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Author Topic: Christie P35 re-review
Mark Gulbrandsen
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From: Music City
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 - posted 03-02-2002 09:29 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Brad,
You forgot about the new glass shutter and all the Ultramittent mods that have been done. Also you didn't mention that it costs more $$ to do all those mods than a new projector costs. I do like the Filmguard on the belt idea though. Time for U to market a new product.
Mark @ GTS

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Brad Miller
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From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 03-02-2002 09:56 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
I have not played with any of the Ultramittent modifications, but have been able to get a very steady image out of 5+ year old Ultramittents when using the alignment tool. Can you elaborate?

On the glass shutter, unless something has been changed, the one I demo'd with Joe 2 years ago left purple-ish streaking on high contrasting bright areas of the screen. For example, if an actor is wearing a white T-shirt in a dark room, the shirt would have purple streaks in it. Has this been corrected? I was extremely impressed with the reduction of flutter from it and it's a great idea, I just haven't seen one yet that has overcome that problem.

On the cost issue, I think you're overexaggerating about the upgrades. Besides, all new production line projectors have all of this as "standard" items.


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Steve Kraus
Film God

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From: Chicago, IL, USA
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 - posted 03-03-2002 11:08 AM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
Woah...a glass shutter? Boy am I out of the loop. Why a glass shutter? They ought to redesign the thing with a properly sized one instead of the tiniest disk that will cut the light beam and then have to make up for poor efficiency by double speeding it. That's assuming the new one is similarly sized. As I said more than once on r.a.m.t. there is a reason other makes have shutters the size they do.

Also, did they finally solve the sound flutter problem?

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Mark Gulbrandsen
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From: Music City
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 - posted 03-03-2002 12:08 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Steve,
The glass shutter is quite unique. Its a 360 deg glass disk but I don't remember the exact types of coatings that Bevan told me they were using. On one half it blocks visible light and passes UV/infrared, and on the other half it blocks UV-Infrared light and passes visible light so the film does not pop as much. This results in vastly improved sharpness on screen. I remember someone else here posting that they worked out very good, dunno why Brads didn't.

No, the flutter problem is still in there on the new machines too. I still feel its due to the double sided belt. Since the inner diameter of the double sided belt is slightly smaller the pitch should also be. But they apparently don't see it that way.
The best P35's are still the older ones with the straight gate, shutter gear box, single sided belts,etc. These machines had no flutter problem.
In the Ultramittent they never did fix the outboard cam ball bearing problem either. It still fails due to condensation. The tiny amount of lube that is in one of those bearings is almost worthless, the fibre shield that covers it is an even bigger joke and totally worthless too. Its odd as moving that bearing in a little further would put it in the Ultramittent oil, and a seal would then be placed between the bearing and the flywheel. Right now the seal is between the two cam bearings.
Mark @ GTS


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Christopher Seo
Jedi Master Film Handler

Posts: 530
From: Los Angeles, CA
Registered: Jun 99


 - posted 03-03-2002 01:46 PM      Profile for Christopher Seo   Email Christopher Seo   Send New Private Message       Edit/Delete Post 
Purple streaks, eh? I've never seen one of these shutters, but it sounds as though the ultraviolet coating wasn't doing its job and was letting in a little visible violet as well during pulldown.

Or perhaps, now that anamorphics have become compact, we can go back to shutters in front of the lens. That would seem to solve the focus flutter problem as well. I guess a shutter between the gate and the lens would be too difficult to engineer.

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Brad Miller
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 - posted 03-03-2002 02:32 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Mark,

When approximately did you last play with one of the glass shutters? It is quite possible the one Joe and I played with was one of the first prototypes and you later got to use one that had been further improved on. I really did like the idea and the image (except for the purple streaks) was fantastic from it.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
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 - posted 03-03-2002 02:36 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Lets see, they've only redesigned or admit you need an upgrade for:

The gate/trap
Motor
Tension bands
Intermittent shoe
Soundhead drum
flywheel
tension arms
tension bands
belts
pulleys
sound damper (which has been both air and oil thoughout the years)
shutter
changeover (thought only the europeans had trouble with them)
changover douser

In short everything that relates to projecting a picture, reproducing sound and the actual drive train. What is left? The main housing?

The original straight gate P-35s were not as rosey as Mark would have one believe, the wow/flutter ranged from passible to horrible depending on if you had an air pot or oil-damped, what day your flanged bearings were made on and such...using a space age light-weight flywheel didn't help either. Even without a meter, I don't think I ever heard a P-35 play a stable tone.

In the Mid-Atlantic area, I believe ALL original P-35s have been pulled after they died, most never made it past their 10th year!

I have always admired the P-35xxx projector's machining...everything looks incredibly well made. I remember swapping heads out when the curve gate came out to try them...no realignment was necessary whatsoever to the picture or plate...even the turrets were swapped. That sort of thing always impresses me because it shows attention to the manufacturing tolerences.

