Hi all,
I'm in the process of designing my new HOn3 layout to go along the rear wall of my garage, however this presents a problem. Due to door placement, in order to fit a car under the layout, the front legs at both ends will have to be offset from the front of the bench by about 1 foot. However, the legs in the middle will be at the front of the bench, and there will be diagonal (45-degree) bracing from the offset legs to the front of the tabletop. Does this seem feasable/stable to you?
Thanks in advance,
tbdanny
The Location: Forests of the Pacific Northwest, OregonThe Year: 1948The Scale: On30The Blog: http://bvlcorr.tumblr.com
We'll need a bit more info. For example, are you going to attach it to the wall? How far out from the wall will the layout project? How wide is the area that will go over the car? What is your planned leg spacing?
TomDiehlare you going to attach it to the wall?
No. We're in a long-term rental, so it has to be free-standing.
TomDiehlHow far out from the wall will the layout project?
TomDiehlHow wide is the area that will go over the car?
1' - this will leave enough room at the back to access the boot.
TomDiehlWhat is your planned leg spacing?
Planned leg spacing is 1'4" on the ends and 2'4" in the middle, minus the width of the pine stud.
tbdanny Hi all, I'm in the process of designing my new HOn3 layout to go along the rear wall of my garage, however this presents a problem. Due to door placement, in order to fit a car under the layout, the front legs at both ends will have to be offset from the front of the bench by about 1 foot. However, the legs in the middle will be at the front of the bench, and there will be diagonal (45-degree) bracing from the offset legs to the front of the tabletop. Does this seem feasable/stable to you? Thanks in advance, tbdanny
If your benchwork is built to 'normal' L-girder standards, the legs are ALWAYS offset from the table edge (I use the term 'table' advisedly - L-girder framework is open frame, usually found under cookie-cut subgrade rather than a solid, flat tabletop.) They are placed at the joint of a joist and the main L-girder.
In my case, the legs are about 13.25 inches in from the joist ends, and 32 inches in from the ends of the main girders of a 5 x 12 not-quite freestanding framework. Diagonal bracing runs inward, not to the joist ends.
Since your benchwork can't be anchored to the wall at the rear, offsetting the legs means that you should place anything heavy to the rear of the benchwork, not on the overhanging edge. You can get the same result by weighting the rear legs.
Chuck (Modeling Central Japan in September, 1964 - on steel stud benchwork)
Seeing as your not planning on attaching it to the wall of the garage I would suggest using open grid style bench work, a rectangular box if you will with perpendicular cross bracing equidistant apart and stand it on 2x4 legs with casters. I would bolt the legs to the "box" with carriage bolt and reinforce each leg with opposing 45 degree bracing to the box. and upside down piece sign just to give you a visual picture. You will have very strong stable legs to support the bench work and if and when the day comes you want to move it being on casters yo can roll it out to where you can load it into a truck and if you have to remove the legs for transport you simply unbolt the carriage bolts. Being as your not building a portable layout I wouldn't be concerned with making the legs fold up as it's unnecessary extra work. as far as offsetting the tow outside legs I can't see where you would have any problem supporting the structure if secure the legs to the bench work and brace them properly. 12 inches form either side is not going to mean a whole heck of a lot in the big picture.
Is the layout useable with the car in the garage? I ask this because even if you are able to set the legs back far enough, if you feel that there just isn't enough support, try having removable or swing up supports to drop to gain the support.
There are other options such as constructing the framework with aluminum or steel I beam or U channel. A strong "beam" will allow to carry a greater span. On one portion of our club layout, we needed a 6-7' span for duckunder access. I built the "L" girder at this point using 1x6 maple on the vertical. It has held w/o sag for about 10 years now. Aluminum channel or "I" beam will easily span the distance you need.
Modeling B&O- Chessie Bob K. www.ssmrc.org
Is the ceiling in the garage finished? Can you screw one or two evebolts into a joist? If answers are No & Yes consider dropping a support wire/cable from the ceiling.
Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/
tbdannyDue to door placement, in order to fit a car under the layout, the front legs at both ends will have to be offset from the front of the bench by about 1 foot. However, the legs in the middle will be at the front of the bench, and there will be diagonal (45-degree) bracing from the offset legs to the front of the tabletop. Does this seem feasable/stable to you?
