It's All Iain's Fault!

Yes this post is definitely all Iain's fault, but I don't mean that in a bad way.

As you all know I've recently been 3D printing lots of small narrow gauge wagons. In fact I'm now up to five different wagons: an 8ft freelance flat wagon, 3 bar slab wagon, an Aberllefenni Box Wagon, a 4 bar slab wagon, and most recently a Rhosydd rubbish wagon. These models have all been fun to design, print and assemble and Iain has kindly provided lots of useful prototype information for a number of them. I also have a couple of other wagons under development that are proving a little tricky to get right (mostly due to weird issues with the 3D printing process) but I thought I was slowly running out of scale drawings that would cause a distraction from building Canopus (I still haven't bitten the bullet and permanently attached the coupling rods). It was at this point Iain pointed me in the direction of Narrow Gauge and Industrial Railway Modelling Review (which I mentioned in the previous post). More importantly he pointed out that there were some very interesting scale drawings in the free sample magazine available from the website. A quick glance and not only had I subscribed to the magazine but I'd started work on yet another wagon model. So you see this model is definitely Iain's fault; thanks Iain!

Pages 33 to 41 of the magazine cover a multitude of wagons that were all used at Trevor Quarry on the Lleyn Peninsula in North Wales. Interestingly this was a granite quarry rather than the more common slate quarries found in North Wales. The specific wagon that caught me eye in the magazine was the rather odd, 3 sided, breaker wagon; the magazine has a photo and scale drawings on pages 35 to 37. While a 3 sided wagon might not have wide spread use it intrigued me enough that I set about designing a 3D print. I'll start by showing you the finished model and then explain how I got there.

The photo is of course a little misleading as this model is actually just 3.2cm long by 1.85cm wide and 1.35cm tall; in other words not very big at all. The relatively small size of the model also causes a few issues when designing it as some parts were too thin to be printed and some parts I decided might cause a problem when printed. This means that the model is actually a mix of 3D printed resin, brass sheet, and some standard copier paper.

The two problem areas that I identified when designing the model were the metal supports at the open side of the wagon, and the protective strip along the top edge of the side wall. These were problematic for different reasons and due to their shape required different solutions.

The two upright supports were a problem as I can't print parts that thin. The minimum wall thickness is 0.3mm but if I'd printed the parts I would have had to widen the wagon to make them fit and to keep the correct proportions. And of course the parts would have been very fragile and liable to break if knocked about. Fortunately the part isn't a particularly complex shape and so it was easy to cut and fold two small pieces of 0.12mm brass sheet to the required shape which could then be glued to the resin print.

The protective strip along the top of the side wall was a problem for a different reason. While I could have easily included this in the model, I've found that overhanging horizontal features, no matter how small, tend to cause other details to be obscured. This is due to the support material reacting with the printed resin. In this case it could easily have led to the side planks ending up with strange markings and would probably have completely obscured the gaps between the planks. My original intention had been to use brass sheet to add this part as well. Unfortunately, even with the hold-and-fold, I found it impossible to make the U shaped part. In the end I just made the part from 100gms copier paper which was then glued in place.

The final touch, before painting, was to add some rivet detail to the new parts which are simply Archer rivet transfers from sheet AR88025.

Painting was my now standard approach for aged wagons. The whole wagon is given a matt black undercoat. The wooden parts are then roughly painted with khaki (Model Color #988) and then a black wash. Drybrushing of khaki, brown sand (Model Color #876) and dark sand (Model Color #847) then follows, before another thin black wash and final drybrushing with dark sand. The metal parts were then painted black (to cover over paint from the wooden parts) and then dry brushed with London grey (Model Color #836) and dark rust (RailMatch #2405). A few wafts of matt varnish then tone down and seal the paints.

As with the other wagons I've printed recently I'll happily sell you one via Penistone Railway Works. I'm not sure there will be much interest given the rather odd nature of the wagon, but it's available if you want one, along with full instructions for adding the extra details.

Having built the breaker wagon I'm tempted to have a go at the mill wagon on page 38 of the sample issue as it appears to be pretty much the same wagon with some additional parts. Watch this apace!

How Many Rivets?

So having realized that there were some problems with the design of the brass upper for the Rhosydd slate quarry rubbish wagon I'm building, I reworked the template and had a second go. This time the template took into account the extra width added by the thickness of the metal when folded, as well as being re-worked to make it easier to fold. This second template works really well and I was able to easily cut out and fold the brass to shape. A small amount of superglue and the whole thing was assembled; from sheet brass to assembled model was about five minutes.