The current version may be all very good but there is quite a bit of history of people having to deal with them.

On an up note, Christie has always been one that looks to keep trying to improve things (some may not always see the changes as improvements but I think the thoughts were in the right place).

------------------
"Old projectionists never die, they just changeover!"

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Steve Kraus
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 - posted 03-03-2002 02:37 PM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
Chris, I think that would be unnecessarily doubling the heat load on the gate & trap and a major increase on the film as well without the shutter blocking the beam during the non-pulldown dark period. The idea of keeping the film heated more continually is an interesting one but it's never going to totally eliminate thermal shifting because you alway have a new frame coming in and being heated up.

Still, a front shutter with no rear shutter would make an interesting experiment and could be easily tried on a Super or E7 or even a Century with a bit of shaft extension. Perhaps one with water cooling.


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Steve Kraus
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From: Chicago, IL, USA
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 - posted 03-03-2002 02:47 PM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
Steve Guttag asked:
>What is left? The main housing?

Reminds me of something I read about the development of the GM/EMC 201-A engine used on some early diesel locomotives. They were asked what parts gave them the most trouble in the design and engineering phase and the response was that it would be much easier to talk about the parts that *didn't* cause them problems. The dipstick, they said, never gave them any trouble. That was it.

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Brad Miller
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From: Plano, TX (36.2 miles NW of Rockwall)
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 - posted 03-03-2002 03:19 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
The gate/trap
Motor
Tension bands
Intermittent shoe
Soundhead drum
flywheel
tension arms
tension bands
belts
pulleys
sound damper (which has been both air and oil thoughout the years)
shutter
changeover (thought only the europeans had trouble with them)
changover douser

Steve, out of everything you listed there (including the "tension bands" of which you listed twice), just how many of them did you personally have a problem with? Let's take for example the two bladed shutter. It worked fine. Then they came out with the single bladed shutter to increase light output. It worked fine too, but with better light. Now they are working on the glass shutter which promises even more advantages. Since the original design worked fine (in this example, the shutter) are you saying that the company should not bother to improve their product? I mean come on, who has had problems with the motor? I've never even heard of anyone having a problem with the motor. Is this a genuine motor complaint of yours, or are you confusing the new motor hinge mount with some sort of motor defect? The older tension bands work just fine and dandy provided you sandwich something tiny under the end to stretch them just a hair more, or in extreme cases you use two tensioning clips together. I've never had a band wear out though and the ones at the Galaxy are all still the ones I installed 4 years ago (except for one with one of the company techs decided "must be a gate band problem" when it was something different). My only complaint with the bands was that the mounting holes should've been just a hair closer together from one end to the other. Have you had a problem with their intermittent shoe? I haven't and am still running the original shoes that came with the machines back in the mid 90's. Since when did their flywheel have a problem? Etc, etc, etc.

If you are going to make a list of things that are wrong with the projector, please follow each one of them up with your reasoning of *why* so the pros and cons can be discussed here productively.


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Mark Gulbrandsen
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From: Music City
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 - posted 03-03-2002 03:32 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
I agree with Steve that even the originals were not to rosy. I never did have any trouble with flutter on those versions though. Next time you are standing next to a running P-35 gearless wonder lightly pull the two ends of the shafts that the lateral guide rollers are mounted on together with your thumb and index finger. You find that you can actually feel it. Tightening the double sided belt up makes it worse, loosening it up alleviates it but not totally, and so on. On the original machines you can't feel this cogging/vibrating problem. I think Steve K had noticed this at a Christie installation he did with me a number of years back.

My experience with straight gate machines was that they put out a much steadier picture than the curved gate machine does.

Steve G. left the Ultramittent off his list. It has gone through some serious changes. Both the Inner Star and Inner Cam ball bearings have been replaced with bronze bushings. The inner ball bearings just did not hold up very well. The Motiograph AA had a similar modification done to it right after it was marketed. Its intermittent was also originally designed as an all ball bearing unit.

Brad,
I'm still waiting for Bevan to send a sample of the glass shutter out. I'm only referring to the fact that it is a novel idea and that some one else posted here that they had them and they worked great.

Yes, the fit/finish is impressive but it takes more than that to make a good projector. You have to have a good design first. Unfortunately there was not a good design to start with and it was re-designed as they went along at much expense to the end user.
Mark @ GTS


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Mark Gulbrandsen
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From: Music City
Registered: Jun 99


 - posted 03-03-2002 03:54 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Brad, I can relate to some of these changes but not all of them......

Motor....They used to burn up quite frequently in the projectors early days, however I can contribute this more to the motor manufacturer than the projector. Strong also has had enough Bodine motor problems to last them a Century(pun intended). They finally quit using them all together . Bodine is a notoriously unsupportave manufacturer.

Gate....Went from straight(better design IMHO) to the curved trap.

Intermittent Shoe....To try and aleviate the snowing effect of running estar base film through a P-35. Oddly the straight gates did not have nearly as much of this shedding problem.

