Thanks for the kind words, Larry.
The turntable is mostly scratchbuilt, although the bridge girders were cut and spliced from a pair of used (cheap) Atlas through girder bridges. These were cemented to a block of wood. The track is a section of Atlas code 83 flex. I removed all of the webs joining the ties, then re-spaced them to allow insertion of longer basswood ties, which support the planked deck. This maintains the track gauge with no additional spiking required. The decking is basswood planks, which I also had on-hand. I was going to throw away all of the basswood, as I much prefer working with styrene, but this was a good way to use it up. If I had used styrene, the total cost of the installed turntable would've been under $10.00.
The pit was cut in a section of 3/4" plywood installed for this purpose (most of the layout is open grid, with plaster-on-screen landforms), then the cut-out piece was used to form the pit bottom. The centre bearing pedestal and the ring rail foundation were cut from good-quality 1/4" plywood, and the pit wall is a piece of 1/8" Masonite.
The control shack was built from scraps of Evergreen styrene siding, and the handrails were built-up using modified metal stanchions (from old-style Athearn diesel handrails), some brass tubing, bits of styrene and some piano wire. Yet to be built and added is a power arch.
The ring rail is cut from another piece of Atlas flex, with the ties shortened using a utility knife. While it's not totally prototypical, it works well and looks passable.
The bridge pivots on a beater shaft from a hand-held mixer, turning in a bearing made from a brass washer and some brass tubing. My original plan was to use the mixer mechanism, driven by a fascia-mount handcrank, for turning the bridge, but mounting the mixer proved difficult. Since the layout here is only 30" deep (and the pit less than 3" from the aisle) I opted for a full "Armstrong-type" bridge, powered by a well-placed single digit from my trusty 0-5-0 switcher. There are wipers beneath the pit which rub on the shaft, supplying current to one of the bridge rails.
The other bridge rail is powered from the ring rail. I used a pair of slightly-modified freight trucks for current collection, with one wheel completely removed from each axle. The other wheels were replaced with metal wheels from an Athearn passenger car, two per axle and install face-to-face on the outer ends of the axles. These overly-wide double-flanged wheels easily accommodate any irregularities in the ring rail, and axle wipers transmit the power to the other bridge rail. I also added a rail wiper, which both picks up current and keeps the ring rail clean.
While my layout is DC controlled, I'm guessing that your connections for DCC would be similar, as this is the equivalent of a turning loop. Power pick-up is from an adjacent live track, and is routed through a dpdt centre-off switch mounted on the layout fascia. The various table and shop tracks are controlled through a separate rotary switch, a feature you wouldn't require for DCC.
Because of the very limited space here, my nominal 90' turntable scales-out to an actual 89-footer. The weeds in the bottom (many tables used dirt bottoms, with solid supports only for the bearing points of the bridge) are an alternative to concrete or brick. They are sprayed regularly, but keep coming back. I also need to add a couple of catch basin grates in the pit bottom: with the layout set in southwestern Ontario's "snowbelt", the railroad has installed steam pipes under the pit to keep things functioning through the winter. The steam plant, across the mainline from the shop, also supplies electricity and compressed air for the shop complex and nearby passenger station. Like those catch basin grates, the overhead piping has yet to be installed.