On3/On30 65ft turntable

65ft O scale (1:48) turntable

On3/On30 gauge. 

This model picks up generic features of US turntables. In standard form, it has a reasonable hint of EBT flavour! From Jan 2023, this kit has a "Durango" variant option with angled stanchions and an air motor deck included at no extra cost.

Photo below: US modeller Mike Klingler built and installed the kit into his On3 empire. K37 on the bridge.

bridge dimensions

65ft 1/4"/ft (1:48 scale) bridge diameter = 415mm

bridge rail length = 413.5mm

deck width between handrails, 75mm for On3/On30

Pit dimensions:

Outer rim = 447.5mm

hole required = 435mm

pit depth:  31mm at centre, 25mm at edge

Drive train options:-

Cheap Motor power    I am no longer offering the original cheap 0.6rpm @ 12V motor with this turntable. While it can turn the bridge just fine, and it can turn extremely slowly for track alignment, it cannot hold the bridge still when stopped - that relies on other system friction. This can and has been done, and indeed, Mikes TT shown in the picture uses it. So while the mount for "El Cheapo" motor is included with the kit, you would have to source the motor yourself (they are really cheap on ebay if you want to give them a go. Search "GW370 Motor gearbox" or "0.6rpm motor gearbox").

Hand from heaven!  In most basic form of the kit turning is hand from above using push poles.  simple!

New KHM/ABC motor/gearbox. the close tolerance gearbox holds the bridge rock still when it is stopped. slow powerful DC motor makes alignment by eye easy. It has to be ordered separately (when it is ready!)

DCC or DC. Like all KHM turntables can be used with either system. The track power connection rings are continuous so loco DCC decoders are contnually powered (best for sound). The contact plungers are 6A rated. Polarity can be handled with a DCC reversing module or a simple DPDT switch.

Primary shaft turning plate: the heart of all KHM turntables and now proven design. This is a jig-built, ready-assembled item with the 4mm primary shaft pinned and epoxied into a milled brass section. She ain't slipping!!

Assembly and construction:-

Bridge frame is made of laser cut ply, with basswood cross beams and hardwood decking. supplied with ply handrail stanchions and piano wire handrails for a stiff robust solution. Glued together with step by step photo instructions. Novices have built my turntables!

Bridge track is not included as there are too many options. Besides you have lots of it for the rest of the railroad!

Pit is laser cut 3mm and 4mm ply. Because of the weight of locos it is best to support the turntable from below, rather than the rim (unlike other KHM turntables)

While the kit will make up a whole pit with base , because of the size it is strongly recommended to fix an additional flat, rigid 3/8" ply surface to the underside to maintain rigidity. This isn't in the kit because that would weigh far too much and be too big to ship!

Ring rail:  code 83 included to the kit, soldered to PCB ties and a simple jig ensures you get it circular and set in the right place. All KHM turntables use this method and its proven over last 5 years. Its simple, even for novice solderers - honest :)

Bridge wheels: turned from Delrin on KHM's lathe with ball-race bearings. They are wide enough to be forgiving of "assembly tolerance" of the ring rail.

Jan 2023 - DURANGO VARIANT  (check the box!) : repeated calls from On3 modellers for a Durango turntable version of this kit means a conversion kit is available that has the angled stanchions and air motor operating deck for Durango. Note that this is done in the same way as the Sn3 turntable - microply and laser card parts that make up a good representation of the air motor - not a detailed casting of it! The existing kit already has a smooth plywood wall option to be able to create the "concrete wall" of Durango.

These additional Durango parts can be retro-fitted to an existing On3/On30 65ft turntable and they are available as a conversion kit.