What about the curves?

How did he handle the curves?   Did he make semi-diagonal cuts and cement the pieces together - or was the plastic soft enough to allow for some bending?

 The plastic was

The plastic was soft enough to allow for bending, both curves and grades.

I don't see an advantage over cookie-cutter or splines

I could see taking 1/1/4" PVC tubing and cutting it lengthwise in half...along its axis, inverting it, and screwing it to risers.  Then, roadbed placed on the upright cusps.  Curving would be natural and as good as splines, although I don't know how much you can bend a given PVC pipe cut in half. 

What I would worry about is noise....the tubing halves would be soundboxes under the roadbed.  It might be okay with cork, though...dunno.  But for all the time saved, I think splines or cookie cutter is fine.

-Crandell

Just to make it clear

Just to make it clear. The PVC pipe in the article was not cut at all. Just screwed to the riser. I don't know about the bending. I have the magazine somewhere. I think he wrote something about bending. I will see if I can find it. Is PVC pipes expensive compared to masonite splines?

Roadbed with PVC Pipe

you could use a heat gun to shape the pipe ?

Pvc pool pipe is cheap and more flexable! it could work.

I know of PVC pipe being used

I know of PVC pipe being used on Garden Railroads.  I've not heard of use indoors.

I have found the article.

I have found the article.

Can someone please tell me if I am allowed to publish the whole article here with pictures and text? 

Publishing articles here from elsewhere

Benny:

The general rule is if the article is freely available somewhere on the web, you ask the author/creator for permission to post his/her content elsewhere, and offer to link back to their site from the new location.

If they say yes, then you're free to post it here. If they say no, then there's your answer - but posting a link to it is generally always okay.

Lifting content from elsewhere on the web and posting it here is only okay if you get permission first, or if you own the content yourself.

Having said all this, there is also the concept of "fair use". Fair use says that if you want to quote an author or use a sample image, or use a short video clip elsewhere in your own work to illustrate a point - that's okay and you don't need to get permission first. But the "fair use" piece you use needs to be a tiny part of your overall work. If the topic of your work is the same as the piece you use, then it's generally considered that you're plagerizing and that's not fair use.

In other words, if your post is about benchwork and you use some material from elsewhere about benchwork, then that's plagerism and not fair use. If your post is about benchwork and you use a quote from an article out of Time magazine in your post to make a point, then that's fair use.

Also, always reference the work you took the piece from, and provide a link back to it on the web. If it's a hardcopy publication, it's automatically under copyright so you can quote a few lines of text to make a point under fair use, but that's all - and you must always reference the work when you do. You can't scan photos in an offline publication and post them without permission.

Bottom line, when in doubt, always get permission first.

I first read about this method in Model Railroader, May 1988

I first read about this method in Model Railroader, May 1988, page 88. The Author's name is M. J. Randall.

I had no layout at that time so I never tried it. I decided to try this method today to see if I like it or not. I will try to explain what I did.

I started with PVC pipe. My pipe is 16 mm in diameter because I could not find any smaller in my city, but the Author used 1/2 inch pipe (12,7 mm). I attacked 2 pipes like this. The distance between the pipes are 6 mm (I used a masonite piece) I did not take any photo of only the pipes but I'm sure you understand the first step.

It's very importent that you fasten the pipe at the bottom to get an even roadbed. Or else it can easely loose it's round shape. I cutted 45 mm long pieces of 6 mm thick masonite and glued it on top of the pipe with latex caulk.

This is what it looks like when the masonite pieces are glued.

Then I glued cork roadbed on top of the masonite pieces.

The result is a very smooth and strong roadbed. I tried to bend the 16 mm pipe to see what radius it can take. It's no problem to use a 32 inch radius. And I'm sure you can use smaller radius with the 1/2 inch pipe.

I think this method is very interesting. It was fast and easy to build. I already have another idea how to make this even better, but that's another story. Maybe I will write about that later...

But I can tell you right now that I will be using PVC pipe, masking tape and cement

Interesting idea.

Thats a nifty way of doing it.. a nice alternative to spline. I wonder if something like that would be possible with N where you would need much smaller pipe?

Chris

Cost?

Is PVC pipe that cheap? I haven't had to buy any in a very long time...

 Jeff,

Jeff,

I don't know what PVC pipes cost in the US. My 2 meter (2,56 foot) pipe here in Sweden costed around 2,5 USD. I calculated the cost compared to masonite splines and the pipe method is slightly cheaper in my case.

How do you attach it to risers?

Benny:

I can see how you put roadbed on the top ... how do you raise up the PVC roadbed and attach it to risers?

Also the benefit of not

Also the benefit of not having to rip it into strips.

