0 Members and 2 Guests are viewing this topic.
Although this is a very interesting thread, splined subroadbed is nothing new. There are all kinds of materials to make it from, and all of my subroadbed (except in yard and large industrial areas) is splined 1/4" & 1/8" Masonite cut into 1" splines.I've been doing this now going on 20 years and several of my model railroad cohorts here in Utah and elsewhere also utilize splined Masonite in both N and HO.Like DKS, I worry about the strength of Styrofoam splined subroadbed and the sag photos you've posted clearly indicate it's not very rigid (to say the least). Yup, it'd help to put something with more structural strength on the outsides and in the middle, but the Styrofoam is not really great as a structural element in anything designed to be stable....which is what model railroad subroadbed is supposed to be.Another help would be to increase the density of your risers. Some of the spans I'm looking at look waaaaaay too long. I'd be afraid that the splined roadbed over the years would start to sag on its own between some of your longer spans.My splined Masonite subroadbed, glued together with either yellow hot glue, or yellow carpenter's glue will support me (245 lbs), balancing with one foot in the middle of a 12" span. Deflection is about 1/16" to 3/32".It's been a while since I bought a 4X8 sheet of anything other than 2" Styrofoam, but I'm guessing that 1/8" tempered Masonite is comparable or less than an equivalent sheet of 1" foam price-wise, so...it might be cheaper than foam.One thing's for certain...it's a helluva lot stronger, and it also deadens engine and track noise more than any other material I've ever used for subroadbed.But....I'm a real proponent for building benchwork and subroadbed out of substantial materials, like plywood, premium pine, redwood, and Masonite...gluing and screwing everything together. You may not be.
IMHO, wood presents it's own share of issues. When I build my final dream layout this will be my method as well. This would work really well for splined modules too. Ever lighter materials will make transporting them easier and easier. The added rigidity of the strips puts it over the top.Frank, have you done any delamiation testing? If you put a drywall screw through the foam into the strips, it should never delaminate and would totally eliminate any clamping. The screws give the screw something to bite into (and one of the reasons I thought of using luaun).
I find this debate about wood vs foam to be completely pointless. The foam is very rigid in this application and clearly suitable as he has used it. Live and let live.
Lou, that hot wire "saw" is damn brilliant. Clamp a fence at a specific distance and you have a ripping tool. How quiclky can the foam pass through the wire?
John,it's not really fast as I have it set up,but I never really messed with different voltage,ETC,on the power supply.On 2' foam,it probably cuts 1 inch a second.I'm happy with it as is,though.Higher heat causes issues like short wire life.OAlso,I cut some complex shapes that require that I stop momentarily to readjust my grip,and a really hot wire puts out so much head,it kind of "drills a hole" where you stop....I do have a fence for it..It's 2 feet deep,so I can use it for a full 4X8 sheet if I want.I use a saw for big cuts,though.One cool thing about it.I map out my grades right in the sheets..I temporarily install the sheet,and glue down the grade.I remove the sheet,and the grade is there,free standing.I use a small hotwire to rough in the slope,then block sand it to the proper shape.Then,I reinstall the original sheet,and contour everything to the grade.I get perfect grades right in the middle of solid sheets..This one was in progress,it's about 2/3 as steep now..
Not to be the contrarian, but your weigh scale almost completely spans the distance between the two wooden supports. Thus it's not applying much pressure at all to the spline's weakest point--rather, it is bridging across it.
I think the foam is a great solution here and the lattice a nice addition. This approach is very good for those without the power tools to rip a lot of wood, just like HCD for those who can't or don't want to build a benchwork frame. Of course, we never hear nay saying or counter point about using HCD, which also flex when 40 pounds pushes down on them... Just saying.