I R cornfused.
Normally when you park a car in a garage the car is in the middle of the floor, that would mean that the legs toward the middle would be inset and the legs to the outside could be wider. You seem to be suggesting the opposite.
Why do you need to vary the positions of the legs? Make them all inset, then they will all line up. If the legs are only inset a foot, why do you want a brace from the leg to the front of the benchwork, wouldn't it be more stable to put a leg to the back of the benchwork, assuming that your benchwork is more than 2 feet deep?
Dave H. Painted side goes up. My website : wnbranch.com
Doc in CT Is the ceiling in the garage finished? Can you screw one or two evebolts into a joist? If answers are No & Yes consider dropping a support wire/cable from the ceiling.
Unfortunately, the ceiling is finished, and a joist is out of the question. I can't make any modifications to the house itself - it's a rental.
dehusmanNormally when you park a car in a garage the car is in the middle of the floor, that would mean that the legs toward the middle would be inset and the legs to the outside could be wider. You seem to be suggesting the opposite.
My bad - it's a two-car garage, and the layout will be stretching across the entire width. I should have said "to fit a car under the layout at each end"
dehusmanWhy do you need to vary the positions of the legs? Make them all inset, then they will all line up. If the legs are only inset a foot, why do you want a brace from the leg to the front of the benchwork, wouldn't it be more stable to put a leg to the back of the benchwork, assuming that your benchwork is more than 2 feet deep?
There are going to be two sets of legs - the ones running along the back, and the front ones that are the topic of this discussion. The reason I want a brace from the front end legs to the front of the benchwork is the same reason that I want the middle legs at the front of the layout - for stability, especially given that they'll be recessed just under halfway back from the front of the benchwork.
If I understand your description correctly, you will have a cantilever of 1 foot at each end with a back section of 1 foot 4 inches. This will put your center of gravity between the legs assuming you don't unduly weight the front. This should be pretty stable as long as you don't lean or climb on the front. You can make it more stable by attaching shelving to the front and back legs and storing heavy stuff there. Also, depending on how you build it, you may want to use longer or thicker screws on the back section.
Enjoy
Paul
With a total depth of 28", I would recommend a cantilever of 1/4 that distance (7"). In addition. I would second Paul's suggestion of adding weight carried by the rear legs. One of many possibilities: attach the legs to a plate on the floor and load the plate with concrete blocks. I fear that you or your guests will-if inadvertently-lean on the cantilever and tip the table (and it will tip).
Dante
PS. Another thought: Extend some of the rear legs to a horizontal member that will just touch the ceiling (but not be fastened to it). That assembly will resist the tipping tendency.
I just remembered a design I used longer ago than I care to admit...
Build your inset legs with a bottom plate that extends out to the fascia line under the cars' front bumpers, which, with the joist at the top looks, sort of like a D with long carets or a square A lying on its side. Solidly constructed (reinforced with a beefy steel L at the bottom of each leg) it moves the forward support back under the front edge of the layout.
When I built mine, the bottom plates were 2x4s placed wide side down. Any wood in the 30-35mm thickness area should do. I also included provision for leveling the legs, both front and back (I lack skill when it comes to precision carpentry.)
Chuck (Modeling Central Japan in September, 1964)
dante PS. Another thought: Extend some of the rear legs to a horizontal member that will just touch the ceiling (but not be fastened to it). That assembly will resist the tipping tendency.
unless there is a mis-judgement between the car and front legs
The one thing I might add is be careful in designing the cantelever. You need to support the member that supports the rest and not just a cross joist. It may hold for awhile, but gravity will win in the end, except for the cross joist that will still be mysteriously standing. In other words, support the member that everything else is attached to.
