Aluminium / Styrene Baseboards

[islandbridgejct]

I've just built 2 baseboards as shown in the pictures below and would be interested in any comments people might have.

 

The basic construction is a clear styrene sheet, 1200x600 mm, braced with L section aluminium angle, 20mm, bolted on. The bolt holes are 6mm while the bolts are 5mm to allow for expansion. Cross bracing is also L section, 20mm, but is not attached to the lengthwise bracing. Essentially, the aluminium is there for rigidity and support, but the styrene is the main structural member.

 

Boards are bolted together using 5mm bolts through the holes in the cross members. The joining pieces were drilled and bolted together before bolting to the boards in order to ensure a level fit.

 

The boards will rest on aluminium U-section, 20mm, attached to a wooden cross-member leading to legs with kitchen unit screw adjustable bases at the bottom. These can be levelled and should then support the cross-members which will hold up the boards while the lenghwise sections hold everything rigid.

 

My reason for using this technique is to avoid problems with warping of timber - the timber we get here in the winter island is pretty awful stuff, with a high moisture content, and I wanted to avoid warping. I reckon that any layout that gets moved around is going to be exposed to differing moisture levels, so I wanted something which cannot warp. I think I've allowed enough for heat expansion, and the bolt-on technique allows me to remove a support if it gets bent and replace it with a new straight piece. I've drilled all the lengthwise pieces from a common template in the hope of being able to produce a new one that fits anywhere if required, though I'm afraid my subsequent drilling of the board will have introduced some errors.

 

The only aluminium boards I've seen on this forum are Torr Giffard's, and they're highly engineered. This is a much more rough and ready approach.

 

Has anyone else tried anything similar? Do ye think will it work? And are there any problems I've overlooked?

 

Thanks,

 

Alan

 

 

 

 

 

[trisonic]

That's a new one on me!

 

Best, Pete.

[Pete 75C]

I like this, again, never heard of styrene used as a baseboard surface!

I reckon you've got yourself a pretty light, rigid structure.

What would worry me is that after a quick "Google", there's a couple of people saying styrene will never warp and a couple of hundred saying "oh yes it does"...

[griffgriff]

...there's a couple of people saying styrene will never warp and a couple of hundred saying "oh yes it does"...

 ... that's 'Panto' plastic

[Pete 75C]

 ... that's 'Panto' plastic

 

I'm a bit slow today - I actually Googled to find out what panto plastic was... duh.

[islandbridgejct]

Thanks for the replies, guys. You've got me on the 'panto' plastic - I'm a bit slow most days.

 

The plastic sheet I'm using is for indoor glazing. It's about 6 or 7 mm thick and has been in the attic for 2 years without warping, so I hope I'm ok on that score.

 

It said it was styrene sheet, so I hope I'm not mis-describing it: it looks like what I always knew as 'perspex'.

 

I'm hoping to protect myself further from warping and to get more noise reduction by attaching the track to a floating sub-base of foam and cork, and attaching the foam to the board at a few points, no more, so that it can be removed if necessary. If that turns out to be too floaty, and allows the track to slip out of alignment at the baseboard joints, I'll have to think again.

 

If anyone has any more tips or warnings, please let me know.

 

Thanks,

 

 

 

Alan

[Black Sheep]

from experience, perspex does warp, although I've only ever known it happen to curve the entire sheet when it's stored on end or stored on a rack formed of two bars (dips between the support)

 

as you've got support along two directions you may be fine, I guess we'll have to wait and see.

[HLT 0109]

I should have thought it would be prone to cracking and chipping. Much greater care will be needed with drilling for droppers, point motors etc and a wayward soldering iron would do it no good at all. If you could make up the frame separately and make it rigid, wouldn't it be strong enough to resist warping if covered in traditional plywood? I can't however, suggest a DIY way to make an aluminium frame rigid.

 

Harold.

[Deev]

Very interesting - I wonder what its sound-deadening properties are like?

[Gruffalo]

The stuff looks like either clear PVC (in which case it has a slight blue tint) or Makralon (much clearer but with a slight brown tint on the edge). If Makralon, it is pretty robust but doesn't like localised heat so beware the soldering iron and even a very hot cup of coffee and may build up internal stresses if you drill it too hard. Clear PVC deforms more readily for the same thickness and gets more pliable as the temperature rises. You can "weld" the PVC version with a clean chisel bit in a fairly hot soldering iron.

