I'm making a stand for a metalworking lathe that weighs 330 lbs. I found an 8-piece workbench bracket kit on several sites, but all of the images are all regular cheap pine number. Wouldn't a hardwood version like using 4x4 hardwood posts and hardwood boards instead of the 4x4 pinewood posts and construction-grade 2x4s be strong enough to hold it up?
330 lbs is chump change. Can you imagine a table sturdy enough to support two grown adults sitting on it?
It would be for a table made entirely of hardwood.
I don't get it, unless you intend to use palm wood, the type of wood matters very little compared to the design and choice of joints when it comes to the solidity of the product. Sure, there are actual differences, and sometimes you might specify Douglas fir instead of pine, but if you are making a purely functional workbench, you are worrying about the wrong things right now, and it is stopping you from achieving results.
> Can you imagine a table sturdy enough to support two grown adults sitting on it?
Or your wife
>your wife (male)
I'm not looking for anything complicated. Just something sturdy for my lathe that will hold it up and won't shake while it's running.
Of course 2x4s are going to be 'strong' enough. How much does the second story of a house weigh? Or a roof? Etc. A single 2x4 is enough to hold up 330lbs. The issue is: will your construction be rigid enough?
I'm not sure how much those brackets cost, but I bet you could achieve the same results using framing plates/structural angle from your local hardware store. (The same kind of stuff used for house framing... it's sized to be used with 2x4s.)
Also think about a bookshelf, or clothes dresser. There is a back panel that, if you removed it, you would be able to push the whole thing over. Kind of collapse the rectangle by skewing it. But the panel prevents that motion. The sheet doesn't even have to be particularly thick. Cross bracing can achieve the same effect, but that's more complicated than gluing & nailing a panel on.
>won't shake while it's running
Two other things that are going to influence that are the bench-ground connection, and the weight of the bench. Have you decided if this is going to be bolted to the floor, or just held down by gravity?
Even if your floor is generally level, it's not locally level. You'll need to have some kind of strategy (adjustable feet, shims, etc) so the thing doesn't teeter back and forth.
For weight, if you're putting shelving beneath, for storing stock, tooling, etc, that works. Some people just toss bags of sand, concrete, etc down there.
The anon in has it right about adding some sort of panel to minimize the legs racking out of square, or corner gussets...that's really most of what the corner brackets in the picture are doing, especially the bottom set...the bottom stretchers have zero load bearing effect.
Consider too that as shown, any load borne by the top set of stretchers I'd hanging off the bracket fasteners alone...it would be far better to run at least the front and back ones across a notch rabbeted into the legs so that you effectively have two trestles that the table part sits on, with the upper stretchers acting like beams that would transfer the load to the tops of the legs.
Personally I'd do that and then just use plywood sides to make the short ends and a partial sheet across the back, with extra framing at key points so the table and a shelf can be glued and fastened down to stiffen it all up...basically more of a beefed up cabinet than a bench.
The other reason to make it more of a cabinet is because with loose tools and parts being set up and vibration effecting anything stored on a shelf underneath the top, shit *will* fall off/out of an open bench andvendbup behind it, and you don't want to have to move a lathe to get at it...for that reason, any shear panel or gussets across the back should stop well short of the floor unless you bolt the whole thing to the wall with no gaps like a kitchen base cabinet (which is actually an option to consider).
Picrel shows what would be the left rear corner layout to make the long stretchers better for load bearing, flip and repeat as needed.
Also keep in mind that the wider the distance between the legs (especially the long dimension), the more the top and stretchers can flex and vibrate with the machine on top, so keeping the dimensions as tight as possible to the machine size so the legs are closer to the weight is best, as long as the height to width ratio is within reason to remain stable against tipping.
make one out of steel sections and concrete top
So, uh, OP....
Did you make any progress on this project?
Like some kinda 10 -> 1 progress?
For the cost of like 1 extra 2x4 you could add elbow bracing
if you need access to one side of the lower shelf you can leave one side unbraced
All of these are over dimensioned. 2x2s with 3/4” OSB on the back side and OSB triangles as corner braces.
> too weak
My motorcycle is 400lbs and easily goes on a similar construction. I use 2”x2-1/2” (44x69) with 3/4” OSB. The elbows shown in are far too thick. It seems intuitive to use the same material and thickness for the legs and the braces, but from a physics perspective that’s always overkill. Plus it’s a lot easier to slap a triangular piece of sheet onto the legs than it is to put braces on the inside like that
This is about the weakest construction you can make with 4x4s
The reason for using 2x4 is so that you can send two screws in per joint that hold good amount of brace wood without pulling through or splitting.
Obviously the racking forces aren't enough to crunch a 2x2, but attaching those would be tough for someone who has to ask how to build a table
The real issue here is that there's no cross members under whatever sheet is going on top - you probably want 2x4 joists every 1'6" or 2'
it's 10% material and 90% design
just because you use hardwood doesn't mean it will be strong
>I found an 8-piece workbench bracket kit
why the hell do you need a bracket kit? get some 2x4's, a sheet of 3/4 plywood and watch a 2 minute youtube video on how load bearing works in a house
I built a L shape workbench out of standard softwood 4x4, 2x6 and 3/4 inch plywood that has a vice and mini mill attached to it. Biggest issue I have had was flipping it over because it was easier to build upside down. Will handle your lathe no problem. Your picture is pathetic.
Metal and wood don't play nice together, screws and bolts will shred softwood and waller out their hole if they experience any substantial loading. It does not take much force to compress construction lumber, and those bolted joints experiencing racking forces are way more than enough to make the entire thing rattle endlessly within a year. Laminate two 2x4s for the legs and shorten one of them by 3.5in so you can half-lap the stretcher and use wood glue instead of screws, and you get something 2x as strong and 8x as durable for probably less money than the metal brackets.
I forgot to mention, making OP's image with hardwood would require either buying S4S hardwood, which would be ludicrously expensive, or dimensioning it yourself with a tablesaw or bandsaw. Either way, doing a proper construction lumber table would be more than good enough while being far cheaper.
Picrel is more what you should be going for, though you probably don't need to cut joints for the diagonal braces like that. If you are worried about vibration, the only cure is mass, so the super thick laminated bench top might actually make a lot of sense. If that's not in the budget just lay two sheets of plywood or MDF on top of eachother and call it a day.
Wood glue is much stronger than screws are, assuming you are gluing the faces of two boards together, so use that for the love of god. Bolts + construction lumber don't make sense if you aren't ok with everything having about a 1/4"-1/8" of play, and it sounds like you aren't.
> Metalworking
> Wants a table made out of fricking wood
Wood is fuel for heating, anon, not a material
Mald lathetroony, I will be of by an 1/8" on every critical dimension and have cozy tables and chairs that only wobble a bit while you spend a gorillion dollars to make a gay ass bolt.