Film-Tech Forum ARCHIVE: Bash on Christie Gearboxes!

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Posted by Manuel Francisco Valencia (Member # 710) on 09-26-2001, 03:14 AM:

You guys are either a bunch of bitching old hags or don't perform maintenance as well as you say. I have never seen one good post on Christie projectors, only negative info, and the funny thing is I have none of the problems you guys describe! No excessive noise, no excessive belt ware, no excessive shedding of prints. The only bad thing I have is the crappy basement readers. I know it is just the readers though because I have seen penthouse readers that work fine.
I have asked this before and I will ask it again, is it you guys or am I just that damn fortunate! Please respond or forever hold your peace!

Posted by Dustin Mitchell (Member # 372) on 09-26-2001, 03:18 AM:

One thing is that not all P35-GP's are created equal. Depending on how old they may or may not have the various improvements Christie has implemented over the years. My theatre has M35-GP's for example. They're slightly different from P35's so I don't have all reported problems with them but some.

I do hear that the newest runs of Christie projectors have most of the bugs worked out.

Posted by Don Sneed (Member # 955) on 09-26-2001, 07:13 AM:

The problems I have here in Japan with Christie projectors is the bearings are always going bad, especially the shutter bearing...well and the sprocket bearings, jack shaft bearings....in fact ALL THE BEARINGS !! They becoming very noisy, if will run you out of the booth not to mention the noise traveling to the seating area !! These are machines that are only two years old, the machines we installed in the states are having no problem with the bearings what so ever, but we have replace every bearing at lease five times at all the theatres in the past two years...it unbelievable but true, we are now using a different brand of bearings (not from Christie) & the problem is almost going away.....

Posted by Mark Gulbrandsen (Member # 72) on 09-26-2001, 09:08 AM:

The older Christie machines with the shutter gearbox are actually a better machine than the gearless wonder. Believe me you are a single example of one that has not had problems with them. Christies own number of modifications, retrofits, etc, alone speaks for its poor design. The bearings they use are crap. The all ball bearing intermittent has had half its ball bearings removed for conventional bushings,the soundhead has had far too many versions...while the original sound head had no problems at all!!!? There were straight gates and now curved gates while the straigt gate projected a far better and steadier image. Shutter pulleys wear out too fast and had to be modified, square tooth pulleys are used where rround tooth should be used, Parts for older machines are pretty much non-existant or only available from your local projector graveyard, the intermittents outer ball bearings are not lubricated by the intermittent oil and consistantly corrode and fail and are way to small for the load they are under. They projector runs noisy, no two are alike, but there is one good thing about them.......They have LaVezzi VKF sprockets.....thats about the ONLY good thing that comes to mind about them if I really think hard.
Mark

Posted by Paul Konen (Member # 41) on 09-26-2001, 09:12 AM:

I will say that in the 2 1/2 years that I have had the Christies, they have worked pretty well. Don't super tighten the belts or you will go through jack shafts and shutter assy. They also will run noisy as hell.

I have had just one projector that I had to replace the upper / lower constant speed sprocket because of grinding. Aside from that, do your normal maintenance things.

Paul

Posted by Jason Burroughs (Member # 68) on 09-26-2001, 01:38 PM:

The statement that all Christie projectors are NOT created equal is very true, I have some that worked very well, were fairly trouble free, gave a very nice picture, ran very quietly, treated the prints VERY nicely, the projector next to it, (next serial# even) was a hell beast and a half, we fed it a steady diet of belts, kept is clean, the douser always wanted to stick, now matter how often we aligned it, we didn't have the basement readers to contend with as far as dolby digital, but had analog sound problems due to the flimsy design of the airpots, bad bearings, etc.

Posted by Will Kutler (Member # 770) on 09-29-2001, 04:49 PM:

Mark

Your comments about the types of gears (straight vs round) is interesting.

In all probability Christie is purchasing their gears in bulk from a manufacturer such as Berg.

Now the types of gears/belts that Christie uses are in fact timing belts. The problem lies with poor engineering with the jackshaft-shuttershaft assemblies.

Berg does in fact make 3-D and twist o flex pulley/belt drives. I have not done any engineering research, so I do not know if they would be approperiate for this application--timing, rpm and torque are definate factors.

Another possible option would be the use of brass/bronze to Delrin gears. Delrin is a self lubricating engineering plastic that is commonly used in gear manufacturer. Once again, torque and rpm is a definate factor.

I was also thinking about a sealed bevel gear box/drive to replace the existing system--but I have not put anything on paper yet--just an engineering idea that I have.

As far as bearings are concerned. Sure, the name brands such as Timkin still exist--but for the most part, bearings are not US made anymore and their quality will vary depending on were they are made. Sure, you might order a Timkin bearing with a certain part no, but you will not know where that particular bearing is made until you get it! In fact, the same bearing might be made is several countries whose quality will differ.

