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L-Girder Question

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L-Girder Question
Posted by donhalshanks on Thursday, August 18, 2005 9:21 PM
What should determine the joist lumber size between 1x3 and 1x4. Seems to me 1x4 is a little overkill, but I seem to see about an equal division in references I read. Just starting bench work, and appreciate the help.

Hal
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Posted by dehusman on Thursday, August 18, 2005 11:59 PM
What determined the size for me was the lumber yard sold 1x4's and not 1x3's.

Dave H.

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Posted by tutaenui on Friday, August 19, 2005 3:30 AM
The larger the size of the joist the greater the span between legs.I have 4x1 joists on my layout and a 8ft spacing between legs. I can walk on the layout with no apparent deflection or sag.
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Posted by Anonymous on Friday, August 19, 2005 6:03 AM
Availability of lumber is the primary determining factor. 1 x 4 seems to be readily available and is thus the size of choice even though the inherent strength of the L girder is over kill for the weight of our layouts. Lynn Westcott needs an attaboy for its introduction to our hobby .
Will
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Posted by Anonymous on Friday, August 19, 2005 6:12 AM
I am not sure what a L- girder is ?[:(]
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Posted by Anonymous on Friday, August 19, 2005 7:32 AM
L-girder is a type of open benchwork construction that gives a bit more flexibility than the traditional open grid work type. Basically, it consists of a 1x3 or 1x4 mounted vertically, with a 1x2 secured to one narrow side of the 1x4 horizontally, making an L-shape. Two L-girders are usually spaced anywhere from 2 - 4' apart, and have legs somewhere near each end (6 - 8' apart, as mentioned above), making a very stable and strong base for the rest of the benchwork. The spacing depends, of course, on how big you want that base to be.

Once the L-girder frame is in place, you use 1x2s mounted on the narrow edge perpendicular to the L-girders as the support for the risers that actually hold the sub-roadbed, scenery base, etc. Again, spacing of the supports depends on the type of sub-roadbed you're using, but 18" - 2' apart is common.

Kalmbach has a great book called something like "Model Railroad Benchwork Made Easy" (can't find my copy right now, so I'm not sure of the exact title [:)]) that goes into great detail on the various types of benchwork systems, and gives step-by-step instructions on building them. Worth the money!
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Posted by Anonymous on Friday, August 19, 2005 7:53 AM
[banghead] I guess that I don't get it[:(], It seems to me that your spending more time and money to make the l girder than a 2x4 would cost. what would the advantage be ? lighter weight? May be it would be helpful if I could see a picture of one some where.
ennout
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Posted by andrechapelon on Friday, August 19, 2005 8:14 AM
QUOTE: Originally posted by ennout

[banghead] I guess that I don't get it[:(], It seems to me that your spending more time and money to make the l girder than a 2x4 would cost. what would the advantage be ? lighter weight? May be it would be helpful if I could see a picture of one some where.
ennout


Try looking at the illustrations here: http://rail.felgall.com/lg.htm

And here : http://kahnawake.pass.free.fr/support_l_girder_angl.html

And here: http://members.fortunecity.com/gknowles1/layout/dl/dl.htm

Hope this helps

Andre
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Posted by claycts on Friday, August 19, 2005 8:43 AM
QUOTE: Originally posted by jsalemi

L-girder is a type of open benchwork construction that gives a bit more flexibility than the traditional open grid work type. Basically, it consists of a 1x3 or 1x4 mounted vertically, with a 1x2 secured to one narrow side of the 1x4 horizontally, making an L-shape. Two L-girders are usually spaced anywhere from 2 - 4' apart, and have legs somewhere near each end (6 - 8' apart, as mentioned above), making a very stable and strong base for the rest of the benchwork. The spacing depends, of course, on how big you want that base to be.


