Page 7 of 13

Re: A Highland Miscellany

Posted: Mon Dec 29, 2014 12:28 pm
by Andy W

Re: A Highland Miscellany

Posted: Mon Dec 29, 2014 8:00 pm
by Colin Parks
Hi Mark,
Those signals are superb!


Re: A Highland Miscellany

Posted: Tue Dec 30, 2014 6:05 pm
by Mark Tatlow
The next bit of catching up relates to a Highland Railway cradle bolster that I have attempted to make etchings for, with the view of offering them to those that are interested in such things from so far north!

This is what the etches looked like from the etchers (PPD):
a.jpg (99.85 KiB) Viewed 7232 times

This is a dia 25 cradle bolster; a type of vehicle that I have not seen on another railway. It has a square cradle that sits on the top of this, with four bolsters protruding from the corners of the cradle. They were used on pairs and the whole cradle rotated when the pair of vehicle went around curves. The intention, I presume, was to offer the load more support by offering more points of contact. Anyway, as no one else had tackled this vehicle before, I thought I would have a go!

As this is my first etched design for a vehicle, I have certainly encountered a number of problems. As the top photograph shows I produced this in both 4mm and 7mm; the latter has proved more successful due to the thickness of metal being greater. The main issue that I created for myself was to half etch the solebar overlays so that the rivets and the ironwork could be portrayed. However, rather than backing them on a further layer of etch (like the etched kits I have built – they evidently knew something……), I spanned it between supports. The intention had been to make the kit fold up more readily but in practise what has happened is that the half etched solebars have distorted (badly in the case of the 4mm one) due to the stresses introduced in the heat from soldering. Thus, whilst I have a working model (at least in 7mm), a rework is going to be required.
b.jpg (84.73 KiB) Viewed 7232 times

Both the 4mm and 7mm versions will have sprung axleboxes, using a varient of the guitar wire sprung version used by Bill Bedford and others. The 7mm chaps don’t seem to use it much and I guess the mass of their models helps. However, it does glide with the springing and is better as a result I reckon.
c.jpg (111.95 KiB) Viewed 7232 times

I have also done a 3-D design for the cradle, which I am proposing to use as a master for some resin castings (certainly in 7mm, I might go down the lost wax brass route in 4mm). A new process that I have not previously attempted. I need to find out where to get axleboxes and buffers from – Larrie Griffin I presume.

Also back from PPD, were some etches for something altogether more bold (which is a worry in the light of the problems I have encountered on a relatively simple wagon!). This is the chassis and body etch for a Drummond Scrap Tank. I have made a start on this and again, some reworking will be required but again there is a viable model in an amongst these parts; it just needs tweeking. More to follow once I have got further with it.
d.jpg (102.85 KiB) Viewed 7232 times

e.jpg (101.39 KiB) Viewed 7232 times

Re: A Highland Miscellany

Posted: Tue Dec 30, 2014 9:38 pm
by David Knight
Hi Mark,

The 'Scrap tank' looks very interesting especially the single etch for the cab, tanks, and spectacle plate as one big bending exercise. You should be awarded a black belt in nickle-silver origami on completion! :thumb I must go and have another look at your Dad's book to see the end product.



Re: A Highland Miscellany

Posted: Tue Dec 30, 2014 10:12 pm
by Mark Tatlow
David Knight wrote:Hi Mark,

The 'Scrap tank' looks very interesting especially the single etch for the cab, tanks, and spectacle plate as one big bending exercise.

It nearly worked too; the tank tops ended up slightly too long so the cab front was part way into the cab! Doh; I guess it is what test etches are for!

The chassis has a number of fold up elements too; I am trying to make getting a running loco painlessly first time - well, nearly painlessly anyway.

I can't claim originality for the ideas; Bill Bedford's chassis use some of them and some of the lovely stuff that the 2mm boys are doing is inspirational.

Re: A Highland Miscellany

Posted: Wed Dec 31, 2014 1:25 am
by DougN
Mark, the Dave Bradwell new technique for hornblocks is dead easy. It has one side of the horn guide fold out from the chassis. The other is a right angle soldered to the other side flat on to the chassis. Jiged by the horn blocks them selves. I will see if I can email you one of his sketches from the q6. It was by far the easiest and pain less way I have seen of doing the chassis. :D

Re: A Highland Miscellany

Posted: Wed Dec 31, 2014 10:11 am
by Terry Bendall
Yes very nice Mark. Good to see that you have put the Christmas break to good use. :) It is not easy to get the operating linkage as neat as you appear to haver done, Can you give us a bit more detail please.

