The later Bell & Howell machines with the ELC type lamp are indeed excellent if they are in good condition.
I've noted the comments regarding lubrication of the worm gear: My experience however, would seem to indicate that there's a bit more to it, ie. a problem in manufacture.
I was given a brand new B & H replacement gear some time ago expecting it to come in useful if / when the one in my machine cracked. It sat on a shelf in my nice clean workshop, on hand if it was ever needed (not that I was looking forward to the half day's work needed to do the job). I happened to glance at it one day and noticed brown lines appearing under the nylon sleeve in exactly the same pattern as a failed gear. My nice new gear was useless! The original one however, is still perfect. I can't help thinking it might be just 'pot luck' ?!?
Solid (replica) replacement gears were available at one time though I'm not sure of the situation now. Best regards, John W
