Film-Tech Forum ARCHIVE: Microswitch-controlled Brains

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Posted by Joe Redifer (Member # 3) on 08-10-2008, 02:19 AM:

Any big fans of microswitch brains here on the forum? Anyone?

I hate 'em! I installed a bunch o' phase control Strong platters in the theater that I am at now many years ago (make and model of platter was NOT my choice, but anything was better than the ORCs we had). They worked pretty well considering that they are Strong platters and are therefore purposely designed to suck ass. But as you know, the LEDs in phase control brains wear out after 4 or 5 years or so and must be replaced. This happened before I returned to this location. When they did start to wear out, the manager at the time (who is also a registered sex offender and was stealing from the company in many ways) ordered the microswitch conversion kit. Only a registered sex offender would be this retarded. He was fired for extreme stupidity.

Usually they work OK, but some times they stick ON or OFF in the middle of a show FOR NO REASON (other than that they are STRONG). This causes the "tension-safe" on the platter to engage and shut off power. The projector keeps pulling film happily through even though the film is piling up on the floor. That is because we use the shitty FP-350 Optical failsafes or whatever they are called (any fans of this failsafe??? Anyone???). The film dumps down and the failsafe doesn't care. Since the payout deck is controlled by the take-up variac (who thought of this idea originally? I bet he was an asshole) the film is wrapping like a mofo on crack. Since Strong brains were designed by people with Down Syndrome™ and have a bunch of little rollers around them, you can get really thick wraps on the order of multiple inches. Eventually the failsafe will decide enough is enough and stop the projector, but not until the film is literally tied into knots inside the brain.

NOTE: This always happens when the guy who rents our theaters for Bollywood movies is telling me what trailers must go on his crappy film and in what order. This trailer is attached to the start of reel 1, the next trailer is attached to the start of reel 5, etc. He also complains to me that the auditorium he is in is too small, like I have anything to do with that or even give a rat's ass. I just nod and walk away.

MORAL OF STORY: Microswitch brains suck. The designers who work at Strong suck even more... or at least the ones who worked there in the past. Change the design for cryin' out loud! Oh, and the FP-350 failsafes also suck.

Posted by Jeremy M Smith (Member # 4913) on 08-10-2008, 02:42 AM:

We have the FP-350 in 2 of our 5 cinema and half of our brains are microswitch's. I hate the FP-350 sometimes if you are not careful they will register that there is no film when you start a show and stop the projector. the other 3 cinema I installed relays in the veriac it self witch work much better and installed a different cue sensor (can't remember the make or model)but I have never had a problem really with the microswitchs but at one point I had to replace most of them. but I could get them from a electronic shop witch was great as it takes about 2 - 3 months to get anything from strong since im in new Zealand

Posted by Joe Redifer (Member # 3) on 08-10-2008, 02:49 AM:

Why did you have to replace your microswitches if you've never had any problems with them?

Posted by Jeremy M Smith (Member # 4913) on 08-10-2008, 02:52 AM:

I had some projectionest complain that they where not working. but every time I used them they where fine so I just went ahead and replaced them anyway. but funny enough they still compained.

Posted by Joe Redifer (Member # 3) on 08-10-2008, 03:01 AM:

I agree that it is difficult to replicate the problems. It is so random.

Posted by Monte L Fullmer (Member # 2797) on 08-10-2008, 03:30 AM:

Agree. Microswitch brains DO suck! Had two brains run wild on me in one night (major backwraps) .. and I had replaced these switches less than a year ago.

You get booth clowns that pull the ring out on an angle and with a microswitch brain and that filmroll not centered, a good case of thrown prints towards the end of the presentation is apparent due to the 'off and on' action of the brain.

But unfortunately, when theatre owners rather go cheap and use micros instead of spending the extra for phase controls, you pay what you pay for.

..Yet, I've got 4 phase controlled brains that I converted back from the micros and they've been working great for over 4 yrs now.

Platter decks are made to turn on a continual motion, not to be shut off and turned on all the time - why I love the AW3(R) platters.

[Confused]

oh well ...

Only prob I have with FP-350's is that one of the wires that is attached to the terminal strip at the end loves to break loose for some odd reason, causing the automation not to function. Otherwise, with routine wiping underneath to clean the sensors, they've been a pretty dependable failsafe unit.

..and it does help if you change out your cues from time to time since they do wear out. Plus, it all depends HOW you're putting the cuetape on for the FP-350 to sense: You take a half-in strip of cue tape and wrap it around the edge of the film soundtrack side inbetween the sprocketholes.

