Saturday, 27 February 2021

Corrugations

It's always dangerous to think. One morning this week I got to thinking about Bowaters and the buildings that were made with corrugated materials. The various sheds were probably corrugated iron and that led me to thinking about how to model it. I quickly knocked up a corrugated sheet in Fusion 360 and set it printing.


The outcome was much better than I expected for a first print. The dimensions are all wrong but it told me that I could print these vertically with a nominal thickness of 0.25mm.

I then had to work out what were realistic dimensions. Matt reminded me of a corrugated iron thread on ngrm and that led me to a picture of a platform store which appeared to be made of sheets of iron that were 7 feet long and 2 feet wide with 9 corrugations across the width. The person who took the picture had so helpfully placed a 6 ft rod against the structure. The rod was painted alternately red and white every foot. I really must make one of those - so helpful.

I suspect that manufactures will have had set widths but different lengths so I drew up an 8x2 sheet. I also made it slightly thinner at 0.2mm and also created a run of 10 sheets with a 1 corrugation overlap. The problem I foresaw was that the thickness of the resin would probably make the overlap too obvious. Putting the overlap in at the print stage allowed me to manage the depth at that point.


Again, not too bad. The corrugations are still visible as are the overlap lines. The thickness is an issue though. They are too flimsy. I also decided the overlap was insufficiently pronounced. It was also short. The length should have been nearer 80mm to represent 10 8x2 sheets

This is where parametric modelling comes into its own. The first attempt was a pair of parallel arcs followed by a rectangle which was then repeated in the opposite direction. When I did the second attempt I made sure that all dimensions were dependent on previous dimensions. This meant I simply changed the thickness of the material once and I changed the dimension of the rectangle once and it all changed shape automatically.


Much better, though I overcooked it in the UV chamber and it started turning brown. I can see the more pronounced overlap. 

When the time comes I should be able to print off various sections, should I want to. In the meantime I've improved my skills which is often what this hobby is all about.

Friday, 19 February 2021

The longest project ever

 Looking back through my blog stream I see that I first posted about the Welshpool coaches in December 2019 and even then they had been on the bench for a while. At last I can report that there has been significant progress. It's still glacial progress but it is definitely progress.


All three have the main bodywork done. Readers with very long memories may recall these are Worsley Works scratch aid kits. They were built with the sides soldered to the floor and a variety of detailing parts added

  • wire and brass strip form the truss rods and queen posts
  • V hanger and my own 3D printed vacuum cylinder
  • finer rods and a frame around the top of the balconies
  • vacuum hoses from Alan Gibson
  • long Greenwich couplings from Tramfabriek
  • door handles and hinges from Roxey Mouldings
  • bogies from Liliput

Allen, at Worsley Works, has also produced internal partitions which are a great addition. The coaches have been sprayed with a bronze green and then a mixture of Humbrol paints have been used for the detailing.

The next stage is transfers and it was looking like having to cut out individual letters from different transfers in different scales but a chance encounter with Andrew Jeffcock of Custom Model Decals convinced me to get him to design a complete set for me and those are now on order and expected soon.

I'm now working on the roofs. More on those in the next post.

Thursday, 31 December 2020

Flying Tigers!

 


The next two coaches are going well. They are more complicated than the first coach since they are brake composites. This means that they have more internal partitions and also a guard's doors on each side. I'm adding more detail and this includes a door handle, 3 hinges and a grab rail. The holes were drilled first, 0.35 mm for the grab rail and door handle and 0.4 mm for the hinges. The grab rail is made up from 0.31 mm diameter nickel silver and the door handles came from Roxey Mouldings. The hinges are the same door handles thinned down a little and pushed home all the way. They are very tiny and hard work to file.

The V hanger was also from Roxey Mouldings and then the step was fabricated from 0.5mm brass wire and some etch sprue from the box. In theory tinning of components and careful placement should make it easy but reality says there are two or three attempts before getting it right.

By now you may be wondering why Flying Tigers. I was struggling to hold the carriage and I didn't want to put it on a flat surface  as that might squash the fittings on the bottom facing side. I hit on using these two wooden pallets to support the carriage. They are probably 1/12 scale and came from Flying Tiger, one of those shops that has all sorts of bits you never knew you needed. Hopefully it is clear from the picture how I am using them. I'm not sure if the pallets are still available as I have had mine for a while.

The real advantage is that they are hollow at the side so the application of a clamp and a piece of wood and the carriage is clamped to the pallet and held robustly without damaging any fittings. Hopefully this picture from the opposite direction shows how they have been utilized. Unfortunately the picture also shows where the paneling is marked but hopefully that will not be so obvious once painted.



 



Sunday, 27 December 2020

Painted Coaches

 


A little bit of progress just before Christmas. The coach has had it's first outing to the paint shop. The panels are sprayed with Bronze Green from a custom paint supplier, the chassis is the same grey I used on Triumph, the balconies were done with coal black, the window surrounds were done with rust and the interior was a mix of antique bronze and ochre.

There are no colour photos from the period so there is a certain level of guesswork along with doing what looks right. The rust could be a little more brown but overall I am happy with the look.

