Film-Tech Forum ARCHIVE: Shaking Vic 5

This is topic Shaking Vic 5 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=010133

Posted by Dominic Espinosa (Member # 2122) on 10-13-2009, 07:16 PM:

Hey guys,

I've got a Cinemechanica Vic 5 here that shakes like a chihuahua.

My casual observation is that the vibration is being caused by the intermittent as the frequency looks like it's in-time with the intermittent. Indeed the entire machine has this rough vibration. The other Vics in this booth don't have it and their image is rock solid.

I have a spare intermittent to drop in but I'm not able to get to it right away and I'd like to know what to expect to have to do to repair the one coming out. If this is in fact the case. I'm relatively new to V5's so any pointers on stabilizing this bad-boy would be great.

Thanks, guys.

Posted by Gordon McLeod (Member # 33) on 10-13-2009, 07:18 PM:

Rebuilding the v 5 movment is a shop job that isn't done in the field
changing it is simple though

Posted by Jarret Chessell (Member # 5077) on 10-13-2009, 07:34 PM:

Do you mean the picture is shaking, or the projector itself?

Posted by Sam D. Chavez (Member # 1841) on 10-13-2009, 07:40 PM:

A shaky V5. What a surprise. I would try a new sprocket first. It might be bad from the start or gotten bent in time.

Posted by Dominic Espinosa (Member # 2122) on 10-13-2009, 08:56 PM:

Picture is vibrating, the machine itself has a very strong vibration in time with the intermittent.
The other machines you can feel a very slight vibration around, say, the lens turret, but on the machine in question it feels like holding onto the handle of a lawn mower.

I'm aware the movement is not an in-the-field type of job.

Posted by Monte L Fullmer (Member # 2797) on 10-13-2009, 09:25 PM:

K, take the belt off of the motor then turn the motor on. Try that to see if you got a motor vibrating on your - issue why of the shakes..

Then, if not, change out the motor belt - you could have a stretched belt..

Then, if not, take the tooth sprockets off and see if you don't have a gob of gunk or grease stuck on the inboard side of the sprockets acting like an extra weight causing the vibration ... and also check the shutter area (you could have a going shutter transmission assembly on you) for something could have caused that to go off-center.

Is the INT sprocket clean - no gunk inbetween the teeth?

Good luck-Monte

Posted by Louis Bornwasser (Member # 3063) on 10-13-2009, 09:40 PM:

V5: most problems involve the intermittent, which influences all else. Louis.

Posted by Ron Lacheur (Member # 1126) on 10-14-2009, 12:53 AM:

Dominic,

We had an issue with one of our turreted Vic5s were the turret lock was loose ( on the machine side ) and the turret was vibrating and was producing a really poor picture. Credits were almost unreadable.

Might want to check that.

Posted by Demetris Thoupis (Member # 833) on 10-14-2009, 01:10 AM:

Try taking the intermittent sprocket out and twist it 180 degrees so it rotates the other way.
Demetris

Posted by Ken McFall (Member # 845) on 10-14-2009, 04:48 AM:

Belt tension can also be the cause of rough running and noise.

Using a firm bristle brush and cleaner make sure the pulley teeth are clear of all crud and that the tension pulley for the inner belt is also running free.

The keeper rollers that run on the flat side of the belt, shutter and intermittent, should also be removed and cleaned.
These are often set too close to the belt and pick up a lot of crud on their surface. The distance from the belt for these should be close enought so they don't spin constantly. They are intended to stop the belt from jumping out of mesh rather that to press them firmly down.

When finished cleaning use NEW belts and see how things feel after tyat.

The other thing to consider is the sproket shaf bearings themselves. Not difficult to replace and not expensive. It's also worth checking the condition of the sproket shafts for play and wear.

The above suggestions are quite simple routine maintenance jobs that don't take too long and involve little cost overall and are worth doing regardless of any current problems. The difference to an older projector can be very noticable.

