Film-Tech Forum ARCHIVE: Projector Leakage question

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Posted by Jerry Arp (Member # 2040) on 11-22-2003, 05:50 PM:

I work with 2 Simplex X-L projection systems. They are pretty old. I think they were manufactured in the 60's. I was wondering what is the acceptable rate of oil leakage for these machines?

Posted by Erick Akers (Member # 875) on 11-22-2003, 05:54 PM:

About how much oil are we talking about?

Posted by Robert E. Allen (Member # 1351) on 11-22-2003, 08:07 PM:

I worked with a number of XLs over the years (first one was made in '49) and never had a leakage problem with any of them. My guess is that you have a bad seal. If you own the thing call your supplier's tech. If it belongs to your boss tell him to call your company tech (if they have one).

Posted by John McConnel (Member # 2000) on 11-22-2003, 09:00 PM:

I use an older XL that leaked excessively, but otherwise is a fine projector. I tightened the back cover, tightened the drive shaft bearing cover that's at the botton on the film side of the projector, tightened the drive shaft bearing retainer on the back side, and tightened the oil gauge bracket. Its leakage was significantly reduced, and is now down to about 2 ounces or so a week. It needs the gasket on the back cover replaced to finish the job.

Donald Wunderlich at Cinema Equipment and Supplies, Inc., in Miami, (800) 759-5905, will work with you to diagnose the problem.

Posted by Mark Gulbrandsen (Member # 72) on 11-22-2003, 09:09 PM:

Having rebuilt literally hundreds of X-L's I'll chirp in on this one......

I'm assumming too that you are not overfilling them....

There are three problems that exist with pre-Strong X-L's that accounts for most of their leakage problems..... you can agree or disagree if ya want to but till you've machined off the front of an X-L to install a TU-2000 turret I'll say you don't have a foot to stand on.

The first and formost problem is the very poorly done main casting itself. The original made by Simplex main castings are extremely thin in some areas, particuluarly the upper front of the casting.... I've seen less than 1/8" thickness here! And the main castings are EXTREMELY porus, looking more like the inside of a fairly thick cracker!!. The later General Precision castings are of somewhat higher quality, thicker, about 1/4" in the areas that needed to be made more sturdy, but still fairly porus as well. Strongs later main castings for the X-L are absolutey top notch, possibly cast centrifigally...at least they have that appreance and are hardly porus at all.

The best cure for the porusity problem is to strip(not sandblast!) the entire casting and have it POWDER COATED by a reputable facility. Power Coating is not however without its own set of unique problems as the old porus castings have a tendency to outgas from within while the powder is transforming on the casting in the 400 deg. oven. There can also be oil bleed out from the casting as its pores have soaked up and retained oil from over the years. A very experienced Powder Coating Shop can deal with many of these problems and you'll end up with at least 98% blemish free Powder Coating. This will for all practical purposes stop leakage through the main casting itself. We use the same Color Powder Paint that Strong uses on the machines at the factory.

The second problem consists of two areas. The main drive shaft penetrating the side of the main casting, and the oil sight gauge assy. These are easy areas to deal with and consist of very carefully rebuilding the sight glass with new seals, and installing a Main Drive Seal Kit onto the main drive shaft. The early Seal Kits developed a poor reputation but the later Seal Kits are worth their weight in gold!! Installing a seal kit allows one to typically quadrupule the tiny amount of oil in an X-L [thumbsup]

. The thing that made the most difference was the fact that Strong now does a seal worthy Finish Grind on the O.D. boss of the drive gear itself. The early gears were not even ground at all and generally tore up the seal lip in a short time. If you install a seal kit on an X-L lightly lubricate the boss O.D. of the gear where the seal rides so it can break in properly. Also install the seal and screws but leave the screws a bit loose and then slide the new gear onto the drive shaft. Then firmly tighten down all the seal flange screws. This allows the gear to perfectly center the seal on itself before things are cranked down permanently. Also the seal kit includes new "O" type rings to replace the flat seals on both sides of the framing shaft. Using these "O" rings is touch and go and eventually they may extrude, or smush away from position and leak even worse. When they are in good shape they do work well, but there is no groove for them in the two bosses they mate against. I say stick with the old flat seals here. They definately last far longer than the "O" rings ever will.

The third problem is the rear door, or gear cover, Several differing problems exist with these rear covers. All of the older doors are light weight die castings... and they warp badly. Be sure the door is flat around the seal perimeter...not many are. Sometimes they can be carefully bent back in a large vise, sometimes not. Some old covers do not have enough screws to tighten down the upper and lower door glass clamp rails, these covers sould be replaced. Look for doors that have only two screws on the top and bottom clamping rails. These doors are good for nothing but the trash can, they will always leak! The next thing to consider is the door and glass seal themselves. The old black, and clear rubber tubing seals are junk and obsolete. Strong has come out with a new red rubber extrusion gasket for the rear cover thats excellent. ONLY BUY THIS SEAL! For the window seal there is only the flat black gasket for older doors, or on late style heavy duty doors the round older seal. Replacing these when they begin to deteriorate is a good idea, or if you're installing the new Red door seal replace the flat gasket at the same time. Neither is very expensive. If your rear door is in really, really poor shape it should be replaced with the new heavy duty door. These new doors do not warp [thumbsup]

.

Hope some of this helps out.....

Mark @ CLACO

Posted by Paul G. Thompson (Member # 655) on 11-23-2003, 12:28 AM:

What is your current oil level, and where is it leaking?

Posted by Kenneth Wuepper (Member # 1174) on 11-23-2003, 07:20 AM:

Hello Jerry,

Welcome to the FORUM. You are in great company here as all who post here are interested in quality theatrical presentation of motion pictures.

It is my experience with the Simplex XL models that there is an operator tendency to overfill the heads and thereby cause the seals to eventually seep lubricant.

If you look through the back glass while the machine is running you will notice that the oil spray is not constant against the glass. The oil sprays over the mechanism and then stops while it recollects in the sump and then sprays again. Although this is normal, there is a tendency to overfill the sump so that there is no pause in the spray.

To determine proper oil bath, look in the upper right corner of the gearcase and notice the funnel shaped collector. This collects the lubricant and directs it to the intermittent. Look carefully at the bottom of the funnel and at the end of the tube which directs the oil to the intermittent. There should be NO INTERRUPTION to this flow during running of the machine. The funnel collects enough oil to CONTINUOUSLY lubricate the intermittent even during the pauses in the spray.

Adding oil beyond the level needed for continuous intermittent lubrication may cause seeping of the oil through the seals and gaskets. If the seals are not completely dry when reassembling the machine, the lubricant will find a path through the gasket and seep.

Hope this is helpful. Happy detective work in finding your leaks.

KEN