8mm Forum: Loop probleme on chinon sound 8000

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Posted by Pierre Mdihi (Member # 6808) on February 18, 2019, 01:23 PM:

Hi,

recently a probleme start to appear on my Chinon sound 8000

here sorme picture of my Chinon 8OOO sound image problem, i post photo from B/W and color movie. I have already clean the inside and all the film passageway with alcohol, putting WD-40 on springs and removing the excess of grease in the motor. It a bit better. But the problem still exist. Have you some advise of what to do? I read on the forum, you can put some bee wax on the passageway, is it effective?

wenn i project in 18image par seconde there is no problem, the problem just appears in 24i/s. The photo of the inside , the 1 (gears to moving up and down the image) and 2 (downside passageway) represente the part wenn i am touching them the picture became a bit better. I hope someone have already experience this issue or have a idear of what to do.

Posted by Leon Norris (Member # 3151) on February 18, 2019, 01:32 PM:

Pierre, To me it looks like a shutter problem! That's why your getting that ghost image! Reajust it to get your right image back! Good luck!

Posted by Pierre Mdihi (Member # 6808) on February 19, 2019, 03:54 PM:

I have start removing part of the projector, can i have more specific detail of what to do.I'm new and it's the first time i try repair this super8 projector. Here some photo of the projector without some part:

Posted by Leon Norris (Member # 3151) on February 19, 2019, 04:15 PM:

Pierre, check the film claw! Its in front of the three blade shutter! It looks like a claw problem? You could have a worn claw pin! That could cause your problem! Let me know how you made out!

Posted by Pierre Mdihi (Member # 6808) on February 19, 2019, 05:34 PM:

I start to take off more piece ta have access to the claw. here a picture of the claw, i don't know if with the photo you can tell if it's worn.

and a photo of the shutter blade maybe it can help:

Posted by Nantawat Kittiwarakul (Member # 6050) on February 19, 2019, 08:54 PM:

Does that mean it would always losing its loop unless you keep pressing the loop former?

If yes,there might be some claw alignment issue there. The protrusion seems plenty,but the lateral position might be off hence it failed to "grab" the sprocket hole. [Confused]

Try laying a piece of film onto the gate and manually inching the shuttle,and see if the claw tip engage the sprocket hole squarely right to it. A magnifier glass would be quite useful. [Wink]

Posted by Leon Norris (Member # 3151) on February 20, 2019, 12:02 PM:

I see on the picture of the claw. It looks like its missing one of its pins? That be the problem. You are supposed to have two pins not one! It could have broken off!

Posted by Dominique De Bast (Member # 3798) on February 20, 2019, 12:39 PM:

Are claws standard I mean same models for different makes, like for the lenses), Leon ? If not, it must ne hard to find.

[ February 20, 2019, 04:32 PM: Message edited by: Dominique De Bast ]

Posted by Leon Norris (Member # 3151) on February 20, 2019, 04:10 PM:

I think all models should use the same claw ? I no the Elmo's do!Some are a pain to put in!

Posted by frank arnstein (Member # 330) on February 21, 2019, 05:39 PM:

Leon
These Chinons have a single pin claw.

dogtor frankarnstein [Smile]

Posted by Phil Murat (Member # 5148) on February 22, 2019, 10:23 AM:

Hi Pierre,

I understand claw "vertical stroke" is out of range....

I suggest you :
A) remove lens to gain acces to image frame
B) Load a "clear" movie
C) Manually move main shaft to observe relative positionnig for picture throughout frame
D) slowly advance picture , frame by frame

Do you observe frame staggering ?

1) If yes, that means :

- If your machine is fitted with a nylon cam and has accumulated hundred hours operating, cam is possibly worn out.
- If this machine has never been serviced, it is possible some thick grease has dryed out on cam race, making a thick coating which change cam profile, in that case , cam assembly has to be clean and service renewed with light grease.

2) If no frame stagering is observed, check if shutter blades are
Properly adjusted on cam shaft (mean angular adjustment)

Let us know
Thanks

Posted by Leon Norris (Member # 3151) on February 22, 2019, 11:54 AM:

Pierre, It could be the claw pin? That's worn down! You see the claw pin rides inside the cam!. Lack of grease wears it down! So if it is that? Then let me know! And I will tell you what to do!

Posted by Pierre Mdihi (Member # 6808) on February 23, 2019, 04:45 PM:

Thank you everyone to take time responding me in order to solve my problem. Sorry for my lack of vocabulary but what is "the came"?
I have take a look at the frame and i don't observe any frame staggering and wenn i put my finger on the frame gate i can feel the claw pin moving up and down.

To adjust the claw spin or the shutter blade is this there:

The precedent owner butcher the projecteur, you can see this screw is totally broken so now i can't fully remove the claw pin.

PS: for the one have loop problem on chinon 8000 look a this spring (in the center) wenn it's to loose you can face loop problem.

Posted by Phil Murat (Member # 5148) on February 24, 2019, 07:44 AM:

Hi Pierre,

Shuter blades , Angular positionning :

- During film vertical pull down light is totaly overshadowed by one blade.

On the first picture from your post before ( posted February 19, 2019 03:54 PM ), shutter assembly appears clearly showing 2 black headless exagonal screws fixture.

Driving Cams are hidden by claw and shutter and installed on main shaft.

Here is a sample of "claw module" showing white nylon Cams :

Concerning damaged screw (Worm Gear, Front Bearing fixture) :

It is a touchy situation, from my side I gently hit screw head with a sharp burin.
Once loosen, replace screw by a CHC screw standard (Certainly Diam 3mm, Lenght 5mm). CHC screws are more professional material.

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