ikcdab

At the moment my focus is on the viaduct. The span is about 1.5m with a depth of about 200mm. Originally I had planned for this to be a standard brick arched viaduct of which there are numerous real life examples. I erected some plywood piers with the intention of covering with brick paper. This idea morphed into a girder bridge on brick piers and I spent a lot of time designing and then 3d printing the girders. This again gave me issues as the 3d printing warped and I found it difficult to get nice, straight girders. That was a long story and changing the type of resin in the printer helped hugely - but I was not 100% convinced I had the right look for the bridge. One of my issues was that I had laid a 6mm plywood track base and traditional sleepered track, whereas what I really wanted was the unballasted "baulk road" effect you see on girder bridges. I had also made the wooden piers too narrow and i needed to add extension pieces to widen it. All in all, I was not happy. Then a friend visited and threw another massive spanner into the works saying that I had too many piers... So yet another rethink. This is the (rather embarrasing) current situation with the abortive 3d printed girders (all now scrap!), the ply track bed and the ply piers. My new (and final answer) to this is to rip the whole viaduct section out and replace it with a structure based on Little Petherick Creek bridge on the North Cornwall LIne. Many pictures here. I had amazing help from fellow RMWeb members who sent me drawings and pictures of the bridge. A lot of hours later I have drawn the structure in Fusion360 and i am now ready to start printing. Although based on the original bridge, that was single track and my bridge will be double line and my piers are much taller. But it will resemble the original. here are the piers drawn up and ready to go. I will have a trial print tomorrow and see how it goes. Luckily I only need two sets - each one is going to take 13 hours to print! I am still looking for pictures and details of the bridge if anyone else can help! Ian

Its been a long time since I did any updates, but we have not been idle. Since January we have been concentrating on scenics. I had been reluctant to do this, I am not sure why, but my daughter firced me to start and we have not looked back. Now i have sat down ti write this, I realise I have not taken many suitable pictures, but here is one looking round the sweep of the lines to Charlton Bridge Junction. More soon

So I guess the canal engineers had an even more difficult job. They had to build an exactly level line and the maps 100 years before the railways were built were even more Spartan.

i really struiggled with my 3d printer when i first got it - a elegoo saturn. I had failure after failure. after much heart rending and almost throwing the thing out of the window, I can now get reliable prints every time. My learning points are: 1. use decent resin. I started with water-washable which was rubbish. Now i am using standard resin, things have massively improved. 2. as said above, make sure things are warm. I heat the room to 20C before printing, and switch the machine on 15mins before i use it. 3. shake the resin bottle or stir whats in the vat. 4. make sure the build plate is exactly level. Take your time, this is critical. 5. check the settings in the slicer software. Mine came with chitubox and the default settings were not appropriate. I had to joggle the exposure time, lift speed and dwell time to get reliable results. 6. supports are critical. i always use "medium" in chitubox as i found that "light" snapped. go through the model layer by layer in the slicer and check the supports are adequate in chitubox. There are various check models you can download to test the settings. 7. accept that it is not "plug and play". it takes loads of fiddling to get it working right. 8. make sure the models are washed very well. I saw no need for a washer and i use a plastic tub and a soft brush to clean the pieces. I find it very effective. Do it very well as any residual liquid resin will result in stickiness. i sometimes think that the UV curers are quite aggressive. If the weather is at all decent I prefer to lay out my models in the conservatory and let the sun do the job, turning from time to time. Its imprecise, but sun-cured do seem to be less brittle than those cured under UV lights. perserve, as once its working well, its brilliant.

to be honest i think it looks brilliant. I can't wait. I am frustrated by those who criticise the most trivial items - "the widgets along the top are at slightly the wrong angle and this means i cannot buy the model" - yet are content to run their trains on totally underscale train set track, use budgie grit as ballast or have cavernous gaps between corridor connections. All modelling is a compromise between accuracy and the cost of production and i think this model captures the look and feel of the original excellently.

One of my current jobs on the West Somerset Railway is to write a short souvenir guide celebrating our 150th anniversary. In doing so, it has occured to me to wonder how lines were laid out before modern surveying techniques were established. For example, in the early 1830s when Brunel stood somewhere on the outskirts of London contemplating which route to Bristol, how did he know which way to set off? Maps were then fairly spartan then and didnt show any contours, just form lines. He might set off in one direction then find himself at the foot of steep hills or with unacceptable gradients - so have to turn around and try another route. When he laid out the WSR he mostly followed small streams which i guess he knew where they ran, but even then he managed to find the lowest crossing point between the Quantocks and the Brendons. I just don't know how they got that "helicopter" view you need in order to make sure you have the best and most efficinet route between two towns. Any insights on how our victorian forefathers determined the route of railways?