Posted by Gordon McLeod (Member # 33) on 09-29-2001, 06:11 PM:

The vic 5 had a sealed gear box with in some cases a delrin gear train
considereing the rpm of a single blade shutter a set of steel gears would probably be best

Posted by Richard Fowler (Member # 893) on 09-29-2001, 06:30 PM:

The V-5 shutter box has been upgraded in the past year to steel drive gears, which are slightly more noisy....so they encase it in a rubber boot....the upgrade was done from the delrin setup since people forget to maintain the grease in the box and was unforgiving with careless operators. I was in a 10 plex Christie booth in Latin America where they had a shutter drive belt ( spare ) tie wrapped on each machine.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com

Posted by Gordon McLeod (Member # 33) on 09-29-2001, 07:10 PM:

Tie wrapping a spare belt in place is probably a very good idea in most theatres as when it breaks the spare can't be found

Posted by Mark Gulbrandsen (Member # 72) on 09-30-2001, 09:51 AM:

In a previous posting Will Kutler made some suggestions regarding a previous posting of mine as to how to improve the Christie projector. Some of these ideas have already been tried or looked at so I thought I'd interject what I know and have learned from experience about some aspects of the Christie.
My personal feeling on the best way to improve it is simply not to buy it and just get a Kinoton instead.

>Your comments about the types of gears (straight vs round) is
>interesting.

This was one of the fixes Strong did to the 5 Star Sound head. It made a huge difference. They have used round tooth metric belts on them for quite a number of years now. The difference in W&F is definately measurable in this case. I have measured the difference myself.

>In all probability Christie is purchasing their gears in bulk from a >manufacturer such as Berg.

You're right except it is a company outside Chicago. Another problem is the extensive use of alumnium pulleys. They should be all Steel. Alumnium is cheaper...using these makes Christies profit margin increase...Oh well....

>Now the types of gears/belts that Christie uses are in fact timing >belts. The problem lies with poor engineering with the jackshaft->shuttershaft assemblies.

I agree to some extent on this. However Christie used to use a 90 degree gear box with hardened steel helical gears. The only problem with the gear box was that the gears were about the diameter of my small finger tip. One would have gear box failures from time to time but 5 years was a normal lifespan for these. Increasing geear size would have been a better fix than to eliminate the gear box for a belt.

>Berg does in fact make 3-D and twist o flex pulley/belt drives. I >have not done any engineering research, so I do not know if they >would be approperiate for this application--timing, rpm and torque >are definate factors.

These are unique belts. In fact I made use of one of the miniature Berg Ladder belts when I built the crystal motor drive for my VistaVision camera. The outer perifery of these is a pair of stainless steel cables. They do last along time and do not shed at all either. A Christie made completely out of these would probably run forever, and very quietly too. These belts can also easily be made to any length in the field.

>Another possible option would be the use of brass/bronze to Delrin >gears. Delrin is a self lubricating engineering plastic that is >commonly used in gear manufacturer. Once again, torque and rpm is a >definate factor.

Not for this applicaton as lubricant is then required due to the rpm involved here. Mr Murphy also enters here...It will leak out and not get replaced. This is the case with many Christie movments I've opened up in past years. The last one had about a half ounce of lube in it!

>I was also thinking about a sealed bevel gear box/drive to replace >the existing system--but I have not put anything on paper yet--just >an engineering idea that I have.

To relace which existing system? If it is to replace the shutter drive this type of gearbox is already a minor neusance on other brands of projectors. So this option is out. Remember, this is supposed to be a no maintainance machine other than once a year servicing. Using spiral bevel gears is also the more efficient route for a 90 degree gear box. This would add to the price too.

>As far as bearings are concerned. Sure, the name brands such as >Timkin still exist--but for the most part, bearings are not US made >anymore and their quality will vary depending on were they are made. >Sure, you might order a Timkin bearing with a certain part no, but >you will not know where that particular bearing is made until you >get it! In fact, the same bearing might be made is several countries >whose quality will differ.

There is a brand of bearing made here in the US, Barden. They are a high end bearing company of the highest quality. There were Barden bearings in my surface grinder spindle to give you an idea of the stuff they make. There are other high end bearing companies in Europe and Scandanavia as well. Also just because of where the bearng is made has nothing really do do with its quality. You just have to spec and order the right version of a given bearing. A cheap bearing is a cheap bearing. I have sucessfully used Barden bearings in many Christie intermittemt overhauls to great sucess. The Bardens I bought to replace in the Ultramittents cost me 60 bucks apiece! And they last, so the higher price is not really much of a factor here. However, I believe the real problem lies in the fact that the bearings used in the Christie movement are way to small to begin with. Also the outer star and cam bearings rely solely on their internal factory grease for lubrication. This in itself is another major problem. In dry climate areas the grease evaporates and the bearing fails. In humid areas like the midwest, the cheap fibre shield on the Christie bearings allows moisture to build up in the bearing from either condensation or just from creeping in and and mixing with the grease itself. This causes the bearings, especially the outer cam bearing to fail rapidly. Larger bearings are needed, especially in the cam end of the mmovement. Perhaps doubling up the inner and outer bearings would work in this case. In the Motiograph AA the outer bearings were double row if I remember correctly and they last forever and in the Ballantyne Pro 35 they used double stacked bearings on the outer cam position as it was getting the drive off of the V belt. Also the Christie cam bearings need to be in the lubricant. In a Christie movement, this would be an easy modification to do in a normal shop. Move the bearing in slightly and install the shaft seal outside of the bearing as on a Ballantyne. My hell now, we wouldn't want them to last too long would we?
Mark @ GTS

