Maxitrak Coronation battery loco

After two years of no new acquisitions or extensions to the Corris Hill Railway, I came across an advert in the Maxitrak Owners Club magazine for a fairly elderly Maxitrak Coronation battery loco complete with two bogie wagons, a driving truck and a pile of aluminium track for a reasonable price. The track will go towards an extension I have been planning for a while. One of the bogie wagons, seen here, gives an excellent ride, though the other one does not, so will probably be dismantled and rebuilt.
The loco was mechanically very sound with little sign of wear. She was christened "Mavis" by my two year old son after a companion of Thomas the Tank Engine and so will be repainted black! I will also replace the 4QD control board as I did in my Ruston.
I decided to restore the bodywork first. The loco was taken apart, and the aluminium shell thoroughly rubbed down with wetordry paper. After filling a few small holes with car body filler and a final rub down, I sprayed the body and roof with Halfords grey primer.
This was followed by four coats of Halfords satin black. The loco spent several weeks sitting on the central heating boiler to help really harden the paint.
I used masking tape to mark out the wasp stripe pattern for the front of the bonnet. The stripes are at 35 degrees to the vertical. The rest of the loco was then covered ready for spraying with Fiat broom yellow.
The chassis was in good condition and ran very freely. This was again stripped down prior to a rub down and painting. It was sprayed with Halfords satin black, with Audi laser red buffer beams and coupling rods.
I obtained a loud Range Rover horn from a car breaker. With a little surgery this just fitted behind the motor. Also visible here is the circuit breaker fitted between the battery and control board.
I replaced the original 4QD model 1QD controller with a new 4QD Vortex 75-12. This can handle a lot more current than needed, and the lower rated Vortex 40-12 would also be fine.
The new controller just fitted behind the control panel. I added a 4QD battery condition meter and key operated on/off switch.
The completed chassis was fitted with the Halfords HB038 battery borrowed from the Ruston. This is the largest battery that can be squeezed in when the bonnet is fitted. The rod at the front is used for securing the bonnet. I also drilled and tapped a pair of small holes at the rear of the cab into which I screwed 4mm bolts. These locate into two holes at the back of the chassis to keep the body in place. The final modification was to fit a 4mm red socket on the rear buffer beam. This is connected directly to the battery positive. The rear coupler is connected to the battery negative - in fact the whole chassis is connected to the negative. This makes it easy to recharge the battery without removing the body. I just connect the charger to the socket and coupler.
The refurbished loco performed extremely well in initial trials. In fact it is around 20% more powerful and faster than the Ruston with a top speed on my straight of 9.3 mph (15 km/h).
I fitted handrails and applied transfers from Maxitrak to add the final finishing touches to this very attractive loco.
I came across a Trax DESM-2 diesel engine sound module and decided this was just what the locomotive needed. I drew up a plan for the speaker holes using Turbocad. I attached this to the box lid which made an excellent and easy to use template to mark out the holes.
Together with the supplied speaker, the sound module just fitted in a Maplin ABS box MB5 reference number YN40T. I fitted a DIN socket for the power and speed controller connections, and an on/off switch (not seen in this photo) so the sound could be turned off if not wanted.
I soldered the power supply leads to the 4QD board and the speed controller sense leads to the speed potentiometer as described in the very clear instructions that came with the sound module.
Finally I set up the idle speed, revs, sound balance and volume, and fitted the completed unit into the cab of the loco with velco strips so it could be easily removed.
Click on the picture to hear what the diesel engine module sounds like (video is 34 secs, 1.4MB, 640x480)