Terry Bendall

Re: A Highland Miscellany

Posted: Fri Jan 02, 2015 12:07 pm
by Dave K

Just finished reading your article on Portchullin in 'Modeller Yearbook' - superb photos. I don't usually buy D&E magazines but the photos are worth the purchase price. Looking forward to see the layout at the Crawley Club's show in April.

Dave Keeler

Re: A Highland Miscellany

Posted: Fri Jan 02, 2015 1:08 pm
by Mark Tatlow
Thanks Dave; you are correct that Portchullin will be at Crawley's show (which is actually in Horsham on 11/12 April). Then it is northwards for the next three shows: Scalefour North (18/19 April), Blythe (not fully confirmed but I am expecting mid August) and finally Hull on (7/8 November).

Terry, what did you mean by "operating linkage"?

Re: A Highland Miscellany

Posted: Fri Jan 02, 2015 1:13 pm
by Mark Tatlow
Still catching up on the last few months activities, the last thing I was working on prior to Christmas was a batch of NER hoppers for Benfieldside. Having acquired the layout, Tim and Julian have very little stock to run on it, so as part of the repayment for the use of their facilities and expertise on my boards for Glenmutchkin, I thought I would help to correct this shortfall.

The origins of all of this present batch of hoppers all go back to the Slaters’ injection moulded kit, which is of diagram P7 wagon. There were around 17,500 of these wagons at the time of the grouping and the LNER carried on building them for some years thereafter with only subtle differences; so not unsurprisingly there were quite a lot of variants. Thus, I have been doing a lot of modifying!

In each case, I replaced the very clunky W irons with Bill Bedford replacements; even though these were to be to EM, I felt that they would improve their performance. The first examples were essentially built as the kit was intended with fairly traditional brake gear (which was to one side only). However, having built my first one, I decided to refine the brake gear by drawing an etch for replacement steps, V hangers, morton brake mechanisms and brake levers. This (along with a comparison with the plastic equivalent – the painted wagon), is below:

However, a significant proportion were modified with end levers that operated a crank that was connected to the Morton gear. At the ends, there was a much more chunky ratchet arrangement to retain the lever in position. Again, I drew this up on the etch, and the arrangement looks like this:

The NER undertook a number of experiments with these vehicles to attempt to reduce rolling resistance and this was the subject of my next modification. On the right (below), shows the provision of a second outside set of W irons. This was to add stiffening to the axles. There is a set of Bill Bedford W irons to cater for this, but I chose instead to create a fresh set on the etch. On the left is a further variant, where an anti-friction bearing was added in addition to the outer W irons. This was a wheel that ran on the top of the axle and I presume the idea was that as it rotated less, there would be less friction. I suspect that the introduction of an open bearing surface that would instantly get contaminated with coal and grot would actually have the exact opposite impact – as these were removed by the grouping era, I may well be right!

The final variation of construction that I have modelled was a slot cut into the ends, which appeared on some vehicles. The NER used these on vehicles that were hauled up rope inclines – of which they had many. A plank of wood was inserted into the hole and wedged such that it was secured behind the end posts to ensure that the haulage point was close to the centre of the wagon. They found without this that there was a tendency to pull the end posts loose due to the uneven point of pressure.

Next up will be the painting and lettering of these; where I have three eras to chose from that would have all been apparent immediately pre- first war, which is when Benfieldside will be set. More on this in a future post.

If there is a desire from anybody for the etches, I would be able to offer them; so drop me a note?

Re: A Highland Miscellany

Posted: Fri Jan 02, 2015 10:22 pm
by Terry Bendall
Mark Tatlow wrote:Terry, what did you mean by "operating linkage

What you did to make the signal arms move. I have made semaphore arms move but the mechanism that you have used looks a lot neater than what I have achieved.

Terry Bendall

Re: A Highland Miscellany

Posted: Sat Jan 03, 2015 1:17 am
by DougN
Mark, they look great. It was my intention to purchase a trains worth of these wagons last year at scalefourum. The challange at the moment is to get the kits as they are not available from cooper craft until his machine gets modified. I knew that C&L once had etches to do the brake gear and the end version. One day in the fullness of time I will get all these bits together and have a go myself. I for one would be interested in seeing the layout also!