Posted by Will Kutler (Member # 770) on 10-02-2001, 12:14 PM:

Mark

Thanks for the info about Barden--I'll look into them. Actually I had gone to several bearing suppliers looking for high end domestic bearings. No one ever mentioned Barden. The info I posted about bearing quality is what I recieved from these suppliers. Please post an address/ph for Barden!

I am glad to hear you made good use of the Berg 3-D belt/pulley system. I was not sure if these would be approperiate for a timing application, and I also think that rpm is another engineering factor.

Christie has replaced the aluminum jackshaft and shuttershaft pulleys with steel ones. You may be able to get these for free via an even exchange?

When changing pulleys, remember that Christie used Locktight on the pulley set screws!

I also saw some brand new Christies lately, and there is a design change to the shuttershaft/jackshaft assemblies.

Posted by John Pytlak (Member # 331) on 10-02-2001, 12:41 PM:

Here's a link to the Christie Technical Support webpage, with manuals and latest parts listings and field bulletins:
Christie Technical Support

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Mark Gulbrandsen (Member # 72) on 10-03-2001, 11:26 PM:

Hi Will,
As I am typing this I am less than 3 blocks from the Christie plant where I am staying here in Cyprus, CA. I thought I might go there and see if they'd give a tour but I have more important things to do and time is limited here anyway.
You can check out Barden Bearings at www.bardenbearings.com Check out the literature section for all sorts of technical stuff on how to install precision bearings and also some interesting stuff on Ceramic Nitride bearings.
Mark @ GTS

Posted by Randy Bowden (Member # 587) on 10-04-2001, 04:27 PM:

We used Barden bearings rather successfully on the Ballanyne Pro 35 outboard assy. when I was a tech for Act 3, lots of Bals!!!!

Posted by Will Kutler (Member # 770) on 10-15-2001, 08:37 PM:

When I worked for my old employer (theater chain) I suggested that they look into the Berg 3-D belts. Although I still needed to discuss engineering details with Berg they were willing to send free sample material to make up one belt as a test piece. Unfortunately my old employeer wanted no part of it--...!

I just had another brainstorm, but I do not know how well it would work? Seeing as how Christie is having major problems with douser warpage and that they are reverting to expensive titanium as I've heard, how about the following instead? Brazing and soldering tile--can cut the material out with an exacto blade! It is also rather inexpensive and can be purchased at any decent hardware or welding supply store. Another idea may be glazed ceramic tile--can be simply/cheaply done at any ceramic/pottery hobby shop.

Posted by German Marin (Member # 918) on 10-16-2001, 02:21 AM:

I've worked with 4 M35GPS and actually i work with 7 P35GPS and the only problem that i had was a malfunction on lens turret on M35GPS. About P35GPS I've got a problem with lamps (I've replaced 3 of 7). I like this projectors because they are easy to operate. Once I had a problem with autowinder 3R: didn't work. I did the work by hand, suddenly it begun to work fine!!
All the 7 projectors are operating good (they was installing on May) and i hope they will a good work.

Posted by Brad Miller (Member # 2) on 10-16-2001, 03:01 AM:

Will, for platter theaters it is much easier to just move two wires on the automation and have the lamp wired through the relays originally intended for the exciter. Lamp comes on when the douser would normally open, lamp goes off when the douser would normally close. Then all you do is remove the dousers and forget about them. No more expenses and no more botched shows because they jammed or did not open fully. This may not work with all automations, but it certainly will work with many of them.

However, Christie's new dousers are indeed quite durable! I would highly recommend a replacement for any theaters that must use them.

Posted by Gordon McLeod (Member # 33) on 10-16-2001, 10:07 AM:

Yes and treat the audience to the lamp repeatecly fireing as it attempts to light if it is a little old

Posted by Heyward Garner (Member # 722) on 10-24-2001, 01:36 AM:

Manuel...

Cover the ears and eyes of the little children around you... My projectors are peices of SHIT! The Christie lamphouses are great, don't get me wrong. I love their lamphouses. ( I don't like the fact they use megasystems automation, but...) My projectors are the biggest pieces of floppy donkey dung. They are the reasons I never have ANY TIME to read or post on here! I should be at least a Jedi-Film master by now, but nooooooooo! Three hours later I leave the office...