Monday, December 26, 2005

Grid wall instruction

UPDATE (June 21, 2006): I've made a few changes to the design, making on site assembly (at the art show) easier and probably even lowering the total cost by $20 or so. Read through this posting first, then take a look at the changes I made here

I promised back in September that I'd get these instructions up in the next couple days. So much for that, but better late than never, so here we go. But before I get into the details, just to clarify for those unfamiliar: 5" = 5 inches, 5' = 5 feet. Don't mix them up

Cut your conduit

First thing we need to do is cut up the conduit. We'll need 22 pieces of 10' long, 1/2" electrical conduit. Take 18 pieces of conduit and cut them all the same: Cut off a 5' 6" section (66"), a 3' 1/8" section (36 1/8"), and your remainder should be about 17 5/8". Next, take 3 more pieces of conduit and cut each one into 4 equal pieces or about 2' 6" (30") each (minus whatever is lost to the sawblade). Finally take the last piece, cut off two 4' 6" sections (54"), and scrap the remaining foot.

In addition, we'll also need 1 piece of 10' long 3/4" electrical conduit, which will be cut into one 5' section and two 2' 6" sections.

Drill and assemble the 9 panel frames

Next, we will need 36 corner braces. I used some heavy duty 3" braces. They are 3" long on each side and have 2 holes approximately 15/16" and 2 9/6" from the corner. If your dimensions are different, you will need to drill some of the holes differently in the next step.

Now we need to prepare the tubes for assembly. Take all 18 of the 66" sections, all 18 of the 36 1/8" sections, all 12 of the 30" sections, but only 6 of the 17 5/8" sections (the other 12 can be set aside for now). First, use a flat file to smooth down the cuts on each end. Now, what we need to do is drill the necessary holes in them according to the diagram below.

There are a few important details. First, it is important that these holes be drilled as accurately as possible. It would be best to use a drill press with a table vice and a production stop. That way you can be sure the corresponding holes get drilled at the same location on all 18 pieces so that they all line up later. Second, you want these holes to be drilled parallel to each other, so that both the entry and exit holes line up. With a drill press, this is no problem when drilling a square piece of stock. However, with a round piece of stock (ie: no flat surface) it's VERY easy to rotate the stock at an angle.

This problem would best be solved with proper machining facilities. However, doing this out of my basement, I had to improvise. The trick I used was to purchase a 6" long 1/4" bolt and small 6 " magnetic level. Assuming your drill press table is level, and your drill bit is perpendicular to the table, you drill your first hole in each piece at any angle. Then for subsequent holes, you place the bolt sticking up through the original hole, stick the level onto the bolt, rotate the piece until it's level (ie: the bolt is pointing perfectly up), clamp it down in the drill press, and drill your hole. After all holes are drilled in each piece, use a round file to clean out the holes and a flat fill to remove any left over burrs.

OK, onto the diagram. Using a 1/4" drill bit, drill holes into each piece of conduit according to the diagram below (click the picture for a full size image).

Now with all the holes drilled, we need to assemble the 9 sections of panel. For each one, we will need two 66" conduits, two 36 1/8" conduits, 4 corner brackets, 16 bolts (1.5" long, 1/4" diameter) and 16 nuts (1/4" diameter"). Connect them together so that they end up like the following picture (note how the excess length of the bolt is on the INSIDE of the frame.

Now that each frame is assembled, you should be left with 4 unused holes on each of long sides. These holes will be used later by the bolts that hold the sections together to form an entire wall. We're not ready for that step yet, but there is one thing you should do at this point. In theory, if you machined all of you pieces identically, then all the holes should line up perfectly. However, in reality there probably are going to be slight differences in the way things line up. To make assembly easier, it would be nice if these holes were opened up slightly to allow some room for error. To do this, I took a hand drill with a 1/4" drill bit, put it in each hole, turned it on, and rocked the drill around to all angles (kind of in a circle). This widens the hole up slighly to allow room for error and to make assembly easier. Then I just filed down the holes again.

Attach grid wire to each panel frame

Once you have that done for all 9 sections, then we need to apply the grid wire. Get a 50' roll of 36" wide grid wire (the holes in the grid should be 2"x4"). If you cut this VERY carefully, you should be able to get all your cuts out of 1 roll (with about 6 inches to spare). You want to cut off 9 section that are 64" long. However, no matter how you cut the wire, either the piece you are currently cutting or the next piece will have some nubs sticking out at the end. What you really want to do is cut the wire just before the 66" mark. The extra 2" nubs will be on the piece you just cut off. Then you can trim them off the current piece you that you have a 64" piece of grid. The diagram below should make this more clear. It depicts the nubs on the right side. After you trim off the 2" nubs, the right side and left side would look the same.