Re: A Highland Miscellany

Posted: Sun Mar 22, 2015 4:42 pm
by Mark Tatlow
I took the weekend off the other week and attended the Spring Railway Modeller’s Weekend at Missenden. It is great to spend two full days just modelling away from the distractions of life and amongst people who are all doing exactly the same. I find it a form of therapy and it is well worth going if you have been thinking about it (and even if you haven’t!).

I took with me the etches that I have had delivered by PPD for the Scrap Tank; with a view to doing a test build using them. The origins of this class are some of the earliest locomotives built for the line; the Raigmore class. In an attempt to increase the life of these new enlarged boilers were fitted to them. Unfortunately for the Highland Railway the boilers were too heavy for their frames and consequently these cracked. This left the Highland with a number of new boilers, wheels and many fittings but no locomotives! Ever the frugal, they recycled these parts into a series of three shunting locomotives which were designed by Peter Drummond and these inevitably quickly picked up the name of Scrap Tanks.

These were rather brutish looking locomotives for the time, characterised by surprisingly large wheels for a shunting locomotive – something compelled on the Highland due to them reusing these from the Raigmore class which were mainline passenger locomotives with 5′ 3″ wheels. For those of you who don’t know what these looked like, this is what we are aiming at:

scrap tank.jpg
scrap tank.jpg (17.31 KiB) Viewed 6637 times

And this is what we are starting with:


Whilst this may (well has!) got me into some trouble, I have sought to design the kit to be easier to build than the average etched brass kit and certainly easier than the Falcon Brass kits that are the staple in 4mm for many of the Highland’s locomotives. I have sought to do this in a number of ways and the first area tackled, the cab front/interior, illustrates one of these; the use of fold up assemblies to assist not only in creating the shapes but also the laminations. Many of the modern etch designers are using these (especially the 2mm boys/girls) but I have sought to do rather more than most (which has made the preciseness of the design rather more challenging, more of which anon).

The bulk of this assembly starts as a single piece, that is folded up to form the cab floor, splasher sides and the bulk of the cab front. To assist the lamination process, jigs either side of the cab front have been used. Wire rods are slipped through the small holes in these to ensure that they are registered on top of each other properly.


The view below shows the laminations now sweated together and illustrates the square cut outs behind the cab front which are to enable glass/Perspex to be slotted in to represent the spectacle glazing. The view also shows the boiler backhead which is made from three layers of etch (not with a folding jig – yet!). I am pretty pleased with this as this is only 13 * 15mm in size, so the wheels on the backhead are only 2mm in diameter.


To be continued…………(soon too!).

Re: A Highland Miscellany

Posted: Sun Mar 22, 2015 6:37 pm
by jon price
I sat next to Mark at Missenden and watched the Scrap Tank grow. He seemed to be doing plenty of notes on alterations but the whole thing looked pretty excellent to me, including some clever integral assembly jigs on the etch. I look forward to seeing the final product.

Re: A Highland Miscellany

Posted: Sun Mar 22, 2015 11:22 pm
by Mark Tatlow
jon price wrote: He seemed to be doing plenty of notes on alterations.

Aghhh, but at least no one can point at the kit and say "well he obviously didn't do a test build!"

I did indeed do a lot of notes (and still am). Many of them are to correct things that are either all out wrong (everybody is going to have a chuckle when we get to the coupling rods!) or not quite as sweat as they could have been. However, a fair number of the notes were thoughts on how it could be made to assemble more easily; new little tweeks were occurring to me but this afternoon!

Both the design and the subsequent building have stimulated the grey cells no end!

PS; we are no longer sceptical glazing!

Re: A Highland Miscellany

Posted: Mon Mar 30, 2015 9:17 pm
by Mark Tatlow
The next stages of the test build were to do the footplate/tank sides/can exterior.

My initial design for the footplate is not particularly radical, but the test build has shown up that until the boiler is put in place (which comes some way into the build process) the front is somewhat delicate, irrespective of whether the footplate valences are fitted or not. Thus, in addition to the temporary stiffener that can be seen to the front of the footplate in the picture below, stiffeners will be provided to the front half of the footplates. The idea of these can be seen in the following view which shows the rear of the cab. By folding these over at 90o during the build, they give strength to the more delicate parts of components. Some will be incorporated into the finished article, others will simply be discarded when their job is done.


