Film-Tech Forum ARCHIVE: Soundhead Oil Question

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Posted by Gary Crawford (Member # 2038) on 07-12-2006, 11:34 PM:

Old booth, I got it running again (Baronet, 4th & Kingsley, Asbury Park NJ) and I have a question about oil in the soundhead. In the booth is a jug of Brenkert oil (for the picture head, a Brenkert), a small can of Simplex oil, and not much else.

The soundhead is a 50s RCA "Photophone Sound Attachment" MI-1040E, type PS-24, and it looks for all the world like a Simplex SH1000 but doesn't say Simplex anywhere.

What kind of oil is recommended for this old relic? Oil in there now, have no idea what it is, and would rather drain it and replace with new.

Thanks guys.

[ 07-13-2006, 11:11 AM: Message edited by: Gary Crawford ]

Posted by Mike Blakesley (Member # 26) on 07-13-2006, 01:16 AM:

Gary, I can't answer your question but take your e-mail address out of your post or the mods will be all over you like a cheap suit. (It's for your own protection so you don't get spammed.)

Posted by Louis Bornwasser (Member # 3063) on 07-13-2006, 06:38 AM:

30 weight non detergent. The older RCA soundheads were actually manufactured by Simplex; hence the very similar design. Parts are not the same, even if they appear so. Oil from any source incl. theatre equipment dealers like us. Louis

Posted by Steve Guttag (Member # 268) on 07-13-2006, 06:48 AM:

30-weight is way too thin...try 40-weight it is closer to the correct stuff.

Posted by Louis Bornwasser (Member # 3063) on 07-13-2006, 08:57 AM:

Reminds me of Nick Mulone's dad ask me what oil to used in a Century C intermittent. I hestitated to answer then he said that he was using 20 weight. How long? "Since 1948." OK, don't stop...it is working for you. Louis

Posted by Richard Fowler (Member # 893) on 07-13-2006, 09:03 AM:

RCA Photophone manual recommends 40 weight for general use and 20 weight for very cold climates. [Smile]

Posted by Dick Prather (Member # 1136) on 07-13-2006, 09:37 AM:

The RCA MI-1040 soundhead dates back to the mid 1930's with lots still operating. 40wt "NON detergent" oil is what's recomended for normal operation. I have used 50wt for warm booth with platter use. The oil slingers and gearbox oiling do not work properly if the oil is too thin or thick

RCA was making soundheads long before Simplex in the late 1920's. I never heard of them making soundheads for RCA. The SH-1000 came out in 1938 and looked like an updated 1040. RCA had new models in 1938 also.
Dick

Posted by Gary Crawford (Member # 2038) on 07-13-2006, 11:17 AM:

Thank you for the help, guys!

Yes, the place is "historic", wasn't sure the equipment was THAT old. Original Supers with hand-crank holes and 1929 "temporary" WE bolt-on sounds heads still there too, but not in operation. Really old Ashcraft arc lamps, and the place runs and runs well after some tinkering. Will let you all know how we make out running the place.

Glad the oil is available most anywhere. I'll go with the 40, no telling when the oil was last changed in there. The booth hasn't run for something like 25 years, but it lives again!

Thanks again everyone.

Posted by Bob Koch (Member # 1062) on 07-13-2006, 12:51 PM:

One more thing after adding the oil; as Steve suggests 40 or heavier, make sure the level visably drops in the gauge glass when the projector is started regardless of the line on the gauge. Have enough oil in there for this to happen.

Posted by Dave Macaulay (Member # 813) on 07-13-2006, 03:03 PM:

When draining or filling the oil, make sure the drain tube is open. I've seen a few with drain pipes plugged with sludge (they apparently rarely checked or changed the oil) and getting the old oil out and new in was rough.
When filling, be aware that the shafts that come out of the gearbox are not sealed. There are "oil slingers" that keep most of the oil dripping around inside from getting out, but if you fill the gearbox above the bottom shaft level... well it's just going to drip out immediately. The mark on the sight glass should allow the bottom sprocket shaft gear to be in oil all the time, the oil just gets carried up the gear train while running and lubricates everything. At extreme projection angles the oil level may need to be lowered as it can come out at the drive shaft to the motor on the front.

Posted by Mark Gulbrandsen (Member # 72) on 07-13-2006, 08:35 PM:

The best lube made today that I have used for bronze gear based sound reproducer gearboxs like yours is Mobil-1 Synthetic Gear Lube. If you use this stuff the lube won't turn black on you like SAE 30 or SAE 40 weight will. The gearbox will also last almost indefinately. We always send the customer a new bottle of it with any rebuilt gearbox. Its also fine to put it into existing gearboxes but I'd reccomend a change at 10 hrs, 20 hrs, and then again at 50 hours and about every 1000 hrs there after. You need to get the old oil and any sludge out of there! Note that this lube has the consistancy of about 30 weight oil but because it does not break down it is rated as a 75/90 weight lube. Its really amazing stuff that also doesn't smell nearly as bad as Hypoid Gear Lube does. Also, if you tear down a gearbox that has had this stuff in it for any length of time you will still find a good coating of it on the upper gear... with regular SAE oil it all runs to the bottom of the gearbox in a matter of hours!

