Servo Operated Knuckle Coupling

thingiverse

This is a completely revised Knuckle coupling for G scale garden Railways. Video is here: https://youtu.be/kimp_JnspIU (Feb 2020) I have uploaded the full set of (non servo) knuckle couplings to this thing for completeness. I was not satisfied with the performance of my previous designs, and so have completely revised this version. Operation should be clear in the video. There is also a "fixed" version of the knuckle that is for carriages etc and is a simple one piece part with integral plastic springing. These connect easily to each other and to the servo operated version. Coupling TO a train can have the moving coupling either open or closed. With it closed, more force (speed) is needed to connect. With it "open", coupling can be done at very low speed, but the alignment of the two couplings is more critical. I used my RC controlled Tram for the videos. The "cutout" versions of the housing and internal body will be needed for some locos, unless you want to cut the loco body to fit the "standard" fully enclosed version. The iges files can be found at https://grabcad.com/library/servo-operated-knuckle-coupling-1 1 Oct 17, made a very small tolerance change to the disconnect lever servo holes, to make it easier to fit the servo horn, plus I have moved the "connection axis" of the coupling 1.2mm to make for better coupling on the track. This revised the Main Hook and the Fixed Knuckle "FIXED_KNUCKLE_7DEG.st" part. FYI, the 7 degrees refers to how "open" the fixed knuckle is. With a o degree open part, the knuckles lock so tightly they cannot be easily parted. 7 degrees was a nice compromise. Locks well, but also allows for release when required. To fit the Fixed knuckle to your trucks and coaches you will need to print (one of) the LGB housings. these are here: https://www.thingiverse.com/thing:1989545 Chose the housing that works best for your truck/coach etc.