You also state that this will go from side to side, with the noses of two cars under the front. If you are going all the way to the walls, I would recommend just using some engineered joists to span the 12' from the center of the garage out to the walls and eliminate any legs in front of the cars. I think the smallest they come are 9-1/4" tall, and any length you want up to 50' and are more than capable of cayying even the longest of consists, since they are probably what is used for the floor in many of our houses that are newer. I'd say use regular SPF, but I-joists are more stable, straight, and lighter. Costs are not much (probably a couple bucks a foot) and are available at about any lumber store/yard. They will probably want you to by them in 2' increments, starting at 12'.
tinman1You also state that this will go from side to side, with the noses of two cars under the front. If you are going all the way to the walls, I would recommend just using some engineered joists to span the 12' from the center of the garage out to the walls and eliminate any legs in front of the cars. I think the smallest they come are 9-1/4" tall, and any length you want up to 50' and are more than capable of cayying even the longest of consists, since they are probably what is used for the floor in many of our houses that are newer. I'd say use regular SPF, but I-joists are more stable, straight, and lighter. Costs are not much (probably a couple bucks a foot) and are available at about any lumber store/yard. They will probably want you to by them in 2' increments, starting at 12'.
I think that Tom's suggestion is a good one. Measure the width of the garage, divide by two, and buy two engineered joists as long as (or longer) than that. Put a leg at each end and a paired one at the centre (2"x6"s, installed "on-edge" and notched at the top to support the joists) and then frame the back of the layout as you would normally. Tie the front to the back with suitable cross members, and you're all set. No posts to interfere with the cars, and if your layout is high enough, lots of storage space below for all the usual junk that accumulates in garages.
Wayne
Still another idea, if you don't mind a bit of 'composite' construction.
My 32 inch (actually 800mm, but why quibble) not quite freestanding 'across the 16 foot wide garage door' strip of benchwork is supported at the ends by the walls (I own, so I can get away with that) and at the (slightly off-) center by a set of 2x4 legs, cross-braced. The main girders are heavywall steel studs, nominal 2 x 4, and the longer one is ten feet long. 2 x 6 studs are also available, but the 2 x 4 size took my not-inconsiderable weight pressing down on it with no noticeable deflection. For 12 feet of clear span, I'd suggest the 2 x 6 size.
One big plus is that the steel is actually quite light. You can place it without help, and you don't need to be Hercules either. It cuts with a hack saw and can be drilled with ordinary drill bits. Once in place it isn't effected by humidity, or much of anything else short of an eight-pound sledgehammer.
tinman1I would recommend just using some engineered joists to span the 12' from the center of the garage out to the walls and eliminate any legs in front of the cars. I think the smallest they come are 9-1/4" tall, and any length you want up to 50' and are more than capable of cayying even the longest of consists, since they are probably what is used for the floor in many of our houses that are newer.
This sounds good, but what exactly is an 'engineered joist'? I'm afraid I'm not really familiar with construction industry terminology.
tbdanny tinman1I would recommend just using some engineered joists to span the 12' from the center of the garage out to the walls and eliminate any legs in front of the cars. I think the smallest they come are 9-1/4" tall, and any length you want up to 50' and are more than capable of cayying even the longest of consists, since they are probably what is used for the floor in many of our houses that are newer. This sounds good, but what exactly is an 'engineered joist'? I'm afraid I'm not really familiar with construction industry terminology.
An engineered joist can come in different forms depending upon load requirements but share the common trait of being man-made from various wood products and binders. They are typically sold "by the foot" and most are made in lengths that fit into a boxcar and then are cut for distribution and stocking at lumberyards. That's why you can get 60' lengths, but they would have to be ordered since they normally cut all those lengths down to 12' and up in 2' increments. The one you would be looking for is simply called an I-joist. When viewed from the end, it has a piece of 2x3 on the top and bottom with a piece of OSB standing vertically between them. There are several variations out there, mostly dependant on the mfg and which store you go to, but they perform about the same. They come in sizes that start at 9-1/4, 11-7/8, 14, 16, 18, and probably bigger yet. 9-1/4 is what you would be looking for since it is capable of spanning 20' and still hold 10/15 lb/ft dead and I forget what live load. I'm not an architect or engineer, I'm just a builder who has to build as designed. (it's a good thing to know a little about that stuff, since achitects and engineers get confused a lot)
Here's a little more info on engineered joists.
Just noticed your location. I would think these are available down there just as they are here. If you know someone with a tablesaw you can actually make your own, like I did.
Mine is made from 1/4" luan and 1x2s, are 8' long, 5" tall and held together with Gorilla Glue. The cost was cheap, about $8 US for a 4x8 sheet of exterior grade luan, 1x2s at a buck n change a piece, and the glue which was $10. The wood on there is over 150 lbs, but that much weight may deflect over time, maybe not.