Category Archives: Workbench (other)
As tonight is Oscar night and I am sure this phrase will make a few outings, I thought I could get in on the bandwagon……………….well, a more honest answer is that work has been rather too intense in the past few weeks for me to have done any modelling so I need an idea for a blog post!
So I thought I would share with you one of the most important tools in the Tatlow modelling armoury – a Proxxon TBM 220 bench drill. The difference of this to my modelling is a much improved control over the drilling – its great when the hole appears where you want it!
Equally important is the really significant saving in drill bits (don’t laugh, it is true!). There is a world of difference from a DIY store bench dril or even a Dremmel to these Proxxon drills. Their accuracy is stunning and they are very well made so are smooth to use so you can control pressure with ease.. Add to this the chucks are such that they will hold down to a 0.3mm drill and these are so delicate that I really don’t think you cna use hand pin vices for these. Thus, this gives you the ability to drill much smaller holes and without costing a fortune in fine drill bits.
I have not presently got the compound table that I would need to enable this to be converted to a lightweight milling machine, but it is on the shopping list!
Mine was a nearly new model from ebay at just over £100 but they are regularly available from a number of supplies such as Axminster Tools or Proxxon themselves. Well worth the buy, so go on…………
This weekend I braved the traffic heading to the Festival of Speed in order to complete the building of a replacement fiddle yard for Portchullin (of which more another day) with Tim & Julian. Once complete, I stopped by to see how Benfieldside has been getting on and in particular what my signals looked like in thier proper home.
First up the gallows signal (which has dropped a bit low on its swing).
And then the twin and three doll brackets.
All the above signals were restorations (although not so much was retain on the two doll); the single posts below were made afresh.
And having inspected the signals it was time for a play with the layout and take some pictures to share with you. So here we go:
The guys are still building up sufficent stock for it so it won’t be out on the road for a year yet but I understand that the layout should be at the South Hants MRC show in November 2017. So hopefully I will see you there?
Putting aside the body for a while, to take a look at the chassis because it is necessary to mount the two together and it is not possible to close up some of the element of the body until this is sorted out.
As with the body, I am trying to take a moderately fresh approach to the chassis to make this a little easier to build than certainly most of the kits I am used to. In this regard, most of the kits for the Highland are quite traditional in their design and I readily admit that all but two of my ideas has been either all out pinched from other designers or at least significantly inspired by them. All I am trying to do is use more of these neat ideas in a single kit to make the life of the builder easier. I am, however, finding that it makes my life more difficult, as there are a lot more moving parts to most components, so more places for the tolerances to be catered for; so as John Price has already said, the list of little tweeks and amendments to make is growing! At least, no one can say this particular kit designer has not built their own model.
Anyway, this is what the chassis looks like in the flat; note that it is a fold up design – this is inspired by the Mousa Models chassis, so a pinched idea!
And this is what it looks like with the basic folds made up. What it achieves is really neat, as it is instantly sufficiently stiff to work as a chassis; by the time a couple of further cross braces have been installed the basic chassis is more than robust enough for its life.
My design uses the same slide in hornblocks as utilised by Comet and Brassmasters for their chassis. After a tiny bit of practise, it is possible to size the hole for the hornguides such that these are just too small when etched. This means that with a few strokes of a light cut file on each side, the hornblock becomes a tight sliding fit. Once all of the hornblocks are in, it is then possible to measure the distance between each on both sides of the chassis and also on the corresponding coupling rod. This is done with digital callipers and by the expediency of measuring the distance at its maximum with the callipers facing outwards and then repeating with them facing inwards the average being the actual distance between the centres. I reckon to be able to measure down to 2 or 3 hundredths of a mm, which is rather better than I can build to! Where there are inconsistences, this is dealt with by a few more strokes of the file on the side which needs to be adjusted to change the centre. This needs to be done anyway to turn the tight sliding fit to a snug but smooth fit for the hornblocks to work properly soif the centre does not need to be changed, the file strokes are undertaken equally on both sides of the hornguides.
This does need to be done after the coupling rods have been formed, of which we will see in the next posting. However, the chassis is also designed with a keeper plate to accommodate all of the cosmetic springing to the model and the ashpan sides. This is secured with a series of 12BA screws to enable it to be removed to allow the wheels/axles to be dropped out. A great boon as the model is built and painted.
To make the assembly of this element easier (in fact in this case a lot easier!) I have created a jig that holds the two layers of the laminate in exactly the right position. The jig is chunky enough to avoid distortion as it is folded up and it locates the parts perfectly. In this particular case, the soldering needs to be done with care as there are folds to make after the jig is cut away and it is important not to fill this with solder before hand.
And this is what the keeper plate looks like – it is pretty delicate until it is mounted but fine thereafter.
And the two components assembled look like this. The beginnings of the cylinders are also visible, this is a slide in module that can be removed for assembly and painting (although the scrap tanks were painted fairly simply, so this is not really relevant on this model).
Whilst I have not put any posts up showing progress with the boards for Glenmutchkin, progress is being made and the last two boards are essentially now finished. I am hoping that with one more day’s work which will mostly be to build up a carrying box for the final two, they can all come home.
In anticipation of this, I have been building some turnouts and a bit of the basic trackwork.
