Hi Guys
I am planning to build some L-Girder benchwork. Am I correct in assuming that the joists are attached to the L-Girders from underneath. This seems rather awkward. Is this how you guys do it? I’m thinking of having some brackets made so I can screw them in from the top.
Thanks, Tom
The whole point is that everything is done from the bottom so if you want to change things, you don’t have to go ripping up scenery to uncover that screw that got covered up because it was driven from the top.
–Randy
The whole idea of L girder is versatility. Screwing thing in from the top eliminates that. Even with open grid, all of my benchwork disassembles from the bottom.
If you are so sure of your plan that you will never, ever, ever, change your mind or have to adjust a single thing, then go ahead and screw it all in from the top.
Thanks for the replies guys, but I’m not sure I see your point.
If I’m far enough along that subroadbed, track and scenery are in place, and I want to change something, I figure I’m pretty well jacked anyway. If I need to move a joist or it is in the way, then out comes the sawsall and I would screw a new one in from underneath.
To build new benchwork, with maybe 50 joists to install, it just seems like a pain to do that on the floor all hunched over.
Hi Dingy: In L girder construction, the joists are attached to the L with a screw at each end. Then, risers are attached to the joist with a cleat at the top to hold up the base for track, scenery, etc. To make a change, to make room for a switch machine, for example, all you have to do is remove the 2 screws from the joist and the screws from the cleats, move it to the new location, install 2 screws back into the joists and the screws into the cleats. Very flexible.
Welcome to “why I’m not a huge fan of L-girders in the first place” I didn’t mention that in the first post because my lack of enthusiasm for l-girders does not answer your question.
–Randy
Nothing says you have to make it versitile. If you want to screw it down from the top and glue every joint, go for it.
I AM a huge fan of L-girder construction, because I find it simple as well as versatile. The ability to move joists (or remove them completely if they aren’t supporting anything) is only one facet. However, if joists are to be moved or removed without arclighting* the finished, sceniced surface of the layout, the fasteners must be accessible from below.
Another, seldom mentioned aspect of L-girder construction is that joists can be made of ANYTHING: finish lumber, 1/2 of a wide board that split down the (approximate) middle, odd sizes, even scrap 2x4 left over from a remodeling project. Since all the subgrade is (supposed to be) supported on risers, the exact height and top condition of joists is non-critical.
Do I practice what I preach? My layout is framed with steel studs: C works like L girders, steel joists of 2 different heights, steel risers - all screwed in vertically upward or sideways. While my joists are on 16 inch centers, there is one 32 inch span - everything that crosses it is either in steel stud troughs or on 1" pine boards, so there was no need for the joist originally installed there, That 60" length of steel 2x3 was recycled into risers for use elsewhere.
Chuck (Modeling Central Japan in September, 1964 - on steel stud benchwork)
You’re right, working on the floor upside down is the pits.
The point of L Girder is not changing the girders after the layout is done - that’s a messy job. The point is that it can be built without precise carpentry, requires few tools, goes together relatively easily, and is flexible in being able to run girders at different angles and lengths as well as adjust them when constructing the subroadbed. You can also add some more during scenery construction if needed.
The down sides include not very portable (if at all) and less usable room under the layout.
Personally, I never use it. I use the underside of my layout for a work bench, test track, storage, and my easy chair. So I want as much headroom as possible. But then I have a radial arm saw that makes building bench work easy.
Enjoy
Paul
Do you have any photos of your layout (benchwork) under construction? I’m always interested in alternative methods.
I’m debating with myself over using L-girder of open grid. I have come to find out what open grid is, but all this L-girder talk is making me rethink my knowledge on such. My thinking was an L-girder was just as it sounds and described as in, one piece of lumber is set verticle, and another piece of lumber is set on the narrow edge in a horizontal matter. But here’s where my thinking differs from what was said so far. Is the subroad and such mounted to another frame which is then mounted to the L-girder? Because my thinking was an L-girder frame, with the plywood attached to the that, and the pink foam glued to the plywood. I want to go with the lightest possible construction technique as I am bulding a…oh how to describe this. A self-sustaining shelf layout. It will be narrow like a shelf layout, say 18 inches deep, but it will have it’s own legs attached.
If L-girder is made the new way I’m thinking, with actaul layout made on one frame and that frame attached to L-girder, L-girder seems to be kind of a waste when you can get the same effect done (access to the underside of the subroad bed) with open grid. I am also contemplating a waffle style bench work like the one featured in an MR issue a few months back, but that seems like it would be expensive with buying all the sheets of luan, some plywood, the dimensional lumber, glue, saw for cutting and clamps. I’m also trying to do this on the lower budget of things. Make it cheap to build but use quality parts is my motto I guess.
