New shop equipment build: 8000 lbs capacity, adjustable height fixture table

[Brucker]

I built my first fixture table, though back then we just called it a fab table, in 2004. One couldn't find a fixture like you can now without spending 10's of thousands on an Acorn table. So I built one. Made out of 1/2" plate and 3/16" thick 3" square tubing. It is 4' wide x 8' long x 41" tall. And the top has a 5" x 5" grid pattern of holes that are tapped 1/2"-13. Mostly because the post style clamps that modern fixture tables accept didn't readily exist. So I went with what I knew, machinist/mill table clamps. I attached a small tool box to one end, and rods to hold C and F clamps on the other. The center has bins for fixtures and jigs. It has served me well for many years, and has taken all the abuse I have thrown at it. Nearly every project that has come out of my shop, from railings to complete chassis, has been on that table.





Through out the years, I have dreamed about building or acquiring another and what that would entail. It changed over the years, especially with the post style clamps and fixture tables becoming so readily available and popular. And as I got older, I started thinking more and more about ergonomics and how I could save my failing body. I really liked a couple different tables from a couple different vendors, and some even offered adjustable height. But none of them offered anything other than 5/8" or 16mm holes. And I have become accustom to using and really like the 1/2" tooling. So I went back and forth about buying and then modifying, only to ultimately realize I would have close to $30-40K into buying an adjustable height table, only to then have to modify it. That seemed like the best solution, so it got added on to the future equipment purchase list for the shop.

Then I stumbled onto this on FB marketplace:









A 4' wide x 12' long dual scissor lift table with a 9600 pound capacity, that can raise from 7" high to almost 60" tall in about 30 seconds. New these table go for over $60k. I was able to bring this one home for under $3k. It was then and there I decided I would just build the table I wanted. So I got to mentally designing, then ordered materials, and got to work. I don't want this to take away any shop time from real work, so I will slowly be fabricating it during nights and weekends.

End goal, 8000 pound capacity, adjustable height fixture table, with an approximate 5' x 12.5' top. The top would be made of 3/8" thick plate, 3/16" thick 3" square tubing, and 1/4" x 3" flat strap. I would use three 3/8" x 4' x 5' plates plus two 3/8" x 3" x 5' wide plates to create the top surface. The 2 smaller plates would separate the 3 sheets, and will be removable. This will allow the use of standard C and F clamps within the tables perimeter. And the entire top will have 2 opposing 4" x 4" grid patterns. One with 16mm holes to accept both 5/8" and 16mm tooling and clamps. And one with 1/2"-13 tapped holes. This should allow for the most clamping options available.

 

[Brucker]

I called around to get quotes for CNC cutting the plates. I only have access to CNC plasma cutting in house. And I really didn't want to add more heat into the top then necessary. So plasma and laser are out with that many holes to cut. So water jet was really the only option I considered. Until the pricing came back. So made the decision to do it all in house with mag drills. It's one I will probably regret later, but such is life. If you want something, you gotta work for it right?

Once the materials arrived, I started cutting pieces for the frame. The outside would be 3" square tubing, and the middle would be filled with a grid pattern of the 3" flat standing on end. With the pieces cut to length, I cut slots into the flat stock so they would interlace together.





With all the pieces cut and cleaned up, I started fitting them together.







And welded the tubing together




And then welded the two sections together ensuring the assembly is finished nice and flat





And then moved the completed assembly to the side

 

[Brucker]

With the top's framework completed, it was time to process the plate. I ordered three 3/8"x4'x8' sheets. I will cut them down to three 4'x5'. Then space them 3" apart to create the 5'x12.5' top.

Plates as they arrived:





To keep heat at bay, I used one of my favorite cordless tools, a Milwaukee M18 metal cutting circular saw. I have found it is just as fast, if not faster, than plasma cutting when you take the clean up into account. And doesn't heat the material, create off gases, nor require respirators or special tinted glasses.


When laying out the sheets, I realized that the "mill edges" were in great shape and were actually parallel. So instead of making 4 cuts per sheet, I would only make two. But this would make the table about an inch and a half longer than planned. This would mean I would either have longer overhangs, or I could add another section of 1.5" x 3" tubing to one end. This would mean one line of holes wouldn't be able to be cut as they would line up with a vertical wall of the frame. But this shouldn't matter as there will be plenty of clamps options still available. So I opted to go with the longer setup.

Here are the plates after being processed. Still have 3 nice sized drops left over for add to inventory!

 

[Brucker]

Laid the plates out face down and added the frame on top. Aligned and properly spaced them and then got them welded up. Then welded up the additional rectangular tubing to one end.





Once welding was complete and flatness was verified, I used the gantry crane to remove the new assembly from the table and flipped it back over.





Then added some mounts made out of angle iron to the bottom of the top. These will mount the top to the scissor lift table. then drilled and tapped the table to accept the new mounts. And got the top mounted to the table:

 

[Brucker]

Time to fill the gaps.

Cut 2 pieces of 3/8" x 3" flat stock to length and cleaned them up. Then added 4 coupling nuts into each void by welding them into position.



Then used some transfer screws to mark the center of each coupling nut onto the flat stock pieces







Then drilled and countersunk the holes in the flat stock





Stamped identifying labels to keep the in the correct location and orientation



And installed them