My expierience with big locos

[Schraddel]

The tender of the M-68 was treated in a similar way as the one for the L-105:


Similar because it is indeed the same prototype as the L-105 tender but different construction. This Max Gray tender is about ten years older.





This pipeline was completely missed and i made it out of brass stock orientated of those of the other tender.





Grab accident safety.
When you handle the M-68 with it's relative heavy weight, you will grab it by the running boards. But what is under the running boards? Here it is a bundle of air lines in fine brackets and these will inevitably bend inwards when you grab the loco to handle it. You know this is a critical point and you can handle it with care to avoid bending the brackets. But there is alway the risk of wrong grabbing and therefor bending the brackets accidentally. Of course you can bend it back to straighten it, but the real question is: How often?
To improve the structural stability here, i set some bores of 0.8mm into the boilershell behind the brackets.





Pieces of 0.8mm wire were soldered onto the lower ends of the brackets od into the bores. This give the much wanted additional structural stabilty and coarse grabbing here does'nt matter anymore. When the boilershell is mounted onto the running gear, you see nothing of these additional stiffeners.





The many bended and askewed details of the cab interior were were rebend an straigthened. And this it looks alike when the cab interior light is turned on (photo without flash).





Here to this socket has 4 poles, but actual only 3 poles are needed, so the the two middle sockets are electrical connected. Thus enables me to plug in here two 2-pole plugs, one for the front head light and one for the cab interior light; remember the cab is detachable. The function "+" (blue wire according NMRA colour code) will plug into the inner two sockets, the white (decoder front head light) into the very left and the green ( decoder function F1, here green) into the very right. This will avoid cable spaghetti.





An other proven device for impeding cable spaghetti is my spectacles shape cable guide. Here 7 cables are to guide, all have black colour because they will be lateron full visible, but should be as invisible a possible.
The 7 cables are (in the photo from bottom to upper):
- pick up left rail (NMRA colour code: black)
- motor (grey)
- front headlight (white)
- common "+" (blue)
- cab light (green)
- motor (orange)
- pick up right (red)
In this strictly order the wires were be soldered onto the connector plug to the tender and the plugs were shrinked in.





The tender wiring loom. Colour codes according NMRA.





The completed electric installation.
The loco to tender plug was marked to avoid wrong connection by distortion of plug and socket to each other. As a safety function there will be a heavy direct short which does not affect the decoder.
There are two more sockets leading from the decoder. One (colour code black and red) is leading to the pick ups of the tender wheels.
The other (colour code blue and yellow) is still unplugged, here later the back up light will be plugged in.





Because with the Max Grey tender the front end sill is part of the shell, so i have to create this solution. This enables me later to demount loco and tender witout the need for soldering. This will be necessary when the loco will be painted or for maintenance purposes. The connector can be slided into the tender to hide it.






That is the connection between loco an tender looks from underneath. A thread was cut into the lower portion of the drawbar pin and a nut screwed onto. This makes the handling of loco and connected tender much easier, because the drawbar could not slip off the pin when you put the loco onto the rails.





Here the movable diaphragm is still missing. The prototype had one and the model should get one.





Everything straight?


Cheers Lutz

Edit: misspelling, syntax