my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Flywheel timing belt snapped (Page 2)

This topic comprises 2 pages: 1  2

Author Topic: Flywheel timing belt snapped Tracy Bellar Film Handler Posts: 72 From: Sciotoville, Oh. Registered: Mar 2005 posted 08-24-2005 04:19 PM                        I don't know this model projector. But, I have seen on Centurys the motor mount bolts loosen and put to much tension on the belt. Then the belt streaches a little and then the motor gets a little crooked and cuts the belt.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 08-24-2005 07:02 PM                        Proper tension: just barely tight enough that you have a little bit of lost motion when you rock the motor flywheel back and forth. Too loose and teeth skip; too tight and undue stress is placed on shafts and bearings. (Even gears have some lost motion.) Louis  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 08-25-2005 01:28 AM                     ..I use the technique of the quarter-inch deflection: pressing down on the section of the belt that is between the two sprockets with your finger. Deflection distance is when there is the quarter-inch looseness when pressing down in the middle between the two sprockets before the belt that is around the two sprockets begin to tighten. -Monte  |  IP: Logged Wolff King Morrow Master Film Handler Posts: 490 From: Denton, TX, USA Registered: Feb 2004 posted 08-25-2005 01:57 AM                        BTW Monte, just did a belt change-out using your guide you wrote me. Did everything to the letter including alignment and the quarter-inch tension trick. Everything worked like a charm and your guide was almost flawless in detail (step 2 had the wrong allen wrench size, but this was easily corrected). Thanks again for you help. I honestly would have had no clue without your guide!  |  IP: Logged Jon Morgan Film Handler Posts: 60 From: Raleigh, NC Registered: Mar 2005 posted 08-25-2005 10:17 AM                     Everything's been taken care of guys, thanks for the comments. And yeah, this belt was incredibly brittle. We'll be checking them on a regular basis from now on. It's times like this when I wish I wasn't such a projection n00b.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 08-25-2005 12:43 PM                     Glad to be of help, Wolff. Which allen size did I goof up on since I was typing that out from memory's sake and sometime myself, I'll pull out the wrong allen blade from my Xcelite screwdriver set, when doing the belt change. I bet it's the allen size in either removing the outer pulley, or the allen size that loosens the bearing from the driveshaft. I always get those two messed up at times. Did you spin the two shafts -drive shaft and scanner drum shaft- to see how these bearing feel and sounded? thx-Monte  |  IP: Logged Wolff King Morrow Master Film Handler Posts: 490 From: Denton, TX, USA Registered: Feb 2004 posted 08-25-2005 01:36 PM                        It was the belt tensioner pulley set screws. I recall you had them listed as 9/64, but they were actually 5/32. I checked the shafts for bearing wear after I got the old belts off, but everything spun smooth with no noises or vibrations. The old belts were riddled with cracks. Thanks again!  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.