The construction of the "L" girder is correct but I would recommend the method from the Book Basic Benchwork, (Title is close) to GLue and Screw the 1x2 to the top of the 1 x4. Also, the 1x2 as the joist is to light, you can not screw to it when putting in a riser with that said using a 1x3 as the joist will give you enough wood to screw to fro your riser. If you are unaware these are NOMINAL sizes for wood actual for a 1x2 is 1/2 x 1 1/2, so you can see that as a joist the 1 1/2 is leg you couls onlt get in 1 screw for a riser which makes a pivot point. not good unless you want it to fold down.
This is my $.02, I am using this method for a 22ft by 18 ft layout now.
Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by TomDiehl on Friday, August 19, 2005 9:57 AM
QUOTE: Originally posted by ennout

[banghead] I guess that I don't get it[:(], It seems to me that your spending more time and money to make the l girder than a 2x4 would cost. what would the advantage be ? lighter weight? May be it would be helpful if I could see a picture of one some where.
ennout


The weight is less for an L-girder, but that's not the main advantage. The big one is the flexibility of construction and ease of modification. If the framework were built of 2x4's in place of the L-girder, you'd have the difficulty of attaching either the cross pieces or the track risers. The cross piece is screwed to the L-girder up through the top plate, into the bottom of the cross piece. If a cross piece needs to be moved (ie. switch machine location, scenery elements, etc), it's a simple matter of pulling out the screws and moving it. One point that may not have been clear, glue the parts of the L-girder together, but NOT the cross members or risers. These should only be screwed into place for the reasons stated above. Wallboard and deck screws, and cordless drills with some torque are newer than the L-girder idea, so these have made it much easier to build.
Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown
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Posted by Anonymous on Friday, August 19, 2005 10:18 AM
QUOTE: Originally posted by claycts

Also, the 1x2 as the joist is to light, you can not screw to it when putting in a riser with that said using a 1x3 as the joist will give you enough wood to screw to fro your riser.


I'm using 1x2 joists and 1x2 risers, and have no problems getting two 1 1/4" drywall screws through the riser to the joist. I just use a countersink drill to place the screw holes on a slight diagonal, and they hold fine -- the risers are solid.

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Posted by donhalshanks on Friday, August 19, 2005 10:38 AM
Really thanks for the fast replies to my question. I just checked at my home store and sure enough, the inventory of 1x3 is not great & the quality is poor to worse, but 1x4 are plentiful with good chance to get some straight ones. I'm going with the 1x4s for my joists.
Hal
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Posted by jkeaton on Friday, August 19, 2005 1:21 PM
In Linn Westcott's excellent book " How to Build Model Railroad Benchwork", there's a table telling you how long a span each size of L-girder (1x3, 1x4, 1x6, etc.) will work without excessive flexing or deflection. An excellent book, everybody should have a copy of the updated edition.

Jim
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Posted by IRONROOSTER on Friday, August 19, 2005 1:45 PM
I find 1x3's usually are precurved for your next boat project. 1x4's are usually straighter, though you sometimes have to search throught the whole bin to find the straight ones.

If you have access to a band saw, table saw or radial arm saw you can cut 1x6's down to 1x3's. That may or may not save you money over buying 1x4's.
Enjoy
Paul
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Posted by sansouci on Friday, August 19, 2005 2:13 PM
The other benefit of the L-Girder method is that cheap 2x3 and 2x4 tend to warp as they dry out (and kiln-dried lumber is expensive) while the built up L-girder, if glued should not warp.
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Posted by Anonymous on Friday, August 19, 2005 2:24 PM
For size, I think 1x4's would do the job. I made a portable layout, using 1x4's for the frame, and I found that they were very heavy, and I think 1x3's would have been better. So, I'd say 1x4 for your L-Girder would be a good, sturdy size.
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Posted by davekelly on Friday, August 19, 2005 4:12 PM
How 'bout making the L girders out of plywood? Sure beats the heck out of searching through the lumber bins, although 3/4 inch ply can be quite heavy!!
If you ain't having fun, you're not doing it right and if you are having fun, don't let anyone tell you you're doing it wrong.
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Posted by claycts on Friday, August 19, 2005 4:29 PM
QUOTE: Originally posted by jsalemi

QUOTE: Originally posted by claycts

Also, the 1x2 as the joist is to light, you can not screw to it when putting in a riser with that said using a 1x3 as the joist will give you enough wood to screw to fro your riser.


