A letter in the February MR refers to the Anderson/Eschelman linkage. Where can I find details of this?
This link explains it
And this is what it looked like. I can't find any indication that it still made.
There is one in HO for sale on ebay. Search Earl Eschelman Link
Henry
COB Potomac & Northern
Shenandoah Valley
this is common practice on the layouts I've seen. The pivot is located between the rails and a simple wire with a v bend connects the switch machine to the bottom arm
greg - Philadelphia & Reading / Reading
I had to do this on one turnout on my previous layout because the throwbar ended up being too close to a crossmember even to fit a tiny servo. The DIY type as illustrated is actually a great improvement on the original Eshelman linkage that was sold as a commercial product for a time, that had a rather large disk on the layout surface that you had to hide somehow.
With a server, there was no need for any sort of bellcrank to transform linear motion to rotary motion. I discovered somewhat by accident that the way I was attaching the music wire to the servo for the traditions "stick the wire up through a hole in the throwbar" installation also resulted in the wire spinning in addition to the side to side movement - before I cut them all off short, I stuck bits of blue tape to the end poking out the top of the layout so I didn't impale myself on one, and while adjusting the servos I noticed the blue flag twisted as it rocked side to side. So for my problem child, it was all just one piece of music wire. Up from the servo horn, through the brass tube where ordinarily it would have been through the throwbar hole. Bent 90 back along the rails to the throwbar, another short 90 hook on the end to go in the throwbar hole. Worked perfectly.
If the throwbar was where the music wire comes up and bends, it would just move side to side, underneath there is nothing special compared to every other turnout on the layout. As you can see, it wasn't even critical to be perfectly in the center.
--Randy
Modeling the Reading Railroad in the 1950's
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