8mm Forum: Trouble with a Bolex 18-5L Super

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Posted by Gregory John (Member # 1821) on November 23, 2009, 12:40 AM:

Hi all, this is my first post so I hope I'm following all the rules. I'll try to keep this short:

My girlfriend has a Bolex 18-5L Super (lovely piece of equipment, weighs a ton). We wanted to watch her old home movies but the Bolex threw a big spark from the outlet when she tried to plug it in. This was about a month ago, and I bought it to Central Camera in Chicago (great old camera store) for repair. Paid through the nose but we got it back about a week ago and it was working great.

We started watching her old family films and all was well for about 45 minutes to an hour until it simply stopped dead. Now, the LAMP stayed on, but the motor stopped turning. She shut it off quickly so it wouldn't wreck the film.

My girlfriend said it had done this once or twice before and it just needed to cool off. However, it did not work later that evening or the next day when I tried it again. The lamp comes on but the motor will not turn.

The fuse under the lamp cover is fine, although it had some black stuff on one end (maybe left from when it sparked the outlet?)

The voltage dial was set to 110. That's what it was set to when it came back from the shop and we left it.

Central Camera gave me a 6 month warranty on the work. However, I'd like to attempt to resolve this myself without having to take it back up there and let them have it another 3 weeks. I don't know much about these old timers but it seems like a pretty simple setup and I'm reasonably proficient with tools.

Has anyone else experienced this issue? Any suggestions as to what the problem could be?

Gregory

Posted by Paul Adsett (Member # 25) on November 23, 2009, 08:31 AM:

Hi Gregory,
I have a Bolex 18-5 and yes it is a superbly crafted projector. Bolex were noted worldwide for the extremely high quality of their film projectors and cameras, so I would think an 18-5 would run for a hundred years or more.
You say the motor is not running, but do you mean the motor or just the mechanism. The motor drives the mechanism through three rubber belts, and these are known to disintegrate over the years. Take the back off the machine (turn that single screw in the center of the back cover anti-clockwise) and then plug the projector into the mains, switch it on, and see if the motor is running. Also look and see if the belts are still in place.
If you need new belts, post back here, and we can steer you in the right direction.

Posted by Peter James Diggle (Member # 1533) on November 23, 2009, 08:48 AM:

I had thesameproblem. Itwas the motor belt that has slackened with time. I put insulation tape around the motor spindle and it works projecting but the flat belt slips off on rewind. Ichecked it today just before I came on the Forum with a view to replace the belt with a wire one. the flat belt is not available here in England. I'm reluctant to wreck the existing lash up unless I can be sure it will work. Ideas or sources of belts welcome.

Posted by Stewart John Boyle (Member # 1785) on November 23, 2009, 10:34 AM:

Hi Peter,
Have you looked at this site?? not sure if its the belts your looking for,dont know much about Bolex.
http://www.cinebelts.co.uk/projector_drive_belts.htm
Regards
Stewart, Welcome to the forum [Smile]

Posted by Paul Adsett (Member # 25) on November 23, 2009, 11:17 AM:

I replaced my belts with 3 Butyl rubber o-rings which I got from Parker Seal Company. That was 15 years ago, and they look like they will last forever.
Here is a previous post I wrote on replacing the 18-5 belts:

Perishing of the original rubber belts on the Bolex 18-5 is a very common occurrence. Fortunately the solution is really simple. You need to get some black Butyl B612-70 or Ethylene-Propylene rubber o-rings from a distributor of Parker O-RINGS here in the USA. The size you need has a wall thickness of about 0.062 ins and an outside diameter of about 1.900 ins. You will need one ring for each of the three drive pulleys (total of 3 belts). I replaced mine 20 years ago and they are still as good as new. Butyl B612 is a superb rubber material, used extensively in aerospace applications, and they will probably last forever on your Bolex. Try ACE HARDWARE stores- they may have something close. They are easy to install: First load up all thre o-rings onto the big pulley. Then, starting at the right most big pulley, stretch each o-ring into the corresponding small pulley groove on the motor shaft. A little bit fiddly, but easy to do.

While you have the back cover off, slap a little grease on the brass worm gear and the other plastic gears, and your projector will run like the Swiss watch that it is for another 50 years. 18-5's are one of the best 8mm projectors ever made. They are very kind to film and almost silent in operation. One of their big virtues is the rear sprung pressure pad in the gate, which results in razor sharp projection across the full picture area.

