Yet Another Code Monkey

February 11, 2010

Project Cleanup part 2 – Grid beam

Filed under: DIY — Tags: — codemonkey @ 5:43 pm

The kids toys downstairs have gotten completely out of hand.  I’m going to make a stand to hold some bins that we can put some of the toys into.  You know what I’m taking about… wooden sides with plastic bins tilted a bit so you can reach into them.  I’ve seem some for sale at the store, but they seemed pretty expensive for what you get.

A few months ago, I saw a blurb about Grid Beam on Hack-a-Day.  There are a few other useful links out there (Makezine and and I made a mental note to look into it some more the next time we needed any kind of furniture, especially for the kids.  So, I sketched out a rough diagram of what it would look like.  3 bins high and 3 wide.  I already had 5 bins; I needed 4 more plus the wood and hardware.  It would end up about 4 feet high, 8 feet wide and 16 inches deep.

Grid beam is a building system where you use sticks (wood or metal) with regular-spaced holes the same distance apart as your sticks are wide.  The pieces are fastened together with bolts.  Because of the hole spacing, the corners come together in a way that help make the whole thing square.  I used 2x2s, which are actually 1 1/2 inches wide, so I’d need holes every inch and a half.

Most of the grid beam pages I looked at recommended using special bolts and nuts called Joint Connector bolts, like these (link type BA or BB).  With these, the heads are flush with the wood so you won’t hurt yourself if you bump into it, which is important since the kids will be using it.  I couldn’t find these locally, and they seemed pretty expensive to order, so I ended up using 3-inch long 1/4-inch bolts and T-nuts.  The nuts required the final hole size to be 5/16-inch.

The list of supplies:

  • 12 8-foot 2x2s.  I only ended up needing 8, but now I have extras
  • 1 3-foot pieces of 2-inch wide aluminum angle stock for the jig
  • 3 5/16-inch drill bits.  I’m drilling hundreds of holes, so they’ll be wearing out.
  • a box of 3-inck long 1/4-inch bolts.  Round head that takes a phillips driver.
  • a box of T-nuts the bolts fit into.

The first task was building a jig for drilling all those holes.  I used a 3-foot piece of aluminum angle stock.  Clamp the ruler to the aluminum at both ends and mark the metal every inch and a half.

Mark hole locations

Now, I’ve already made two mistakes.  The first one is that line all the holes are on should be a distance of 1/2 of the hole spacing from the corner of the jig.  Here, I’ve clamped the ruler 1 1/2 inches (one whole hole spacing) where it should have been 3/4 inch.  The second problem is that the first hole should also be a half-hole-space from the end, not a whole-hole-space.

Anyway… score a line along the length of the ruler.

Scored along the ruler

And drill a pilot hole each place where the lines cross

Pilot holes

Here’s a picture of the jig when all the holes are drilled at the correct 3/4-inch spacing from the angle: the holes on the top.  The holes on the bottom edge are the incorrect 1 1/2-inch distance.  I guess I could use it for 2x4s…

Final holes

And finally, after cutting off 3/4 inch from the end


At this point, I have a good jig,  The next issue is that when I went to the lumberyard to get 2x2s, it was pretty slim pickings.  Pretty much every single piece was bent and/or twisted, so I could only pick out the least warped pieces.  Next time, it might make more sense to get 2x4s and rip them down to 2x2s myself, since 2x4s are less likely to be really warped.

I don’t have a drill press either, so the best plan was to take several clamps and force the wood straight, at least long enough to drill the holes.  Oh yeah, and hope the holes are straight.

clamped wood

Since my wood is 8 feet long and the jig is only 3 feet, after drilling a batch of holes, I had to move the jig down and reclamp it.  I used a 5/16 bolt to position the jig in the last hole drilled before I moved the jig.

More holes

A dozen 8-foot 2x2s and about a zillion holes later, I’m done drilling.  The jig is pretty much worn out from the side of the drill bit eating away at the holes.  If I’d used steel for the jig, or had a drill press to make cleaner holes, it might not have been so bad.  The picture isn’t really clear, but it’s supposed to show the 5/16 drill bit (the original size) in one of the holes.  I was able to fit a piece of 14-gauge wire in the space, but not 12-gauge, which means it’s 0.064-inch (just over 1/16) oversized.

Worn out jig

Worn out jig

Finally, here’s a picture of the T-nuts I’m using, in case you’re not familiar with them


1 Comment »

  1. [...] the last post, I made up all the beams for the kids’ new toy bins.  Because of the way these grid beam [...]

    Pingback by Project Cleanup part 3 – More grid beam | Yet Another Code Monkey — February 16, 2010 @ 10:36 am

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