Now you want to take each section of grid wire, grind off any sharp ends from your cuts, set them in place in each of the 9 frames, then use a couple dozen 7 inch zip ties to secure the grid wire in place. When you attach the zip ties, it's a good idea if you space them out evenly, and its also helpful if you attach them at the same locations on each panel. After attaching all of the zip ties and pulling them all tight, you can now use wire cutters to trim off the excess.

Assemble 9 panels into 3 walls (3 panels each)

Now you should have 9 panels built. Next step is to assemble each of the 3 walls (and you will need to do this each time you set up your display). Take 3 of your panels and lay them on the ground. Take two 17 5/8" pieces and place them between each pair of panels at the top edge, so that about 1" of tubing will stick out over the top of the panels once they are assembled. Now take 4 of the 30" pieces, and place these at the bottom so that they stick out about 16" to form the legs, one on the left end, one on the right end, and 1 between each pair of panels. Now we need to bolt them on. To do so, use 1/4" bolts and nuts. Use a pair of 2" length bolts to attach each of the 2 legs on the ends. Then use a pair of 2.5" length bolt on each of the middle legs and each of the upper arms.

One note before bolting these down. You may notice that the heads of some of the other bolt on the 3 panels will be sticking out, getting in the way of each of these tubes you try to bolt on. My solution was to take a pair of 1/4" hex nuts, tape them to the jaws of a vice so that they line up (one on each jaw), mark each piece of tubing where a bolt will be in the way, place the tube in the vice so that the taped hex nuts line up with the marks, then tighten the vice to indent there areas. You can kind of see how this looks in the top picture above. I also found that the straps from the zip ties also got in the way a little. To deal with this, I just place that section of the tube in the vice (without the hex nuts...using the bare jaws) and tightened it down to indent it JUST A LITTLE BIT. Don't overdo it. Once you have this done for all the pieces, go back and assemble them with the bolts as indicated above. Repeat assembly instructions for each of the other 2 wall.

Attach the walls to your canopy frame

If you followed instructions correctly, you should now have a full wall, approximately 9.5' wide (I never measured it exactly). This should fit perfectly between the legs of an EZ-Up canopy. Take each of the 3 walls, stand them up between the canopy legs, then zip tie them to the legs using some heavy duty zip ties. I initally took 2 of my 7" zip ties, connected them together to form a longer one, and used this. However, I have since purches some heavier duty 11" ties instead. Whatever you decide, you will want to use 4 ties on each wall (one at the top and bottom of each end).

Assemble crossbar supports

Your display should now be pretty sturdy. It could probably stand on it's own this way just fine. However, I wanted to be a little more careful, and add a little more support. And that's what the little 1" nubs sticking out at the top of each wall are for. I built some cross supports. I put one long support going from the left wall to the right wall, and the a shorter support going diagonally from each of the side walls to the back wall. When all 3 are attached, you get a sort of triangle shape, but with the points of the triangle flattened off . You can see these supports in the photo below.

To consturct the longer support, take the 5' section of the 3/4" conduit, and slide one of the 54" section of 1/2" conduit into each end. You will need to find a way to bold these pipes together tightly. The easiest way I found was to use soome litle threaded inserts...the kind used to add metal thread holes into a wooden object. I used ones that are threaded to accept 1/4" bolts. I then drill a hole in each end of the 3/4" conduit big enough for the insert to poke through, then placed the insert through the hole from the INSIDE of the conduit sticking out. The problem here was, because of the shape of the threaded insert, there was no longer enough clearance inside the conduit for the 1/2" conduit to fit. To fix this, I had to file off a lot of the insert to make it fit better. It's really difficult to explain this in words, so the pictures below should make this clearer.

unmodified threaded insert

threaded insert, filed down

threaded insert installed in cross bar

Instead of doing all of this, you could just use a single long piece of 1/2" conduit for the support. However, you then have to make sure to cut it at the exact length, and you need to fit this nearly 10 foot long piece of conduit into your vehicle. With the design I used, the length is adjustable, and it disassembled to a much more manageable length.

Now you need to repeat this process for each of the smaller supports. For each one, use one of your 2' 6" sections of 3/4" conduit along with two of your remaining 17 5/8". Repeat the process of drilling holes and inserting the threads.

Finally, you will need to attach each of these sections to the walls. You'll need to use six L-connectors for 1/2" electical conduit, as shown in the image below.

Loosen the bolts on the support bracket, attched on of these L-connectors to each end, tighten down the screw on each connector, puth the entire support in place, tighten it down on the wall section, then tighten the bolts on the support.

Enjoy your grid walls

This is certainly no easy task to get these all assembled, but if you made it this far...congratulations.

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