Ben
is constructed from an IP Engineering 'Punch' kit, but with the standard Punch
chassis replaced by IP Engineering's heavy duty chassis. This was done to
achieve the fly-rods connecting the wheels and the result is quite pleasing (to
my eye!), having a more substantial appearance alongside my other stock.
Ben was initially radio controlled on 27MHz using an
M-Tronik speed controller behind
the front buffer beam and a receiver behind the rear. The photo shows how it all
fitted.
The batteries (six AA cells) are rechargeable and fitted under the bonnet,
a charging socket situated below the drivers control panel. Six cells give Ben
an enthusiastic trundle at best, but he will pull well and run several hours
before charge is required. The M-Tronik controller allowed the transmitter to be
switched off once Ben is running and he will carry on regardless until you power
up again.
The cannister on the starboard running board is a tube from a felt tip pen with a plastic bolt salvaged from our house For Sale sign. The aerial for the r/c was wrapped around the bolt all save the last four or five inches, which are passed through the copper tube on top of the bonnet. The end of the aerial is soldered to the end of the tube, which rests on the back of the radiator top, held by sufficient epoxy to insulate it from the bodywork.
REPAIRS!
A recent repair to Ben was necessary due to the main drive cog slipping on the axle. The motor and gearbox are a single unit held together with glue, the gearbox consisting of two white metal parts with brass axle bushes. The drive gear is a nylon cog push fitted to the axle, meshing with a worm on the motor shaft. At some time, the nylon has released its grip on the shaft, allowing the gear to turn. This became apparent when Ben stalled with the motor running and only a single wagon in tow. The remedy was to dismantle the 'box by prising apart the sides and levering away from the motor. The bonds broke easily and cleanly.
I then drilled 1.5mm dia through the gear and axle and pushed a piece of 1.5mm brass rod into the hole, thus pinning the gear and axle together. Of course, this was done with the axle and gear in place in the gearbox, else you wouldn't be able to reassemble it. Make sure there are no burrs on the gear left by the drill and that the rod is below the root of the gears teeth.
The 'box was then fitted back to the motor using a screw through the holes already present and the cover replaced with a drop of cyanoacrylate.
Ben is now back in service!
UPDATE
Use of Ben was showing that the transmitter was more often than not switched off, allowing No.2 to run unattended, lazily ambling around with a line of wagons in tow. It was such that when a decision was made to make No.6 r/c battery, the r/c gear from Ben was replaced by a simple switch and the MTroniks controller removed.
Early in 2008 Ben came to a complete and abrupt halt whilst on shunting duty, despite an almost full charge, the motor refused to turn. Disassembly showed that the previously pinned drive cog had split where the pin went through, resulting in two halves inside the gearbox, jamming the worm on the motor.
At the 16mm AGM in Stoneleigh 2009, a replacement gear set was obtained very reasonably from PPS and this week workshop time was allocated for the replacement.
Removing the gearbox itself required removal of on side frame from the loco, and of course the side rods. The gearbox cover was already removed so the single holding screw released the motor. The previously fitted pin then needed removal to allow the axle to slide from the gearbox housing. To fit the new gearwheel, I found I had to drill the nylon bore to 3.1mm dia, as it was far too tight as supplied. The edges left in the axle from the pinning seemed at add some security to the assembly. Liberal application of graphite grease inside the 'box, some oil on the bearings and everything was returned to its proper place.
After a short proving run, Ben sits in the sunshine waiting for a turn of duty. A couple of additional details were added during the workshop period, including an oil can, bucket and brush on the footplate, and a billy can for the drivers tea on the bonnet top.