8mm Forum: Problem with my Revere p90

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Posted by Nic Fernandez (Member # 3460) on January 27, 2013, 11:41 AM:

Hello, forum. I am new to 8mm film and film projectors. I took apart my p90 to clean the hairs behind the film gate. When I put it back together I came across two problems.

[I used old home movie film to test]

1) The film seemed to flutter really fast, as if there is a problem with the film claw.

2) The film began to back up, from the bottom timing wheel (under the lens)

I would greatly appreciate it if some one could instruct me on what may have gone wrong.

New Film Hobbyist,

Nic Fernandez

Posted by Rob Young. (Member # 131) on January 27, 2013, 01:29 PM:

Hello Nic; a warm welcome to this mine of filmic information!

My first thoughts are always to look at the simplest explanations first, then worry about more complex promblems later.

Firstly, have you run film successfully in this projector before cleaning it, or just looked at the projected empty gate (the white image from the projector with no film in it) and seen hairs that need removing?

Secondly, it sounds like the film has simply mis-threaded and not engaged the second sprocket (that's the timing wheel - its called a sprocket, or sprocket wheel; hence the holes in the film are called sprocket holes).

Have you tried to remove the film, re-trim the end as per the projector specifications and tried again?

Let's go from there before the "oh, you've got a bent claw brigand" get in!! [Wink]

Posted by Nic Fernandez (Member # 3460) on January 27, 2013, 02:30 PM:

Thank for the prompt reply. [Smile]

Yes, I ran probably 2hrs worth of film through it, before I finally got tired of looking at the hairs. And during that time I had no problem.

I will check the sprocket again [Smile]

and not sure what trim to specs mean. I apologize I am a newbie hahahahahaha

I'll see if this works. Thanks again [Smile]

Posted by Pasquale DAlessio (Member # 2052) on January 27, 2013, 02:36 PM:

Nic

WELCOME TO THE FORUM!!!

PatD

Posted by Nic Fernandez (Member # 3460) on January 27, 2013, 04:59 PM:

Thank you for the welcome PatD [Smile]

I checked the sprocket, threading and the film looks as though it is the right size to specification. It seems to me that the sprocket wheel and the claw are out of sync somehow.

For example: When I engage the clutch with the projector (on the take up setting), the film at the lower part of the gate pulls tight, then begins to run through the projector...and the film still flutters really fast.

Thank you everyone for the welcome and assistance [Smile]

Posted by Rob Young. (Member # 131) on January 27, 2013, 11:43 PM:

Trim to spec just means that some projectors come with film trimmers which cut the leader in different ways and sometimes if you don't trim it according to the projector, it doesn't always thread properly.

It does sound like the claw isn't engaging the sprocket holes correctly though; if it isn't passing through the gate properly, the lower loop of film which forms after the gate and before the lower sprocket would tighten.

Maybe you could tell us what you did to clean the projector and that would give some clues? [Smile]

Posted by Nic Fernandez (Member # 3460) on January 28, 2013, 12:16 AM:

To get to the open area behind the film gate (where the hairs were built up). I disassembled the back, removed the shutter and the black plate in front of the light filter. I also loosened the claw, but only enough to move it a bit to clean and to apply a small amount of white lithium grease, at the base of the claw, close to the second fan.

[out of curiosity I turned the main rod (the silver knob on the front) to see how the gears worked]

Thanks again, Rob. I really appreciate this [Smile]

Posted by Rob Young. (Member # 131) on January 29, 2013, 03:29 AM:

Ah, sounds like you've got something out of adjustment then.

The shutter and claw do have to be synchronised or you will see ghosting (where instead of the shutter opening to show a still frame, it opens as the claw moves the film and you project the movement instead of a still image).

But that in itself shouldn't cause the lower loop to be lost (tighten).

It sounds like maybe the claw isn't engaing the sprocket holes correctly. I'm not familiar with the Revere, so we'll have to call upon some of the projector technitions here on the forum.

I'd double check everything you took apart to make sure it all looks tight. If the claw isn't protruding correctly through the gate, it will mis-engage the sprocket holes and cause the film to stutter, or if it is mis-aligned, it can hit the film itself rather than the sprocket holes and cause a similar result.

Alignment of the claw is quite a precise and tricky business.

Either way, as it isn't travelling throught the gate properly, the lower sprocket will cause the lower loop to tighten and possibly cause damage to the film.

If we can get this sorted, for future cleaning, it shouldn't really be neccesary to dismantle anything. Projectors are designed differently, some have gates which swing completely open by swinging the lens and gate pressure plate assembly open, others are more difficult to access, but you should be able to get enough access to gently clean with a cotton bud or compressed air duster.

Last thought, if you can see the gate pressure plate, that's the sprung part of the gate just behind the lens, make sure it is correctly in place by giving it a couple of moves back and forth on it's springs.

Calling our projector techs on the forum!!! [Smile]

Posted by Nic Fernandez (Member # 3460) on January 29, 2013, 10:29 AM:

Thank you, Rob. [Smile]

And yes, calling all projector techs....

Posted by Nic Fernandez (Member # 3460) on January 29, 2013, 10:00 PM:

Thanks again for all your help, Rob. I learned a lot from your posts [Smile]

Unfortunately it seems as though I have to find some way to align the claw properly...I suppose it's going to be trial an error from here on out or at least until I get proper instruction.

Posted by Barry Fritz (Member # 1865) on January 29, 2013, 10:35 PM:

Does this unit have an inching knob? If so, thread it up and advance the fim using the knob. See if you can see the claw engage the sprocket holes.

Posted by Nic Fernandez (Member # 3460) on January 30, 2013, 10:06 AM:

Hello, Barry. Excellent idea [Smile]

I'm not sure if it has an inching knob, but I think I can turn the knob to the main driver shaft to see if the claw is engaging the sprocket holes correctly. Although, it might be difficult to see, because the spring gate has to be closed for the film to run through properly?

Thank you for your help [Smile]

Posted by Barry Fritz (Member # 1865) on January 31, 2013, 01:56 PM:

That knob serves as the inching knob. Yes, gate will be closed but by watching and listening closely, you should be able to see if claw is engaging and working correctly. If it isn't, you may hear it snag on the sprocket holes. If it is out of time and not going into the holes you will see the gate pushed out slightly each time the claw moves out.

Posted by Nic Fernandez (Member # 3460) on January 31, 2013, 08:22 PM:

Thank you, Barry

I'm going to work on it this weekend. Wish me luck everyone [Smile]

Posted by Barry Fritz (Member # 1865) on February 01, 2013, 08:38 AM:

Good luck. I meant that you will see the pressure plate move slightly, not the gate.

Posted by Nic Fernandez (Member # 3460) on February 01, 2013, 12:17 PM:

Thanks again, Barry

Posted by Nic Fernandez (Member # 3460) on February 03, 2013, 03:00 PM:

Hello everyone. Film is running through my revere, properly. A big thank you to all those that helped. However there appears to be a slight bit of ghosting (I think) or some kind of flicker from the shutter.

The odd thing about this, is there seems to be only one way to put the shutter on. The shutter itself has a hole for a washer with a pin on it to go through. And on the cam - gear there's a small hole to fit it all together...so I'm kind of stumped.

Thanks again, everyone.

Posted by Rob Young. (Member # 131) on February 07, 2013, 01:51 PM:

Good news!

Nic, maybe you can share with us the kind of films you are running in a new thread.

Not to critcise the Revere, but maybe there are some nice projectors out there, at a reasonable cost, that don't have "ghosting"! [Smile]

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