Category Archives: Workbench (other)
Etching Artwork
I have not actually picked up a modelling knife or soldering iron for a couple of weeks now; largely because I got a bit of a bug for sorting out the etch artwork.
I have now completed, I hope, all of the artwork I will need for all of the signals that will be required on Glenmutchkin. Indeed, it should do all the signals I and just about anyone else ever needs for any scheme based on the Highland era!!!!
I am fortunate that I have a couple of an 1895 McKenzie & Holland catalogue and a further partial copy from a bit later. I have also been provided with a number of really good drawings of bracket signals from M&H, prompted by my ramblings on the web. This has given me with a pretty good handle on how they were constructed and I can draw up rather more comprehensive (and a little more specific to the Highland) artwork than are available form any of the other sources.
So this is what I have come up with. Firstly, an etch of all of the arms, balance weights and a track mechanism for raising the lamp to the top of the post (I think this was peculiar to the Highland):
and then an etch that includes the large brackets used for the multi-doll signals and all of the support brackets and landing.
and this one is the smaller bracket; used on twin doll signals:
I have been recommended to use PPD as a first port of call for etching, so they have been winged off tonight. Lets see what a week or so brings us…………..
As this is now out of copyright, an article by OS Nock on the Highland’s signals from the Model Engineer might be of interest too – it may even show what I am trying to make in the etchings a little more clearly.
And for my next task, I am going to have another bash at the water column and the finial; more on this when I think I have been successful!
Brighton Road and Some Etch Masters
Less modelling has been achieved this week – due to a combination of work taking me a little more afield than normal and also because I was playing with someone else’s trainset.
In this case, the layout was Barry Luck’s (with assistance of the Mid-Sussex AG of the S4 Society) Brighton Road. It was shown in the carriage repair shop at Horsted Keynes; so we were serenaded by the sound of the real thing (and the occasional burble of a Sulzer as they had a class 33 working too.
Some rather nice photos from Jonathan Hughes are here:
and if you wish to see anymore; then go to here http://www.flickr.com/photos/nimbus20/sets/72157634415164752/
I was not totally idle otherwise, as I have had a bash at producing my own artwork for etching. I think this (it is a bracket for a signal a little like the one here https://highlandmiscellany.com/2013/02/03/first-signal-for-glenmutchkin/) is capable of being etched. I’ll be submitting it too Grange & Hodder soon to find out!
Whilst I appreciate that there are many that are now quite experienced etch designers, even if this started as a means to forward their own builds, I am still taking first steps in this direction so I am pretty proud of the above. Mind you, I might be counting chickens before…………….
No, this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning. Interlocked Lever Frame – Part 4
With thanks to someone else for the quote.
I managed to get all of the locking bars, installed over the weekend and the dogs (the teeth that engage in the sliding bars) to get the interlocking going. And this is what I get to:
This shows all of the components assembled in place. The dogs engage in slots in the sliding bars but the dogs have angled sides – so if nothing holds them in place the movement of the slider pushes them to one side and the slider can move. When another slider is in the way (ie there is an opposing lock set) then this can not occur – so it locks shut.
To stop the sliders popping up when they encounter a lock, a lid has been fashioned. I wanted all of the locking to remain visible, so this is just a skeleton.
I did find that the angles of the slots needed to be just over 45 degrees for the locking bar to move easily and they also need to match the dogs quite neatly. If I do this for real, I think some lost wax masters and then castings will be required to ease the process of manufacture.
The frame does lock well and neatly. Of course I made a few errors in where slots were to go but having made it from plastic, these were actually quite easy to sort out. What is more significant is that there is some slop in the levers – this occurs worst where the yoke of the bar that runs through to operate the toggle switch and sliding bars goes over the base of the lever. The hole in this is a bit too big and it means that the lever can move 30 % of its intended movement before it makes the sliding bar move and hence encounter the lock. This does slightly defeat the object of the locking and will need some work. I have an idea of linking the two more physically but if this does not work, then it may be back to the drawing board.
All in all, it works though and it is quite fun working through the desired move, working out what then needs to be thrown and in what order – although this may send my team a bit over the edge in the heat of an exhibition! However, some manufacturing refinement is going to be needed to make it work better. I remain tempted to use the potential kit that might be available but this makes the locking invisible and I am not so certain about this. Food for thought!
Interlocked Lever Frame – Part 3; the experiment continues
The saga continues and I have now made all the trays and the bars that the locks go into. As I have yet to colour the actual levers on the frame, I have coloured these to ease my understanding of things.
As this is an experiment, I am making this out of plasticard/evergreen strip to speed construction. The final thing will be in soldered and milled brass. I have yet to come up with a plate to secure all these bars in place, so they will not flop out as they presently appear that they might. This is what we currently looks like:
I have been warned that I may snap my tappets from the locking bars or something else. This is due to the significant mechanical advantage that the lever has over the through of the bar – if you look at the end view you can see that it is about 10:1, so I can see why I am being warned. Ultimately this is an experiment so I will take it easy with the frame if it breaks I will know that it will need to be tougher next time!
Interlocked Lever Frame – Part 2; More Experimentation……
With a lot of help from Keith Norgrove (thanks Keith) the locking design for the lever frame should now be concluded. This is where we are at:
The lever frame is also ready to receive the beginnings of the locking frame; so guess what i am doing this weekend………..
The Road Overbridge – Part 2
The bridge is coming along and is now close to finished (constructionally).
It has taken a lot of time with plastic filler to get the stones to meet neatly at the corners and also to be coursed sensibly at the corners. Having said this, I am inclined to think it is one of the more important parts of modeling structures and buildings. Cracks or missing sides/ends on a building are just a total no no and even an untrained eye (I am a chartered surveyor so it is worse for me!) spots the error immediately.
This is where we have got too:
Lots of filler in evidence – but there is still more too do!
The abutments end on
With a carriage to give a sense of scale – the Microrail Drummond All Third has only been on the stocks for 15 years………..
I am not happy with the string course at the moment, it sticks out too abruptly and possibly the same for the copings to the top of the parapet – so more filing and sanding………….
However, it does look like a bridge and I doubt the civils guys will condemn it!
The Road Overbridge – Part 1
The bridge is in fact modelled on the one at Killiecrankie, but there were very similar ones at The Mound, Kyle of Lochalsh, Keith amongst others. Heres a picture of the Kyle one:
Copyright by Ben Brookshank and reproduced under a creative commons licence
The advantage of using the Killiecrankie bridge is that I had previously modelled one for a layout of this station and whilst the abutments are still firmly attached to some mothballed boards, the deck could be reused. The deck has a nice skew to it to make it a bit more interesting and utilises lattice girders; which few seem to bother modelling. This is what it looks like:
In terms of abutments, most Highland (and indeed this is common to most scottish lines) had bridges with curved wingwalls swept back from the face of the abutment. To give the layout some locational character, this was something I wished to produce. This is where we are at presently with the abutments:
Typically, the random or dressed stone ranges from Wills are my favoured mediums but seeing Andy G making a good go utilising Slaters 7mm coursed stone I thought I would have an experiement with this. This is because many of the later bridges on the Highland used the same coarsely dressed stone; like this one at Dalwhinnie:
And these show the bridge deck on the abutments as they stand:
_________________ Mark Tatlow
Interlocked Lever Frame – Part 1; Experiments
And this is the locking chart that I think is right:
If people out there think there are errors in this; especially the locking chart (locking logic is a bit mind twisting) then please pipe up as I will be building it soon!
highland miscellany 