Film-Tech Forum ARCHIVE: Should I attempt to retrofit a Kelmar Lens change turret to Simplex 35?

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Posted by Brad Allen (Member # 470) on 02-27-2004, 02:54 PM:

I have the urge to have lense turrets.
How much of a pain are the Kelmar auto Lense turrets to retrofit to a Simplex 35?
I've read the instructions, doesn't "sound bad" on paper. But we all know the actual event sometimes doesn't compare to the read.
I'm I nuts for considering this?
Are they reliable in day to day use?

Posted by Manny Knowles (Member # 1171) on 02-27-2004, 03:45 PM:

I have the ones that look like a bow tie. In my experience, they are very reliable.

We've had about 20 of them in service here since around 1998 and only one of them ever had a problem -- busted drive chain -- and that was due to operator mishandling.

Aligning the lenses took some getting used to but I became very proficient after "playing" with them for the better part of a day.

As for whether it's worth it, I guess it would depend on how often you are changing lenses and how much of a "pain" you consider that to be.

We often have mixed format presentations (flat trailers on a scope movie) and so they were kind-of a necessity.

[ 02-27-2004, 07:24 PM: Message edited by: Manny Knowles ]

Posted by Mark Gulbrandsen (Member # 72) on 02-27-2004, 07:05 PM:

I've instlled lots of these on both Centurys and Simplexs. You will actually see a huge improvement in your image, especially if your Simplex's have straight gates in them. The Kelmar gate that comes with the kit also has about 75% LESS PARTS than the Simplex gate and trap amd open/close mechanism! The Kelmar uses the same gate bands that the Simplex curved trap does. The bands are used on both the trap and on the face of the curved runner so the curved runner never has to be replaced....just replace the bands.

The Turrett is a bit unorthodox but once you understand its adjustments and functions you'll love them. Its available in either manual or auto versions. The mamnual versions are actually an inexpensive upgrade that nets you huge improvments in image quality.

Keep in mind that cutting the front off your projector is no small event. You need the correct blades 14 tooth-skip tooth type blades. This type of blade will not clog up with the alumnium. You will also need the special jigs from Kelmar to lay out the area to be cut out and then the special blocks to align the turrett sub plate to the main casting once its ready to go. For those mounting the kit onto an old cast iron Century C its best to have the fronts cut off by the plasma cutting method. This is some of the hardest cast iron on earth and it'll take you in excess of a week with your sawzall and a case of blades to cut the front out. No joke!

Briefly here are the steps involved for cinverting either a Century or Simplex.....

1. Remove everything from the film side of the machine.

2. Using the Kelmar template scribe the outline of the area you need to cut out.

3. Using a heavy duty Sabre saw with the proper blades and with someone else holding a very powerful shop vac to pick up all metal dust carefully cut out that scribed section. This works fine with either a Simplex or Century SA. Both are alumnium castings.

4. With other Kelmar jigs and using the correct size drill bit drill through and then tap those holes(Kelmar used to give you the drill and tap with every kit). Use something like Tap Magic for alumnium or some other alumnuim tapping solution on the tap when you do each hole.

5. Mount the alignment kit to the projector.

6. Mount the mounting plate to the front of the ptojector take your time and be very accurate doing this as the accuracy of mounting and aligning this plate will determine how good the the turrett will be aligned to the trap.

7. Re-install all film side components including the new Kelmar trap.

8. Re-install the head back onto the sound reproducer.

10. Mount the turret to the sub plate. Check alignment of the projector to lamphouse using the Alignotron or some equivelent device. Perform all the necessary lens alignments. In the future you can remove the turrett as you need to without loosing the accuracy of any of the adjustments. Just don't remove that subplate!!

11. File the new dual aperature plate. BE ABSOLUTELY SURE that your lenses are properly aligned before filing out this 40.00 plate!

This should give you some idea of whats involved. PLan on at least a day for your first one. If you are very mechanically inclined, good with tools and familiar with the projector involved then perhaps less time, a half day or so.

I always did them during rebuilds so I had a bit of an advantage at keeping metal particles out of the mechanism.

Mark @ CLACO