Ryoken's adjustable Welding/Fab Table

[ryoken]

ok, many have read the design thoughts, etc in Mutt's thread, time to stop cluttering that build up and get it's own thread...



as many know, the 3/8 plate had a bow...... as is often the case with me, I was fretting over nothing...




it bends easy peezy....... when it has a house on it...

now obviously it keeps springing back even going a 1/4" the other way.. so I cranked it down to 3/8" or so the other way, and I'll let it sit overnight...

and even if that fails, it should be easy to weld the frame braces with it tweaked flat... those 3" x 3" x 1/8" are plenty stout...


as per the drawings, not sure what I'll do about the drawer end, may just frame it the same as the other end, and modify my drawer idea... but I'll see how the bending goes...





for those that don't read Mutt's thread...

 

[ryoken]

ALL HAIL THE BANDSAW.!!!

man that thing makes life easier... that's all the "structure" pieces... well, that 4th leg component is on the ceiling...


the only new issue now is I forgot about the inner weld seam/bump that is inside the square tube... that would have been the advantage of buying/running smaller typical receiver tube....

it's not a huge deal, I'm actually just gonna cut a light notch lengthwise on the inner sliding tube so it slides good......

 

[tRustyK5]

You could use heat to straighten that plate...which is what I'd do if I wanted dead flat. I also wouldn't weld anything to that plate once I got it flat. Instead I'd build the frame for it, then drill blind holes on the underside of the plate and bolt it through the frame and into the plate from underneath.

 

[ryoken]

it's only 3/8 thick.. drilling blind holes and tapping it is out of the question..

I'm fine with welding it.. I'm not gonna be pouring a ton of heat into it, just some stitches here and there...

I thought of running the cutting torch down the crown to alleviate the stress/tighten it.. that may happen tomorrow, thanks..

I'm pretty confident I've got a good handle on getting a pretty balls flat surface at this point...

 

[tRustyK5]

I have found every single fab table we've ever built never came out balls flat until we threw em up on the mill after and surfaced them. Even being very conservative with the frame to top welding the overhang of the top sheet would always get pulled down. That was true of the smaller tables we built right up to my last one which was 1.250" plate, 60" x 120". The beast was the one we finally made the legs removable and added really HD levellers, and surfaced the whole thing.

The only draw back after that was it needed a regular spritz of anti spatter...

Anyways, just trying to help, not suggesting you don't know what you're doing.

 

[ryoken]

I have found every single fab table we've ever built never came out balls flat until we threw em up on the mill after and surfaced them. Even being very conservative with the frame to top welding the overhang of the top sheet would always get pulled down. That was true of the smaller tables we built right up to my last one which was 1.250" plate, 60" x 120". The beast was the one we finally made the legs removable and added really HD levellers, and surfaced the whole thing.

The only draw back after that was it needed a regular spritz of anti spatter...

Anyways, just trying to help, not suggesting you don't know what you're doing.

nah I know, thanks... always appreciate your metal insight...

was gonna send you a pm here, see how things where and ask ya a question, but I may as well ask it here...

if I want to assist in tweaking that thing straight by heating with the cutting torch, I should be pouring it in on the high side of the crown correct? so it draws up the outer edges, right?

 

[Stomis]

Chock the plate up with tube along the bend spaces off it and heat it down the bow slowly. The weight of its self should let it fall flat.

 

[ryoken]

with tube along the bend spaces off it

English please..

 

[Deuling]

Bring that bent ass plate back and get flat


Subd.


I LOL'd when i saw the "with a house on it" comment.

 

[tRustyK5]

nah I know, thanks... always appreciate your metal insight...

was gonna send you a pm here, see how things where and ask ya a question, but I may as well ask it here...

if I want to assist in tweaking that thing straight by heating with the cutting torch, I should be pouring it in on the high side of the crown correct? so it draws up the outer edges, right?

Depends on how crowned it is, will determine how much heat you'll need. I usually soapstone the ridge using a good straight-edge to get a better visual. The straight-edge also shows me how much it's gonna need. I will usually use the torch to get a medium red spot, then move along the ridge creating a series of the same trying to mimic the heat affected area a weld would have. I'd start with 25% in 2-3" increments along the ridge. Let it cool naturally and re-check. If it needs more you do more based on how much the first set helped. I know guys that quench after heat, but I feel that is just impatience and that it actually diminishes the amount of pull. With your house sitting on it you might add some heat, let it cool and release the jack. Weight helping along with the heat obviously increases the effectiveness.