-Monte

Posted by Jaime Tuzzio (Member # 4760) on 08-10-2008, 03:40 AM:

Oh, that just brought back some fantastic memories.

The only time I ever had a microswitch brain suddenly stick ON or OFF (usually ON) in the middle of a show was when the switch needed calibrated or changed. My only unexplained random brain issues have been with the SCDC platter system. Fortunately, 98% of the time whatever the problem is starts up right at show start, so I'm immediately aware of it and can usually fix it without stopping the show.

Posted by Joe Redifer (Member # 3) on 08-10-2008, 03:41 AM:

One of the very few things I like about the Strong platter is I can lift the ring straight up without collapsing it and the print doesn't move, not even the leader. The ring comes out as easily as the brain. Takes two hands, but what do I know? Regardless, the prints stay centered... at least on my shifts.

I have tried cleaning the bottom of the FP-350s and they read cues fine but I think the issue may be more of the film falling down where the failsafe isn't looking due to poor design.

Would microswitch brains cause extra wear on a platter motor? I need all of the ammo I can get when trying to order phase control conversion kits which I will surely be denied. I have such a hard time getting anything it is ridiculous.

Posted by Frank Angel (Member # 248) on 08-10-2008, 04:45 AM:

I have a boss who's got a microswitch-controlled brain.

Baud-ump-bump.

Posted by Mark Gulbrandsen (Member # 72) on 08-10-2008, 10:37 AM:

quote: Joe Redifer
Usually they work OK, but some times they stick ON or OFF in the middle of a show FOR NO REASON (other than that they are STRONG).

I service more locations with microswitch Alphas than any other kinda platter and they rarely if ever give any trouble. If the switches are replaced every two years as they are supposed to be(as per Bob Potts) then 99% of the time they give no problem at all. Also, you have to use the correct microswitch... use of the wrong one will definately lead to problems as well as poor pay out performance. Also, Honeywell makes the switches, not Wrong International. Make sure the switch clicks right in the center of the P.O. arm swing.

FWIW: The drive motors used on these platters are not stable enough to be able to use a linear feed control device like the phase control. They may work now but they will come back to haunt you in the near future!

Mark

Posted by Louis Belloisy (Member # 3836) on 08-10-2008, 11:26 AM:

Our little theater is equipped with 6 Potts platters and they are all micro switch controlled. Back a few years ago the owner converted one platter (3 disc's) to optical and they have all eventually failed. I just replaced the optical device with a micro-switch. Once in a blue moon, one will stick and cause a brain wrap, a little burst of WD-40 will clear it up. Once every few months i give each switch a little lube with with the WD-40 and really not have had a problem.

Louis

Posted by Jeremy Weigel (Member # 4208) on 08-10-2008, 04:23 PM:

Converted all 6 of our Strong platters from carbon switches to micro-switches 15 years ago and haven't had a switch go bad or a thrown print.

Posted by Troy Hilsman Powell (Member # 4326) on 08-10-2008, 05:02 PM:

Here is a trick that has always worked for me.Go to radio shack and pick up some caps,one for each brain and wire the cap across the switch.Radio shack skew number is 272-1055.This will stop the arcing across the contacts in the switch hence stopping the switch from sticking.

Posted by Mark Gulbrandsen (Member # 72) on 08-10-2008, 05:31 PM:

Troy,

Right on, I wasn't going to let Joe in on that secret though becuase he already knows everything! Thats called a snubber. The safest way to do it is to place a 10 ohm 1/2 watt resistor in series with the cap.... at least a .01 at 600 volt or greater ceramic disk type. If the cap happens to short out the resistor will burn up so the platter doesn't go into high speed payout. The cap acts to quench the spark (actually high frequency rf) that happens across the micro-switch contacts when they break contact.

Mark

Posted by Joe Redifer (Member # 3) on 08-10-2008, 05:35 PM:

quote:
FWIW: The drive motors used on these platters are not stable enough to be able to use a linear feed control device like the phase control. They may work now but they will come back to haunt you in the near future!

2 things:

#1 - These were all originally phase control platters.

#2 - if they are not stable enough for "linear feed" then they would not be stable enough to be used as take-up since it has no choice to be, you know, linear.

Posted by Mark Gulbrandsen (Member # 72) on 08-10-2008, 06:19 PM:

quote:
#1 - These were all originally phase control platters.

A). YEP! And we had zero problems AFTER we converted them all over to micro.

quote:
#2 - if they are not stable enough for "linear feed" then they would not be stable enough to be used as take-up since it has no choice to be, you know, linear.

