Monday, 26 April 2021

April 2021 Meeting


 At last out attention turns to the possibility of a 'real' meeting in the months ahead. A chance to closely inspect and handle, and discuss techniques and practical solutions.

The blog will still play it's part, as it did before restrictions, a running digest of our work around Lightermans Yard and individual projects.

Here is April's account;

Pete King; Brixham. I’m not exactly breaking any records here but the track is now laid on both the main station boards (below). On the lower right of the layout (as viewed in the photo) the track will carry on up a 1 in 78 incline for a short distance before diving through a hole in the sky. The incline starts just past the first turnout (lower right).

I have also been working on an adjustable mount for the crossing polarity micro-switches. Photo below shows the assembly with the centre screw locking the switch to the adjustable base. The other two screws pass through this base into the fixed base and hold the whole assembly together. By slackening these outside screws it allows the adjustable base to be rotated right and left via the radial slot. Photo 3 shows how it will look when fixed under the baseboards.



 

 

 

 

 

 

 

Alan Smith: Evercreech Junction. Progress has been slow as I have been tied up on other projects.
From last month the track through the station was laid but not fixed down. I needed to check for clearances against the platform edges. As there is a central track I had nowhere to go if things got tight.

After a couple of attempts at the platform I clad both facing edges with stone Plasticard, only to find that the up platform was indeed built from brick. The stone facing was duly stripped off and brick facia applied. I now have to fabricate the platform flag stones and line the edge. At least now I have a uniform curve with the platform edges from which I can lay in my track and know that locos and rolling stock will pass through.

The sidings and point work in the station yard have progressed a little I have now to fit the point blades and open out the tie bar areas on the underside of the boards to allow the servo arms to fit.


Because of the location of some of the points an extended arm
will be required, more of this next time.


The other projects....
Are a die set for the association tools.
The main blocks for this are supplied precision ground all over and bored to fit the guide pins and bushes. The pins and bushes are a press fit into the blocks the rears of which locate further blocks behind. My main job was to machine a socked in each die plate to take the tool plates.
As received from the original moulder and maker of the plates only the front edge and rear edge were parallel to each other. The sides of the tool were just rough sawn and looked like they had been attacked by a hungry beaver! the sides were duly cleaned up to make the plates 95mm wide with the ingate in the centre. these then had to be fitted to the die plates and secured with screws. It was found that some of the proposed screw holes interfered with old existing tooling holes, these were duly plugged up and re machined flat so that the new screws could fit unhindered.
The next job was to fit the push pins and ejector pins. The location of these was already laid out in the tool plates so these were duly transferred into the main blocks 4mm pins for ejectors and 6mm for the push backs. A further 2 off 1.5mm pins were also duly transferred. Drilling through 38mm of steel plate with a 1.5 drill was achieved by multiple 'pecks' and lots of cutting oil. Not applying too much feed also assisted in keeping the bore straight. All the holes were then reamed to their correct diameters.

The pins themselves are precision ground and hardened and as supplied are about 50mm too long so would need cutting down. Before I could do this I had to drill and counterbore the pin plates.
Again these are precision ground and one plate needs to be drilled and counterbored to fit the heads of the pins. These pin plates are screwed together trapping the base of the pin between them to drive the pin assembly back and forth, so the counterbores need to be fairly accurate or the pins could become sloppy in their action.
I made a few small CNC programs which enabled me to centre up each hole in turn and counterbore for the pin bases. Once I had the pin plates completed the die set was assembled and I could determine the final length of the pins. As I mentioned earlier these pins are hardened and ground so I had to grind these to length. I dug out my home made cutter grinder and duly rigged up a contraption to assist the grinding of these pins. This set up enabled me to get the lengths fairly consistent we shall see if they need any adjustment when the tool is run,
Fingers crossed....

Richard Doust: Following on from the animated stills of Lightermans Yard for the Virtual RailEX. Ian Morgan has come to our rescue with some great video footage of the layout. I am currently incorporating this into our video.

Next meeting; Sunday 9 May at 13.00 online


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