Posted by Gregory John (Member # 1821) on November 23, 2009, 01:35 PM:

Hi folks,

Thanks for all the replies! Sorry I wasn't more clear before- I did replace all three rubber belts not long ago, so those are fine. The problem is that the motor itself stopped. It makes no sound, no movement, no nothing, regardless of which selection I choose on the control. It is acting as if it is getting no power, which is strange to me. I am able to advance it manually using the little knob on the front. Any other ideas?

Thanks again for all your help!
Gregory

Posted by Peter James Diggle (Member # 1533) on November 24, 2009, 02:24 AM:

Thank you for all the info, unfortunately my 18/5 is the early type with single flat belt which is no longer produced. I will attempt a wire belt solution, grooving the spindle and flywheel if necessary. The machine is too good to abandon. The picture is the best I have ever seen on Standard 8.

Posted by Peter James Diggle (Member # 1533) on November 24, 2009, 02:26 AM:

Thank you for all the info, unfortunately my 18/5 is the early type with single flat belt which is no longer produced. I will attempt a wire belt solution, grooving the spindle and flywheel if necessary. The machine is too good to abandon. The picture is the best I have ever seen on Standard 8.

Posted by Jon Byler (Member # 3933) on September 22, 2013, 10:22 AM:

I know this is a pretty old thread, but I thought someone might search the archives and come across it. My 18-5 that I picked up yesterday has an electrolytic capacitor that connects I think to the motor. Depending on the AC motor design, the capacitor can be needed either to start or run the motor. It's rare to see a motor of this size with either a start or run capacitor, but the Swiss are known for their good engineering, so I imagine it provides superior performance to the other alternatives.

Anyway, these capacitors have a limited lifespan, and they deteriorate faster when not in use. It may be that the motor doesn't run because this capacitor has shorted out internally and needs replaced.

One other thing to note, when setting the voltage, Bolex recommend in the user manual that if your voltage is between any of the settings to go for the setting 1 higher than your voltage. They have options of 110,117, and 125. One should test the line voltage in their house because it can and does vary depending on where you are, especially in relation to the transformer on the utility pole. So if your voltage is 120, which is what American voltage seems to have finally standardized at, one should set the projector to the 125v setting. This is more for the bulb circuit than for the motor, which will not get to bothered by some over or under voltage. The bulb, however will. 10% higher voltage gives an increase in light output, but does something like halve the bulb life. Conversely, running a bulb at 10% less voltage is supposed to give increased bulb life, but less output.

When in doubt in the US, the 125 setting is probably best, in europe, if only the options of 220 and 240 exist, the 240 option is probably going to be better for lamp life.

Posted by Paul Adsett (Member # 25) on September 22, 2013, 02:34 PM:

Hi John,
Everything you say makes perfect sense. However I have found, at least on my Eumig projectors, that the 12 volt EFP bulb is getting applied voltages as low as 11.2 volts when the transformer is set on the 117 volt tap, which results in a pretty dim picture. So for several years now I have run my Eumigs on the 110 volt tap, which brings the bulb voltage up to 11.9 volts. I get a far brighter picture this way, and I would rather have that than a very long lamp life, as the lamps are pretty inexpensive.
So I would agree with all you say, but would suggest measuring the actual voltage that the lamp is getting on any particular machine, to determine which is the best transformet tap to use.

Posted by Jon Byler (Member # 3933) on September 22, 2013, 02:47 PM:

Important to note is to measure the voltage under load, with the lamp lit. A lot of those 12 volt bulbs are cheap, but on these Bolex 18-5's, at least the ones I have seen, they take an odd 8 volt bulb i think is quite a bit less common than the bulbs available for some, and more expensive too.

Posted by Paul Adsett (Member # 25) on September 22, 2013, 03:22 PM:

Yes, the voltage must be measured with the lamp pluhgged in and switched on.
The Bolex 18-5 uses the 8volt 50 watt 'Robby the Robot' CXR/CXL lamp, which is a lot more expensive than the ubiquitous 12 volt EFP. so I agree you do not want to over run it.
My 18-5 is set at 117v, and the lamps seem to last forever.

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