Chris

Joe,

Joe,

Drill a 3-4 mm hole thru the top and bottom of the pipe. Then you drill the top hole a little larger then the screw head. Screw the pipe to the riser with regular drywall screws. Take a look at this picture and you will see the screw at the bottom of the pipe. It's very important that you don't screw it to the top because when you tighten the screw the pipe will loose it's circular shape making the roadbed uneven. That's why you must screw the pipe only at the bottom.

Is there any problem with vertical flexing?

Is there any problem with vertical flexing? I would be concerned that it does not have strength to resist pressure pushing up or down.

Chris

Pipe roadbed version 2

I have a real bad headache right now. I always get that when I'm very excited.

This is version 2 of the pipe roadbed method. 

I used masking tape on the underside of the pipes. Then I added cement between the pipes!!! You don't need to cut all these masonite pieces anymore. Just glue cork roadbed on top of the cement. The cement will not move at all because the round shape of the pipes will no allow it. My cement was not fresh so I got lumps in it. I will try to even out the surface by adding a thin layer of spackle. I think that will be very easy to do because you use the top of the pipes as a I support when you even out the spackle. I can asure you that this roadbed will not move in any direction. It must be the strongest roadbed ever... The only thing I need to do is to change the distance between the pipes. It must be a little more when you use cement between the pipes. But I used the same distance in this experiment. One more thing...

I showed this pipe method on trains.com forum and a guy suggested that the pipes can be used for track power. One cable inside each pipe. WOW, that's a great idea!!! No visible cables. 

Pipe roadbed and track power

My only concerns with running power through the pipe would be where the dowels are used to join the sections.  Also, modifications, repairs, and troubleshooting could be future issues if wires were run through the pipes.

I wonder if poly underground sprinkler pipe would work as well?  I bought 400 feet of it for about $50.

Join with pipe inside pipe

Maybe it's possible to join the pipes with smaller pipes. Then you can still use the pipes for track power.

Run wires in the pipes?

I can't imagine a better way to make access to the wires more difficult than to run them in a pipe.  One would need to cut  sizeable holes on the bottoms or sides of the pipes to give access to where the jumper wires connect the rails to the bus line.  This would be a bother to do and could seriously weaken the structure.

Also, cutting the pipes in half as one person suggested would be disaster on curves because the half-pipes would twist.

While pipes would make it easy to contruct transitional curves, the tightness of the radius is seriously limited by the flexibility of plastic pipe.

So far, I don't see any significant advantages that outweigh the disadvantages of using pipe.

This is intriguing

Hi Benny:

I had forgotten about this, but the idea is very interesting indeed.  I just checked the price of 1/2" PVC pipe at Lowes and it can be had for $1.37 for a 10' section.  3/4" is $1.57 for 10'.

How far apart are your supports for the pipe?  Have you experimented at all with different lengths between risers to see what sag is like?

I also wonder if the cement is even necessary between the pipes.  Using 3/4" pipe and mounting them directly next to each other gives (oddly enough) 3/4" from top surface to top surface.  That is about the same as HO track gauge.  Cork roadbed should fit over the pipe just fine.  I do not know the bendability of this pipe.  I would think it would depend on the purpose the pipe is built for.  If it is meant to carry water under pressure (as in a sprinkler system) it will have a thicker wall than pipe that merely drains water and is under little pressure, if my limited water engineering skills are correct.  The thinner the wall the easier to bend.

Hmmmmmmmm...you've got me wondering here.  Maybe I'll run over to Lowes tonight and see how flexible this stuff is.  Thanks for the thread, Benny.

PVC Pipe

Be careful with PVC pipethere are two types, Schedule 40 and Schedule 80, yup you guessed it Schedule 80 is stronger (thicker) and more expensive than Schedule 40.

http://www.harvel.com/piping-pvc.asp

You should have all the specs at this URL.

Bendability

So I hiked on over to Lowes tonight to have a look at the pipe.  First, a word about the Schedules as mentioned by Les above.  The Schedule 40 pipe did not bend at all.  This might be something to consider in an area where you need a dead level surface.  The other pipe I looked at did not have a schedule listing at all.  The 1/2" pipe was somewhat easier to bend (duh!) than the 3/4".  I bent the 3/4" to what seemed like about a 36" radius and it was under quite a bit of stress.  The 1/2" bent to about a 30" radius was under somewhat less stress, or so it seemed to me.  Are there any pipe experts out there who can tell us how much the various thicknesses of pipe will bend and how much their expected useful lives may be affected by being under this kind of stress?

Thanks, dudes (and/or dudettes).

More on pipe

I strolled back over to my friendly Lowes to have another look at the pipe.  What I had neglected to notice is that the 1/2" is the inside measurement.  The outside is right about 5/8" (.625"), or almost the same as HO track gauge (.649").  Thus it would seem to me that butting two pieces of 1/2" pipe directly next to each other would give you support almost directly under the rails.  I might grab me a couple of these ($2.77 per 10' length) and give them a try in my staging area.  I'll keep you posted.