There is no single resource for that. You have to dig around and see whats available. To be honest, for a modenr station, the easiest thing is to go there ane measure it up. You can alslo generally estimate dimensions good enough for our purposes from photographs. you can get a reasonable idea of the overall footprint by measuring on google earth. Bearing in mind how recent Newton station is, I would start by looking at the local authority planning permission website and see if plans were submitted for that (do railways need to get planning permission for station rebuilds?) or try and track down to contractor or designer?

looks perfect! thanks. now to find more details about it. Ian

The three big ones seem to be: Fox transfers Railtec Cambridge custom transfers. they all have large ranges - happy browsing!

stl files are scaleless and easily resized from oo to ho. I usually do this in the slicing software. scale factor will be 114%

yes of course, but i don't know how to do it. I guess you could use a reed switch or infra red sensor of some sort fairly easily. However, even on my fairly lengthy continuous run, the gates would be constantly on the move. What is more important to me is a section that is dead when the gates are across the line such that the trains stop and don't crash into them. I have the facility to do this, I just havent implemented it yet.

I don't know this model at all, but you should be able to determine where the problem lies. If the motor turns but the wheels do not, then there are only three options: 1. the worm is loose on the motor shaft. so you would see a static worm when the motor is turning. I think this is the least likely, but the easiest to fix. Loctite would fix it. 2. the worm is not meshing with the axle gear - you would see the worm turning, but not the axle gear. this happens is the motor mount has come loose or is broken. If you push down on the motor then the worm would engage. Or the teeth on the axle gear may have stripped. 3. the axle gear is loose on ther axle - you would see the gear turning but not the wheel. have a look and see which it is.

here is a better diagram that I have just found.....

Hi Tim, does the attached photo help. My gates are also the MSE whitemetal ones and I also attached brass rod to the gate and through a tube in the baseboard. Though i think my brass rod was probably 1mm or 1.5mm. I then made the brass fittings seen in the pic. I epoxied a piece of brass tube into the recess in the top of the servo horn. The rod from the gate simply slides into that brass tube. The collar at the top is there so that i could drill and tap for a grub screw to hold the gate rod. It needed a bit of space to accommodate the fitting, hence i made the servo mounts which you can see. Here is a better pic and below is a diagram. Hope that helps. I'm not sure where you are, but if you're passing through Taunton, pop in and have a look. Ian

I did think the same as you, that scratchbuilding was beyond me. I tried some scalescenes kits and then it was a natural step to create my own "kits" using scalescenes materials. The freedom it gives you to design exactly what you want is immeasurable. Try it and see how it goes.

This is how I did it. Just four servos connected directly though the baseboard to the gates. You don't need cranks. All connected to a merg servo4 board. Programmed to give me bounce too. If you would like some of the servo mounts, I am happy to send you some foc. Ian

What type of switch do you use? This maybe grannies and eggs, but this setup only requires momentary input. Once the point has thrown, the current needs to be switched off. Constant current will cook the motor.

If you have a multimeter then you can test the continuity through the solenoids. You should get the same result through each one. You don't say what your initial wiring error was, but these things are fairly robust and unless you applied a sustained high voltage, you are unlikely to have damaged it. The other option is to swap in a spare motor and see if that works.

As was the case on the Minehead branch. When Whittaker automatic token changing was installed, the distants became worked. A cleared distant then not meant a clear line through the loop, but also that the automatic token changing was in use so speeds of up to 40mph were allowed.

Ive never had much success 3d printing fine things such as hand rails. they need to be added from wire! I will add holes for them as per the prototype pics

thanks for the photos. I have amended my 3d drawing - see below. Of anyone wants any of these 3d printed, just let me know. Ian

Looks good. How did you do the foliage?

If you put the transfers directly onto the factory finish, then that should be smooth enough to stick. The issue comes with putting them on hand applied matt paint which can be rough. But it also depends on how you wetted them, too much water and the glue washes away. Anyway, you will probably know by now if the transfers are going to peel off. Then as to sealing. I guess the answer is to try something and try and match the finish of the loco. If it's a satin finish, then try satin varnish. I generally find that the factory finish is too shiny and I need to use Matt varnish over the whole loco anyway. Especially if you have applied any kind of weathering. However, if you do need to spray the whole loco, then yes, mask off glazing. Little bits of post-it note work quite well, or just hold a bit of paper a small distance away as you spray, you don't want a hard line, so a bit of feathering is good. And as to which sprays to use. Definitely go for a modelling spray. Normal household or hobby sprays chuck out far too much varnish and give you too thick a coat. Modelling sprays (army painter is one) tend to be finer. Hope that helps.

If you want truly reliable running, then don't rely on rail joiners for continuity. I guess it's more difficult with setrack, but having a feed for each piece of track is the way to go.

I've just run out of my WWS layering spray. And it's £12 to £14 for a replacement. Lots of talk on here about using hairspray instead. So whats the best hairspray to look for? I guess "extra hold" sounds good, but a lot of these boast " no stickiness" which seems the opposite of what we need. I'm tempted to go into B&M and just buy the cheapest, which I guess will be sticky.... Any suggestions?