If none of these help you are left with the intermittent or shutter gearbox. It's difficult not having seen or heard the projector running and you don't say you have sever picture jump or random picture ghosting. So these items should be looked at once all of the other work has been done so you know you are working with a mechanically sound mech.

The intermittent isn't too difficult to swap with the shutter gear box being more involved. If you do have to go this far make sure you set up the shutter with the intermittent and shutter timeing red dots in the right place....

Hope some of this helps.

REgards.

Posted by Pete Naples (Member # 761) on 10-14-2009, 05:47 AM:

Amen to that Ken!

Whenever I take a call from a customer about a Vic 5 running rough, the first thing I suggest they do is change the belts and give all the belt sprockets, idlers etc a good clean.

9 times out of 10 said Vic 5 is then running as sweetly as they ever do.

Posted by Marco Giustini (Member # 4544) on 10-14-2009, 08:18 AM:

All good suggestions, but I quote Demetris one. I made a rock steady V5 flipping the intermittent sprocket 180°

Posted by Randy Stankey (Member # 64) on 10-14-2009, 09:29 AM:

I don't work with Vic 5s but I'm going to second Ken's and Pete's suggestions on grounds of "Do the easy things first."

I can't tell you how many times I have spent an hour trying to fix a problem only to find out that it could have been fixed in five minutes if I just checked some simple thing first.

It doesn't matter if you're working on projectors or working on your car. The same thing applies.

When you hear the sound of galloping hooves, don't assume it's an approaching herd of zebras!
[Wink]

Posted by Dominic Espinosa (Member # 2122) on 10-14-2009, 10:10 PM:

Thanks guys for all the info. Ken, great write-up as usual!
Everything was in good shape in there. More goop and crud than I like to see but it was decent.

I ended up changing the intermittent assembly with a rebuilt one we had on-hand (which I discovered looking for a tool while taking one out of an old head recently removed from service!).
That steadied it right up. Much less vibration, much less noise, and very solid picture.

I am however having a HELL of a time getting the shutter phasing just right. It almost seems like the shutter is too small. It's the normal double blade by the way.
I've done timing on these (but not this house) before but never had such a problem.

Posted by Ken McFall (Member # 845) on 10-15-2009, 02:12 AM:

Good to hear you have a much smoother projector now.

There should be no problem with shutter timimg when set-up with the rod dots correctly positiond as per the manual. However there may be a difference in the position of the dot on the 'newer' intermittent.

The actual shutter blade does not have full 360 degree adjustment. So if you find you cannot move it in the required direction you will have to take out all of the shutter clamping screws and turn it so you are using the next slots to clamp with. (Hope this makes sense to you).

However, I would be surprised if this was in fact the case.

The method I use is to slacken off one of the shutter clamping screws and slacken off the other leaving it just tight enough to hold the shutter in place. This helps to make slight adjustments of the timimg without having to apply too much torque to undo the clamp which risks moveing the shutter out of position.

Run a loop with some white on black text.

I was taught to remember BRAT when timing shutters.
Bottom retard >> Top advance.

When you have determined where the travel ghost appears firmly lock/hold the belt in place and slacken the clamping screw that was left just holding. Adjust very slightly in the required direction. Then clamp in place slightly with one screw and run the loop again.

Once done correctly, with line up dots in place, I make a very clear scratch from the edge of the clamping plate onto the shutter blade for future reference.

Hope some of this helps.

Regards.

Posted by Marco Giustini (Member # 4544) on 10-15-2009, 02:39 AM:

I usually draw a white line between the shutter and the locking plaque after the first rough adjustment. This helps understanding how much I'm moving the shutter when I loose the screws. If you don't have a reference, when you loose the screws you do not realize that the shutter has moved a bit. And do not tight the belts AFTER setting the shutter, do it before!

Posted by Dominic Espinosa (Member # 2122) on 10-15-2009, 07:10 PM:

Well, after much fanfare our machine is in much better shape.
There still seems to be a small bit of latterral instability in the image that I haven't tracked the source of yet but it's SIGNIFICANTLY better than it was.