The roof is still in grey primer. I'll aim to darken it a little but colours of roofs after several years service were always indeterminate. What I am not happy with is the bend in the roof which the photograph has cruelly exposed. I've bent it back into shape a little but I am thinking it will be replaced. This roof was made from 5 thou brass sheet and I am wondering if the issue will be less pronounced if I use 10 thou sheet.

The other 2 coaches are on the bench so I suspect I'll do a batch of 3 roofs and see how they come out.





Sunday, 6 December 2020

Progress on the Welshpool Coaches

 


The Welshpool coaches have been on on the back burner for too long. It was time to make progress. The first action today was to complete the roof. I had previously cut the roof with a V at each end and had them rolled to the required radius. I had also cut out some inserts to go in the V. The trick was to hold the roof upside down against some double sided sellotape with the insert roughly placed and then tack a bit of solder to give a little strength and then tack a bit in the other corner. Working like this you can push the ends of the insert around quite a bit until happy with the rough position. After that I bend a bit of waste fret into the inside and soldered that in to provide a base for the join. Adding solder from above then fills the inevitable gap and it is out with the files to smooth it down and make the end shape. The rain strip is then soldered on from 0.31mm brass wire. It gets a little dicey towards the ends as you are in danger of undoing the work already done on the joins.

The fittings on the roof are my own 3D prints and they are superglued in place. The roof was cleaned under the tap with soapy water and then took a turn in the ultrasonic cleaner to remove any final residue.

The next task was to add the truss rods underneath. The undersides of wagons and coaches are always hard to see but I decided the posts for the truss rods were really transverse girders. They should be attached to the underside of the solebars but mine go onto the underside of the floor to provide more strength. After that it was simply a case of adding some 0.5mm wire for the truss rods themselves. A clean and a session in the ultrasonic cleaner and now everything is in the airing cupboard drying out and warming up ahead of priming.

Sunday, 22 November 2020

Sierra Leone No. 85

 


Another lockdown project has been completed. This time it is the Welshpool Sierra Leone No. 85 loco. I first referenced it in one of my October posts. It's been a relatively quick build because that's what I wanted after the length of time it took to complete Triumph. 

One of the ways to make it happen quickly was to adopt the plain black livery that the Welshpool & Llanfair adopted for the engine's last year of running in 2009. They put the engine back to it's original Sierra Leone livery and condition which meant reinstating the front coal bunkers and removing the Welshpool plates from the side of the cab panelling.

The engine is sat on my usual Dapol 2-6-2 Ivatt chassis which needed minimal bits cutting off. I made a few changes to the body. The coal bunkers which were just too chunky in whitemetal. The rear ones I fabricated from brass sheet and rod, the front ones are 3D prints I made. I fitted Greenwich couplings which necessitated some modification to the buffer beams. The air cylinder was a 3D print as the original suffered badly from mould lines where the two halves must have been badly aligned. The supplied tool box just didn't fit so that was another quick 3D print though a chunk of plasticard would have done just as well.

Lastly I made a fresh roof out of 10 thou brass. Having bought a set of G. W. Models bending rollers over lockdown I now wonder how I ever managed without them (actually I didn't, I have largely steered clear of brass till recently). I also modelled the open roof vent since every picture I have seen of this engine has it open. I am guessing that like many steam engines it is hot in the cab.

Overall the Dundas Models kit is excellent. For a whitemetal kit the parts are very crisp and fit together well. There was a slight discrepancy on the length of the side tanks but a bit of filler sorted that and I guessed, correctly as it turned out, that it would not be noticeable once painted.

Having done this one I am tempted to build a second one in the blue livery which it carried from 2003 to 2009. To me, the blue livery is much more attractive than the red North Staffordshire livery it carried from 1992 to 2003. The only problem is the lining which is much more complex than the one engine I have done so far.

That said, there are a lot of kits in the stash and it's time to finish the Welshpool coaches that have been in a semi built state for over a year now...

Monday, 2 November 2020

Photographing models

Recently I have found that I have struggled to take good photos of models. I would balance track on different boxes or mounting board but it was never a good experience. I can always use Melin Dolrhyd but the lighting isn't as far forward as it really needs to be for good photographs. I had a piece of track that originally was a DCC programming track set on something that could be fashioned into an embankment but it had no depth so something had to be done.

I found an offcut of MDF and started cutting out foamboard. I had an idea of a curve of track, set on an incline with a platform that could be used to host non track based products. The first picture shows the basic shape. A piece of wood is holding the stone walling join against the platform edge.


After that it was a case of laying track, putting some sandpaper down to represent the platform surface. Rummaging through the bits and pieces box I found some fencing from my first 009 layout and then I found a nameboard from the layout. I had to pause then as most work is done early morning and late night and I realised that static grass cannot be done in artificial light. It needs some natural, if grey, light to help with the colour blending. The second progress shows the progress after doing the grass.


After that it was onto the homeward stretch for a little bit of weathering and a hedge across the back to help with hiding the back. I also have a piece of backscene on a some floating mounting board that can go behind. The final picture is the finished product with Triumph on display with its nameplates that arrived from Narrow Planet recently.


All in all just a few hours work and now I have something readily available for photography.

Corrugations

It's always dangerous to think. One morning this week I got to thinking about Bowaters and the buildings that were made with corrugated ...