Tweet
I have obtained one of the new lower film tension rollers designed and manufactured by forum member Steven Lee. This roller is intended to replace the spring loaded black plastic film tensioner located between the sound pressure roller and the bottom sprocketof the GS1200. The existing Elmo black tensioner is a known source of film scratches.
The kit from Steve comes nicely packaged in a little plastic box and includes the following items:
1. The roller assembly, consisting of the rubber roller which is mounted on a miniature roller bearing, and already attached to a 3D printed black plastic arm. The roller is centered on the shaft by two small compression springs, which push on the inner race of the bearing only, thus allowing the outer race and rubber sleeve to spin absolutely freely while keeping the roller in its exact central position on the shaft. A very nice design.
2. A shoulder bolt, which bolts the roller assembly to the existing hole in the projector chassis.
3. A tiny tension spring, used to attach between the black plastic arm of the new roller assembly and the existing metal eyelet on the projector,
4. A hex wrench for the new shoulder bolt.
There were no instructions supplied.
In order to gain access to the parts, I began by removing the lower green film guide around the bottom sprocket, and also the pressure roller arm over the sound head. Next I removed the existing Elmo black plastic film tensioner and its associated tension spring.
The new roller and arm bolts right in place with no problems, and when the shoulder bolt is fully tightened the roller can move freely up and down. I found it very difficult to attach the new spring which is much stiffer than the existing Elmo spring. I finally gave up and reverted to the original Elmo spring. Even so it is best to attach the spring to the black arm and metal eyelet BEFORE bolting the arm and roller and eyelet in place. Then adjust the spring tension by rotating the metal eyelet. I set my eyelet to about a 7 o'clock position.
After replacing the lower green film and the pinch roller arm, I ran a few reels of film and observed that the roller was happily spinning freely at all times, and the roller arm was moving gently up and down when required to correct film tension. Needless to say, no scratches were caused on the projected films.
I think Steven has done a wonderful job here and has come up with a design that totally achieves its goal of eliminating film scratches from the existing Elmo black plastic tensioner.
Well done indeed!
Highly recommended *****