Film-Tech Forum ARCHIVE: Simplex XL: why 2 vs 3 piece pressure pad in trap?

This is topic Simplex XL: why 2 vs 3 piece pressure pad in trap? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Gary A. Hoselton (Member # 3447) on 11-11-2015, 06:56 PM:

I have two Simplex XL's in changeover setup. The film trap door (gate) in one has 2-piece pressure pad (the rails which press the film against the trap and aperture), the other has 3-piece. Why the difference, and is one preferable?

Posted by Brad Miller (Member # 2) on 11-11-2015, 07:05 PM:

The 2 piece was a prototype thing. (At least that's how it was explained to me.) They are VERY hard on splices and just generally suck. The 3 piece is much more gentle on the film. I have never seen a performance difference on screen between the two.

Posted by John Eickhof (Member # 323) on 11-11-2015, 08:59 PM:

The two shoe straight gate was not a prototype, it was the original factory gate that the XL was originally designed with. It had a solid long pad and a small top pad and was the stock type sold that way throughout the run of the XL into the 1980's. (the curved gate was not introduced until the late 1960s) The three shoe trap was known and specified as the 'studio trap' as they were designed by Howard Straight in the early sixties for studio use by using the Simplex E7 style pads.(later a factory option when buying a new projector) Howard also did a mod to the trap by installing a screw stop to pre-adjust tension on the trap door as the stock straight gates were notorious for having excessive tension on film. (similar to the primary tension adjustment setscrew provided on the curved gate) Heads with the mod were quiet and smooth and were comparable to the E7 for picture quality. In fact, most studios preferred the E7 long into the late 60's. Howard also made the first Simplex 35/70s and the rock and roll (reversing) studio XLs in his shop. (Straight Industries, Los Angeles) He was a factory consultant for decades to Simplex and Strong. I knew him for several decades and am proud that he willed his home machine shop equipment to me when he passed years ago. I miss the wealth of information that he was regarding first quality projection. And, Gary, if your XLs were ever rebuilt or worked on by the late Dick Prather of Portland, they probably have the tension mod already done, and both will probably exhibit a high quality image. Dick was very meticulous about film tension and picture quality. Only for sake of standardized parts spares, would I suggest you go with the two shoe type. Only the trap door is different so you could pick up another one of the type you prefer. Personally, I have found the two piece with the tension mod is less noisy and handles worn film better than the three piece. I tend to stay away from the curved gate as they are definitely louder and unsteady when running curled or edge damaged prints as well as unlubricated film. If you need parts for either type,let me know.

Posted by Monte L Fullmer (Member # 2797) on 11-12-2015, 01:50 AM:

And I'll add:

I made a post here long ago on F-T in which I called the "perfect threading" technique.

Perfect Threading

Works great with the flat trap XL units and other makes..which does make the operation extremely quiet.

Goo Luck ! - Monte