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Topic: Platters and Projector drive trains

Barry Floyd
Phenomenal Film Handler

Posts: 1079
From: Lebanon, Tennessee, USA
Registered: Mar 2000

posted 07-13-2001 11:36 AM

Somebody answer this for me...

I believe I read somewhere or was told by someone to not try to use a Brenkert projector with a platter because the main shaft in the gear train is horizontal as opposed to the vertical shafts in the Simplex XL and others.

I've seen a Brenkert working with an Eprad Double MUT, but never a platter. Any truth to this "horizontal" vs. "vertical" shaft dilema?

------------------
Barry Floyd
Floyd Entertainment Group
Nashville, Tennessee
(Drive-In Theatre - Start-Up)

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 07-13-2001 11:49 AM

There are many Brenkerts runnng quite happily with platter

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 07-13-2001 01:28 PM

There are two things to consider when running a Brenkert on a platter.
1. Be sure to keep the main drive and idler gears oiled at least daily as these do not get oiled by the machine itself(unless the rear door gasket is really bad).
2. Consider that there are very few parts available for them anymore.

Also the Brenkert by its nature presents a VERY heavy load to a gear reduction type sound head as compared to other oil bath type machines so expect to have to replace bronze gears and pinions once in a while.
MArk @ GTS

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Michael Cunningham
Expert Film Handler

Posts: 186
From: Anchorage, AK
Registered: Nov 1999

posted 07-14-2001 01:43 AM

Umm, maybe I'm missing the point here, but why would the orientation of the projector's drive shaft affect whether or not you can use a platter? The platter is an independent unit that is not driven from the projector drive train, so as long as you can establish clear film paths to and from there should be no problem...???

-Mike

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 07-14-2001 09:21 AM

Actually the probblem isn't as much just the drive shaft but the duty cycle.
Alot of older machines were designed around a duty cycle of running a 20 min reel and then sitting for 20 min. Not being exposed to heat and operation for 2+ hours.
That being said many of the older machines sun just fine with platters or large reels but there are some cautionary notes go with that.
1 is lubrication most of the one shot systems (oil pump or oil can type) we designed to ensure sufficient lubrication for that duty cycle and there lubrication requiresments increase with larger reels
Also different machines represented different loads on the soundhead which haveing the motor attached to it becomes the drive source for the projector. The brenkerts due to there gear train design is a higher load than say a century is and as such even the soundhead motor will get a lot hotter after a 2 hour show with a platter than with 3 20 min reels.
The gear train in the soundhead also has more stress on it driving the larger gear train of the projector head and as such it will wear that much faster.
Of late the discussion has been around the verticle vs the oblique shaft in the E7 machine. Even with 20 min reels the oblique shaft was a problem. In fact the E7 went out of production for a year over the problems it had and the super waskept in production even after the verticle shafted E7 hit the market in the mid 40's
Personally I have little use for the oblique shaft in the E7 for any application. A well tuned verticle shaft is just as quiet and definetly far more reliable. By placeing the shaft on an angle they introduced a whole group of stresses that it just wasn't designed for.
The E7 was never a machine I was very impressed with anyway. Of all the machines built during that period there was better engineering done at Centruy and Motiograph. I always felt even a Devry or Superior was a better machine -end of rant

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Tom Hutchinson
Film Handler

Posts: 11
From: Edmonton, Alberta, Canada
Registered: May 2001

posted 07-14-2001 11:35 AM

The Brenkert works actually better with a platter than with 20 minute reels, since the greatest strain on the gear train is at starting and stopping. Make sure you use a decent soundhead; Simplex SH-1000 or XL; RCA 9030 or 9050; the soundhead has to be heavy enough to stand up to the load of the projector, and a belt driven arrangement doesn't work well. Also the heavy flywheel on the above soundheads allows a really smooth start, which the Brenkert wants. They put out a good picture and are generally quite reliable (except for the shutter drive gears on the double shutter models).

We have a number of them in use here in grind applications.

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000

posted 07-14-2001 11:59 AM

Gordon and Mark are correct about the Brenkert.

Also, what Gordon said about the oblique shaft in the E-7's is also correct. They were a problem. The best I ever got out of the shutter gear on the oblique shaft of an E-7 was about 5 years. I ofter wondered if I was doing something wrong when I installed new shutter shaft spiral gear and the oblique shaft gear.

I asked a rebuilder in Seattle that question, and he said if I got 5 years out of those gears, I must have been doing something right, and invited me down to show him how to install them. He said he was lucky if he got 4 years out of them.

I would guess it has something to do with the quality of the gears. The third-party gears for the shutter of the E-7 as well as the bevel gear for the Brenkerts were crap as compared to orginal equipment. Gordon and Mark, what is your opinion on this?

The Brenkert BX-60 didn't have the bevel gear driving the shutter shaft setup like the BX-40's, 80's, and 100's. The only problems I ever had with the Brenkert BX-60 was the intermediate gear bushing failure and the framing sector gear wore out because of the people using the framing knob excessively.

The intermediate bushing was a nominal size bushing, and could be obtained very easily. However, it had to be modified with slots 90 degrees apart (like the old bushing) so that oil could get to the bushing and shaft. A sure sign of that bushing failure was the oil turned black in color, but the machine still ran fine. (lots of "WOOGA WOGGA", but it ran.....)

The framing sector gear is unavailable, and has been that way for the last 20 years.

Paul

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99

posted 07-14-2001 12:39 PM

Paul said"I would guess it has something to do with the quality of the gears."
I don't think it was the quality but the design. With the shaft on an angle the angle of the cut of the gear teeth was very extreme and put a lot of unecassary force on them. Also the bearing arrangement was less than ideal

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