiver, switch harness and two micro
servos’ (Hitec HS81 or equivalent).
Standard or mini servos will not fit correctly. If three or four
channel equipment is used, only two channels are needed for
this locomotive.

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Construction
Folding battery box and chassis cover plate.
First of all, fold up the etched brass battery box and chassis
cover plate as shown above and paint them as required. Note
that all half etched fold lines should be to the inside of the fold.
All painting is left to the builder and Acrylic paint is readily
available in spray cans for a good finish. A good primer is
essential and, if available, an etch primer should be used on
brass parts. A good model shop will stock more specialised
paints and should include etch primer in the range. Read
carefully and follow the maker’s instructions that appear on
the can before using any paint. All parts must be thoroughly
cleaned and rubbed down with fine wet and dry paper prior to
painting.

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The locomotive body should first be removed to allow
installation of the radio control equipment.
Reversing Servo
1 - Reversing servo-mounting posts. 2 - Reversing servo.
3 - Short servo horn. 4 - Reversing control rod.
5 - Quicklink connector.
Fit the reversing servo that operates the Walschaerts valve-
gear first.
The servo mounts on to the left hand side of the footplate with
the three coloured lead to the rear, using the two brass posts.
Fit the brass servo posts to the servo first using two M3 brass
screws and two brass washers. Fit the servo and posts to the
cab floor using two M3 brass screws) as shown above.
The lead should be fastened to the bottom of the rear servo

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mounting post with a plastic cable tie, and then passed down
through the small rectangular hole to the left of the boiler.
Do not fit the horn or linkage at this time.
Regulator Servo
1 - Regulator arm.
2 - Push rod connector.
3 - Regulator control rod with Quicklink and lock nut.
4 - Regulator servo.
Fit the regulator servo to the bracket on the right hand side of

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the foot plate (which you fitted during the body construction).
The servo is passed through the rectangular hole in the
bracket from the rear with the lead to the top. The lead can
then be passed down the front of the servo between it and the
gas tank and through the rectangular hole in the footplate to
the left of the servo. Fasten the servo in place with a M3 x 6
brass screw, washer and nut through the top and bottom
mounting flange.
Do not fit the horn or linkage at this time.
Fit the switch to the rear of the
right hand frame, in the cut out
in the frame. The switch body
sits on the inside of the frame
with the slider pointing out.
One of the switch leads (see
your r/c equipment instruction book for details) will plug into
the receiver, do not alter this. The other lead will go to the
battery holder and this must be modified to connect to the new
battery holder supplied with this kit.
Switch harnesses from different manufacturers vary in length
and the type of plug and socket used to connect their normal
battery holder. It is often easier just to cut the plug from the
end of this lead and attach the PP9 lead, but check lengths
before doing so. The lead must be extended by soldering the
PP9 type clip to its end to give an overall length of about 6½"
from the floor. Before soldering the wires together, pass the
lead up through the left hand footplate cut-out (where the
reversing servo lead passes through). Slide the battery lead
through the large diameter heat shrink tubing, but do not
shrink the tubing yet.
Ensure that both red wires and both black wires are

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connected together. Two short lengths of the small diameter
shrink-wrap about ½" (13mm) long should be cut from the
2” (5 cm) piece supplied, to insulate the soldered joints.
Shrink-wrap is a special rubber tube, which reduces in
diameter when heated. To use it, first slide it over the end of
one of the two wires to be joined then, after the wires are
soldered together, slide it back to cover the exposed joint and
overlap the insulation at little at each side.
Finally, rub the hot soldering iron over the shrink-wrap and it
will close tightly round the joint.
In order to set and adjust the linkages, the r/c equipment must
be connected up and batteries fitted.
The short lead from the switch should be plugged into the
receiver in the socket typically marked (B) or BATT. The other
lead with the PP9 clip then attaches to the battery holder. For
now, just lay the battery holder at the side of the loco; it will be
fitted to the body later.
The receiver will be housed between the frames under the
footplate area and retained by the chassis cover plate
supplied with this kit.

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Chassis Cover Plate
Plug the regulator servo lead into channel 2 on the receiver
and the reversing servo lead into channel 1.
All loose wires, except the long battery wire can be tidied up
using the cable ties supplied. Ensure that none are in contact
with hot pipes or fittings and out of the way of any moving
parts. Finally, fit the chassis cover plate to protect the switch
and receiver. The two small tags which are bent upwards go
either side of the chassis and will line up with two tapped
holes in the frames for two M3 x 6 brass retaining screws. The

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large flap fits up between the frames behind the rear wheels.
When in place this cover boxes in the rear portion of the
chassis - see picture on opposite page.
Now that the main items are installed, we can fit and adjust
the linkages, first however, the spring which self-centres the
left hand (regulator) control arm on the transmitter needs
removing. The right hand control (reverser) can be left
sprung loaded to centre as this gives a convenient mid-gear
position. Refer to the manufacturer’s instructions regarding
the removal of this spring as details vary on different makes
of radio control equipment.
Fit four AA batteries in the receiver battery clip then connect
the battery clip to the end of the battery lead from the switch.
Switch on both transmitter and receiver.
Moving the right hand control lever should now cause the
reversing servo to operate and moving the left hand lever
should cause the regulator servo to operate. If this is not the
case, check all connections and batteries.
Set the reversing servo up first as follows.
Prepare a servo horn so that it has a single arm with a
connection hole approximately 8mm from the centre. If none
of the arms supplied with your r/c set have a suitably
positioned hole, you will have to drill one using a 1/16" or
1.6mm drill. The positioning of this hole is quite critical as it
will affect the travel of the radius rod in the expansion link,
but as different makes and types of servo have slightly
different angles of movement, it is not possible to give an
exact measurement - some trial and error is required.

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Reversing Servo Push Rod Connection
1- Starlock washer.
2- Pushrod connector.
3- Lock screw
Fit a push rod connector as shown in diagram 5. Push the
spigot through the hole from the front and push the Starlock
washer over the spigot to lock it on. Fit the screw in the end of
the connector loosely.
Trim the plastic servo arm to length.
Ensure that the control lever on the transmitter is in the centre
and that the trimmer (small black lever below the main lever)
is also in the centre then push the short servo arm up onto the
splined servo spindle pointing in towards the boiler at 90
degrees and fix in place with its retaining screw.
The shaped cut-out in the footplate below the servo will allow
screwdriver access to the horn and push rod connector