Film-Tech Forum ARCHIVE: Isolating platter rumble vibration.

This is topic Isolating platter rumble vibration. in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Eric Robinson (Member # 2966) on 07-30-2010, 12:13 PM:

I service a theatre which has poor sound / vibration isolation between the floor of the booth and the auditorium below. The booth floor extends about 12 feet over the back wall of the auditorium. The platter system is audible in the auditorium. I have moved the platter system relocating it farther to the right, and have used 3 layers of carpeting to try and isolate the vibration. Is there a recommended vibration isolation product I could use? Equipment Christie AW3R.

Posted by Tony Bandiera Jr (Member # 2365) on 07-30-2010, 01:22 PM:

Eric, Pads aren't going to help you in this case. What you need to do is replace the rubber drive tires on the motors and stop the rumbling. A properly timed and good condition AW3 is very quiet, and never loud enough to be heard through a floor, even a badly constructed one.

I am pretty sure I have those tires in stock, contact me by PM and we can discuss the details.

In the meantime, make sure the drive rims of all three decks are clean and don't have dents or rubber build-up on them.

Posted by Aaron Mehocic (Member # 15) on 07-31-2010, 02:46 PM:

You may also want to recommend they periodically disengage the platters overnight or longer so as the decking does not wear a flat spot into the drive tire. I find this wearing to be common in very humid booths. Admittedly, I have never worked with Christie platters so I am not sure if this is possible. However, I am very diligent about this on our Neutronics and SPECO 280's.

Posted by Brad Miller (Member # 2) on 07-31-2010, 03:44 PM:

Use only the black or ivory ones. If your drive wheels have any sort of red or orange tint to them, you have the self-destructing drive wheels that were made of silly putty.

Posted by Louis Bornwasser (Member # 3063) on 07-31-2010, 05:08 PM:

Brad; I suspect that all of them have drooped into destruction by now, mercifly. Louis

Posted by Brad Miller (Member # 2) on 07-31-2010, 06:42 PM:

Not the black or ivory ones. I've yet to see one fail.

Posted by Sean McKinnon (Member # 612) on 08-01-2010, 10:32 AM:

In the past I had very good luck using the Big Sky drive wheels on Christie AW3R's they seemed to be constructed a little stronger and in my opinion made the platters run a little quieter compared to ones with new Christie drive wheels I believe they are also cheaper to boot!

Posted by Eric Robinson (Member # 2966) on 08-01-2010, 05:06 PM:

OK, I have new drive wheels on order.

Was Stevie Wonder singing about drive wheels when he made his song "Ebony and Ivory" (bad joke sorry.)

Also, I have one platter which I installed new drive wheels and cleaned the deck drive wheel mating surface meticulously, but after a period of time a black gummy sticky mess builds up on the platter wheel mating surface. Anyone else have this problem?

Posted by Monte L Fullmer (Member # 2797) on 08-01-2010, 05:27 PM:

There was that bad batch of them tires that came out in 1997-98.

At our 21 plex during this time, we had to replace every tire on our AW3R's (dang, that was a changeout-63 tires and ordered 70 so I could have some spares) since they all definitely self destructed in the short time from opening til less than a year later.

I have one AW3R that has a little rumble on one deck and checked that tire (black type-after I cleaned, then regreased the platter bearing and deck's brass sleeves), for it's reminding me that it might have to go.

-Monte