Given that I was happy with how this one had turned out I decided to add the rivets that are quite prominent on the prototype. Amazingly the Archer rivet transfers (sheet AR88025) I bought for detailing the Quarry Hunslet are a perfect match with exactly the right spacing. The only problem is just how many rivets there are to apply to such a small model. I think I added 26 strips totalling 238 rivets, which took the best part of two hours to apply. Time well spent though as I think the end result looks great. The next step will be to spray it with a red oxide primer to fix the rivets in place and to give a nice rust coloured base coat.

Quarry Hunslet: Now With Brass Knobs On!

So today's job was to fit the final detailing pieces to the locomotive; the handrails. I'd put this off as I had a feeling it might not be particularly easy to get all four handrail knobs in the right place so that the rails are both horizontal and at the same height on both sides of the saddle tank. I wasn't wrong as it's taken me a number of attempts to get it right.

I started by looking at a number of photographs and eventually spotted that the knobs were at the same height on the saddle tank as the rivets on the cab front. This made positioning the rear two knobs fairly easy. It also turned out that the 6mm masking tape I had to hand was a perfect fit between the bottom of the tank casting and the rivets. This meant, in theory, that I could lay a piece of tape along the length of the tank to get the right height for the front two knobs. After aligning the tape, I drilled the four holes and test fitted the knobs (these are the short handrail knobs from Eileen's Emporium) and brass wire for the rails themselves. The right hand side (as seen from the front) was pretty much spot on but the left side was terrible; somehow I'd ended up with the hole too far forward and too far down. I filled the hole with some Deluxe Materials Perfect Plastic Putty, waited for it to dry and then drilled a new hole in what I thought was a better spot. I'm not sure how, given how close the two holes were, but this time I was too far back and too far up. So the hole was filled again and then a third hole drilled. This one is much better, although not perfect, but by this point I was running out of casting to drill into so it will do.

I haven't glued the handrail knobs into place as it makes sense to do that after I've painted the tank, which also means I haven't finally trimmed the rails to the right length either, but the video should give you a pretty good sense of how it now looks.

As well as getting it to run further in each direction along the track (just for GB) the eagle eyed amongst you may notice that I've been at the Archer rivet transfers again. the whistle mounting bracket is now riveted to the cab front, if that isn't attention to detail then I don't know what is!

The only things now missing are the things I can't fit until it is painted; the reversing lever (which I can't fit until the cab is fixed in place), the whistle, and name and maker plates, which haven't yet arrived from Narrow Planet. This means the next step is to find a can of primer

Quarry Hunslet: Even More Riveting

Having added rivets to the door runners on the rear of the cab I decided I'd do something about the lack of rivets on the front buffer beam using the same approach; resin transfers from Archer.

Having looked at a few photos of both Dorothea (the prototype the kit is based on) and other locos in the same class there doesn't seem to be a common pattern to the rivet placement on the front buffer beam. Not only do the placements of the rivets vary between locos but they also appear to vary slightly over time on the same loco. Having said that in most cases there are rivets across the top of the buffer and at least one line of vertical rivets where the side frame attaches to the buffer, so I've used that as the basis for detailing the model.

Adding these rivets was a little more challenging than doing the door runners. The two sets of vertical rivets were easy as the parallel lines are part of the transfer sheet. The line across the top was a bit more tricky though as essentially I've used one rivet from eleven separate lines on the sheet. This means that there is no real gap between the rivets and the next in line so the piece I had to cut out was very very thin and fragile. In fact it took me three goes to get it right, which is a pity given how expensive the transfers are! I think it was well worth it though as it certainly adds more character to the front of the loco.

Quarry Hunslet: Riveting

As I pointed out in a recent post there was a slightly problem with fitting the rear cab doors. Essentially the cab wall had nice etched rivet detail that would be completely hidden by the door runners. I did contemplate fitting the doors to the inside of the cab instead, but not only would this not be prototypical I don't think it wuold have looked great either. The only solution then was to file off the etched rivets and add new rivets to the runners.

Given that the runners were made from etched brass it would have been possible to punch new rivet marks into the soft metal, but I decided that doing it well and getting the spacing right might be difficult. Fortunately in the comments on another post the possibility of using resin transfers to add rivets had been raised, and Paul had even recommended a particular transfer sheet. So I ordered Archer's resin transfer sheet number A88025 from their main UK stockist, DCC Supplies, and set about adding the doors.

As you can see this was a three step process. First I had to file off the original rivets to enable the door runner to fit flush against the wall. In the photo you can still see the rivets, but I couldn't feel them and took the decision that was good enough as I didn't want to risk filing away too much material. The next step was to glue the doors and runners in place. In the end one of the doors is on a bit of an angle, but they were fiddly enough to fit as it was so I decided to leave it as it adds character. The final step was to add the new rivets.

The rivets are resin on a transfer film and are applied in the same way as any other transfer; get it wet and slide it off the backing paper and in to place. The only difference to normal transfers is that you apply them before painting rather than after. While it's a shame I had to file off the etched rivets I think the result looks pretty good.