Thursday, December 24, 2015
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 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.
Tuesday, December 22, 2015
Christmas Mystery Objects Quiz
I seem to spend a lot of time over the Christmas period doing quizzes of one form or another. This year the GCHQ one is worth a go if you happen to like your quiz questions on the fiendish side. Anyway I had a Shapeways delivery this morning that contained a couple of test pieces that I thought I'd turn into a mini mystery object quiz. So without further waffle what are these?
Sunday, December 20, 2015
Driven By Him
So here we are, the last post on the build of this the third Clayton prototype (the second never got made up but allowed me to test the keeper plate). The driver is now in place which means the whole loco now weighs in at 34g. Possibly a little light for an O14 loco but there isn't much space to add extra weight.
Obviously it's not entirely finished as it needs painting and the name and works plates fitting but these will be left to David as my painting skills aren't up to producing a loco that would fit in well with the quality of Rhyd. It seems strange packing it up to send it off to it's new home as I've never built a model for anyone else before. Hopefully David will enjoy it and if you see Rhyd at an exhibition you might even see the Clayton working the quarry tramway. For everyone else here is one final video of the loco in action.
Obviously it's not entirely finished as it needs painting and the name and works plates fitting but these will be left to David as my painting skills aren't up to producing a loco that would fit in well with the quality of Rhyd. It seems strange packing it up to send it off to it's new home as I've never built a model for anyone else before. Hopefully David will enjoy it and if you see Rhyd at an exhibition you might even see the Clayton working the quarry tramway. For everyone else here is one final video of the loco in action.
Starlight Express
One of the first comments I received when I announced I was working on a model of the Clayton was that the light mouldings really were crying out to be fitted with working lights, and who am I to refuse such a sensible suggestion. The problem is that while the mouldings are big in relation to the size of the model they still aren't very large. Fortunately LEDs are available that will fit but they are very very small.
The smallest surface mount components I've used before are the resistors in the Hudson-Hunslet, which come in a 1206 package. They are known as 1206 as that is the imperial measurements of the component, i.e. 0.126" by 0.063" or in metric just 3.2mm by 1.6mm. For the lights on this loco I've had to go for LEDs in a 0402 package which is 0.039" by 0.020" or an eye wateringly small 1.0mm by 0.5mm. Given that those dimensions are for the entire LED you can probably imagine just how small the two contacts are that you need to solder wires to. My eyesight for close work might be quite good and I have a brilliant magnifying lamp on my desk but I don't think I would have the patience or dexterity to wire these up. Fortunately you can buy them pre-wired on eBay! This helps but the wire itself (referred to as magnet wire) is also ridiculously thin so it's still a fun challenge wiring these up.
Of course there isn't just the LEDs to wire in, but a resistor to protect them from the full track voltage (2.2K Ohm in this case) and a capacitor to help reduce flickering all of which need to be connected together and then stuffed into the small space behind the motor.
As you can see there is quite a bit of stuff, even if some of those wires were trimmed back before I finished) to get into the body so there was a fair amount of careful stuffing involved. Once the body was on the result though is this.
I could probably have used a slightly bigger resistor to drop the brightness a little further but for a loco that originally worked in a long dark tunnel this seems okay, and a bigger value capacitor might have reduced the flickering a little further, but in general I'm really happy with the result.
The smallest surface mount components I've used before are the resistors in the Hudson-Hunslet, which come in a 1206 package. They are known as 1206 as that is the imperial measurements of the component, i.e. 0.126" by 0.063" or in metric just 3.2mm by 1.6mm. For the lights on this loco I've had to go for LEDs in a 0402 package which is 0.039" by 0.020" or an eye wateringly small 1.0mm by 0.5mm. Given that those dimensions are for the entire LED you can probably imagine just how small the two contacts are that you need to solder wires to. My eyesight for close work might be quite good and I have a brilliant magnifying lamp on my desk but I don't think I would have the patience or dexterity to wire these up. Fortunately you can buy them pre-wired on eBay! This helps but the wire itself (referred to as magnet wire) is also ridiculously thin so it's still a fun challenge wiring these up.
Of course there isn't just the LEDs to wire in, but a resistor to protect them from the full track voltage (2.2K Ohm in this case) and a capacitor to help reduce flickering all of which need to be connected together and then stuffed into the small space behind the motor.
As you can see there is quite a bit of stuff, even if some of those wires were trimmed back before I finished) to get into the body so there was a fair amount of careful stuffing involved. Once the body was on the result though is this.
I could probably have used a slightly bigger resistor to drop the brightness a little further but for a loco that originally worked in a long dark tunnel this seems okay, and a bigger value capacitor might have reduced the flickering a little further, but in general I'm really happy with the result.
Saturday, December 19, 2015
Powered Chassis Test
After a break of afew days due to visiting family I'm now back to building the Clayton loco and fortunately, given the little time remaining to post it on Monday, things seem to be going quite well, although the carpet monster did eat the small pulley although it then spat back two 1.5mm bearings! Anyway here is the current state of play.
The main job today is to fit and wire up the lights, and then I can add the final body details. Then tomorrow I need to finish the driver figure and to give the whole thing another good test run.
