Gavino200's Layout phase II - Modeling

[kvp]

For a straddle beam monorail mech, i would suggest using a Tomytec bus as a base for powering it. Not the steering part, just the back of the chassis with the motor, rear axle and control logic. The batteries on top could be hidden in another car if the height of the cassis is too much.

[cteno4]

Not sure if the bus would have the umph to move the monorail on the rail as I expect there is quite a bit of resistance around the rail. Rail is also pretty thin. Bus magnet control is useless if you need more than one mech on the train to move it.

 

jeff

[kvp]

2 hours ago, cteno4 said:

Not sure if the bus would have the umph to move the monorail on the rail as I expect there is quite a bit of resistance around the rail. Rail is also pretty thin. Bus magnet control is useless if you need more than one mech on the train to move it.

I would say 1 motor for every 2 cars. The beam is wide enough for the inner wheels to ride on. Magnet control should work if you connect one sensor to all drives. (just use shared batteries with common power rail between cars) Imho the non powered bogies should be equipped with freely rolling wheels with locked steering. The original is also using rubber wheels so this should work.

 

Btw. one great home made straddle monorail system i've seen used normal model railway powered bogies with the wheels turned around on the axles to have their flanges outside and added two metal strips on top of the plastic beam. For narrow beam designs, narrow gauge bogies should be used. (Z gauge ones for Nj scale cars in this case)

Edited December 2, 2017 by kvp

[gavino200]

Layout alteration 1 - Designated tramline

 

a) Remove tiny yard - It was too small to be much use or fun anyway. This also creates space for some diorama - probably a suburb or just more city. Final identity still undecided.

b) Sacrifice main yard line #6 to create a designated tram line. This would gradually decline from elevation to meet the old small stock yard line.

c) This would likely be a single tram line. It would likely either reverse or have a loop at each end.

 

I'm pretty happy with this change. 

 

 

 

 

[gavino200]

It might be nice to automate the tram line so that I could have three trams running. 

[Kiha66]

Since it would be a dedicated line, you could use tomix track and use a tomix tcs unit to easily automate it.  For three trams you could have two Double tracked stations at each end, and it your save you the expense of adding DCC to each tram.

http://www.1999.co.jp/eng/10040736

Edited December 2, 2017 by Kiha66

[gavino200]

I made a full-size mock-up of the left side to the layout. I'll need to make sure to get the tracks marked in exactly the right places. My plan is to build the raised city/tunnel on the mock-up and then transfer it to the layout. That way it won't interrupt train play and it'll be easier to work on.

 

[gavino200]

I went to my local art supply store and picked up a big sheet of 5mm and 3mm foamboard. Those are the only foam thickness they had. I looked at Hobbylobby too (though I hate to buy from them). They didn't have anything else either.

 

Where do y'all get your 1, 2, and 4 mm thick foamboard? Online? It's basically for filling holes and bringing buildings up to height, so I'm guessing small areas, suitable for shipping should be ok. Right?

[katoftw]

The art supply store should have 1mm thick styrene sheets.  If not, heaps on ebay.

[gavino200]

5 minutes ago, katoftw said:

The art supply store should have 1mm thick styrene sheets.  If not, heaps on ebay.

 

I didn't ask for (or look for) sytrene. Just foamboard. I was thinking they were the same. I'll go back tomorrow. 

[cteno4]

That's about it for foamcore here, 1/8" and 3/16". Foamcore is styrene foam core that's sandwiched between two layers of paper. You can also get ultraboard that's styrene faces and styrene foam core. Syntra is the same but all out of pvc.

 

fome cores don't like to bend much. Ultraboard is uber uber stiff. Syntra can bend quite a bit and will thermoform with hot water or heat gun.

 

Art supply places here and even craft stores here rarely sell any styrene sheet. This you usually get from hobby shops (usually evergreen or plastruct) and it can be expensive.

 

for sheet styrene find your local plastics supplier or sign shop, they will sell a 4'x8' sheets of 020 (0.5mm) for around $10 usually! They usually have several thicker sizes as well. 020 is easy to cut and very flexible.

 

Jeff

 

[gavino200]

22 hours ago, cteno4 said:

That's about it for foamcore here, 1/8" and 3/16". Foamcore is styrene foam core that's sandwiched between two layers of paper. You can also get ultraboard that's styrene faces and styrene foam core. Syntra is the same but all out of pvc.

