Welding table frame structure thoughts

[Snip]

So I found the material for the top, 1/2" plate 6'x8' and the legs 3 1/2" square tube. Found reasonable at different locations on Marketplace. I will most likely cut the top down to 4x8, 5x8 at the most. I will be using 6 legs. My thoughts are to leave a 4-6" overhang for clamping and doing a sub-structure under the top, one permitter band connecting all of the legs and then cross bracing the 2 sides together. Trying to eliminate as much "bounce" as possible in the table. The two options I am looking at would be either 5x3/8" flat bar placed vertical or 5x1-3/4 channel with a .190 web. Price wise not much difference, 25.00 a 20" stick. Which do you think would give the least bounce/rebound? The top will be welded to the frame, I'm 61 so the odds of needing to replace it while I'm here are slim.

 

[matt_i]

Out of the channel you can create a ladder frame.

I tried to make my bench to be able to be disassembled into the major pieces. Ultimately I got forklifts and that didn't matter but if I had to move to a new shop the plan was to allow it to be doable without special rigging.

The "hardest" spots on the table will be over the legs. You can tap around with a hammer and find this out when its built. The old timers who invented and used post-vises knew something about this.

 

[travisn1]

I doubt a 1/2" plate will bounce any. I'd also only use 4 legs.

Try it out then add as needed, you may be surprised.

 

[Jackfre]

I built this table a couple years ago. Wish I could find a sheet like yours but I did the frame out of 3x3x.019 legs and 2x2x.019 Stretchers. Having the stretchers 6” below the top I can store long clamps etc across. I did put one cross stretcher in the middle. I took a 1/2” bolt screwed up to the table. I welded a small plate onto a nut which sits atop the bolt. With that I pulled string lines diagonally to find flat on the table and double nutted the jam. It has stayed in position. I know because I check it before every project. Such confidence, eh?
The ladder frame Matt proposed is a good idea if you can make it dead flat. If you take it to 4x8 you could double the top thickness. That would dampen and rebound. The feet on my table are HDPE. I’m happy with that. The table is heavy enough that I can beat on it and it doesn’t go anywhere but I I want to move it I can unload it, throw a sling around the legs and drag it where I want it. At 72, that isn’t far. Post some pics as you go. I’m interested to see how it comes together.
I’m just starting a Roubo type woodworking bench and have decided on a steel base for it as well. Not sure what exactly that frame will look like but it is kinda sorta forming in my mind.

 

[ez-duzit]

If you weld the top to the frame it will likely warp.

Look at successful examples.

 

[sweetk30]

Your sounding almost like my table .

Skim over my build and you will get a solid plan .

And yes even 1inch plate can flex when sitting on 4 pads on a car lift spaced about 7ft apart on a 4x8x1" plate . So watch your 1/2" plate .

I do like my 2 4x8 tables but find my self going to the 4x6 for every day jobs.

My build thread https://www.garagejournal.com/forum/showthread.php?t=392532

 

[Snip]

Sweetk30,
You have built some very nice tables, pretty much could rebuild a tank on them i'm sure. Thank you for the link. My original thought was to weld the top to the frame, Not continuous but enough short welds to make it one with the frame and limit the rebound while "Persuading" steel to do what I want. However I am now thinking about welding Clips to the frame, drilling and tapping the top and bolting from the underside, Thank you.

I was also planing to put recevier tubes at several locations for removable tooling. Have you installed the receiver tubes yet? Did you weld them, and where if so did you weld to the frame or the underside of the top? Do you have any pictures? My thoughts were to use 2-1/2X1/4" Sq tube and removing the weld seam, with 2 x 1/4" for the removable part. I would have to fly cut a little of the 2" for a good slip fit. 2 on each long end and 2 on one of the short end. Reserving the other end for a 2x4" fold down cut table.

 

[tarmy]

If you weld the top to the frame it will likely warp.

Look at successful examples.

Not if done carefully and done right. As you note...the risk is real that warpage can occur. This is 1/2” and welded...tacked would be a more accurate description. I wanted a dead flat surface for cabinet body making...and this is.

OP...you should be able to strategically tack the top and achieve your goal. I have a welding table top that is secured with adjustable slats as well.

 

[Jackfre]

Tarmy, would you please expand a bit on that welding table. That is sweet. More pics and how did you attach the slats to the bolts...etc. Please feel free to bore me with details

 

[Snip]

Tarmy,
Two very nice examples. Sweet use of the slide tubes with threaded locks. Thank you for sharing.

I know the "its a mater of preference" on table height, but what are most of you building the finished height to? I'm 5'8".

 

[tarmy]

Tarmy, would you please expand a bit on that welding table. That is sweet. More pics and how did you attach the slats to the bolts...etc. Please feel free to bore me with details

Many of the details were STOLEN by me from folks on this site and Welding Web (great forum by the way).

In one of the photos you can see a 1/8” sheet I slid in below the welding surface. That is a great feature because you can slide it out occasionally and clean up the mess. I also store cut offs and long clamps in there too.

The receiver hitch feature is handy too...I have a vice and grinder that are mounted on 2x2 tube and go in there are well.

 

[sweetk30]

Updated my build thread for you with hitch pics . Anymore just ask buddy .

 

[jbfab]

...The two options I am looking at would be either 5x3/8" flat bar placed vertical or 5x1-3/4 channel with a .190 web. Price wise not much difference, 25.00 a 20" stick. Which do you think would give the least bounce/rebound? ...

Of those two materials, the channel will receive about half as much bending stress under the same load. Mostly due to the added material at the extreme fibers (the flanges). I'll echo some of the above posts by saying don't go crazy welding the top down. Small welds with as little heat input as possible are what you are looking for. Burning a nice fat fillet is what you will want to do, but that will result in a wavy warped top. If you think about it, gravity is doing most of the work for you. A 4x6 top of 1/2" plate is ~480 lbs - that's enough to slide around even if it isn't tacked.

My table is actually a 3" channel frame with 3/8 x 2 flat bars spanning the 4' direction with 3/16 plate for the top. The table is 4'x6' and has served me well for about 20 years. It would still be flat if I hadn't borrowed it to my previous employer. One of their smarter employees put a ratchet strap across the center and ratcheted for all it was worth . I got it pretty close to straight with heat, but it still bugs me a decade later. lol

 

[whateg01]

...I did the frame out of 3x3x.019 legs and 2x2x.019 Stretchers. ...

I highly doubt you did!

Dave