Clamp-on 360° swivel hobby vise
3" spring clamp
Screws and other hardware
Step 1: Research and Planning
I kept coming back to the idea of the classic swing-arm lamp that clamps to a desk or drafting table. Using one of those as the core of my project would take a lot of the mechanical fiddling out of the process. I was concerned that it wouldn't have the juice to hold up the work, though, so I went searching through instructables to find other folks who had re-purposed these mechanisms.
That turned out to be surprisingly tricky. At first I thought I was looking for "Tensor" lamps, but that is a completely different technology. The lamps I was picturing were usually called "swing-arm lamps", but non-US 'iblers more often called them "Anglepoise lamps". I also saw people calling them "balanced-arm" and "floating-arm" lamps.
In the end, I created a Guide to pull all of these projects together, so you don't have to. You're welcome. :-)
I determined that one of these lamp arms would probably hold a bead loom or mid-sized embroidery hoop with no trouble. The Edmunds model is heavier-duty, but people use those to hold big embroidery frames loaded with a yard or more of fabric. My wife doesn't do anything like that. At least, not yet.
I also knew I would need a means to adjust the angle at the end of the arm. I decided to keep my options open, but I liked the look of this multi-directional hobby vise. The whole thing would be too heavy for my purpose, but I thought I could cannibalize it for the ball-and-socket joint.
Step 2: Procurement
I bought my swing-arm lamp at a secondhand store in Stillwater, OK, where I happened to be for a day. There was no brand-name or other identification. There are many like it, but this one is mine. Cost: $6
I went to Re Tool for inspiration on the business end of the arm. This is a franchise business selling used power and hand tools. It's an extremely dangerous place to enter with a credit card. I resisted temptation after temptation as I searched. I was hoping to find one of the aforementioned hobby vises, but they didn't have one. I did pick up a small spring clamp for the "hand" at the end. Cost: $1
My next stop was Steve's Wholesale Tools, a regional business (headquartered in OKC) selling new tools and equipment. There I found the vise I saw online. Since I was able to take it out of the box and examine it, I found that it would come apart easily and would work for my needs. This was the only part of the project I purchased new. Cost: I don't recall exactly, but in the range of $20
Whenever possible, I purchase materials, tools, and eqipment from locally-owned independent businesses. For me, part of the maker ethos is improving your community, and contributing to the local economy is part of that. Thus endeth the sermon.
All other materials were on-hand at my home.
Step 3: Discombobulation
The lamp socket is standard hardware. The switch protrudes from the back of the shade and is attached with a knurled nut. Remove the nut, push the switch through, and pull it out the front. You may need to reach in and pull on the cord to get enough slack.
There is a metal bracket holding the rotary switch in place. You'll need to remove that to have access to the wire screws. When you do, the switch will come off, and a tiny brass piece that acts as the electrical contact will fall out of the bottom of the switch and get lost in the carpet. If you ever want to use the lamp socket, find it and put it with the rest of the pieces into a plastic bag.
Remove the wires from the socket. I left the wire running through the swing arm because I plan to add a task light to the stand. If you don't have need for the wire, take it out. It provides no structural support.
The shade attaches to the threaded pivot axle with one nut. A socket wrench will make quick work of it, but pliers and fingers work just fine. From other instructables I've seen, this is one of the parts that varies most widely. Do what you must to get this taken apart.
The pivot assembly is attached to the arm with a carriage bolt and nut. Remove those and a collection of small parts will fall out and get lost in the carpet. Why are you doing this in the living room, again? Dig them out and put them in the plastic bag with the switch and socket parts.
The vise jaws are attached to the ball-and-socket joint with a single socket-headed cap screw, but to get to that, you need to remove the vise screw. A set-screw holds that in. Back the moving jaw all the way off the end of the vise screw, remove the set-screw and the vise screw, and unscrew the vise body from the ball-and-socket. Re-assemble the vise, because it's a useful and functional tool. It can act as a clamp, or as a vise if attached to a suitable base. Bonus!
To reduce weight, remove the socket portion of the ball-and-socket joint from the clamp base. A hacksaw does the job nicely. Hey, look! Another free clamp. The answer to the question, "How many clamps do you need, anyway?" is always, "Just one more."
There's a hole in the spring clamp's handle, hidden under the plasti-dip. Ream it out. Done.
Step 4: Combobulation Part 1
The hole in the spring clamp is the right size to pass the socket-head cap screw that attaches to the ball. That's nice. If it wasn't, I would have drilled it out. I may still add a lock washer to keep it from rotating, but for now the plasti-dip on the handle works fine.
One side of the socket would slide between the jaws at the top of the swing-arm for a short distance. I thought about drilling a hole and installing it there, but it was too close to the edge of the socket for my liking. I got the hacksaw back out and cut a slit perpendicular to the bottom of the socket. Not having planned particularly well, I chose an arbitrary depth of the width of my hacksaw blade. This was a mistake, as you'll see in a moment.
The slit wasn't wide enough to admit the sheetmetal jaw, so I used my Dremel tool to hog it out. The attachment was a grout-removal bit that made short work of the aluminum socket. Once it was wide enough, I slid it into place, marked a spot to drill my hole, and drilled it.
Then I put it together, a fiddly process since the carriage bolt has no screw slot, meaning that I had to have the nut on the outside. Luckily there was enough clearance to put the bolt in one side, slide the socket into place, wiggle the bolt through the socket hole and the second jaw, and then attach the nut.
Here's where my error showed up. The hole I drilled was too close to the top of the socket, so when I put the joint together, it interfered with the cap and made it impossible to tighten the joint. I took it apart, assembled the joint and marked a clearance line, then disassembled the joint, put the socket back on the arm in a way that would allow enough clearance, marked a spot for the new hole, and drilled.
Measure twice, cut once.
That took care of the arm. Now I needed a base.
Step 5: Combobulation Part 2
I thought about drilling a hole in the top of the 2x4 to accept the peg at the bottom of the swing arm, but I was afraid it would wear out and split over time. Also, the peg was slightly larger than my largest drill bit.
I dug through some boxes of junk and found that the peg fit into a pipe nipple with enough play that it rotated smoothly. More hardware hunting yielded two brackets meant to hold roller blinds and a bolt and nut that fit the holes in those brackets. I mounted the nipple with a plywood stop-block on the bottom, the brackets on either side, and the bolt squeezing the brackets tight against the nipple. If I had set the nipple flush with the top of the base, the arm could have rotated a full 360º. I didn't want that, because it would be unbalanced with the arm extended out the back of the base. I chose to put the nipple lower, so that the radius of the arm was limited. In practice, it's still a bit unbalanced with the arm all the way to one side or the other. I may add more stop blocks later to limit the turning radius to 90º.
Step 6: Extras
I also haven't painted or finished it in any way. After the holidays, when my wife has had some time to work with it and I've made any changes it needs, I will probably paint the base black.