8mm Forum: Bell & Howell 644 problem

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Posted by Brian Collins (Member # 761) on November 06, 2008, 03:17 AM:

Hi, Have just obtained a Bell & Howell Filmosound Model 644, when switching on only the lamp works,it is in quite good condition with only 146 hours on the meter, I have check all the fuses that I can find, I expect it is a scrap job but seems a shame if it is not too mnuch of a problem to put right, would any of you technical buffs have any ideas where I could start looking for a solution (besides taking it to the tip). many thanks for any advice.

Posted by Maurice Leakey (Member # 916) on November 06, 2008, 05:35 AM:

Brian

I have the 642 which is the optical only version of the 644 and I believe the only fuse is in the lamphouse cover alongside the voltage selector. This fuse is a 2-amp cartridge.

I am confused by your comment about the hours on the meter, I was not aware that there any meter other than the one for record level.

Does the amplifier work? This is switched on by the left hand amplifier knob. It clicks on at about "8 o'clock" position. The exciter lamp should then light up and after a while there should be a "hum" from the speaker.

It could be that the motor is jammed due to a faulty worm, or could even have burnt out due to this jamming.

The 644 dates from 1962 so is now very long in the tooth. If you need a new worm you are looking at around £150 for a rebuild to include a new worm. You may not consider it worthwhile.

Posted by Brian Collins (Member # 761) on November 06, 2008, 10:32 AM:

Thanks Maurice, The bottom lever on the left has Run & Stop on it but moving it does nothing no hum or light, sounds U/S to me.
The meter is situated on the end casing below the knob that turns the motor manualy, it has Sangamo/Weston written above the window and Hours written below the window, in the window is 4figure reading & tenths in red, the reading is 0146 and 3 tenths so I take it that means it has done 146 hours.Could be wrong of course(which is not unusual)

Posted by Maurice Leakey (Member # 916) on November 06, 2008, 11:04 AM:

Brian

I am referring to the left rotary knob which is one of the four amplifier controls on the lower sloping panel. The two position switch to which you refer is the run/still control.

In the RUN position it, of course, runs. At STILL the transport freezes for examination of the frame. In this position you can "burst" it forwards by pressing the button at lower left marked ANIMATION.

As regards the meter it sounds more like a frame counter, although I did not know this model had one. I can't imagine why it should have an hour meter.

Sorry that I can't offer the advice you need.

Posted by Brian Collins (Member # 761) on November 06, 2008, 01:58 PM:

Thanks Maurice, I have tried the knob that you refer to, it has got Base written on it, but still nothing, never mind it was only a thought and worth a try,

Posted by Barry Johnson (Member # 84) on November 07, 2008, 06:46 AM:

If you can switch the lamp on then the power is going where it should.If the motor does not run then it could be siezed up do to standing.If a good lubricating of the gears and manually rotating the inching knob to free it then it may well be due to broken worm drive as Michael correctly points out.If thats the case then you can buy another for less cost than the repair on ebay.
Dont give up on it too easily though as it just may be total lack of use of this fine machine.

Posted by Maurice Leakey (Member # 916) on November 10, 2008, 03:00 AM:

Brian

The old rubber mains lead used can often fracture. The four sockets are wired Pin 13 Earth, Pin 14 Neutral, Pin 15 Live to Lamp, Pin 16 Live to remainder of projector. Note that Pin 15 goes direct to lamp and not via any switch.

Check that you have 230v/240v on pin 16. I was wrong in advising that there is only one fuse. In addition to the one in the lamphouse there are four fuses on the mains transformer and one fuse underneath in the amplifier.

The motor is a capacitor start and if this has "gone down" it will not provide any "kick" to turn over the motor. Check for free running of the mechanism by rotating the inching knob at the left rear. When you have the back off check the condition of the worm gear.

There is a pilot lamp on the rear of the control panel. Does this light up? Remove it and check with a meter. The exciter lamp will only light up if the optical/magnetic switch is in the optical position.

My professional advisor tells me that in his view the "hour meter" appears to have been added by a previous user. Don't worry about it.

The lower panel should be from left to right. Record button. Record level meter. 3.5mm Monitor/Earphone socket. Rotary knobs for BASS (incorporates amplifier switch). TREBLE. VOLUME for PA. VOLUME for film. Last small button is for Animation.

Please say where you live and I may be able to advise on a Service Engineer in your area.

If you finally give up you should be able to get a fiver for the lamp!

Posted by Brian Collins (Member # 761) on November 10, 2008, 08:30 AM:

Thanks Maurice for the info. Although it runs OK it sounds very dry, the worm etc looks in very good condition, needs a good cleaning and lubricating, I have silicone grease would that be best for the gears. by the way I live in Christchurch Dorset

Posted by Maurice Leakey (Member # 916) on November 10, 2008, 09:45 AM:

Brian

I do not do servicing. I rely on my engineer. I've asked about your possible use of silicone grease and he advises not to use this for gears, etc.

He uses "Molykote" but says that any multi-purpose grease will be OK.

Don't lubricate over the old grease. Clean off as much as you can, an old toothbrush is useful for this.

Posted by Richard C Patchett (Member # 974) on November 12, 2008, 10:08 AM:

Greetings
Please do not use a multipurpose grease. As a repair person for a number of years i find that this type of junk is the same as they use on cars & trucks Black in color . Ever try to clean it off of any thing? Now you want to put this on a plastic gear. and spreed it all over the inside of the projector..

This is just my opinion as a repair (Service) Person
what i use is call Super gel or super lube. it is a Teflon base

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