It's more of an art than a science...but being observant and seeing how much pull you get from a certain amount of heat can get you really close.

I'd try to remove the ridge with some heat first, then fully weld your frame up. Last I'd secure the top plate to the frame with a half dozen 1/2" welds. You really don't need much more anyways. Once it's cooled, check the overhang of your plate, and if it did curl down a bit, break out the torch again.

A flat table is worth the effort IMO.

The big thing is to not through heat the plate. You want the red hot area to stay on the high side of the plate, so when it cools it shrinks the high side. Through heat will defeat all the effort.

 

[ryoken]

ok, cool.. thanks, that all makes sense.. the crown seems be just a very mild hump to the whole thing, not a crown per se..

I'm just used to shrinking sheetmetal, not 3/8 plate...

 

[ryoken]

and, of course, the acetylene is empty....

 

[tRustyK5]

I've done a crap ton on heavy plate and structural stuff, but sheet metal not at all...so we're even.

 

[ryoken]

got it flat, while cold...

bending it a few times past flat 2" to 3".. took it out... probably had about 8, 9 ton's downward pressure on it... LAB™ beam to the rescue!


working on the legs currently... all blasted and belt-tabled.. grooved one and it slides nice inside the 3"... going down to do the other 3 and start running the pin holes thru them...

all that huge steel order and I forgot to get the 3/16 strip steel for the caster pads.. I need something else for Mutt too, so I'll run up to the Wall store on fri probably..

 

[Stomis]

Thats good you got it flat while its cold. Reading your quote of my instructions made me feel like theres was some terrible rainman disconnect between my brand and fingers lol.



When you to assemble this thing I would suggest you weld the frame and then pretension the middle of the plate the same way you straightened it. It wont take a lot of heat for that thing to want to pop up again.

 

[ryoken]

yeah, think I have a good plan for mounting it at this point... I'm gonna leave it with just light pressure on the jack as I attach the frame upside down... but I want to fully build/drill the legs before assembling the frame...

 

[beags86]

Depends on how crowned it is, will determine how much heat you'll need. I usually soapstone the ridge using a good straight-edge to get a better visual. The straight-edge also shows me how much it's gonna need. I will usually use the torch to get a medium red spot, then move along the ridge creating a series of the same trying to mimic the heat affected area a weld would have. I'd start with 25% in 2-3" increments along the ridge. Let it cool naturally and re-check. If it needs more you do more based on how much the first set helped. I know guys that quench after heat, but I feel that is just impatience and that it actually diminishes the amount of pull. With your house sitting on it you might add some heat, let it cool and release the jack. Weight helping along with the heat obviously increases the effectiveness.

It's more of an art than a science...but being observant and seeing how much pull you get from a certain amount of heat can get you really close.



I'd try to remove the ridge with some heat first, then fully weld your frame up. Last I'd secure the top plate to the frame with a half dozen 1/2" welds. You really don't need much more anyways. Once it's cooled, check the overhang of your plate, and if it did curl down a bit, break out the torch again.

A flat table is worth the effort IMO.

The big thing is to not through heat the plate. You want the red hot area to stay on the high side of the plate, so when it cools it shrinks the high side. Through heat will defeat all the effort.

Can I ask you want you do for a living? Do you work to a code?

 

[tRustyK5]

I was a steel fabricator for 21 years. The last 8 or so spent building aircraft tooling for Boeing, Gulfstream, Fairchild-Dornier, Lockheed etc.

Now, I drive a garbage truck. Sounds less impressive, but pays better and I'm happier.

 

[ryoken]

slides done.. tomorrow I'll drill the other legs and try to get the structure welded up...




leg fully extended... table will adjust from 29" to 43" high, in 2" increments... I could probably get another 2" out of it, but I'm thinking 43" is plenty high...

 

[tRustyK5]

Height adjustable is nice. We never built height adjustable tables, usually settled on 36" as a nice working height. Higher or lower seemed to play hell on your back if you were working on it for long. Certain jobs the adjustability would have been nice though.

You gonna add levellers to the bottom or?