Update on Track Plan and Benchwork

I would turn the top support on the right side 90 degrees and extend the l-girder on that side.  You can build the L-girder bearing legs off set.

Jim Miller

Havre de Grace Maryland.

When you say 1X4 for the girders, are you going to add the top flange 1X2? If you are, spanning 8ft. is no problem. Without the flange, the span is shortened a lot. You can extend past about 1/3 the span or a little over 2 ft. It's also important to brace the legs deeply and cross-brace. The stiffer the leg, the bigger the cantilever can be. I'm spanning 4 feet between joists using 1x3's. I'm also extending out beyond the girders up to 8". I believe it will be quite stiff as long as the risers spread the load across the joists and don't concentrate it in the center.

Before you get started you should have a copy of Lynn Wescotts book in hand.

Secondly, consider building your entire layout from 3/4" sheet goods. All of your components will be much straighter, lighter, and you will utilized nearly every piece of plywood with little or no waste. Below is a photo of my mock up for my recent turntable addition, note all plywood construction, right down the the legs which are 3-1/4" piece 90 degrees to a 4" piece, glued and stapled to form the legs to support the L girders. This is a very strong and effective method of construction.

Definitely! Everything I've learned about L-girder is from that book. 

Using sheet goods makes good sense, but I didn't have a way (other than with a hand circular saw) to rip all that very heavy ply. I was unable to get a 4 X 8 down the cellar steps so all the OSB had to be cut in the garage. 

Thanks much for the advice. 

Trainman...The L-girders will definitely have the 1x2 across the top.  I'll price out the difference between ripping a wider board to get the 1x2 and the cost of buying the narrower board and then buying 1x2's.  My cross braces will be deep, going from the girder to within a few inches of the floor and will be blocked and screwed where they intersect each other.

gregj410...I'll look for the Westcott book. I'm sure I can get it online. I have quite a bit of lumber left from building my post and beam cedar home.  All my legs will be clear cedar as wil lmany of the joists resting of the girders.  I even have some 12" TJI floor joists left (but not long enough to use and that would certainly be "over-kill")!!!  I also have some 3/4 inch ply left over, but not enough to do much.  All the joints, including the top of the L-gerder will be screwed and glued. Along with the cross bracing, the platfrom should be quite stable.

Thanks again,

Jim

Salida, Colorado

"The Heart of the Rockies"

That's a good benchwork plan.  I would use 1X4's, (I always use a finger jointed pine product called Windsor One- it's straight and stable- clear cedar would certainly work- I love working with cedar), at 16" on center, cantilevered  12-16" over your beams, which looks like what you have on your plan.  I would figure about 5-6' spacing for the legs, like what you have on the left hand side of your plan. 

Just build it.  You don't need a book, you obviously have a good handle on the task at hand.  You need some basic carpentry tools, some elbow grease and to make a pile of sawdust.  Have Fun & Good Luck.  That certainly is a cool layout plan.  I would love to build that.