The two tanks, along with the sides to the cab/bunker, are conceived as a single piece (if you go back to my previous posting, you can see this in the flat in the etch). The two halves are separated by temporary spacers to both assist in locating them but also to give strength to the assembly prior to the fitting of the boiler which is where it will get its strength from. It was when I tackled this part, I reached the first disaster – the etchers had failed to half etch from behind so I was missing some fold lines. This was pretty frustrating as it entirely negated the intended efficiency of the design and even though I now have a corrected etch, I had to solder on by cutting the parts at the intended line of the half etch and soldering them together in the more traditional manner – exactly what my design was intended to avoid. As a result of this, there are no neat photos of the tanks being folded up and secured in place, we have to jump on a bit to see this.
_DSC0260 (2)compress.JPG

_DSC0261 (2)compress.JPG

The cab fronts that were constructed earlier were no slid into place and I was pleased to find that it all fitted very snugly and in exactly the correct location. I did find that I could put in a further pair of fold up tabs on the running plate that meant that it was essentially impossible to put this in the wrong location, so this is another little refinement that will make its way into the production batch.

The rear of the cab was a similar fold up unit to that to the front, which was pretty easy to build but did have one dimensional error at its base that needed cutting away – well that is the purpose of a test build! All of this, has been created from one piece in maybe three minutes!

And this is what it looks like with the cab rear in place. If you look carefully, a couple of 12 BA screws are just visible in the cut out to the rear of the cab – the purpose of these will become apparent in a future posting but it is another one of my little ideas to make this easier to build/better when built.
_DSC0262 (2)compress.JPG

And this is what the cab bow looks like from above, after the addition of the splasher tops and backs. One of the issues this illustrates is that this kit, as it stands, will only work for EM or P4 modellers. There is insufficient room to get the narrower gauge/wider wheel treads into the splashers.
_DSC0267 (2)compress.JPG

Next up will be the cab roof………….

Re: A Highland Miscellany

Posted: Fri Apr 03, 2015 7:01 pm
by Mark Tatlow
I have designed the cab roof and much of the cab interior to be a separate assembly, that can be secured by a series of screws. As can be seen below, there are two screws at the rear that locate into a tool box that sits on where the bunker projects into the rear of the cab. As the screws are somewhat lost in the bunker, I have come up with a little dodge where these are retained by an initial nut that traps them in place but still allows them to twist and thus engage in the cab roof assembly. The other screw comes through the top of the boiler, just inside the backhead.
Cab abovecompress.jpg

To connect the cab roof to the points of fixing, there is a front and rear section. The former includes the top of the boiler that is within the cab and the latter the toolbox within which the securing nuts are hidden. You can just rebate in the rear spectacle plate that will take the glazing material.
Cab below 1compress.jpg

The actual cab roof has a double skin, to aid its strength, include the lamp irons and also to assist with locating it on the cab. The outer skin includes the ribs that appear on the real roof, including a grove to allow brass wire to be used to form the seam to this. To the perimeter of this, there is a valance.
Cab above 1compress.jpg

And this is what it looks like on. I find that I just can’t make roofs sufficiently well to sit perfectly on the body and nothing shouts “its a model” more than gaps where there shouldn’t be any – be this under buildings, roofs or between parts that have to be joined to structurally stand up! This is my solution, which I have used on other builds that I have done but it is so much easier when it is designed in.
Cab 1compress.jpg

Cab rear 2compress.jpg

Re: A Highland Miscellany

Posted: Tue Apr 07, 2015 10:44 pm
by Mark Tatlow
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!
Chassis 6compress.JPG

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.
Chassis 3compress.JPG

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).

Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 12:00 am
by DougN
Mark that is looking fantastic. I have just completed a J72 chassis from Highlevel and it proved to me that you have to be able to drop the wheelsets out. as when it is all together it is a Nightmare to figure out if something has gone wrong.... The chassis finally gave in and is now runnning but I have to get a lathe to make new tighter coupling rod bearings as I opened out the holes too far. (any suggested fixes not using a lathe would be most helpful at the moment!)

So I think your fold up keeper plate is a brill idea and an easy build! :thumb

Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 7:32 am
by Mark Tatlow

A neat trick if you have opened out the crankpin holes too much is to get a hard brass washer of the appropriate size (I think this is 10BA but it might be 12BA). You may find that you need to open up your hole further to get it in and once it fits but is tight, insert and solder in place. You are likely to need two on top of each other two, to make up the full depth of the coupling rod. The "revised" hole is rather smaller and can thus be opened up to the right size.