I am a little concerned about the 20mm aluminium having sufficient strength to resist twisting moments. I would have chosen 50x50x3 or thicker. I have used cut-back 20x20x3 aluminium angle to support a deck when spanning over a track, but only as a spreader between more normal structural members (50 or 75x9 ply)so that I could get a clearance to run OO stock under the deck with the least possible gradient.

[islandbridgejct]

Thanks for the comments.

 

I didn't notice a blue tint or a brown tint, and I think it said it was styrene on the backing sheet (but I removed that and threw it away, so now I'm not sure.) There was certainly a warning about chipping if drilled - I drilled a 3mm pilot hole first and followed up with a 5mm or 6 mm one as appropriate.

 

The point about the soldering iron is one I'll have to watch out for.

 

I'm relying on the combination of plastic and aluminium, and bolts every 20 - 25 cm to give sufficient rigidity. I suppose if I need 50x50x3 I may be able to retrofit. As Black Sheep says, I guess I'll just have to wait and see.

 

Sound deadening is certainly an issue. I'm hoping to decouple the track sufficiently from the board, but am a bit concerned what the consequences of that will be.

 

I'm wondering how to work points. Manual levers with wire in tube could be run above board, but wouldn't work across board joints. Point motors would have to go underneath, which would pose problems for attaching to the board.

 

I'm working on the legs at the moment. I'll post again when I have more done.

 

Alan

[Hesperus]

Depending on your plan, could you get away with point motors mounted in buildings above the surface with rods between them and the points?

[Pete 75C]

If the styrene's 6-7mm thick you could attach point motors with small 5mm self tapping screws, having drilled a tiny pilot hole first.

[roger440]

I have pondered the use of Aluminium framing for some time, though a little larger with the sizes than yours. However, rather than styrene, i was thinking about the pink insulation board (there is thread on here somewhere about it) as the actual board.

[34theletterbetweenB&D]

Don't see why not. In my exploratory phase to see whether an indoor model railway was still fun, I quickly threw together a structure from aluminium sections (secondary double glazing frames) with chipboard panels as surfaces, all salvaged from the newly purchased house. Very rigid over much longer spans than I would attempt with timber, takes my 14 stone, deflects, and then bounces back unharmed when the load comes off. Every aluminium joint precison made-not with two self tappers. If I can be that careless and get a robust and reliable result then a design using ally framing is in with a good chance.

[islandbridgejct]

Thanks for those.

 

Lifeboat Man, I like the idea of the self-tapping screws with a sub-assembly for point motors, though for a test track I might just go for manual levers using heavy wire with flexible attachments along the lines suggested by Gormo on here. I've a fair deal of figuring out to do with live frogs and point building before I can move on to a layout.

 

Hesperus, I know point motors are mounted in buildings on Adavoyle, which is about as rock solid a P4 layout as exists, so no doubt it's a good idea. I don't know if I'll have many buildings on the test track. Mind you, as it's a test track, anything goes. I might try all options and see which I prefer.

 

I found a part of the backing, and it says the material is clear polystyrene.

 

In terms of progress since the last posting, I added 10mm bedroll to the surface, with 3mm cork on top. I lightly glued the foam at the corners and the cork along its length. That's my floating track base. I'm anticipating it'll be too much float, but I'll see how it goes.

 

 

 

Then I weighted it down to help the pva stick. With everything on top the deflection was about 5mm. On removing everything, deflection was down to 1mm which is probably acceptable, but I'll try to reduce it. I think some plastic washers and those bolts with the rubber insert to prevent themselves working loose may help, so I'll try them first.

 

 

 

Next step was to do the second board. So far I've just attached the foam and cut out holes where the nuts come through. This is to avoid bumps in the foam. The gaps are about 12 x 12mm, so the cork should cover them with no adverse effects on the track work.

 

[Photos for this are not uploading, so I may try to add them later.]

 

As the photos show, I'm not getting the foam sitting even on the baseboard, so I'll have to go back and look at this. Maybe spray mounting adhesive with bolts at the edges to keep everything firmly under tension.

 

But as Black Sheep said, I guess we'll have to wait and see.

 

Alan

 

Edit to add photos: