Rail Cutting Jigs

So having given you a few days to think about the mystery 3D printed objects I'll put you all out of your misery. They are jigs to help cut rail at the correct angle for making Hudson Type 1 and Type 2 points in O14. While I have the KBscale jigs for actually soldering the rails together they rely on you cutting or filing the rail ends to either 15 or 9 degrees and I found doing this accurately was a bit of a nightmare and so a jig or two sounded like a good option.

The printed jigs are actually the third iteration of the basic idea which was to trap the rail in such a way that a razor saw could cut it at the given angle. The first attempt, which I've unfortunately thrown away so can't show you, used four pieces of 4mm square section styrene stuck to flat sheet, two on each side of the rail. The pieces on each side were offset so that you ran the saw across the rail resting it against the ends of the blocks. It worked well enough to produce the first crossing I made but it wasn't easy to hold the rail still while pushing the saw against the blocks.

The second jig used 12BA nuts and bolts to both clamp the rail and to help position the saw. The screw holes being carefully positioned so that they both allowed the nuts to grip the web of the rail, but also to act as the guide for the saw. While this was much better at keeping the rail in place it was still difficult to keep the saw in place against the upright screws, there was a danger of sawing into the nuts, and the cheesehead screws meant that the jig wasn't very stable on the worktop. It did, however, allow me to build two Type 2 point without requiring any extra filing of the rail ends.

The printed versions continue the idea but without relying on the screws to guide the saw. The two printed parts are used to clamp the rail in combination with grooves in both halves. The slightly bendy nature of the strong and flexible plastic is actually really useful here as it allows you to really tighten the jig so that the rail doesn't move at all. The saw then fits within in the guide formed between the top part and the block on the bottom half making it much easier to cut the rail.

I haven't had a chance to build a point using the new jigs but I have cut a couple of rails to check that they work and they appear to work very nicely which should make it easy to churn out more crossings in the future.

The Makings of a Point

I've really enjoyed working in O14 building the Clayton loco, but if I want somewhere to run the loco that isn't a simple straight bit of track I'm going to need to build some points. When I was at ExpoNG I picked up both the Type 1 and Type 2 crossing jigs from KBscale in preparation for this but it took until this weekend to find time to have a go. Even with a jig to help hold all the parts it's still quite tricky (or maybe I just haven't had enough practice). The first problem is finding a reliable way of cutting/filing the ends of the rails at 15 degrees. In the end I built a small jig from styrene which seems to do the job but it feels like there should be an easier way. Once all the rails have been cut and fitted to the jig the problems don't end. Because the jog is metal it's impossible to get enough heat into the join with my soldering iron as it just soaks into the jig instead. The trick is to use the kitchen blow torch (usually used for creme brulee) to pump in lots of heat.

Once it's cooled and cleaned up it looks as if it will do the job nicely. Unfortunately I then cut the rails back but measured badly so they are too short for the type 1 turnout I was trying to build. Not to worry though as the practice was well worthwhile. Unfortunately I seem to be almost out of the PECO IL-115 rail so will have to order some more before I can have another go. Also looking at the instructions I'm not sure I like the suggestions for hinging the switch rails (a wire down through the sleeper). I'm wondering if I can just do without a hinge and rely on the slight flex of the rail, but that experiment will have to wait until I get some more rail.

Reinventing the Wheel

A recurring problem when modelling in OO9 is wheels. There are actually two problems. Firstly there are only a few different sizes of wheels available which limits the locomotives and wagons you can accurately model. Even if you are lucky enough to find wheels of the right size the second problem is likely to bite in that they will be of the wrong design. Fortunately many of the available wheels are actually metal tyres around plastic centres, and so as an experiment I've had a go at producing an alternative design by 3D printing replacement centres. I actually started this a while back but managed to misplace the printed parts.

To make life as complicated as possible I've tried to produce some wheels that could take crank pins for modelling inside frame locomotives. Specifically I've produced centres for a Deutz diesel locomotives.

My best guess (from that photo and some other drawings) was that the Parkside Dundas 5.1mm wagon wheels where the closest size wise but having seven curly spokes would usually rule them out. Fortunately, like many other wheels, the plastic centres push out. Some careful measuring with a set of digital callipers allowed me to determine the main dimensions of the centre which I could then use to design a Deutz style replacement. Probably more by luck than design the centres are a perfect fit inside the tyres and are a tight push fit to the original axle -- I've painted the centres red as the FUD prints are difficult to photograph.

Unfortunately I designed the centres to take a 16BA screw as the crank pin only to find I'm actually out of stock so I haven't been able to test that aspect. The plan though would be to fit a screw into the centre and then cut the head off, slide the coupling rod on, and then use a 16BA nut to hold everything in place. Alternatively you could slide the coupling rod onto a screw and screw it into the wheel so the screw head holds it in place. You'd then cut the screw flush with the back of the wheel and file the screw head flat. Either should work, but I'll have to wait until I get some 16BA screws before I know for certain.

One other interesting thing I've discovered is that the Parkside Dundas wheels, and hence my replacement centres, use the same diameter axle as the O14 axles available from KBscale. This is great as it means that you could replace the axle and model outside frames with flycranks. Usually you can't replace the axles as each manufacturer uses a slightly different size so this is very useful. Of course if I'm designing my own plastic centres then I could design them to fit any diameter axle.

For a simple experiment it shows promise although until I take the next step and build at least a rolling chassis I won't know for certain how well it will work.

Dual Gauge Track

While most of my modelling recently has been focused on my entry for the Dave Brewer challenge in October I've not forgotten about the Clayton battery locomotive.

Mostly I've been writing a long list of all the small issues I've found with the current design now I've got the first prototype print in my hands. It's turning into quite a long list, but fortunately most of them can be solved on the current print with a little bit of thought, which allows me to test the changes before ordering another print. Before I can assemble and test the locomotive though I need some track to run it on.

If you remember I'm building this model in O14, 7mm to the foot scale running on 14mm track to represent 2 foot gauge track, as the loco is too small to model in my usual scale of OO9. The problem is I've never modelled in O14 so I didn't have any 14mm track. Fortunately I'd planned in advance for this and ordered some roller gauges from KBscale. Given that I'm short on desk space I decided to produce a test track that would let me test both O14 and OO9 (O9 and Gnine as well if I wanted to branch out) models, so I now have a 60cm dual gauge test track.

Round and Round She Goes, and Where She Stops Nobody Knows

The last time you saw any work on my new layout there was just a new paper track template. Things have moved on quite a bit since then.

Firstly I spent quite a lot of time at the mind numbing task of cutting and then filing a groove into the 90 sleepers required for the layout. I used the same jig as before to help measure and cut the sleepers which definitely makes the job easier although it's still rather boring. The sleepers were then all attached to the template using double sided sticky tape. That is the easy part, next up is the rails.

Obviously the rails needed to be curved into shape before I could try soldering them to the sleepers. Curving them as I went would just have ended in disaster. Now I don't know of anyone who sells a rail bender for OO9 gauge but I bought one from KBscale designed for use with a slightly large rail (their market is 7mm scale modelling). This consists of three sets of washers bolted to a plate. Sliding the rail between the washers introduces a curve into the rail while keeping it flat and not allowing it to twist. I used the tightest setting and it worked perfectly. In fact it produced rails with a curve slightly tighter than I needed.

With the rail nicely curved I soldered on the outside rail first using the template to guide the positioning. I needed two pieces of rail to complete the circle so there are two gaps, one is a nice flush join, the other is a little wider than I would like, but I've now filled it with some solder and filed it back and it seems okay. With the outer rail in place I then soldered the inner rail in place using the excellent rail gauges Paul turned for me. Again two pieces of rail were needed to make the circle but I made a better job of the joints.

Of course having two rails at roughly the right distance apart doesn't mean they will work as track. The only way to know for certain is to add a locomotive and some electricity and see what happens...

I thought I might have to adjust a few tight spots but I couldn't spot any obvious problems so it looks like the track is done (structurally at least, it still needs painting etc.). The video was taken before I filled the over large gap in the outside rail which is what you can hear as the loco passes through the left side of the circle. With the gap filled in the noise is a lot less obvious.

While I was really happy with the short test track, given it was my first attempt at building track, I'm really impressed with how this has come out. I always assumed I'd just be buying track when I built a new layout so I owe a huge thanks to Paul for providing the gauges and everyone who has provided suggestions, advice, and encouragement!