8mm Forum


  
my profile | my password | search | faq | register | forum home
  next oldest topic   next newest topic
» 8mm Forum   » 8mm Forum   » Eumig 807 slow running

 - UBBFriend: Email this page to someone!    
Author Topic: Eumig 807 slow running
Steve Castle
Junior
Posts: 6
From: Sydney, NSW, Australia
Registered: Jan 2015


 - posted January 12, 2015 02:20 PM      Profile for Steve Castle   Email Steve Castle   Send New Private Message       Edit/Delete Post 
Hi all,

I have an 807D I have had since new. I am in a 50Hz power country and have set the power frequency selector to 60 Hz and adjusted the speed to approx 16.66 for telecine using a DSLR in movie mode set to 1/50 for telecine transfer. However, this setup causes the projector to sometimes stop feeding film, especially in reverse. It works fine when set to normal settings. I have read that the rubber disc on top of the motor can cause this problem. However, I cannot find that disk. would someone be able to enlighten me as to the exact loacation, perhaps with a photo? I have been adjusting the take up reel clutch as well due to poor performance of the take up reel.

Regards,

Steve

 |  IP: Logged

Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007


 - posted January 13, 2015 02:31 AM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
Click the link and scroll down to see a picture of the drive from the motor and the two rubber discs. One for forward and one for reverse.
The motor pulley tilts in each position dependent of the main control knob.
http://www.repaire.net/forums/film-argentique-projection-numerisation/228491-eumig-mark-s807-chargement-automatique.html

--------------------
Maurice

 |  IP: Logged

Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008


 - posted January 13, 2015 04:04 AM      Profile for Martin Jones   Email Martin Jones   Send New Private Message       Edit/Delete Post 
There is no "rubber disc on top of the motor". The "disc" is a STEEL BALL on the motor shaft which, as Maurice says, contacts the rubber surface of one or other of the large aluminium discs on the main horizontal drive shaft.
Your problem is usually due to the rubber surface being slippery at certain points, allowing the drive to slip.
Causes.... oil or grease on the rubber or the rubber surface being worn smooth.
Cures..... first make sure that the whole mechanism is clean, lubricated properly and free to turn. Then clean the rubber discs and roughen the surfaces slightly with fine sandpaper.

Lots written about this on the Forum: use search engines.

--------------------
Retired TV Service Engineer
Ongoing interest in Telecine....

 |  IP: Logged

Dominique De Bast
Film God

Posts: 4486
From: Brussels, Belgium
Registered: Jun 2013


 - posted January 13, 2015 04:27 AM      Profile for Dominique De Bast   Email Dominique De Bast   Send New Private Message       Edit/Delete Post 
What I don't understand in this case is why it works fine at 50Hz and not at 60Hz. If the disc is the problem, what's the link with the Hz ?

--------------------
Dominique

 |  IP: Logged

Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008


 - posted January 13, 2015 04:46 AM      Profile for Martin Jones   Email Martin Jones   Send New Private Message       Edit/Delete Post 
The position of the "Hz" flag should not affect the speed obtained; it only moves the end stops of the travel of the speed adjustment.
If the speed on 50 hZ mains is 16.667 with the flag at 50 hZ, it will still be the same if you move the flag to 60 hZ. , SO LONG AS YOU DO NOT MOVE THE SPEED LEVER.
So I am as puzzled as Dominique.
On my similar machine I make sure that the speed setting I use is a stable one close to, and above, 16.667 fps, then reduce the speed electronically. I NEVER use a different Ball/Disc setting to change the speed.

--------------------
Retired TV Service Engineer
Ongoing interest in Telecine....

 |  IP: Logged

Maurizio Di Cintio
Jedi Master Film Handler

Posts: 977
From: Ortona, Italy
Registered: Jan 2004


 - posted January 13, 2015 01:18 PM      Profile for Maurizio Di Cintio   Email Maurizio Di Cintio   Send New Private Message       Edit/Delete Post 
If you move the flag from 60 Hz to 50, this will affect the lower position of the speed selector and it will set to 18 fps (at 50 Hz). AND it will affect the resulting speed...

This flag slightly changes the speed-change range keeping the difference between min and max speed the same in both cases.

At 50 Hz setting and feeding the beast with 50 Hz AC mains, you'll get speeds from circa 18 fps to 24 fps; at 60 Hz setting, feeding the same type of current, you will slow down the speed from about 15 fps to 21 fps.

Fact is this motor turns somewhat faster at 60 Hz than it does at 50. The position of the flag forces the steel ball pulley to work on the most suitable area on the discs' surface in order to compensate for this: the rubber surface is not perfectly even but is bevel, albeit to a very low degree; that enables speed change at constant torque.

In Steve's case the reason why the pulley slips at one of the Hz- setting could be the pulley itself wore out the disc surface somthing that tends to give it a groove-like appearance.

The solution is always the same: sandpaper.

Also be wary of clutch regulation: if it's too tight, it will cause strain on the entire transmission system in certain conditions (e.g. at the beginning of a reel in the case of the take up spool arm).

I hope this helps.

--------------------
Maurizio

 |  IP: Logged

Steve Castle
Junior
Posts: 6
From: Sydney, NSW, Australia
Registered: Jan 2015


 - posted January 14, 2015 09:50 PM      Profile for Steve Castle   Email Steve Castle   Send New Private Message       Edit/Delete Post 
Thanks all. For some reason the problem seems to have rectified itself. I did run the unit with no film at the 16.66 setting for an hour to loosen everything up at it now seems to work fine, although the problem did disappear before I did that. I have been running the unit extensively recently anyway.

Re the clutch, I adjusted that until the reel was just taking pressure. The main issue here was that some of my take up spools are poorly made (too narrow) and catch the film, causing poor take up.

 |  IP: Logged



All times are Central  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:

Visit www.film-tech.com for free equipment manual downloads. Copyright 2003-2019 Film-Tech Cinema Systems LLC

Powered by Infopop Corporation
UBB.classicTM 6.3.1.2