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

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Timing the Christie M35GP. It flickers unless its perfect. (Page 1)

This topic comprises 2 pages: 1  2

Author Topic: Timing the Christie M35GP. It flickers unless its perfect. Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 12-31-2005 09:22 PM                    When replacing a shutter assembly or something that requires retiming, the manual stats that after loosening the shutter on the shaft, turn the crank by hand until 3 sprockets are advanced. Well, thats all good, but the picture flickers. So, instead of 3, we tend to go about 2.5 sprockets and that seems about right. Sometimes...only 2. is there a correct way to time these projectors in order to take guess work out of it? also, when you turn the lamp on to test the timing, do you run any film loop? We have tended to shine just white light briefly, but have found that sometimes, thats all it takes to crack a lens. Advice? I have the manual...and read it..but field experience seems different. Thanks!!  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-01-2006 12:12 AM                     Loosen up the shutter blade on the shaft of the shutter drive assembly so the half blade spins freely. Put the "X" on the shutter blade dead center of the aperture opening. roll the pulldown knob until the third tooth of the intermittent sprocket is at a pointer that you made- usually a pencil (and you count the first tooth of the four teeth as one). Then,lock down the shutter with the "X" in the aperture opening. Way I did to get the shutter in center is to find a vertical line in the framework of the 35GP and have the shutter blade parallel that vertical line. Then snug one allen screw and go around to see if the "X" is dead center in the aperture opening. This all takes place AFTER the upper jackshaft assembly is adjusted to have the proper shutter belt tension-which is where the belt crosses, the facing teeth of the belt should just barely touch when the belt is squeezed at the crossing point of the belt. Could be that the shutter belt is way too loose causing the flicker that you're having...or needs replaced due to bad teeth and cord separation in the belt itself (and the 12 and 16 groove sprockets, if aluminum needs replacing as well...) -Monte  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 01-01-2006 12:14 AM                     I haven't read the manual, but it really says 3 sprocket teeth? You should do 2 because you want the intermittent in the middle of its pulldown. Right at that point you want the shutter centered as well. I usually run some test film to check any shutter ghosting. Rick Just read Montes post. We replied at the same time. Am I missing something here?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-01-2006 02:56 AM                     Yea, Rick - for when I posted my note and then returned back one page, your post was there. Probably our posts entered in at the same time-just yours got below mine..probably due to a timestamp protocol. True..it can be a bugger to time in a P35GPS since these units are a bit more complicated to do than a Simplex. thx-Monte  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-01-2006 09:18 AM                     Happy New Year to all! quote: Monte L Fullmer True..it can be a bugger to time in a P35GPS since these units are a bit more complicated to do than a Simplex. Monte, This is the simplest machine on the planet! It should take you less than 60 seconds to time a shutter on a Christie even with having to remove the back cover. They have made it easy for you by placing the cross mark on the shutter. It can be done just as easily with or without the trap in place. It can be done in half that time with an assistant. 1. Assuming trap is in place set the aperature to Scope. 2. Loosen the shutter clamp screws on its shaft so the shutter can be moved..... but not too loose! Use the long T-Handle Allen Wrench Christie provides with each projector for doing this. 3. Place a screwdriver tip by one of the intermittent sprocket teeth and then slowly turn the projector over until the sprocket advances 2 teeth, STOP! 4. While holding the Ultramittent flywheel move the shutter until the cross mark is centered in the scope aperature. Tighten the shutter blade clamp screws back down. An assistant in back doing this part cuts the time in half! 5. Turn the machine over by hand several cycles and double check that the setting is correct. If its still correct there's no need to run a test film! The P35GP is really the easiest machine on the planet to repair and maintain . You should be able to..... Change a shutter belt in less than - 3 min. Change the Ultramittent and re-time in less than - 10 min. Re-belt the machine and minor clean up in - 15 min. Coating the belts with Film-Guard - Timeless  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-01-2006 02:27 PM                     Oh yes Mark, you are true on this. I remember my first time in belt changeout: took forever since I had the units that didn't have the motor hinge option and no manual to go by - found out the hard way of the "hidden idler sprocket" underneath the motor when lacing up that outer belt. But with time, I was able to do a changout within 20min of all three belts and do the timing. ..and FG'd the belts afterwards...(lol) -Monte  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 01-01-2006 02:36 PM                     Have to agree with Mark here, the P35GPS is the easiest projector to service. The only clarification I need to make to that statement is that you have to have some experience at it. You can't just hand someone a belt diagram and say "change this belt", as they will certainly get the belts too tight or too loose. There is a little bit of an art to get it right. Once you figure it out (or are shown), these things are a BREEZE. If only the picture was steadier!  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-01-2006 04:39 PM                     Absolutely agree Brad, Some experience is a must on them. but Monte's line surprused me as he has significent experience with them but finds them harder than a simplex to work on. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-01-2006 04:51 PM                     I find that the Simplexes just need less work period...and as for most maintenence free...Kinoton PK-60D...damn near zero there.  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 01-01-2006 06:41 PM                    quote: Mark Gulbrandsen Re-belt the machine and minor clean up in - 15 min Are you a GOD? Do you have super human powers? We don't have hinges on our motors so 15 mins can be spent taking them off and putting them back on. As far as the timing goes, I will try 2 sprockets next time. 3 seems wrong, and usually is. I guess my question is to Mark, you said: quote: 5. Turn the machine over by hand several cycles and double check that the setting is correct. If its still correct there's no need to run a test film! I don't understand how you can know the timing is correct without actually turning the projector on?? Even though I'm careful when I time it, its mandatory to check my work to make sure we don't have flicker or ghosting. If you know how to check the projector timing without actually turning it on, please share. Thanks!  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-01-2006 06:58 PM                     The way that both Richardson and Cameron staight to time a shutter usually works with the intermitent is in the dwell hold a pencil point between any two sprocket teeth of the intermitent and then advance the mech until 2 teeth have passed and you are between teeth 2 and three at that point the shutter blade must be set to exactly half cover the apperture (ie be centered on the apperture) The machines that are an exception are brenkert and cinemecanica After timing it turn the machine over and verify that the apperture is masked during the entire pull down  |  IP: Logged Will Kutler Phenomenal Film Handler Posts: 1506 From: Tucson, AZ, USA Registered: Feb 2001 posted 01-01-2006 07:05 PM                     Ohhhh Boy! Talk about me having experience timing Christies! Got that down to an art within a few minutes...including the time needed to retrieve tools and parts. I do think that the one major flaw of the Christie P35GPS is the design of that Jackshaft Assembly. That belt twist is an inappropriate design that has been a thorn in many a peoples side! It's been a while, but I was thinking about how to redesign that Jackshaft Assembly by using a miniature miter gearbox assembly with maybe a brass to stainless gear combo and a "wet-type" gearbox machined out of a solid block of aluminum that could be filled with oil w/o a leakage problem. Maybe if I had a P35GPS in front of me I could work on it as a college product! Even with the heavier steel gears, that Shutter Assembly can sure get the Gate and Trap assembly dirty! And they can take lots of time (on a weekly basis) to thouroughly clean. I did try to convince my old employer to purchase one or two Ultrasonic cleaners, but that was futile. The other thing that I dislike about Christie is their dependance on Locktight. Personally, I cannot stand the stuff! As an aircraft mechanic, nothing beats the appropriate type of mechanical locking hardware! I did experience loads of hardware loosening problems with the Christie Gates/Traps. The two screws that attach the Curved Shoe can loosen up and if your not careful,can put a nice scratch right down the middle of your print. So, I got used to inspecting them after every show. Another problem I had on one occasion was the Lateral Guide set-screws loosening up during a show, the Lateral Guide falling out, and me having to find the Jewl in the carpeting. The method Christie uses to secure those set screws in place (by using opposing set screws) is an inappropriate design. An appropriate design would have been to use hardware such as Long-Lok or Nylok set screws from W.M.Berg, Inc. But if Nylon will not hold up due to heat, I believe that brass inserts are also available. Anyhow, when hardware started loosening up on several machines I spoke to Bevan about what to do. He recommended a certain type of Locktight, and I immediately serviced all 20 machines. It worked for several months, but then about the time I left that theatre, screws started to loosen up, again. Another thing to be careful of on these machines is that the Gate/Trap assembly is held onto the projector by two socket-head cap screws. Some idiot at that theatre (I do not know who)actually managed to cross-thread one w/o telling anyone and left the screw there folat'in around! I repaired it, but forgot what I did...I was either able to chase the thread with a tap...or I installed a Helicoil...its been too long and I forgot what I did. But it jst goes to show you how todays popcorn floor staff can things up!  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-01-2006 07:08 PM                     that stupid twist in a timing belt was their solution to problems they experienced with having a shutter gearbox much like the victoria 5 one  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-01-2006 07:32 PM                     quote: Mark Gulbrandsen but finds them harder than a simplex to work on. ..just wished that Christie had access to the shutter blade out front like the Simplex, then a timing factor would be tons faster....otherwise, I really had no problem with the P35 units. Have to give me a bit of slack since I've only was working with the P35 units for only 4 yrs whereas the Simplex has been my mainstay machine for almost 25yrs. thx-Monte  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 01-01-2006 08:29 PM                    When the shutter and jackshaft assemblies bearings go bad, do you (as projectionists) rebuild them yourself or just get a rebuilt unit and swap them out? I think I've had enough of the "rebuilding my own" thing. At first I didnt mind, but I've found that the shutter blades don't seem to want to go on to the shafts easily at all...and that leads to problems timing the projectors. Anyone know why the shutter blades (and sometimes the pulleys) dont seem to fit the shaft anymore? It seems that in order to get the pull or shutter blade on the shaft, I'd have to almost hammer it on...which is definately no good.  |  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.