D.I.Y. Rostrum Part Two

The Filmcraft 80 Rostrum is suitable for 8mm cameras and light 16mm cameras. In issue 14 we described how to build the main framework. David Jefferson continues with the base.

As mentioned in part one of this article, the methods given are the ones I used. They are only intended as a guide and you can adapt them to suit your own skills, materials and requirements. Study the drawings and photographs before you begin and check that the measurements match the size of paper and eels you will be using. My stand was designed for 10 field paper 8½” x 10½”.

I began by ironing on the edging strips for the Contiplas chipboard. This is trimmed off and finished with a wood file.

The plastic peg bars slide in grooves cut with an electric router. The bars I used were exactly half an inch wide so a half-inch router bit did the job. The bars were held in place by a magnetic strip. I came across the magnetic strip in a glass merchants. It is used to fit light-weight secondary plastic double glazing. The strip is made by 3M and marketed under the name of ‘Magnetherm’ flexible magnetic fixing system. It consists of a flexible plastic which has magnetic properties and a thin metal strip. Both have a peel-off strip that exposes a sticky back. I fixed the metal strip to the underside of the peg bars and put the plastic strip in the bottom of the groove. (Drawing 1.) The depth of the groove is calculated to accommodate these three thicknesses.

The base is designed to slide left and right, forward and backward. It can also be locked in any position by tightening two bolts. This was done with a series of aluminium angle, channel and flat strips. The way they go together is shown in drawing 2. The sliding assemblies are drilled and countersunk to take the chipboard screws that attach them to the baseboards. The lower board slides left and right while the upper board slides backwards and forwards. The locking bolts turn in threads cut with a thread tap. I standardised on ¼” Whitworth. I stuck rulers on the baseboards in both directions to use as a panning guide.

I will give construction details of the glass pressure plate in the next issue.

page 1 | page 2