Kitwood Hill Models 48ft Turntable

FOR SOME WHILE I had been toying with the idea of a small loco shed layout with a turntable to add some interest. Casting around to find a suitable turntable kit, I came across the Kitwood Hill range of laser cut kits, made by Simon Cox. Turntable diameters are available ranging from 30ft to 75ft, and I chose the 48ft version as all my engines fit on this length of deck.

The instructions are sent in PDF form and are very comprehensive and include many photographs, running to 22 pages if printed. As I was thinking of purchasing a kit Simon kindly emailed me the instructions to peruse.

The kit includes pretty much everything needed to complete the model. A geared motor drive, and the rail and chairs for the deck are optional. Wiring instructions are also included, although a changeover switch (or perhaps a frog juicer if using DCC) will need to be supplied by the builder to reverse the polarity of the deck rails. The builder will also need a 3mm hex key for the motor shaft coupling. Glue and paint are not of course included.

The instructions inform us that the turntable is based on a shortened version of the 70ft vacuum operated one extant at Yeovil Jn. The kit is available with or without the extra decking on one side, incorporating the vacuum motor. This was my first dilemma. I figured a small 48ft installation would probably be hand operated, vacuum operation being reserved for larger depots. However, I have yet to train my Modelu loco crews to get out and push the turntable around manually. I thought it would look a bit odd if the loco turned with no visible means of propulsion.

It then occurred to be that some smaller turntables used a windlass for propulsion, so I could easily modify the platform containing the vacuum gear to represent this method, and with a couple of figures in suitable pose, this would be a good compromise.

I began construction, using Everbuild 502 wood glue, which allows handling in around 10 minutes. The first module was the turntable base assembly. Progress was relatively rapid, everything fitted together exactly as it should, and no problems were encountered, although it took me a while to figure out how the various discs went together in the correct order. Despite the instructions and photographs indicating the parts only fit one way, believe me, it is possible to get it wrong.

Having assembled the basic well, a jig is supplied to fit with race rail, this worked well, but it is important to get the rail aligned vertically at the join, as a slight step here will cause problems when turning. After this the top rim and walls of the well were fitted.

Two options are supplied for the walls, thin plain ply panels, which could be decorated to taste, or laser engraved brickwork, which has been very nicely done and has the correct bond. This, if used, is overlaid on the ply panels, and I chose this option. A small amount of opening out of the brick courses on the joining sections was necessary, and for this I used abrasive sticks for filing fingernails, which were ideal. It is advised that the walls are painted before fitting. Some turntables had their pit walls painted white, so after painting the brickwork I dry brushed off-white paint vertically, leaving the brick colour showing through.

I noted there was usually a small access pit at some point in the side of the pit wall. This was for maintenance of the bridge. The tops were covered with planking, old sleepers, or steel plating. This is not provided for in the kit, so I left a 32mm gap in the side walls in order to fit this later.

The base now has steps in the pit where the various discs have been fitted. The base needs to be dished as per the prototype. The instructions suggest this can be done by gluing on scenic gravel with neat PVA, however, I was not sure if the “steps” could be completely disguised using this method, and I also wanted to represent a concrete base to the well. I decided to try using DAS white modelling clay, which was built up on a thin layer of neat PVA. A 3in decorator’s scraper was used to smooth it all, and this was occasionally dipped in a bowl of water.

When the DAS hardened I lightly sanded and filled any depressions in the surface until I was happy with the result, although a potter’s wheel may have been useful. A 500g pack was more than enough to do the job.

I decided to build the bridge next, as I needed to ensure the DAS in the well did not foul it. I found the best tool to separate some of the smaller parts from the fret was an Exacto knife with a chisel blade, held vertically.

I decided to opt for the operating platform. Two longer lengths of 0.8mm piano wire are supplied for the handrails on this side. This wire needs bending to shape. A jig is supplied for this but, being springy, the wire needs a little tweaking to become completely square. It is important to get both handrails the same, or the posts will not sit correctly.

