Film-Tech Forum ARCHIVE: Cinemeccanica V-5 problem-

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Posted by Frank Bruno (Member # 1871) on 03-19-2008, 06:53 PM:

At the risk of sounding dumb...

For some reason the scope lens on one of my v-5s plays a bit higher on the screen then it should; it's playing over the top masking with dark space above the bottom. I'm told that there should be some kind of vertical adjustment but for the life of me I cannot find it. I've checked my turret high & low; I know it is not the allen screw on the side of the lens mounting; I already knew that would let me turn the lens & give me side to side play, but I tried again anyway. I should know what to do about this, but I don't.

I have a manual but it only includes exploded one-lens holders & a 3-lens turret in the parts sections; it is the same one in the "Manuals" section of this site.

I realize I sound a bit dumb, but can anybody help with this?

Posted by Richard Fowler (Member # 893) on 03-19-2008, 07:30 PM:

The other eccentric screw shaft opposite from the one that allows side to side on the lens mount in the turret, will give you up and down. After you loosen the cooresponding allen set screw, you adjust on the eccentric shaft with a straight blade screw driver. There has to be compromise between flat and scope positions, assuming your aperture plate was cut correctly and the lamphouse "bullseye" is correctly set to the film trap / lens turret. I have also had Cinemeccanica consoles "drift down" on the rear adjustment slides due to the weight of the head.

Posted by Marco Giustini (Member # 4544) on 03-19-2008, 08:41 PM:

suggestion. After you loose the allen screw, close the turret and rotate it twice. Then adjust. If you open the turret, rotate it twice when you close it.

Then open slowly the turret, tighten the allen screw.

Ciao
Marco

Posted by John Walsh (Member # 168) on 03-19-2008, 11:16 PM:

What year V5 do you have? I saw a 3-4 year-old V5 recently and it did not have the X-Y setup that I was used to seeing on the older (1976 or so) 3-lens turrets. The holes were in the casting for the cam-rods, but they were plugged with plastic caps.

Posted by Frank Bruno (Member # 1871) on 03-29-2008, 02:34 PM:

Mr Fowler- My turrets don't seem to have another screw shaft opposite the one that loosens the lens itself. There are four flat-head screws on the front of the turret; I get no play at all from them so I imagine I would have to loosen something else, but damned if I know where. I actually have a spare v-5 we use for parts, & I took the turret on that apart to see if I could find something hiding. No dice.

Signor (?) Giustini- I tired your suggestion. it didn't work but I do appreciate it.

Mr Walsh- I'm actually not sure what year my v-5s are; they have all been in my theater since installed at opening in 1990-91-ish. No capped holes on mine; at least then I'd have had some idea where it SHOULD be.

Well, thank you all; sorry it took me a while to check back in. ANy other suggestions I would really appreciate them.

Posted by Richard Fowler (Member # 893) on 03-29-2008, 08:26 PM:

Frank,
the eccentric shaft lock screw is part #1007008...it is a allen screw either 1.5 / 2mm in size buried in an access hole about 20mm deep. The access holes are just in front of the rear castings holding the upper and lower eccentric shafts for each lens support collar. The location is about -35 degree for the lower and +35 degree for the upper shaft in reference to the mid point of the shafts. I have replaced or reworked many of these eccentric shafts which have been "scored" by a locked down allen screw when someone has turned the front of the shaft with a slot screwdriver.
If you look at page 34 of the V-5 parts book on this site you will see the screw just out of one of the access holes just above part # E-680

Posted by Frank Bruno (Member # 1871) on 03-30-2008, 02:27 AM:

Thanks, Ill look again on Monday

Posted by Marco Giustini (Member # 4544) on 03-30-2008, 05:05 PM:

Frank

Thanks for the "signor", it is not necessary! Marco is enough [Smile]

My suggestion is just a precaution so that your adjustment is made correctly. If you adjust the lens shift after you close the turret, the inner ring of the turret will be not in its "final" position and what you'll see is not what you'll get after an automatic turret rotation.

So, when you have to adjust, close and rotate the turret BEFORE make any adjustment. The CNM turrets have some plays on it and this way you take them into consideration.

Ciao
Marco

Posted by Richard Fowler (Member # 893) on 03-30-2008, 06:09 PM:

In addition to the turret play concerns, you also may have aperture locating issues.....not unusual to be off vertically and horizontally on the plates due to the wear / age of the projector.

Posted by Marco Giustini (Member # 4544) on 03-30-2008, 07:47 PM:

But Lens shift should solve the problem, am I correct?

Ciao
Marco

Posted by Jarrad Salmon (Member # 3818) on 03-31-2008, 03:47 AM:

Also, adding to the checking of the apperture plate before the lense is adjusted...

Check that the turret has rotated to and stopped in the correct resting place. I once had a microswitch loosen and that resulted in the turret stopping a little out of alignment. Picture was close to what you have described.

Posted by Frank Bruno (Member # 1871) on 04-02-2008, 04:42 PM:

Hey,

Mr Fowler was right about the set screws i needed being buried down an access hole; tiny holes at that.

I went in to check this again; our amc tech had finally stopped by & beat me to it. Honestly felt a little defeated... at least its fixed now.

Thanks everybody.