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.

Also, did they finally solve the sound flutter problem?
 

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

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.
 

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.
 

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!"
 

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.

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.
 

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.

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

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

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.
 

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

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

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"Old projectionists never die, they just changeover!"

Yes, the shutter belt still has a twist in it. The trick is simply to make the belt as loose as possible without the belt being able to jump. I've got machines here that haven't had their belts changed in 3 years and they are still trucking along fine. Granted the insides of the projectors are nasty because there wasn't belt dressing (or even Joe's combination belt dressing/FilmGuard trick) 3 years ago, but they're chugging along fine and dandy still.

(Mark and Steve, I expect a full show between you two in front of the Christie booth this week. Steve, which booth shall we have our platter vs. changeover argument at?)

Paul
SMPTE Hollywood Section
Otaku Over Forty
Unemployed mercenary film/video projectionist/engineer
"When the money runs out, so does I."
-17

 

quote:

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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...

---

At the very least. Shutters mounted in front of the lens disappeared from use in the 1920s when increasing projection speeds resulted in a move from three-blade to two-blade shutters, and with it a rise in lamp intensity. Two blade designs were found to be much safer because (i) the consequences of sticking your fingers in the wrong place were not as severe, and (ii) it kept the film stock cooler - a big deal, given that the film stock in use at the time was nitrate.

OK we don't use nitrate anymore but the other safety argument still holds. Furthermore, polyester warps and embosses when subjected to intense heat more than acetate does, and the rear-mounted, housed shutter also provides greater airflow round the gate area, keeping the film cooler. IMHO, a return to shutters mounted in front of the lens would not be a good idea.
 

Can someone explain why early projectors used front-of-lens shutters in the first place? Given the fire and finger hazard, it would seem like the logical place would have been behind the gate all along.
 

Cheers
 

The very first 35mm moving picture projectors were either combined camera/printer/projector devices such as the Lumière Cinématographe (which, when used as projectors, could not survive the heat of an intense light source and so were unsuitable for use in large auditoria) or mechanisms designed to bolt onto the front of a magic lantern (i.e. a slide projector). Placing a rotating shutter behind the gate was difficult in these setups because both the shutter itself and the mechanical linkages driving it would have fouled parts of the existing lantern.

This arrangement persisted long after there was any technical need for it, and external shutters didn't totally go out of use until around the conversion to sound, although the rethinking of projector design in the decade following WWI was what really kick-started the process. Auditoria got bigger, so the throw from projector to screen increased and the light sources used got more powerful (and thus they generated more heat). The film in use being nitrate, cooling became more of an issue and the introduction of two-blade shutters to maximise light efficiency soon followed, together with an increase in shooting and projection speeds.

Suggested reading: Raymond Fielding (ed.), 'A Technological History of Motion Pictures and Television' (Berkeley, California UP, 1957).

Contact your booth supplier for pricing regarding the motor hinge kit.

Paul
-11

 

I am a little disappointed to hear that the shutter pullys don't last very long.