All of the parts fitted together quite tightly. I found it best to assemble the parts dry and run a little superglue into the joint when everything was aligned. I lightly sanded the ends of the tags on the more delicate parts to enable them to go together without too much force. Constant reference to the instructions ensured all the parts were fitted in the correct place.

The motor unit was then fitted. This has two brass top hat bearings for the bridge; these lined up nicely. With the bridge temporarily fitted, power was applied via a 12V DC controller. Operation was smooth and silent at the first attempt. Rotation is 0.6 RPM at 12V. A copper disc is supplied to conduct power to the track via sprung brass plungers. The only soldering involved in building the kit is the power to the track and the drive motor, eight joints in all.

The kit includes the rails for the deck and C&L chairs. I must admit I was a bit disappointed with the chairs, which sat on a skew after threading them on the rails. Fortunately I had a few spare sprues left over from other projects, and I think they were earlier versions, being a red colour rather than the brown ones supplied. In the end I replaced more than half of them. The deck and the rails thereon need painting before fitting them together, so I sprayed the deck with Halfords matt black. The rails and chairs were sprayed with Humbrol dark earth 29 as a base coat. I tested gluing the chairs with plastic weld on a scrap piece of fret as I was unsure if this would affect the paint finish. This worked well and, using the track gauges supplied with the kit, the rails were fitted.

A cut-out in the outer ring was made to fit the aperture, which was made from 0.040in plastic card with a 0.020in brick overlay.

The turntable needs approximately a 365mm diameter hole to be cut in the baseboard. This position of the turntable was marked out and a 6mm hole drilled in the baseboard at the centre, and using a length of batten, having two holes drilled at 182mm centres. With a 6mm bolt in the centre hole and a pencil at the other end the circle was marked. A jig saw was then used for the cut out. This operation is not too critical due to the width of the lip. I had to then make a rectangular cut out for the maintenance pit mentioned earlier.

One problem encountered was the fact that the instructions advise the deck of the table (the bit with the rails on) is not glued to the bridge, but pushed on over the tags, (which locate it quite tightly anyway). This is to enable the wires from the rails to the pick-up disc to be accessed should it become necessary at a later date. The deck, however, had a slight bow in it, probably as a result of attaching the rails and painting, so one end would not quite sit down on the supporting structure, causing about a 1mm step between turntable and approach rails at one end.

To overcome this, I glued two blocks of hardwood 13mm thick under either end of the deck and screwed plates under the bridge to pull the deck down.

This cured the problem and still allows removal of the deck if required. Once installed the complete bridge is easily removable by loosening the grub screws on the motor shaft coupling.

I also did not glue the carriers for the deck wheels to the underside of the deck. They are a tight push-fit and should it be necessary to make any adjustments this can easily be done (see comments below.)

As built, the wheels of the deck appear to carry the weight of the bridge and loco. To obtain the very smoothest rotation, I lightly relieved the centre bearing using a tapered reamer to give a tiny amount of play on the centre spindle. I fitted a 0.050in shim washer on the spindle of the bridge to allow about 0.25mm tilt at each end. I replaced the rigid motor coupling supplied with a ball and socket coupling as shown in the photo. This allows the weight of the loco to be carried on the centre bearing rather than the outer wheels, which just act as stabilisers as per the prototype (i.e. when turning, only one set of wheels should be revolving, with the opposite set just clear of the race rail).

There is a tiny amount of backlash on the gearbox, which is magnified by the length of the bridge, resulting in about 7-10mm of free play. This can cause a loco moving on or off the turntable to move the bridge, thus misaligning the track and derailing. To overcome this, by shaving a few millimetres from one side of the motor mounting frame, a wooden clothes peg was clamped on the drive coupling. This acts as a damper and works quite successfully, the motor having plenty of power to cope with the extra friction.

Overall this is an excellent kit which goes together extremely well and is very good value for money. I found it easy to build, being rather like a jigsaw with instructions.