Page:Popular Science Monthly Volume 91.djvu/794

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��Popular Science Monthly

��Making a Re-Winder for a Motion Picture Film

AFTER a motion picture film has been run through a projecting machine it is necessary to re-wind it upon another reel before it can be exhibited again. There are many devices on the market for doing this. For the amateur possessing a small machine and not wishing to purchase a re-winder, the device described herewith will be found adequate.

The re-winder consists simply of two supports fitted with suitable shafts for the film reels to revolve upon, one of which is provided with a crank and ratio of gearing, to enable the speedy re-winding of films. The one described in this article is intended for the standard iooo-foot reels, which are about 10 in. in diameter, but the dimen- sions may be varied to accommodate larger reels, if desired.

The supports are two posts, preferably of hard wood, 8 in. long and 2 in. square. At a point 1 in. from the top of each post a J^-in. hole is bored through the center. From 1/16-in. sheet steel four plates are cut, two of them 2 in. square, and two 3^ by 2 in. The two smaller plates are drilled as shown in the drawing with three 3<£-in. holes, and screwed to the sides of one of the posts so that the central hole coin- cides with the hole in the post. This forms the bearing for the shaft which sup- ports the reel. The two larger plates are drilled with four holes, and screwed to opposite sides of the other post so that the two central holes coincide with the two

���A film must be reeled back before it can be run through the projecting lantern again

holes in the post. The reel supports are now completed.

The shafts on which the film reels revolve are 4^ in. long and are cut from J^-in. brass tubing. At a point i^-i in. from the end of one of these rods a 1/16-in. hole is drilled and a small brad driven into it and filed off, leaving a point about 3/16 in. long

��projecting. This is to fit into the corre- sponding slot in the reel so that it will revolve with the shaft. The shafts are slipped into their bearings in the posts and held in place with collars and set screws placed .on either side of the posts. The shaft to which the crank is screwed is 2% in. long. After the shaft is slip- ped through the holewhich serves as a bearing, a large spur-gear is fastened to it close to the post,

��-SHAFT-

Brad to engage slot i n film reel

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���Dimensions of the parts, plates and shafts for making a convenient re-winder for films

meshing with a smaller gear on the reel shaft. These gears may be of any con- venient size, but a good ratio is three to one, the smaller gear being % in. in diame- ter, and the larger one 2 34 in.

The two supports now completed are screwed to a base consisting of a board 24 in. long, 6 in. wide and Y2 m - thick. To allow an inspection of the film as it passes from one reel to the other, these should be placed about 20 in. apart. When it is desired to re-wind a reel of film, the collars on the protruding ends of the shafts are removed, the reels slipped in place, and the collars replaced. — Lucius E. Winchester.

��A Hard Finish for a Lunch Counter Top

THE best finish for a bar or lunch coun- ter is linseed oil well rubbed into the wood when it is new, and often later on.

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