 

fome cores don't like to bend much. Ultraboard is uber uber stiff. Syntra can bend quite a bit and will thermoform with hot water or heat gun.

 

Art supply places here and even craft stores here rarely sell any styrene sheet. This you usually get from hobby shops (usually evergreen or plastruct) and it can be expensive.

 

for sheet styrene find your local plastics supplier or sign shop, they will sell a 4'x8' sheets of 020 (0.5mm) for around $10 usually! They usually have several thicker sizes as well. 020 is easy to cut and very flexible.

 

Jeff

 

 

Thanks. I ordered some supplies last night. Coming from far away but should be here long before I need them.

[gavino200]

This is probably madness, but we've decided on a round tunnel profile.

General elements will be, concrete walls, cables running along the walls, dim lights and a walkway.

 

The Seikan tunnel would be a good example, but there are many.

 

https://commons.wikimedia.org/wiki/File:Seikan-tunnel-yoshioka.jpg

 

For a portal we're going for modern and concrete, either flat or rounded and tube-like like an ICE tunnel, maybe one of each.

 

https://www.japantimes.co.jp/news/2016/04/06/national/shinkansen-makes-emergency-stop-hokkaidos-subsea-tunnel/#.WiS4i0qnFVI

 

https://commons.wikimedia.org/wiki/File:Irlahuell_tunnel_south_portal.jpg

 

However, I also found this cool road tunnel portal. I'm interested in re-creating this for a train tunnel.

 

https://commons.wikimedia.org/wiki/File:Kanmon_Roadway_Tunnel_-_01.JPG

 

 

 

 

[cteno4]

Gavin,

 

mad totally mad! It will be challenging. Best is probably to carve the inside area of the tunnel out of foam and Then cast the tunnel wall around it. Probably need to split the cast in the top of the roof. You'll need to experiment some with mould release, process, etc. I expect using plaster cloth and some external strips of styrene embedded will make something not too heavy, but sturdy. It will be some work.

 

jeff

[gavino200]

16 minutes ago, cteno4 said:

Gavin,

 

mad totally mad! It will be challenging. Best is probably to carve the inside area of the tunnel out of foam and Then cast the tunnel wall around it. Probably need to split the cast in the top of the roof. You'll need to experiment some with mould release, process, etc. I expect using plaster cloth and some external strips of styrene embedded will make something not too heavy, but sturdy. It will be some work.

 

jeff

 

Wow, that's totally the opposite of what I was thinking. I'm not convinced it would be any easier for me to carve a "negative" image of the tunnel, than to just carve the tunnel out of a block of foam.

 

Here's what I was thinking.

 

Idea 1. 

Start with blocks of solid foam. Probably three. Sort of arranged in a C-shape to form the curve of the tunnel. Likely I'd make use more than three, but the fewer joints, the better

Draw the footprint of the tunnel on the bottom of the block (now considering only one section)

Carve down into the block using a coronal section template as a guide. I'd use geometry as much as possible and then freehand the rest. 

Smooth everything down.

For surface, either cladding with "concrete" textured plastic thermoplasticly molded to the surface, or just paint in concrete grey.

Then add detailing.

 

Idea 2.

Try to construct a hot foam cutter with a stiff wire shaped as the outline of the tunnel cross section.

Try to set this up on a track according to the Kato Unitrack path. 

Tunnel through the foam with the hot foam cutter to create the tunnel.

 

Idea two is far-fetched but worth researching. 

 

Idea 3.

While this is a complex sculpture, it's a fairly simple CAD design.

Find a free or cheep, easy to use, program that allows me to design a computer image of the tunnel interior.

Or find someone to do that if it's not ridiculously expensive.

Have the tunnel surface 3D printed.

 

 

Edited December 4, 2017 by gavino200

[cteno4]

Usually just easier to shape the negative space instead of trying to carve out the positive like this. You actually get to see how the shape looks easily that in the positive and add filer and sand shoot to just the perfect shape. Then casting is not really much then. If it's a constant radius curve you just need to do a section and then cast a few ones and join them.

 

You could carve out the positive crudely and then smooth with plaster to make even.

 

using a hoop hot wire cutter will be the easiest to carve out the positive. I doubt you can smoothly do it in one profile cut with a shaped wire that size. Get a wire cutter and experiment, they take some getting use to, but are handy to do this kind of carving. Do it outside!

 

jeff

Edited December 4, 2017 by cteno4

[gavino200]

Idea 4.