I am concerned because it's unstable still that the intermittent may have been only a symptom and not the true cause. And I am concerned the new one will become bad sooner rather than later in the same way.

Posted by Gordon McLeod (Member # 33) on 10-15-2009, 08:10 PM:

Which version of gate and trap do you have

Posted by Marco Giustini (Member # 4544) on 10-16-2009, 02:48 AM:

I don't think that there was the possibility to damage the intermittent of a V5 by external factors...

Posted by Gordon McLeod (Member # 33) on 10-16-2009, 09:58 PM:

An intermitent can be damaged by external factors by objects hitting the sprocket film pile ups

Posted by Damien Taylor (Member # 4255) on 10-16-2009, 10:24 PM:

A toothbrush has found its way somewhere it should not be while the projector is running.

Posted by Marco Giustini (Member # 4544) on 10-17-2009, 04:55 AM:

Sure, I mean that Dominc is concerned about a hidden cause (belt, runners...) that could damage this new intermittent unit as well.

Check that the roller under the intermittent sprocket is not pressing hard against the intermittent sprocket itself. It has a stop on the back and it should be set so as the roller does not touch the print.

Posted by Gordon McLeod (Member # 33) on 10-17-2009, 12:23 PM:

If there is a eccentric idler it can put a pulsing stress on the movenents bearing on the drive side

Posted by Dominic Espinosa (Member # 2122) on 01-12-2010, 11:16 PM:

Gordon,

Haven't been on this machine for a while. Was running digital in this house.

All I can tell so far is that it's a straight gate.

I'll check later tonight for a part #.

Posted by Phil Blake (Member # 2012) on 01-16-2010, 01:19 AM:

and i have discovered that not all intermittents are made equal...
our of my 3 vic 5's one was very noisy ,hammering and unstable image.

i removed the assembley and took it apart on the bench ( i can hear the techs groaning) after carefull inspection found the maltese cross to be binding on its shaft , i gently cleaned the shaft with very fine wet and dry paper , reassembled everything , now that machine runs the best out of my 3 it is so quiet now.

phil

Posted by Demetris Thoupis (Member # 833) on 01-16-2010, 02:01 AM:

Oil in the intermittent should be periodicaly changed at 500 hours to reduce the possibility of the oil thickenning and becoming a residue on the maltese cross pin. Unfortunately most ppl thing the projectors are meant to run forever without any maintenance or very little. The way I do it and never had a V5 fail is to do this
Change intermittent oil every 500 Hours

1st year in operation rotate Belts and intermittent sprocket so they both rotate the oposite way. Thorough clean of projector. Re-Grease the shutter assembly

2nd year in operation change belts and intermittent sprocket completely. If it is a curved gate change the springs. Re-Grease the shutter assembly.

And 3rd year in operation I ususally make a very thorough clean of all parts by completely removing them and putting them back together. It is a time consuming process but its worth it and also redo the procedures for year 1 in operation and make the cycle over again.

Demetris

Posted by Dominic Espinosa (Member # 2122) on 02-05-2010, 11:46 PM:

Well, after much ado we did the simple thing: swapped out the gate/trap assembly.

It's strange because most of the components in the old assembly had been replaced by another tech in attempt to steady the image.

No more shake and much quieter now.

Posted by Demetris Thoupis (Member # 833) on 02-06-2010, 12:00 AM:

I serviced an extremely shaky V4 the past few weeks. Even though the Intermittent did improve it, it was the gate trap that solved the shaking to 0. Keep that in mind.
Demetris

Posted by Louis Bornwasser (Member # 3063) on 02-06-2010, 10:19 AM:

V5 shaking? Don't they all shake? I am only kidding a little bit.

I saw V5 intermittents being built at the factory in Milan. The ones that were adjusted were fine. The other 96% caused belt oscillations enough to require constant shutter drive gear replacement. Rebuild or at least adjust all of them. Louis