After a break of afew days due to visiting family I'm now back to building the Clayton loco and fortunately, given the little time remaining to post it on Monday, things seem to be going quite well, although the carpet monster did eat the small pulley although it then spat back two 1.5mm bearings! Anyway here is the current state of play.The main job today is to fit and wire up the lights, and then I can add the final body details. Then tomorrow I need to finish the driver figure and to give the whole thing another good test run.
Tuesday, December 15, 2015
A Tiny Worker (Bee or Ant)
As you probably all gathered I really enjoyed building the Blacketty Water bridge model for this years Dave Brewer Memorial Challenge. Being given a set of constraints and a time limit helped me to focus and build something I'm really proud of as well as learning a whole new bunch of skills. I was expecting the challenge for 2016 to be announced sometime early next year, given that this years challenge was announced at the end of February, so I was a bit surprised when the announcement came at the end of November. There will be a blog post about the new challenge at some point as I do have an idea for it, but this post is about another challenge that I'm going to enter that was announced on the same day.
In general I'm not a forum person, the one exception to this is Narrow Gauge Railway Modelling Online (usually just abbreviated as NGRM) where I'm now a frequent visitor and poster. In the past they have held modelling challenges and they have decided it is time for another one, specifically to scratch build a locomotive. There is a full description and set of rules on the forum (you have to be a member to read them I'm afraid), but the motivation is
I've never scratch built a loco before, and certainly never a chassis, but personally it wouldn't be a challenge if I didn't go all in at level 3! Having decided to enter though I had no idea quite what I was going to try and build but, not surprising given the locos I've been designing and building recently, I thought I'd look for something small and quirky.
Fortunately the UK has it's fair share of both small and quirky locos so I didn't have to look very hard to find something and here it is (photo from Wikipedia).
This is one of two locos (this one is Bee the other is Ant) that were built in 2004 for the Great Laxey Mine Railway on the Isle of Man. They are replicas of the original locos used at the mine which were unfortunately scrapped in the 1930s.
It should be clear from even just a quick glance at the photo, that this loco is both small and quirky. Having managed to find a set of drawings (thanks Rob) that appeared in the April 1991 issue of 009 News, I know just how small it is. According to the drawings it's just 4' 9" from rail to chimney top, but more interestingly the track gauge is just 19", which is really very narrow.
As yet I haven't decided what scale to build a model of this loco in. I had wondered about using a standard track gauge (9mm, 14mm, 16.5mm etc.) and then picking a scale to match, but if I want to be able to put the loco with any scenic stuff or figures etc. then using a standard scale and hand building track to match probably makes more sense. My current thinking is possibly to go up yet another scale from my usual modelling to 16mm to the foot scale, which will still give a tiny loco; just 76mm from rail to chimney top. I need to make a few more measurements before making a final decision though.
In general I'm not a forum person, the one exception to this is Narrow Gauge Railway Modelling Online (usually just abbreviated as NGRM) where I'm now a frequent visitor and poster. In the past they have held modelling challenges and they have decided it is time for another one, specifically to scratch build a locomotive. There is a full description and set of rules on the forum (you have to be a member to read them I'm afraid), but the motivation is
This challenge has been created to promote scratch building using various tools and materials. Over the years I have seen some very interesting locomotives scratch built using the very basic of hand tools in plastic, brass, and complete mix of other materials. You don't have to be a professional model maker to take part, all you need is patience and basic hand tools. Entrants are asked to respect the spirit of the competition when taking part.To try and interest as many people as possible there are three different levels:
- Level 1: scratch built body on a ready to run chassis.
- Level 2: scratch built body on a modified ready to run chassis (e.g. Farish 08 with added cylinders, valve gear etc.)
- Level 3: scratch built body and chassis.
I've never scratch built a loco before, and certainly never a chassis, but personally it wouldn't be a challenge if I didn't go all in at level 3! Having decided to enter though I had no idea quite what I was going to try and build but, not surprising given the locos I've been designing and building recently, I thought I'd look for something small and quirky.
Fortunately the UK has it's fair share of both small and quirky locos so I didn't have to look very hard to find something and here it is (photo from Wikipedia).
This is one of two locos (this one is Bee the other is Ant) that were built in 2004 for the Great Laxey Mine Railway on the Isle of Man. They are replicas of the original locos used at the mine which were unfortunately scrapped in the 1930s.
It should be clear from even just a quick glance at the photo, that this loco is both small and quirky. Having managed to find a set of drawings (thanks Rob) that appeared in the April 1991 issue of 009 News, I know just how small it is. According to the drawings it's just 4' 9" from rail to chimney top, but more interestingly the track gauge is just 19", which is really very narrow.
As yet I haven't decided what scale to build a model of this loco in. I had wondered about using a standard track gauge (9mm, 14mm, 16.5mm etc.) and then picking a scale to match, but if I want to be able to put the loco with any scenic stuff or figures etc. then using a standard scale and hand building track to match probably makes more sense. My current thinking is possibly to go up yet another scale from my usual modelling to 16mm to the foot scale, which will still give a tiny loco; just 76mm from rail to chimney top. I need to make a few more measurements before making a final decision though.
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