Temporarily Extending 2 Dragon Wagons

[wheelz]

I bought 2 of the 24" x 36" Dragon Wagons. That’s really all I could (barely) afford right now. I can put them together to get 48" x 36" table. However, I have to put together a steel rectangle tube frame where the bottom part is 41" x 40" and the top part is 39" x 38". The 48" direction is plenty of room for the larger dimensions, however I have a 3-4" gap plus additional needed space for perimeter clamping for the even the smaller dimensions on the 36" direction. I know that the tower block is made for this but at almost $500 a pop, that isn’t in the cards right now.

I was trying to think of ways to connect the 2 tables but space them apart while maintaining flatness & alignment as best I can (good enough anyway as it’s not for aerospace or anything). My first thought was putting some threads on some 3/4" steel rods to use them a long bolts. Perhaps I could use some steel plate to fill the gap, if I can figure out a way to bring the plate from the rods (side hole) level up to table level? However, I wanted to see if anyone else has tried this or had any better ideas. It is just a temporary setup to get this one frame built.

[Fireball_Jason]

Can you post a photo of the desired table configuration? But if it’s only a few inches that you need to separate the tables I’d go with a tall riser bolted to the sides.

[wheelz]

I would but I’m still waiting for the hardware to put the legs on . It’s a basic rectangle though with probably about a 6" gap between them on the 36" side. Here is what I need to make if that helps:

The bottom, top, and columns will all be separate pieces that bolt together so I just have to weld them up separately. It’s the bottom and top parts that I won’t be able to clamp all at once with the tables bolted together flush.

[mRhAnKbOt]

That’s a slick way to do it Jason. Maybe not perfectly flat and level, but I bet it gets it pretty close.

[DanM82]

I think wheelz took the frame weld distortion challenge to a new level lol.

[wheelz]

Actually I think I had it wrong in my head. Having them flush with each other on the 36" sides, would give me the 48" (24" + 24"). So really I’d need to have them flush but would either need to offset them (to extend the 36" side on opposite sides) or just extend one side outright. Well, crap…

[wheelz]

LOL, yea, perhaps. I’m not saying that is the best design but it’s what I came up with. This is going to be a frame that needs to support a CNC mill, targeting a max weight of 4,500 lbs (that’s with buffer) that it will need to support (the mill, tooling, stock material, extra components, etc.). The reason for all the changing of direction of the piping is to allow access to assembly / disassembly of bolts. There will be 8 heavy duty casters so it can be moved around relatively easily (the small 2"x6" outward opening pieces on the bottom). The two long lengths are to allow for a fork lift, if it needs to move farther. It is just the frame so I think as long as I can keep it to 1/16", I should be ok. It just has to line right up to be assembled and be reasonably flat.

[Knick]

Wow that will fun to keep square, plum and flat. Let us know how its comes out I am curious.

[DanM82]

Out of curiosity, whats the wall thickness on your tube?

[wheelz]

All 3/16" and the top plate is 1/2" thick.

[DanM82]

Well that throws out leaving the tubes one piece, and just tapping the bolt holes in them…

[wheelz]

I could use rivet nuts and I will in some cases where there isn’t a lot of weight on it. However, at the top, the bolts that will connect it to the frame will be embedded in concrete so I have to be able to get in there and put a nut on the bolt end and I’ll won’t be able to turn the bolt. For the bottom where the casters will attach, I’d rather not bet on a rivet nut to hold.

[wheelz]

I think I’ve determined that for the base, I will start on the inside and go out. The inside frame (with the two 41" long pieces for the fork lift) will fit on the two tables butted together. Then I can shift it from one side to the other to add the outside width frame.

With the top, I can do something similar since I have the back rectangle frame. Then once I have that welded up, I’ll shift it over to do the front part of the frame.

My thought is that since I only have a 2-4 inches of overhang on the each component and I’ve already established a smaller inside frame that is reasonably square & flat, then it shouldn’t matter if that part of it will extend past the table. I can probably clamp some something flat to the end to give the overhang I won’t be working on some support. Please let me know if you see any problems / holes with that idea.

[wheelz]

As requested, I’m providing an update. I know… only 9 months later. Keep in mind that I’m doing this in my spare time and when I first posted this last March, I had never welded before and was starting from scratch. So I had to build out my workshop area in my garage with electrical runs, heat, insulation, tooling, storage, compressed air, welding curtain & track, DIY exhaust, etc. and learn to weld. However now the rubber is finally hitting the road. Also the appearance of welds & grinds are low on my list of priorities with this as I just need it to do the job. Here was my cut pieces for the base:

The two 2’ x 3’ dragon wagons weren’t big enough to do it all in one go so I broke it into sections. I did the center part first. Here is the fit up for that:

There still wasn’t enough room to place the fixtures, but it was close. So I got creative, and I used the 4x1x1 fence blocks to step back the 4x1x2 fence blocks by 1". This was kind of handy because it left a 1" tall riser to raise the outside edges off the table. I ran out of those so in a some places I had to use 6x1x2 fence blocks with the pins spaced so the back side could hang off the edge of the table (only 1 pin in a table hole) and kept them from pivoting with 4x1x2 fence blocks next to it at a 90 degree angle.

Then to get each side section, I had to shift the work piece over, one side at a time, hanging off the table. So weld, flip, weld, shift, weld, flip, weld, shift, etc. Here you can see the bottom view with the last side:

Here it is with the bottom 32 holes drilled and the leveling casters test mounted:

And the top with the welds rough ground flat:

Here are the results of how I did with how accurate I got the dimensions, how square, and and how flat (for the top as I don’t care to grind down the bottom welds): Nearly all the way around was about dead on, except one center measurement was less than 1/8" short (still good for my purposes). The diagonal measurements put it within 1/16" of square. I don’t have as good a straight edge as Jason does but I have a quality 4’ level. According to that, taking it across both diagonals, there were only a couple spots that deviated and the worst was only 3/32":

This was across a 40" x 41" footprint. I’m not sure where that ranks with the more experienced folks on here but that seems pretty tight tolerance to me, definitely good enough for my purposes. I know I would not have been able to do that without the fixture table & fixtures, and it seems like it did a really good job at limiting the weld distortion, even in the hands of someone new to fabrication & welding.

[Fireball_Jason]

Looks really good to me.Ive found that tubing your using is notorious for being puffy in the center of the rectangle, so it doesn’t sit flat in the table. This is out of our control so the flatness you showed is acceptable.