Jib Arm

I've separated the main components into the tripod, the basket, the arm with pivots and the counter weight. We'll start with the basket and work our way back.

This is the basket with a gl-1 in it. It's all welded together. If you don't weld and don't know anyone who can (or don't want to pay someone), you could just as easily make it out of wood or another building material that you are more comfortable in. I prefer the durability of mild steel and welding. But there are other options. I used 2-inch flat bar as the main piece and half-inch angle iron to build the basket that extends off the main bar. The triangle support piece is to make sure it didn't sag with the weight of the camera–probably a little overkill, but who cares. I bought a piece of plumber's gasket material (at any hardware store) to seat the camera to the metal plate so it wouldn't slide around. This is the cork-looking stuff that tripods used before rubber. Then I drilled holes in the plate and gasket and put a quarter-20 thumbscrew up through the bottom of the plate to secure the camera.

I love theses cheap digital cameras. It's always properly exposed and in focus. Here you can see the thumbscrew I use to fasten the camera. You can also see the main bearings and bolt (overexposed on the left). I chose to go overkill and use the largest bearing I could get that would fit in the box tubing. My reason for this is that it'd have less angular play, which might be a concern since all the weight will be on one side of the bearing set. Remember, you need bearings on both sides of the box tubing. Don't buy expensive bearings, but also don't buy cheap bearings that have stamped steel casings–It's gotta be cast. The wire going back to the left is for the field video monitor. More on this later.

Whoo hoo! Another shot in focus. For now on, I'm calling it the 'selective focus' feature on my camera. This is the top of the basket and the other arm that creates the 4-link system. In theory it doesn't hold any weight, but it's important that it doesn't bend because then it'll change the properties of the 4-link and the camera will no longer be level. The idea behind a 4-link is if you have two poles standing vertically with one mounted and one movable. And you connecting them with two other orthogonal poles that are exactly the same length and attached exactly the same distance from each other, no matter how you pivot the movable pole, it will always be parallel with the vertical fixed pole. Enough physics, so the second arm is connected with a rod end found at an auto store or grangers type industrial supply store. I welded a stud into the end of the arm so the rod end just screws on. The nut is to lock it in place so it doesn't move. It's also great for fine-tuning the setup to get the two arms exactly the same length.

So what is the piece of metal with all the holes drilled in it? Well, it's a way to relocate the second arm, which also controls the tilt of the camera basket. When I want to do bird-eye shots that I wouldn't be able to do with the arm connected in its normal position, I bolt it in one of those holes.

So lets move back a little to the other side of the 4-link.

Hopefully this is all starting to make sense. You see that the two arms–which are the same length bolt-to-bolt–are attached to the tripod the exact same distance apart as they are on the camera basket. For the main, larger arm, I've used the same bearing set as on the other end. For the second arm, I've used the same welded stud and tie rod end system with a bolt going through. Now, it's tough to see, but the second arm is attached to a pivoting arm of its own (the large hex bolt is where the pivot is–bearings are behind the bolt). By undoing the wing nut shown, I can tilt the camera up and down by moving the bar forward and back. To get more exaggerated tilting motion, I unbolt the second arm and bolt it through the hole in the very top of the bar. I'm told by friends smarter than I, that this is all basic physics ... mechanical advantage stuff we're supposed to learn in high school. What is that arch on the back of the setup? It's a way to lock the arm in place. A bolt and washer go through the hole in the arm (you can barely see it) and lock to the plate. I cheated and used a plasma cutter, but you could cut an arc with a jigsaw or other common tools. Building this entire jib only needs basic tools.

This is setup to do a bird's eye shots such as the picture earlier. With this setup, I will be able to go from a birds eye to a level shot all in one motion. I won't be able to tilt up very far in this configuration, but I could do if I set it up differently. Again, I wanted this to be as versatile as possible.

Moving to the back, the main arm is counter weighted by cheap, second hand lifting weights bought for 15 cents a pound at a play-it-again sports-type store. I designed a way to rough- and fine-tune the balance with counter-weights. The rough way to adjust the balance is to add more weights--simple enough, just unscrew the wing nut. I bought 20, 15, 7, 5, and 2 1/2 pound weights. Metric weights work just as well.

This is the fine-tuning of the balance. The counterweights are attached to a smaller piece of box tubing that slides inside the main arm. By sliding the counterweight farther or closer to the pivot, it will alter the weight supporting the camera on the other side of the jib arm. Again, I'm told this is basic physics. I designed these two wing nuts to keep the counterweights solidly in place. I drilled a hole in the box tubing large enough for the thumb screw threads to loosely fit it. Then I welded nuts onto the box tubing over the holes. So, when I tighten the thumb screws, it clamped down on the inner box tubing. There was a problem, however. After hundreds of adjustments, I didn't want to crimp and destroy the thin walled box tubing. So, I created an insert to go between the thumb screws and the box tubing.

