The following article is a guest post by Dwight Duckstein.
I purchased a used Nikkor 70-200mm, 2.8f lens – the old style that didn’t have a tripod ring. Not wanting to spend even more money on an aftermarket ring that would interfere with the A ring, I decided to make my own. Granted, the materials cost me some change, but it is designed the way I want it, and it works. Your dimensions may vary, depending on which lens and which camera you mount it to, so I am not providing much dimension detail here.
- Aluminum bar, anything around 2” wide, and 1/8” thick.
- Rubber coupling for 3” pipe – the kind with two hose clamps on a rubber tube
- 8-32 x 3/8” screw, flat head
- Brass 8-32 knurled nut – wing nut would be fine too
- 1/4 – 20 nut
- 1/4 – 20 bolt/knob for tripod hole in camera
- 1/4” bolt keeper
- Canned Aerosol truck bed liner spray
- Tube JB Weld epoxy
- Small square red gasket rubber
- Glue – I used E6000
All of this stuff came from a good local hardware store. I lost track of the actual cost for one bracket – so it’s entirely possible this thing costs as much as a commercially available one, but I doubt it.
1. Main Rail
I began by bending the offsets in the metal. You could leave the metal straight, but it might tend to flex a bit in use. The bends break up the length of the bracket into smaller runs that won’t bend as easily. I didn’t get the angles exactly as I wanted them, but was able to do some minor adjusting and live with the results. Use a bench vise to do the bending. The amount of offset is pure guesswork, however if it is too much offset you will have problems with the dimensions between the ends and the tripod hole in the center.
2. Lens Ring
The lens ring consists of ½ of the 3” rubber coupling with some additions. Cut one ring of the rubber off the main coupling, leaving about 1/4” material on either side of the groove that holds the hose clamp. Drill a 3/16” hole in the hose clamp where the strap is solid – between the adjusting screw and the beginning of the slotted portion. Insert a flat-head 8-32 screw through the hole pointing outboard. The knurled nut will be used to attach the ring to the rail.
I sprayed the hose clamp and the main rail with the black undercoating that is intended for truck bed liners. You could also just paint it or leave it natural.
Drill a 3/16” hole in the end of the rail to accept the lens ring. At the appropriate length for your camera, drill a 5/16” hole for the camera screw in the opposite end. Insert the screw up through the hole and attach it with the bolt retainer. Bolt retainers are just a washer that is too small to pass the bolt, but with slots made into the inner circle to engage the threads. Attach the rail to the camera and determine the approximate center of gravity by setting it over something like a dowel on a table – teeter totter it till you find the balance point. Drill a 7/32” hole in the center of the rail at that point. Tap it to 1/4-20 threads. Screw a waste 1/4-20 bolt up through the hole. Screw a 1/4-20 nut down from above and glue it in place with the JB Weld or similar manner. Once dry, remove the bolt. This reinforced threaded hole is for your tripod mount. I also attached a sheet of thin rubber to the surfaces that touch the tripod mount and the camera mount to help stabilize the bracket.