Knuckle Coupler for LGB by dagnall53

Last crawled date: 3 years ago

Updated Dec 2019:
added the "V2" Opening Knuckle versions from the Motorised coupler..
Updated Oct 2017: I have added the "fixed 7 degree" version of my revised geometry couplings here. These are single piece parts, and need the lock ring to push them down firmly in the housings. It has similar "push" performance to the two part version and they do interlock, but the single piece geometry is designed to work "optimally" with my servo operated coupling, which uses the same geometry, but has the fully working knuckle.https://www.thingiverse.com/thing:2553019.
The two piece parts were originally revised 27 Feb 2017 to provide better "push" performance, because I discovered that my original design had a fault when "pushing" a long train. When the coupling is subject to strong push forces, the old design allows the coupling to open. . (I have added a picture to show four coupled together with me pushing them together. You can see the left (old) coupling opening, whilst the right (new) coupling remains in line)
The new "push" versions has a very small additional feature on the knuckle, which engages with the opposite knuckle in push mode and holds the two together better. I have also very slightly increased the spring strength.
It has been designed to work with LGB and LGB type models fitted with the "LGB peg". The strange cut outs in the housings are there to allow it to fit without having to modify the train or coaches.
Once fitted, it sits below the central LGB buffer on the Coaches, but the Central buffer on the Stainz loco is larger and has to be removed. This is a press fit part, so the process is fully reversible if you wish to return to hook and eye couplers later.
This design differs from Raby's original design in that the "hook" is now above the "tang", and so this design cannot use the iron bar type decoupling. However, the "Hook" eye is now fitted directly to the LGB peg on the train model, so should transfer loads well. I have tested one version at about 1.5kg pull and it survived. (27-02-2017.. See also my comments on pushing)
It has been tested to fit the LGB Stainz loco, and the coaches from the standard starter set. It has been tested pulling this around standard R1 curves, and up and down on a garden railway.
There is a small hole in the "peg" part of the main body that you can use to screw a screw into the ""peg" on the coach if you want ultimate strength, but I have not used this so far.
The photos show a slightly earlier version, with a "knob" on the end of the spring. This actually limited side to side movement a bit, so I have removed it in the final version.
In the photo, the coach and Loco are fitted with my electrical connection, http://www.thingiverse.com/thing:1023944