B). Go ahead and time them as you normally would and let them run for 10 to 15 min... they will be way out of time from each other. If they're not then I owe you a bag of sliders from White Castle! The problem is that the motors are not constant torque nor speed. They are just vaccum cleaner motors. For take up the constant torque happens through the variac coupled through the slide trombone (time for a music lesson too!) which constantly takes care of any speed/torque offset.

Payout is a totally different story... as the motors drift the linear control device can't detect this and hence can't control it fine enough by proper offset. Micros just do it by demand and as a result the timming can be a mile off (which is normal for this platter) and the thing can still pay out really well.
The motor drift problem was the whole reason for the digital platter drive... it is actually a form of servo and the mpu looks at the AC feed to the motor and sees a slight pulse generated by the brushes. This pulse is the feedback signal to offset the servo and the actual speed the motor is running at stays constant with the actual speed itself determined by where the P.O. arm is at in its travel.

Microswitch and DMC platter 2, Phase Control 0!

Mark

Posted by Joe Redifer (Member # 3) on 08-11-2008, 12:30 AM:

quote: Mark Gulbrandsen
A). YEP! And we had zero problems AFTER we converted them all over to micro.

These are not platters imported from Utah.

I cannot comprehend why theaters do not just buy Christie platters or at least Speco LP-280 digital platters. The design on both is better through and through than anything that Strong can offer, period. This is fact, not opinion. That includes SCDC or "DMC". Why do people buy Strong... anything?

Posted by Monte L Fullmer (Member # 2797) on 08-11-2008, 03:31 AM:

quote: Joe Redifer
Why do people buy Strong... anything?

Cuz, they're cheap and made for K.I.S.S. booths ... [Big Grin]

This looks like a simple arguement between the usage between phase controls and micro with the simple reason on "why do one have to do a yearly maintenance on brains with one certain part, whereas a different part in the same place of the brain can remain for a long time and the brain can be maintenance free?", or "Other manufacture brains never need the maintenance attention as do the STRONG micro brains."

It seems a trend that why Strong got into many locations around the nation is that these locations doesn't have quality booth personnel to handle the more complicated and maintenance prone makes of other company's equipment, thus it was equipment that can stand up to being mistreated, operated incorrectly and can still come up fighting.

Plus, as with my locations, a lot of locations that were first constucted as small multiscreens in the 80's, about the only thing available domestically that had any backbone to it, were STRONG products. Yes, there were ORC who had Century, Cinemeccania V-5 with Xetron consoles, Ballantyne with their PRO-35's, et.al., but these didn't have the power as did Strong-Hanovia during this time.

Granted, I fully agree with Joe, Brad and others about Christie equipment when it comes to film handling quality this one company has proven itself-totally convinced on how Christie can handle film, but their equipment is designed for a well qualified, on-location projection manager and technician.

..and sorry, I don't know anything about the European makes of Kinoton and Ernemann (even though I did run a FP-23 for one showing and was totally impressed on how this portable operated..), thus I can't make the fair comparison to our domestic makes and models.

So anywhos, I have to work with what I got..and let my superiors know that one of these days, some STRONG products we use know are now dinosaurs, or will be dinosaurs down the road.

Guess, digital is really approaching on the horizon for a lot of locations...

-Monte

Posted by Joe Redifer (Member # 3) on 08-11-2008, 05:52 AM:

However both the Christie and Speco LP-280 platters are far easier to thread than the Strong. The Strong requires navigating through more rollers and has more places where the film can be scratched and wrapped. Who thought that all of those little rollers around the brain would be a good idea? I see people accidentally threading around those all of the time. Of course that causes wraps-a-plenty. The payout arm is upside down as well. That's just retarded. I don't know why Strong never bothered to change this design to something more well thought out. Let's not forget about the ball bearing rollers. This is also not a good idea.

Posted by Dustin Mitchell (Member # 372) on 08-11-2008, 06:17 AM:

Never had a problem with either phase controls or microswitchs. I replaced the carbon switches on 6 platters with phase controls in late 1999/early 2000 (my memory is a bit foggy) and they ran perfectly fine-no drifting to speak of-all the way up until our digital conversion 2 years ago. So call it a mininum of 6 years in service. The houses that are dual 35/digital still have the phase control brains and during the occasional use they get they still work fine.

I'm sure the Christie platters are better-I wouldn't know, have never used them-but in the time I've used Strong platters I don't really see how they're *that* aweful as people make them out to be.

Posted by Mark Gulbrandsen (Member # 72) on 08-11-2008, 07:58 AM:

quote: Joe Redifer
Why do people buy Strong... anything?

Now thats certainly one of the finest most truthful statements I've seen posted here in the last several decades.