Sound drum...It now has an "O" ring on it...and what the heck is it that supposed to do???

Tension arms...Three times now! They went from long to longer to a central pivot design which works no better than either of the others did.

Pulleys....They finally realized that when you run a belt over a soft alumnium pulley at an angle that it will eventually machine the pully to that angle causing very fast wear to the belt. Hardened pulleys now replace those that drive the shutter.

Shutter...From a normal 2 winger to a double speed single winger. Machines with the double winger sometimes had a strange shimmering problem to the on screen image. Early shutters were black anodized but warped quickly as the black coloring absorbed the heat.

Changeovers....Went from an atop the projector Essanay unit to one of their own design. The Internal Christie design is a real pro at falling apart.

Dowser Blade....Well, you know about that one.

I'll throw in another one here..Motor mount from a solid plate to hinged plate so you can service the beast more easily.

Steve G. Are you talking about the sound flywheel or the motor flywheel. I think the motor flywheel has been changed once.

Steve K., Somehow I just knew you were going to drag in diesel locomotives to this thread for a quick comparison........Christie should have put a EMC dipstick in the P-35!

Any way gotta take the dogs to the park.......
Mark @ GTS


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Steve Kraus
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 - posted 03-03-2002 04:39 PM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
Mark, correct me if I'm wrong but didn't the original double blade 1X speed shutters have a problem with travel ghosting in some lamp situations because it simply could not block the entire light beam. I thought that was the reason they changed to the single blade 2X speed shutter. I'd wager that the 2X shutter is still barely as efficient as a conventional machine's 1X two blader, given the degrees of rotation it takes to go from full on to full off, since the less time spent in transition is more time that could have been spent fully on.

I also recall your unhappiness with the shutter drive belt arrangement and the heat it was exposed to but I don't remember if that was a hypothetical concern or one born of bad experience.

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Mark Gulbrandsen
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From: Music City
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 - posted 03-03-2002 06:30 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Steve,
I don't remember any distinct travel ghosting, but more of a flickering/shimmering at installations I(we) did with the Christies. What I do remember was a huge improvement in pix quality after we put the single blade shutters in them and the flickering/shimmering completely vanished. I think you are right about the blade being too small to completely cut the beam off with some short focus lamphouses.

My theory of too much heat on the belt was perhaps a bit pre-mature as there are theatres around here running 4 kw and larger lamps all day and night on them. As tiny as the shutter belt is they actually do last along time.

I serviced a P35GP at BYU that had not been touched for over 5 years! Probably a record for a P-35!! All it needed was an Ultramittent overhaul and new belts. I opened the unit up and there was about an ounce of oil left inside it. Oddly no traces of oil were found on the machine or anywhere around it leading me to believe that it never had any oil in it in the first place. I also installed the longer arms for the lateral guide rollers while I was there for whatever that was worth.
Mark @ GTS


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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
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 - posted 03-03-2002 09:08 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Well Mark covered most of my points (psssst Mark, we are feuding, remember...get it straight for the Show...we have people to entertain!)

The motor:

First, a little bitty thing, then the more familiar one.

However, it first came without any capacitors OR flywheel! That didn't work...Started way too fast...

Ok so they added the flywheel...not much space in there so one was shoe-horned in. Calmed it down on the bang-up starts a little but too many failures...aha added a start capacitor.

The P-35's original soundhead flywheel was also changed to the current beefier one.

The Shutter. The two-bladed one gave me and other headaches...man what a flicker. Sure the frequency was 48Hz but the dwell killed it...it always flickered...I won't go into how many times they reinvented the gear box for the original shutter design...one had to keep track of the colored paint on the shafts to know which improvement one had.

My claim is that the original did NOT work fine and many of their design issues seemed like they could have been learned before coming out with the machine in the first place...most projector manufacturers stopped using straight gates back in the 50s and 60s for theatrical use (they are still popular in low heat situations like in studios...probably a key to the original Christie design).

I absolutely think it is great that a company will keep on working to improve their product. I hope you did not infer that that was the source of the crtique. That projector just seemed, to me at least, to have many major flaws that have, in essence required a complete redesign.

As to your commment on the tension bands, I'm sorry I listed it twice (I like tension bands ) place cardboard under them? That is a field fix for a manufacturing defect. Why wouldn't Christie recall the bad bands and replace them with the correct ones? It isn't the customer's fault. But see I find that normally that Christie DOES handle defects such as these with great care. I'm surprised you have had to shim them, will Christie not take them back.

Does the shutter drive belt still have a twist in it?

I maintian that the projection equipment that need the most service are the belt driven ones...projectors or soundheads. I wish Simplex would return the SH-10XX series soundheads...they were tanks. Maybe improve the drum/tension design so the pinch roller doesnt ride in the middle of the picture area and boy would you have something.

Steve

------------------
"Old projectionists never die, they just changeover!"


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