The Filmcraft 80 Rostrum is suitable for 8mm cameras and light 16mm cameras. David Jefferson tells you how you can build your own version of it.
When I designed the Filmcraft 80 Rostrum in 1979 I had three basic criteria apart from the obvious one of it doing the job well.
1: It had to have a professional quality finish.
2: It had to pack flat to go through the postal system.
3: It had to be possible to make with conventional D.I.Y. tools.
When you come to make your own rostrum you may decide that items 1 and 2 are not top priority. Also you may not have the same tools as me. The idea of this article is to give you a guide. It is up to you to select methods and materials to suit your circumstances. I usually search around my workshop to see what odds and ends are available when I am building something for my own use.
It is difficult to say what it will cost you to make as prices of materials vary so much from shop to shop. All I can say is that the complete thing cost me around £50 in materials, excluding the lamp units, when I last made one a couple of years ago.
The tools I used were an electric drill on a stand, with bits to suit the bolts used, a router, a hacksaw, a metal file, a hammer and a screw driver. A sturdy workbench and metalwork vice were used for precision but you could make do with any firm table.
Animation books show a great variety of Constructions ranging from an upturned table with the camera resting on a wooden platform above the legs, to elaborate rostrums made out of TV aerial masts and Dexion angle. None of these fitted my first requirement of professional quality finish. An enquiry to a local engineering firm about welding some tubes up to form the framework resulted in a quote of £20, far too high for the budget price stand I had in mind. The reason given was the need to set up jigs to hold the tubes during the welding operation.
Then I discovered Dexion Speedframe. This is a marvellous tube and joint system used extensively in shop fitting, for knock-down exhibition stands and one off office and laboratory benches. It consists of square tube with a glossy black finish, available in any length up to twelve feet. There is a three-quarter inch and a one inch size with a system of joints to match each one. It is not sold in shops, it is distributed by the manufacturer through their own outlets around the country (see head office address below). My local Speedframe distribution centre is on a factory estate. They will sell a few feet over the counter for cash. If you take along the measurements they will cut it to size for a small extra charge.
Construction method
Work out the required lengths of Speedframe and cut them to size. I arrived at the stand height shown in the drawing as follows: The nearest point of focus of the zoom lens of the camera I had in mind was five feet. A two dioptre close-up lens would be used to bring this down to 18 inches. When a supplementary lens is used the distance is measured from the front of the lens to the subject and not from the film gate as with the camera’s own lens.
The total height of the frame will be 18 inches plus the distance from the front of your camera’s lens to a line through the camera representing the tripod bush. See sketch 1. The focus of a supplementary lens can be adjusted with the normal lens focusing system. This means that the distance from the baseboard to the lens is not all that critical.
The length of the top arms will be determined by the distance from the tripod bush the the lens. The measurements shown are for a camera with a pistol grip. The centre of the lens should be about 8 inches from the back uprights.
I ended up with two lengths of 1 inch Speedframe at 23 inches and two lengths at 14 inches. One length of three-quarter inch Speedframe at 37 inches and two lengths at 4 inches.
I used two corner bunts at one inch and two at three-quarter inch. Two base plates are used. All these joints come in packs of four although my local stockist was prepared to split a pack. One of the ways of fixing the tripod bush plate requires two extra one-inch corner joints.
When you have cut the Speed-frame clean up the ends with a file. Drill holes, as shown in the drawing. Paint the ends of the frame and the edges of the holes with a black gloss paint.
Assemble the frame. You can get extra information on this from the Dexion catalogue available from stockists. The joints for Speedframe are supplied with plastic sleeves. These are put into the ends of the tubes and the joints hammered home with a soft faced hammer. If you don’t have a soft faced hammer then the blows from a normal hammer can be softened by putting a folded newspaper over the joint for protection. The joints are made of alloy so they would soon dent otherwise.
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