The latest is for a 2mm scale Farish 04. Its a standard N item which has had the coupling pocket removed from the plastic keeper plate, plus 2mm finescale wheels (yes I know the spoke pattern is wrong for an 04!).
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEHZMzI2pec0ghsnaIh27miwvM9yfqfSkLRPQjmxcYqmSWo7i6gb0TdOCg-s8dJIc1VA4otlgxplYeTICTrkCLmZ6T2bqOU02B6xigkNyftjvzFoT_L4sEdLY_vQUkUM7M3rwffzIseNdv/s320/IMG_0806.jpg)
Picture shows coil on bench held on bit of bluetac. The coil wires are 45swg (0.07mm dia), or about the same as hair. The scale behind is a 1mm divisions.
The movie below shows it in operation. I will turn down the movement both forwards and backwards for real operations (various DCC CV settings) as they are currently a bit too large.
The chip driving the 04 is a CT DCX74. The DCX74 and DCX75 both support movement and coupling control from a single function press. It is intended for Krois uncouplers and I am exploiting the control here. The manuals from CT are fairly cryptic, but I think I have untangled most of the uncoupler issues. (The Zimo MX63 and MX620 are a bit larger, and also have functions for Krois couplers, though fractionally different in the way they operate. The Zimo documentation is a lot easier to follow). For those using JMRI (Decoder Pro), I have put my revised decoder file for the CT DCX chips in the JMRIUsers Yahoo group files area, when its had some more testing, I'll submit it for a future JMRI release.
I can see scope for a slightly larger version of this design (parts easier to handle!), with the frame and swing arm etched in nickel silver for 4mm use. I have a sketch design for the parts, and they should work with either a rotating AJ (like my earlier Armstrong Diesel) or the standard "pivoting" AJ with the pivot perpendicular to the coupling axis. I need to talk to someone who can put the etch bits on the side of a test-sheet, plus try out a few more electromagnet coil size options.
1 comment:
Nigel,
I will see this on Sunday. It certainly looks good to me.
Mick
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