This is also a trick that can be used on RTR coupling rods, as some of them have outsized crank-pin holes for your standard crankpins.

Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 9:53 am
by essdee
Hi Mark,

That is a lovely, neat and simple idea to combine keeper/springs and ashpan detail - nice one! Latterly I have been spending ages adding two 'hangers' and a 'stalk' to each of the salvaged springs which are (sometimes) provided on a chassis etch, so that the spring can be soldered into the slot on the underside of each (High Level) bearing. Invariably they need some tweaking before they all come level. So this method would save much labour in future! Other designers please note?

Following this thread with much interest....



Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 10:47 am
by Jol Wilkinson
essdee wrote:Hi Mark,

That is a lovely, neat and simple idea to combine keeper/springs and ashpan detail - nice one! Latterly I have been spending ages adding two 'hangers' and a 'stalk' to each of the salvaged springs which are (sometimes) provided on a chassis etch, so that the spring can be soldered into the slot on the underside of each (High Level) bearing. Invariably they need some tweaking before they all come level. So this method would save much labour in future! Other designers please note?

Following this thread with much interest....




the design approach adopted by Mark works very well but is limited to one 4mm gauge.

When designing a loco chassis for a 4mm kit which needs to cover OO, EM and P4 you need to adopt a more universal approach or design and produce three different sets of frames and keeper, thus putting up the cost/waste.


Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 11:14 am
by Philip Hall

Alan Gibson sells coupling rod conversion bushes which are intended to bush the oversize holes in RTR rods. Sometimes these are too small (nothing is standard in RTR!) and then I often use concentric brass tube. Of course turning up some small bushes is very nice but the tube is quicker. If you have accidentally opened up the holes too much, I would put hornblock alignment jigs into the chassis to ensure the remade holes in the rods actually match the chassis.


Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 11:16 am
by Mark Tatlow
A perfectly fair point from Jol and something I should have remembered to mention. I am doing (actually done but not yet built) a OO chassis for the same loco - it is a rigid chassis and does not have a separate keeper plate.

Because the genesis of this kit is that it is "for me" primarily, I am not that worried about wastage and I am doing the OO one because enough people in the Highland Railway Society have expressed a desire to make me feel that it should be done. I have a feeling that the EM boys will have to suffer the use of washers on the OO chassis or a bit of butchery - sorry to them, but it took an extra day to redesign what I had done for the OO chassis and I have a finite life!

Actually, the issues go much wider than just the chassis as the cab splashers needed a full redesign and degree of redesign was required on much of the rest of the chassis/front splashers to accomodate the OO version.

I would observe that one of the other things that I have learnt from doing this is that we owe a huge debt to the kit designers/kit manufacturers of our stuff - a lot of what we have to use is essentially a favour. This is a pretty esoteric prototype that not only never strayed off the Highland's system but with a few exceptions did not stray away from the Perth or Inverness yards. I reckon I will sell 5-6 in P4 tops and maybe twice that in 00 or three times if I am lucky. Not a great business model as I will get no contribution for my time in developing the kit unless anyone fancies paying £250 for an 0-6-0T kit?

Re: A Highland Miscellany

Posted: Wed Apr 08, 2015 12:19 pm
by essdee
Mark, Jol,

Yes indeed, a fair point about the P4/EM/00 spacer issue; and a neat semi-solution from Mark. I admit I was primarily thinking of P4/EM historical modellers, for the (extremely!) niche market which Mark's efforts are aimed at.

Looking at the wider market required for eg. LRM productions; Jol, is there any mileage in a single fold-up unit, dimensioned so that separate laminates for the spring/ashpan profile are added either inside the fold- up, for EM gauge, or outside it for P4? It would probably require the ashpan to be included on both the laminate layer and the fold-up part; the P4 or EM modeller would have to remove one or other as appropriate, along a half-etch line, strengthened by solder on the retained ashpan.

This would reduce the amount of wastage of unwanted material; the 00 modeller could be accommodated by providing half-etch cutting lines to reduce the width of the fold-up unit perhaps?

Just an idle thought......

Now back to an ancient kit from an un-named stable, and the similar problem of cab splasher widths, geared 'over-generous' for 00 only (as was the one-piece fold-up tender chassis, apparently designed for pin-point bearings?); build is to EM. Good news is, they are completely the wrong shape, so it's 'merely' a scratch-build exercise; saves so much time!