This is that insert. I welded on oversized nuts, and then ground them down to better 'locate' the insert onto the thumb screws. This setup has worked very well. The only downside is that there's one more small piece to loose when transporting the jib arm.

Moving right along, this is the base. All the steel was scrap steel. It was overkill, but free, so I used it anyway. I did feel it was important to gusset the base to the wood round so there'd be little give and play. A little wobble here could dramatically alter the framing of your shot. The metal is bolted to a plywood round bought a home depot. The round is then bolted to a lazy Susan bearing (also bought at home depot), then the lazy Susan bearing is bolted to a second plywood round. Then this round is bolted to a metal frame by which the tripod legs attach. I must admit, this is the weakest part of my design. The !@#$ lazy Susan dolly is made of cheap stamped sheet metal and after the rig fell over off my dolly in an intense day of shooting, it bent the bearing–I've since replaced it. It will still work for you, just make sure you don't put any angular pressure on it (that includes severely imbalanced loads). To the right, you can see a platform with two holes on it. That was originally intended for the field monitor. I decided I preferred to just gaffer's tape the monitor where ever it was most comfortable for that particular shot. The monitor is a POS lcd with about 250 total lines of resolution. The only thing it's good for is framing. This monitor can run plugged into an outlet or via 12 volt camera battery (like the ones for ENG cameras) so it's good for loaction work.

Another angle. In this shot, you can see the bubble to tell if the device is level. This is important as when you pan, your horizon will get canted or Dutch (or sideways in non-camera talk) if you're not level.

Okay, the last thing is the tripod. Why didn't I just adapt an already built tripod? Well, in the interest of making it as versatile as possible, and keeping it as cheap as possible, building worked much better than buying. The downside is that by building a tripod out of steel, I added a lot more weight. I can carry the fully setup camera myself, but, especially if there's a camera on it, I like to use two or three people for safety. The tripod is made out of thin-walled 3/4 inch box tubing. I borrowed the design off many pro tripods by doing a two box tubing lengths sandwiching a third that can be adjsut for height design. This allow almost limitless options in terms of height. By putting in a ten or so foot length of tubing in the tripod legs, I can get the camera 25+ feet tall. Take a moment think about the production value that adds.

This is how the tubing sections are sandwiched together. As previously stated, it's all fully adjustable. It uses the same idea behind the main counterweight system. Drill a hole in the box tubing, weld a nut, and screw in a thumb screw. An in all of these, I use an insert similar to the one in the counter weight system. Obviously, this is done for each tripod leg so there's six total.

This is the bottom of all the legs. I welded a nut onto the end of the center tube and threaded about a foot of all-thread (with a nut welded on the end) into it. This is how I fine-tune the leveling of the base. Also, if I'm trying to get the jib arm as high as it will possibly go, I'll back these out all the way. Note, when using the crane in delicate areas, I gaffers tape clean rags to the feet so no grease, dirt, rust, or paint will come off on rug/hardwood floor/etc. Tread lightly!

All tripods need spreaders. They make it that much more stable by locking everything together. By this picture you can tell I welded tabs onto the lower tube clamps. I bolted three equal length pieces (this is important) of steel flat bar. The center triangle is another contraption invented by me. By pulling (or kicking) the triangle up, the legs fold together for transportation. If you want to set the spreaders into the 'lock' position, step on the triangle. I welded a small piece of flat stock onto the top of where the spreaders attach so they will lock in an extended position and not just fall to the ground. When on a dolly, sand bag the spreaders. If you're not careful, it'll tip on you if not secured properly.

This is all the pieces of the jib arm ready to transport or store. The tripod is folded close and the counterweight and arms are disconnected. I could take it apart a little more, but this fits into most small pickups or SUVs. The three box tubbing poles on the right are for extending the tripod. Like I said before, you can put any length poles in the tripod.

Here it is fully extended up and down.

So really, how much did it cost? Much less than you'd think. If you take the field monitor ($350) out of the equation (at first, I used a second camera set on VTR because I couldn't afford a field monitor), the jib arm costs around $85. The largest cost was the bearings (6 large bearings, 2 tie rods ends, and a lazy Susan bearing). The steel was only about 25 bucks (although I did have some laying around as scrap). It was cheap to build and took about a week on and off to plan and a weekend to build. I'm glad I built instead of bought--it was well worth it.

Hope this was helpful. Feel free to contact me if you have any questions. Below are some of the questions I've recieved. This is my version of a FAQ.