4/25/2015
Roundhouse Progress Report
The work session went well yesterday. Jerry and I did some work on roadbed and when Banks arrived Jerry helped Bill install his new p42 layout breaker protection system. Jerry put together a base with an edge clip to hold the board then wired it up to a bus strip to interface Bill's layout. In about an hour it was up and running. Just to check it out I shorted all four tracks with a can of coke and all worked perfectly. Nice looking device there Jerry and Bill.
I should note that the blocks strengthening the turntable hole and mounting screw holes looked good as well. Two problems solved.
In the meantime Banks and I continued on with laying out and gluing down the roadbed for the main tracks, the entry turnouts and the main receiving track. Next will be laying out the steam servicing-turntable approach tracks, the yard and the diesel service area. Thanks to Bill for putting out some photos. Doesn't look very impressive but it did take 3 hours. Thanks to all!
We do need a right hand no. 8 turnout (anyone going to Johnson's?)and the track can then be laid out on the in-place roadbed. We will have to devise a turnout motor mounting method which is going to be tricky given the nature of the chintzy board (door) construction. There is a new system of using small servo motors under turnouts that would be adaptable to the situation. The manufacturer is called Tam Valley. They could be mounted on circular 1/4 in bases with a center hole for the throw wire up to the turnout throw rod then glued into a recess hole ( perhaps 2 in diameter) in the bottom of the door/table. The catch is then a control board is needed to run and adjust the servos. Big plus is the servos can then be controlled by a Digitrax DT400. I will get some Tam Valley data to you.
Alternatively we could use expensive (+- $20) Tortoise turnout motors which have the advantage of including built-in switches that could be used to control track power to the double-slip turnouts. DPDT toggle switches could control the Tortoises. No DT400 control though. Tam Valley does make a control board for Tortoises that would get the DT400 option back. Mounting the Tortoise would be a challenge given the door construction.
The double-slips must be isolated from the yellow/white main tracks they are imbedded in and the red/black line as well. When a train from the red/black line crosses into the roundhouse tracks the Tortoise would automatically set the slip to red power and then back to yellow when it has passed and the turnout reset. This is necessary because the yellow line may be running DC and any train entering the roundhouse trackage must be DCC. The two systems ( DC/DCC) would short out each other if there is electrical contact. The normal state would have the yellow line power on the slips which could be either DC or DCC. You would only enter the roundhouse area if the engine is DCC. If running a DC engine a dead short would occur if the engine attempted to enter the roundhouse track. There is no protection against this occurring if an unaware operator running a DC train had it in mind to enter the roundhouse area. This might be prevented by using a DC relay to hold the slip-switch motors inoperable when the yellow line is DC but this would also require an override when properly coming off the red line with a DCC engine. That also could be accomplished. Depends on how foolproof we want the system to be.
One other point - we will probably use the DCS 100 base unit for powering the roundhouse. It could just be used at the roundhouse on the occasional times we run the roundhouse.
Well I'm glad you read through this hodge-podge of ideas. Better make sure you got the gist of the above because we will be discussing it and some other stuff at the next business meeting a week from next Tuesday. I'm working on an agenda. I might add that I am open to suggestions on any of the above options, any alternatives or anything I missed.
Reed Ostrander
President PMRC HO Division