Well, I guess I’m a little confused. If you screw the joist to the L-girder from the bottom, you’re drilling through the 3/4 inch thickness of the L-girder flange with your pilot hole. If you attach the joist from the top, then you need to have your pilot hole, and probably a counterbore, penetrate the width of the 1X3 or 1X4 joist. I’m not sure how I see that this is exactly easier.
I did see that you mentioned making some support brackets to hold the joists, but this sort of defeats one of the (alledged) benefits of L-girder construction, which is less wood used to perform a task.
I’m also confused by the hunched over on the floor comment. Most of the time I’ve seen L-girder used, the girders are assembled and supported on the legs. Then the joists are positioned and the assembler is sort of under the structure drilling upward. No reason why the pilot holes can’t be drilled down from the top while in a standing position, and only the screws inserted from the bottom.
Finally, you made the comment about being far enough along with the railroad to the point where track and scenery are in place. Most of us are building the support structure long before any of that is in place. And unless you have a very accurate plan as to where everything is going to go, I’d venture to bet that there will be a lot of things that don’t end up exactly where you thought they’d be, or the track alignment will be better if moved slightly. So, is it easier to remove one screw from the bottom to move one end of a joist an inch to accommodate a switch machine, or use the saws-all to remove the joist completely?
Some of L-girder’s chief strengths are that it goes up amazingly fast and very little precision is needed in the cutting of the wood. When I’ve worked on L-girder layouts in the past, the ability to shift joists around at some point after their intial installation has been helpful and I’ve been glad the screws were driven from the bottom. Chief drawbacks are the added depth and relative difficulty in transporting completed sections of the layout vs. open grid.
Linn Westcott suggested “build bridges, not tables” when referring to benchwork, and L-girder certainly qualifies.
For most mid-sized and larger layouts, a mix of open grid, L-girder, shelf brackets, etc., etc. will be useful at different locations. IMHO, more time and energy is completely wasted on the topic of “what kind of benchwork?” than nearly any other in the hobby. Multiple approaches work, and there are few situations that completely rule out one or another.
Byron
Model RR Blog
If you are building a shelf or a flat top (foam or plywood) layout, the only real benefits to L girder construction is the lack of need for precision carpentry and the ability to move joists easily to install switch machines or similar (assumes you attach plywood to joists with cleats). Risers and cleats are used with both open grid and L girder so that scenery can easily drop below track level. Flat tops directly on the grid or joists limit
L girder excels when the benchwork has a flowing shape, when the fascia will be flowing curves iether to match the shape of the track or to bulge out for various scenic or design effects. It is also excellent at accomodating deep releif in the scenery and grades to the track work.
It is not designed for thin crossection benchwork or ultralight benchwork.
Hmm…well I’m pretty convinced there are more benefits to screwing them from the bottom than I thought. Still not looking forward to that part of it though. Maybe I’ll try to do as much pre-drilling as I can.
Thanks for your help.
I like using the L-girder or T-girder configuration for my bench work. It is the flexibility of the system that is appealing. You can make adjustments pretty easily without a big to-do about it. On the layout that I’m building with my Dad, we used plywood ripped down to make our T-girders. With the ply, they turn out remarkably strong. Here is a link to another forum that I show some pix of the girders we made, and the beginnings of the bench work.
http://www.modelrailroadforums.com/forum/showthread.php?t=4961&page=2
I hope this helps you in your building process.
Thanks YourOwnGod,
I’ve seen that thread before and I really like how you packed alot of railroad into a medium sized space without making it look too overcrowded. In your experience do you think it would be a bad idea to mount the joists to the L-Girders from above using some kind of sheet metal angle bracket?
Thanks again, Tom
L-Girder provides a very strong and ridgid foundation for your layout. other methods would consume more building materials (wood) to achieve the same strength. wood will warp over time for various reasons. L-Girder technique is designed to prevent this from happening and you will be happy in the long run with a solid foundation years down the road. model railroads weigh more than you might think. strong & sturdy foundation is a must.
a house is only as good as its foundation. same with your model railroad. the technique may seem odd at first, but you will enjoy the benefits once you get it going.
With all the hundreds of things you have to get under the layout to do (wiring, switch linkages, attaching roadbed to the risers, etc), what is the big deal about screwing in the joists from the bottom? If you had a 10 x 20 room with around the walls layout with 16’ OC joists, you would only be securing about 40 joists, that’s only 80 screws. Heck, if you start from one end you could lean over from the top and screw them up into the bottom without crawling under the layout. Seems like a lot of obsessing over a pretty minor thing I’ve handlaid about 1/3 of my layout 12x23 layout and I’ve gone through about 5000 spikes and about 3 boxes of various drywall screws on the benchwork. Driving 6 dozen screws for joists out of the several hundred I’ve driven in from the bottom doesn’t seem like such a big deal (two for every switch, 4 to 10 for every joint in the roadbed, one to four for every riser with 2-3 risers per joist) . Its an awful lot of worrying about a job that shouldn’t take you more than two or three hours at the most.