Mark

Posted by Brad Allen (Member # 470) on 07-15-2006, 01:16 PM:

Just for curiosity sake, why wouldn't some grade of Mobile1 synthetic be better for a Simplex 1040 film head, than the typical oil used?

Posted by Tim Reed (Member # 137) on 07-15-2006, 01:24 PM:

FWIW, I have used 90wt. gear lube in bronze gearbox reproducers, as Mark suggests, with excellent results (though not specifically in a 1040); little to no leakage, and the gear teeth hold it well over a long period of time. [Smile]

Posted by Louis Bornwasser (Member # 3063) on 07-15-2006, 05:28 PM:

In the soundhead, lubrication is direct. In other words, some of it gets directly on the teeth and on the bearing races.

In the 1040, there is, in addition to the gear meshes, a series of bronze bearings that are lubricated by having one end exposed to oil wetness, which then wicks onward to the place where oil is required. The heavier the oil, the less the oil will flow into all places where it is needed. Louis

Posted by Tim Reed (Member # 137) on 07-15-2006, 11:58 PM:

Roger that, Louis. I wasn't sure about the 1040s.

Posted by Mark Gulbrandsen (Member # 72) on 07-16-2006, 07:34 AM:

I believe we have a couple of 1040's running Mobil-1 gear oil over in Colorado, these have no flywheels in the motors (perhaps PS-24's?). The nice thing about the Mobil-1 is that its not a very heavy lubricant like actual 90 wenght gear grease is.... I would peg its actual consistancy(pourability) somewhere about the same as SAE 30 to 40 weight oil. It has a slightly similar smell as actual 90 weight gear lube does but nowhere near as smelly.

Mark

Posted by Robert Minichino (Member # 3495) on 07-16-2006, 08:40 AM:

An SAE 85W gear oil is about the same viscosity as an SAE 30 motor oil; they're on a different scale.

Here's a cool chart: http://www.experimentalhelo.com/eh_oilVisChart_fullT.htm

Posted by Pete Lawrence (Member # 130) on 07-16-2006, 09:33 AM:

quote:
In the 1040, there is, in addition to the gear meshes, a series of bronze bearings that are lubricated by having one end exposed to oil wetness, ...

Are we talking about the same 1040 (RCA MI-1040)? Mine are 100% ball bearing. Not a bronze bearing anywhere, just the two bronze gears.

Posted by Mark Gulbrandsen (Member # 72) on 07-16-2006, 10:27 AM:

Yes, I have seen some of the very old gear boxes that have bronze bushings in them. Its extremely rare to find any of them still operating today. I can't say for sure if the sound heads in Colorado are bushing or not since I've never had them apart. We also have a 1040 in Jackson, WY at the Teton Theater that is ball bearing... rebuilt that gar box about a year ago but only because of excessive leaks... the gearing was fine.

The one thing that the Synthetic GEar Lube has over regular 90 weight gear lube is that it just doesn't change viscosity at temperature extremes. Take 90 weight gear lube down to about 40 degrees as might be expereinced in a drive-in sometime and it almost gets like mud. Synthetic stays the same viscosity and flows freely.

Mark

Posted by Louis Bornwasser (Member # 3063) on 07-16-2006, 11:32 AM:

I think we are confusing MI-1040 soundheads and 1040 XL heads. Louis

Posted by Chris Unwin (Member # 3792) on 07-17-2006, 04:48 AM:

Hey Gary.

Out of curiosity, I saw you mentioned carbon arc lamphouses. Are you going to keep the carbons!?

Posted by Mark Gulbrandsen (Member # 72) on 07-17-2006, 07:37 AM:

quote: Louis Bornwasser
In the 1040, there is, in addition to the gear meshes, a series of bronze bearings that are lubricated by having one end exposed to oil wetness, which then wicks onward to the place where oil is required. The heavier the oil, the less the oil will flow into all places where it is needed.

Thats the place in the all pot metal X-L that is still in the dark ages. I've replaced more bronze bushings in X-L sprocket assemblies than any other bushings I can think of. They never get quite enough oil but if they get too much then they drip.... and on older machines the spirals are almost always found plugged up with the bronze material from the bushings. Steel shafts in Cast Iron bushings are the best way to go if one has to have bushings. Simplex never did do this the right way in the X-L, Both Brenkert and Phillips did it correctly.

Posted by System Notices (Member # 2357) on 10-16-2013, 08:32 AM:

It has been 2648 days since the last post.