I'm using 1x2 joists and 1x2 risers, and have no problems getting two 1 1/4" drywall screws through the riser to the joist. I just use a countersink drill to place the screw holes on a slight diagonal, and they hold fine -- the risers are solid.



Neat, I will try taht in the log area, it is not framed yet.
See live and learn.
Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by ham99 on Friday, August 19, 2005 6:14 PM
I used 1x4 ash [hardwood similar to oak] for my L-girders. Ripped them into two 1x2 strips for 2 3/4 x 2 L-girders. Hardwood is more expensive, but it is straight, dry, and strong. And it doesn't take a truckload to build a layout. Then I used construction grade lumber for the crossbars, legs, and braces.
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Posted by ARTHILL on Friday, August 19, 2005 6:48 PM
I used 2x4s and used a pocket hole drill on the crossmembers so I could fasten the crossmembers from the top. It was faster and easier. Scewing up through the L girder into the crossmembers is hard. The strengnth issue is no longer there is you use foam instead of 100lbs of plaster.
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Posted by jkeaton on Tuesday, August 23, 2005 9:16 AM
What's a "pocket hole drill"? I'm trying to imagine you drilling a hole the long way down through a 1x3 crossmember, but I'm sure that's not what you mean, ARTHILL.

Jim
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Posted by claycts on Tuesday, August 23, 2005 9:25 AM
QUOTE: Originally posted by ARTHILL

I used 2x4s and used a pocket hole drill on the crossmembers so I could fasten the crossmembers from the top. It was faster and easier. Scewing up through the L girder into the crossmembers is hard. The strengnth issue is no longer there is you use foam instead of 100lbs of plaster.

Is that a FOSNER BIT (spelling)?
Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by loucad on Tuesday, August 23, 2005 9:56 AM
Do not overlook going to a lumber yard for your lumber. I have found the prices to be competitive and the quality to be much better than the big home improvement stores. Also, the selection of lumber grades is often better.

I have used plywood to make l-girders for table legs for a project table. I cut the boards to size on my table saw and fabricated the pieces. Very strong; very stable.

Use glue as well as screws. The time and efforst pays big, big dividends.
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Posted by joeh19012 on Tuesday, August 23, 2005 4:17 PM
I used 1x4's and 1x2's to make my L-Girders, too, following all the steps in Linn Westcott's book. The resulting platform is incredibly strong, and doesn't move, particularly if you brace the legs the way he suggests.

RE: glue and screws. I matched a 1x4 with a 1x2 and then clamped them together. Next, I drilled pilot holes for screws about every 12-16 inches. I unclamped the wood, glued the flange (1x2) to the web (1x4) and then inserted the screws into the pilot holes. The screws then act as clamps while the glue sets. When the glue dries, remove the screws. There will be nothing to get in the way of your joists or risers. If you need to fill the holes (unlikely), you can use plastic wood.

If you work with standard length lumber (8 or 10 feet), you can then cut your girders directly with a miter or table saw.

Hope this info helps. Good luck.

Joe from the Philly 'burbs Disclaimer: Any mention of any type of commercial or retail enterprise is presented for informational purposes only, and does not represent an endorsement. I have no significant financial interest in any of the named companies.

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Posted by Medina1128 on Tuesday, August 23, 2005 9:06 PM
I found a good source for risers on my open-grid layout. Most lumber stores have a pile of pallets that they throw away, or stack up with a "FREE PALLETS" sign over it. I just run them over my table saw and use the slats. If you can get the nails out, the 2x4s that most runners are made of make good leg braces. If I could figure how to do it without stinking up the house, I'd recycle my sawdust back into boards. [:)]

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