Making your own custom length Rail for Oehler SkyScreen III Units
This technique for making your own rails for Oehler skyscreens (SkyScreen III) was given to me by the Oehler technical support staff.
One of the great features of the Oehler Model 35P chronograph is that you can use different skyscreen spacing to meet your particular needs. If you need more portability, you can use shorter spacing. If you need more accuracy and can use a longer spacing between skyscreens.
You can make your own rail for the SkyScreen III units used on Oehler Model 35P Chronographs and the Oehler Model 43 Personal Ballistic Laboratory. Rails can be made for any spacing supported by your unit. The most common lengths are 2 feet, 4 feet, and 8 feet. Use standard half-inch EMT electrical conduit for the rail. Use a piece of conduit that is at least one inch longer than your intended spacing between the start and stop screens. I prefer to cut mine 2 to 3 inches longer. On a flat floor, put all three skyscreens on the rod, with each skyscreen upside down with the optical window slits against the floor, and at their approximate positions. This will assure that all three skyscreens are lined up perfectly, and that none of them are canted on the rod. Carefully space them on the rail to the desired spacing, making sure that they are spaced correctly, with less than 1/64 of an inch error. Use a c-clamp or vice grips to clamp the two halves of the start screen together. Do not clamp it too tight. You just want to make sure that it does not spread during the next steps. Use a ¼” bolt or all-thread with the stand course thread pitch of 20 tpi to dimple the rail by screwing it into the base of the skyscreen until it touches the conduit, then turn no more than one and a half turns more. This should be sufficient to dimple the rod so that you can return to this exact position each time you attach the skyscreen to the rail. I recommend that you NOT use the studs that come with the skyscreens because the end of the threads will likely be damaged by this process. Repeat this step on each of the other two skyscreens, being careful not to move the skyscreens, and double checking the spacing before tightening down the screws and creating the dimples.
This technique for making your own rails for Oehler skyscreens (SkyScreen III) was given to me by the Oehler technical support staff.
One of the great features of the Oehler Model 35P chronograph is that you can use different skyscreen spacing to meet your particular needs. If you need more portability, you can use shorter spacing. If you need more accuracy and can use a longer spacing between skyscreens.
You can make your own rail for the SkyScreen III units used on Oehler Model 35P Chronographs and the Oehler Model 43 Personal Ballistic Laboratory. Rails can be made for any spacing supported by your unit. The most common lengths are 2 feet, 4 feet, and 8 feet. Use standard half-inch EMT electrical conduit for the rail. Use a piece of conduit that is at least one inch longer than your intended spacing between the start and stop screens. I prefer to cut mine 2 to 3 inches longer. On a flat floor, put all three skyscreens on the rod, with each skyscreen upside down with the optical window slits against the floor, and at their approximate positions. This will assure that all three skyscreens are lined up perfectly, and that none of them are canted on the rod. Carefully space them on the rail to the desired spacing, making sure that they are spaced correctly, with less than 1/64 of an inch error. Use a c-clamp or vice grips to clamp the two halves of the start screen together. Do not clamp it too tight. You just want to make sure that it does not spread during the next steps. Use a ¼” bolt or all-thread with the stand course thread pitch of 20 tpi to dimple the rail by screwing it into the base of the skyscreen until it touches the conduit, then turn no more than one and a half turns more. This should be sufficient to dimple the rod so that you can return to this exact position each time you attach the skyscreen to the rail. I recommend that you NOT use the studs that come with the skyscreens because the end of the threads will likely be damaged by this process. Repeat this step on each of the other two skyscreens, being careful not to move the skyscreens, and double checking the spacing before tightening down the screws and creating the dimples.
