Andy's Modelmaking Misadventures

[Reynard]

If you make the long sections as an I-beam (an H turned round through 90 degrees effectively) then you should have fewer problems with sagging.

You might get away with glueing a web of, say, two thicknesses of card along the bottom edge (and perpendicular to it) in order to solve the banana issue without having to re-work anything.

 

[Andy in Germany]

If you make the long sections as an I-beam (an H turned round through 90 degrees effectively) then you should have fewer problems with sagging.

You might get away with glueing a web of, say, two thicknesses of card along the bottom edge (and perpendicular to it) in order to solve the banana issue without having to re-work anything.

The side is already a sideways U, but the next version will be an 'I' made with thicker materials. One suggestion was for a square section piece of brass along the lower section of the wagon: it'd be hidden in the I beam...

I can take the opportunity to redesign a few other bits of the wagon I wasn't entirely happy about...

 

[Andy in Germany]

Those look fabulous to me

Only thing that's missing is a guard's van and one of those railway lanterns with the red blinky light hanging off the back...

I missed this post.

Unfortunately German railways didn't go for brake vans; this is rather sad as that was my Grandad's job for almost the whole of his working life.

German railways preferred a small cabin for a brakesman on each wagon, in pre continuous brakes days and would spread operators along the train. Bearing in mind the gradients on German railways I can understand this, but it was a pretty rubbish system and was replaced by continuous brakes by the 1930's.

 

[Reynard]

The side is already a sideways U, but the next version will be an 'I' made with thicker materials. One suggestion was for a square section piece of brass along the lower section of the wagon: it'd be hidden in the I beam...

I can take the opportunity to redesign a few other bits of the wagon I wasn't entirely happy about...

If you are re-making it, don't make it a continuous section - put webs in at regular intervals. What this does, is effectively turn one long beam into several much shorter ones, which will drastically improve the stiffness.

 

[Andy in Germany]

If you are re-making it, don't make it a continuous section - put webs in at regular intervals. What this does, is effectively turn one long beam into several much shorter ones, which will drastically improve the stiffness.

What are "webs"?

Your description sounds a lot like the way I'd use small bits of wood when making a wider plank that won't twist as much.

 

[Reynard]

I missed this post.

Unfortunately German railways didn't go for brake vans; this is rather sad as that was my Grandad's job for almost the whole of his working life.

German railways preferred a small cabin for a brakesman on each wagon, in pre continuous brakes days and would spread operators along the train. Bearing in mind the gradients on German railways I can understand this, but it was a pretty rubbish system and was replaced by continuous brakes by the 1930's.

Ah, that's a shame...

Mind, they're as rare as hen's teeth on UK railways now too. When I first moved out here, they were a regular on many of the freight trains that passed by; the Ely-March-Peterborough line carries more freight than passenger traffic. Now it's just a red lantern on the back of the last waggon.

 

[Reynard]

What are "webs"?

Your description sounds a lot like the way I'd use small bits of wood when making a wider plank that won't twist as much.

Basically, what I mean is that they are sections perpendicular to the longitudinal axis of the beam. What they do is turn the beam into a cellular structure. And yes, it does improve performance under torsional loading as well as tension / compression.

 

[Andy in Germany]

Basically, what I mean is that they are sections perpendicular to the longitudinal axis of the beam. What they do is turn the beam into a cellular structure. And yes, it does improve performance under torsional loading as well as tension / compression.

@Reynard: you're talking to a non engineer here okay? I'm taking a run at the post above and hoping I understood about half of it and throwing a wild guess at the rest. Are you talking about a beam that would look a bit like this from above?

Notice high level enineeringy type drawing

 

[Reynard]

@Reynard: you're talking to a non engineer here okay? I'm taking a run at the post above and hoping I understood about half of it and throwing a wild guess at the rest. Are you talking about a beam that would look a bit like this from above?

View attachment 583625

Notice high level enineeringy type drawing

If it's going to be made from square box section, then pretty well much if that's sliced through the middle

Just think of it as loads of little boxes stuck end-to-end.

 

[Andy in Germany]

After some consultation here and elsewhere, I've made a badly executed sketch of version 2.0. Any suggestions welcome...

Is that the "webbing" you meant @Reynard?

 

[Reynard]

That looks promising @Andy in Germany

Although given how long those sections along the outside edges are, i.e. the well of the waggon, I would make your I-beam flanges thicker than 1mm. That's probably the root of the buckling (i.e. banana) problem. If it fubars the scale, then either a switch to box section should help, or maybe look at using stiffer card.

There is maths to work it out though.

 

[Andy in Germany]

A minor misadventure took place on the Ingermany workbench over the last month.

The desk lamp I've been using has been gradually dying: firstly it would switch off at random, then only work on "white" light, then when the cable was waggled about, and finally refused to turn on at all, even though the little light on the switch was fine. I tried to work with the main light in the room, but this is a cellar apartment and it was casting deep shadows, so a week ago I finally caved and ordered a pair of LED Desk lights, as I'd long had problems with shadows from only using one light source anyway.

Those came this week; all was well until I found one was flickering. I swapped USB/plug adaptors and found the other flickered.

On impulse I put the original lamp back into a different adaptor; it worked.

Now I feel a twit.

On the other hand, I have no more problems with shadows: in fact the model making bench is probably now visible from space.

The disadvantage if this is that the messiest part of the room is now the best illuminated...

 

[Andy in Germany]

In anticipation of actually having a layout soon, I finally bought something shiny:

By curious coincidence, the German toy manufacturer Siku makes diecasts almost exactly the right scale for the model I'm building.

This will now be weathered to within an inch of its life and possible even repainted.

 

[classic33]

In anticipation of actually having a layout soon, I finally bought something shiny:

View attachment 584508

By curious coincidence, the German toy manufacturer Siku makes diecasts almost exactly the right scale for the model I'm building.

This will now be weathered to within an inch of its life and possible even repainted.

HO narrow guage(ON30)?

Siku's range is well sized to most of the model railway scales. Including N guage narrow. Used to recommend them to people who were looking for a certain type of vehicle. They were often cheaper than ones from the main named UK manufacturers.

 

[Andy in Germany]

HO narrow guage(ON30)?

Siku's range is well sized to most of the model railway scales. Including N guage narrow. Used to recommend them to people who were looking for a certain type of vehicle. They were often cheaper than ones from the main named UK manufacturers.

1:55 scale Narrow Gauge. In this scale 16.5mm represents, metre gauge; roughly... If you squint.