I am only able to do the turnouts which I am reasonably confident will not change shape when the track is finally laid out on the boards. In essence this means the crossings in the bay, the main line and the goods yard. I have also done one of the turnouts in the yard. So seven down, twelve to go including a slip!
I have also developed my approach to TOU’s slightly from Portchullin. As a finished article they look like this:
You will see that relatively little of the TOU is exposed (and when it is painted it blend away further). Equally it is much more durable than most of the other options out there because the switchblade is held by both a wire strip but also to some brass strip that is tight to the underside of both the switchrail and the switchblade. By installing this strip in this location, the switchblade is held in a vertical plane much better than other solutions. I think this leads to better running.
This is what it looks like as it is being assembled. You will see that in essence is it is merely a bit of copper clad below the switchblades, but lowered somewhat further due to the use of the brass strip. This allows the whole lot to be hidden below the boards.
You will note the rather unusual arrangement of sleepers. This is called interlacing and was very common on many pre-grouping lines, including the Highland. I will expand on this in a future posting.
We have not had an update on the signals for Benfieldside for a bit. The first four of these, including the three that were restorations (although in respect of the twin doll signal, very little was reused indeed) are complete. This is what they look like (with thanks to Phil Hall & the Scalefour Society for the pictures):
The gubbins for operating these is not shown in the views and I will write up a bit more on this at some point but an article I wrote for Rail Express on the signals I did for Elcot Road can be found here. A few of you may have played with these on the MERG stand at Scaleforum too, as I understnad it they kept people amused. There is more Benfieldside signal updates to follow, when I can get my camera out in the light to take some piccies.
I will be making at least some of the items that I have been developing available for sale.
Therefore, I have set up a separate website entitled Miscellany Models that shows what is available, how to get them and (when I get some time to do it) will become a repository for prototype information that I have on the items I have made, construction/finished photographs and instructions.
You can find this website here. If you look hard, you will see some hints as to what other things I have been working on and are expected to be made available in due course.
We haven’t had an update on the etching and mastering that I have been doing for the signals for a while.
Well, I have had both the rapid-prototype masters and etching in. Using the former, I have also had my first set of lost wax casting done – in this case for the lamps and finials. This is what they look like – which I think is pretty good and a lot better than the white metal ones from MSE.
and the etching looks like this – brackets, arms, ladders and a few other bits and pieces.
So it was time to make a signal – in this case a fairly simple single arm Highland signal. So using a post from Lochgorm and then my parts for the arms, spectacle plates, windlass, balance levers, ladders, finials and lamp, this is what it has come out like:
and the castings close up looked like this.
So all in all, I am pretty chuffed!
It does mean that I think there is some more signal building to come on these pages……….
In the summer, my 16 year old decided to rejoin the human race (having spent the previous three years on the planet “grunt”) sufficient that he and his mate decided that they might actually want a week away with a boring middle aged bloke. So after some discussion, we decided to go and get some “fest” in at Edinburgh, cycle the Dava way, bag a couple of munros and take in a distillery tour or two.
We stayed at Aviemore so I went on one of my photo recons and whilst I must have been past it several times before I found this rather nice yard hand crane.
I thought it ouzed atmosphere and would make a lovely little model; so I have had a bash with it – again trying to use modern means to make it so that it could be replicated if need be. So other than what I think is a brake at the rear (which I forgot until I loaded the picture up above) I think it is done.
The base piece, sides and the cowl that goes over the base of the main wheel (the green bit) are intended to be etched; the rest will go down the route of 3 D printing again.
So it is time to spend some money with Shapeways and PPD again……….. I have also done some work on the other things that I had etched and printed before; hopefully they will have the little glitches sorted this time; a little present for myself for Christmas!
I have had the test etches back for some time and have had a play with them. This is what they look like back from the etchers:
I did find that I had made a number of the components to fine. I had prototype information, so I had made things like the balance levers to absolute scale and this is too delicate, certainly for 4mm. So they look beautiful in the etch but would not survive on a layout. Fortunately, I had also done an etch of the arms and signal components in 7mm, so I was able to do a little bit of 7mm modelling. This used a Lochgorm Models etched post and my design of base is where it gets too (sorry, slightly fuzzy picture):
I also got the first of the 3d prints back from Shapeways and these are very good indeed, so I am well chuffed with them! They are slightly difficult to photograph but here is what these look like:
I need to make a couple of tweeks to these and get a revised print done of them. I have a miniature etch for the handles done, then I will make a few resin copies of them and they are done!
I also had the finials and lamps printed; the lamps worked fine and so did the finials in 7mm but they proved far to fragile in 4mm – so again I need to make a few key elements overscale to be able to use it.
Whilst my orders for earlier work are underway, I have done a bit more drawing and have now drafted up some lamps for the signals; as below:
I have also managed to sort out a drawing that I did some time ago for a water column. The larger of the models for 3 D printing need to be hollowed out (to save on the printing medium, which is charged for by its volume). This took some time to get right, as I had multiple different parts I was working on.
So these have also be sent of to Shapeways for printing. As before, I will use the lamps as masters for lost wax casting (another new trick to learn!) but the water column will be used as a master for some resin casting (the old dog really is going for lots of new tricks) – it will also need an etch for its operating arm.
However, lets see how good they come back first – as I think I am probably counting chickens prematurely here……….