Make a tunnel profile outline out of metal, Sharpen the metal to make it into something like a cookie cutter.

Make a track for the cookie cutter that is the outline of the Kato unitrack. 

Place modeling clay or some kind of foam material in the path of the cookie cutter. 

Move the cutter around the curve to create a solid tunnel interior negative image.

Cast the negative image.

[gavino200]

2 minutes ago, cteno4 said:

Usually just easier to shape the negative space instead of trying to carve out the positive like this. 

 

You could carve out the positive crudely and then smooth with plaster to make even.

 

using a hoop hot wire cutter will be the easiest to carve out the positive. I doubt you can smoothly do it in one profile cut with a shaped wire that size. Get a wire cutter and experiment, they take some getting use to, but are handy to do this kind of carving. Do it outside!

 

jeff

 

What are your thoughts on idea 4?

[gavino200]

Ok. I agree. Carving the negative, then casting is the way to go.

 

1. Need to make an outline and rails. I think this is very doable.

2. Need to choose a material. This will take some research. 

 

3.If I were to make a negative out of modelling clay, I should be able to add texture to the surface. Perhaps I could use pre-made plastic "concrete texture/pattern" sheets to imprint onto the wet clay, so that the casted positive would have concrete texture.

[cteno4]

If you just cut a section of the negative c square you can then just start sanding round and have an outline template you just check it with as you go. If you sand too much then use some joint compound to fill and sand. Should be very quick to sand the section round. Could even do a fairly small section and just make more casts. Join them up and fill gaps with some filler.

 

btw if you can get expired cast stuff it makes excellent shells like this, really tough and light! 

 

Jeff

[cteno4]

Actually cement texture at 1/150 scale is basically rough matte acrylic paint! 

 

Clay can be pretty messy to use like this.

 

polystyene insulation foam board is perfect for this and used a lot in making scenery. Usually at the big box store or local builders supply in 1-2" thicknesses. Pink and blue usually (slightly different densities) and brand name formular but others as well. There is liquid nails cement to glue it together. 

 

Is the curve constant radius? If so then just use a yardstick compass to draw the diameter larger and smaller than your track needed. Then use a keyhole/compass Saw to roughly cut it out. Then use 60 grit sandpaper and or a rasp to do the rough rounding and then finer sandpapers. For final you can paint layer and sand smooth then coat in mould release and plaster.

 

easy to experiment and try. It's uber messy carving foam, so do it somewhere you can make a mess and have the shop vac handy as the bits get statically charged and stick to everything. Dust mask as well. But it's quick to do and easy to shape. Most of Las Vegas 3d bling is made like this!

 

cherrs

 

jeff

[gavino200]

Nice cross-section of the Seikan tunnel on this page. The rest is all greek to me.

 

 

http://mixanikosose.blogspot.co.uk/2015/06/blog-post_26.html

 

[cteno4]

Cool, make it a bit fat or make sure to check radius by drawing out on paper and running cars around it to make sure they don't scrape the walls as you will be using much tighter radiuses than the prototype.

 

btw one of the euro n scale does a flanged high speed tunnel entrance and inob did some casting of a Japanese one.

 

jeff

[gavino200]

5 minutes ago, cteno4 said:

Actually cement texture at 1/150 scale is basically rough matte acrylic paint! 

 

 

 

No, I don't mean cement texture. I mean the imprint of slabs of pre-made concrete.

 

Like this.

 

http://www.1999.co.jp/eng/image/10300495/20/1

 

Even though this is flat it could still be used to imprint a negative onto a curved surface, to give the final positive a "concrete" slab imprint.

[gavino200]

Just now, cteno4 said:

Cool, make it a bit fat or make sure to check radius by drawing out on paper and running cars around it to make sure they don't scrape the walls as you will be using much tighter radiuses than the prototype.

 

btw one of the euro n scale does a flanged high speed tunnel entrance and inob did some casting of a Japanese one.

 

jeff

 

Yes. I was thinking that. 

 

The first step will be to finish my layout section copy, and to make sure it's exactly accurate. I'll probably used a grid and compass, and lot's of checking. I ordered a few sections of super-el kato track so I can complete the mock-up. I only had one spare section of the right radius left. 

 

Then I'll run the Shinks and other long cars over it and mark the overhang. 

 

Then add a fudge factor to determine the tunnel width. I'll alter the Seikan geometry a little if I oversize the width. I don't want to add any extra height.