Tweet
I had a Bolex 18-5 for some time and recently determined to press it into service and sort out various problems, and I am sharing this experience.
The first problem was the lamp failed to light in either the forward or reverse positions.
The second problem was the shutter blades were stuck, and the clever mechanism to swap nine to three blades failed to work, the three weights were stuck.
Also the metal ring behind the airflow cowl had got unstuck sometime, and collided with the fan and thus distorted some blades.
Otherwise generally tidy and working. The foam sealing round the plug sockets at the rear had disintegrated and were replaced with draught excluder after some treatment to the rust residue, access for this task is easier after the removal of the cowl. The belts are in good condition. The fuse needed a clean to remove oxidation.
The shutter blades were flushed with some lighter fuel to dissolve the sticky substance holding everything solid. It looked as though it might have been WD40, or some other spray lubricant. My guess is that the shutter runs dry, with some tiny trace of lubricant at the centre – (Happy to be corrected here). Pleased to hear the familiar tick of the shutter weights flying out when the motor starts up at 18 fps, and retreat to the ‘parked’ position when the projector runs at 5 fps. A clever solution to change the shutter for flicker-free projection at 18 and 5 fps.
The bulb still failed to light after the contacts on the bulb holder were cleaned, and of course the bulb tested on the Cinovid. The switch is not easy to see inside, and the soldered wire connections on the back face visible to the extent of the short wiring looked clean and tidy. I could hear the switch blocks flipping over as the switch was moved. Time to take it apart…
It is possible to separate the front part of the switch from the rear paxolin plate carrying the wire connections, held in place with 5 screws (with 5 short spacers), and then possible to get to the plate with the mechanism that flips the contact blocks over from one side to the other, (from one set of contacts to the other) and it was possible to investigate the problem with the lamp contacts. These pairs of contacts are paired with the 'room lamp connection' (provided the right adaptor plug is available!) and I discovered one of the small contact pieces was stuck fast to the nylon block and this tiny lack of movement was enough for the contact piece to fail to meet the contact pin on the round paxolin piece where the wires are soldered. Also the general assembly was thick with some sticky lubricant (WD40?) that seemed similar to the stuff holding the shutter stuck. After cleaning with cotton buds and topical application of lighter fuel to carefully un-stuck the contact strip, and so allowed it to feel and behave like the other strips on the other nylon contact 'flippers'.
The working of the switch ‘flippers’ can be checked with the switch plate separated from the back plate. Care needed to ensure the lamp and room light set of contacts lines up to the top of the switch and the aluminium face plate, and note the circular printed plate with the voltages is not fixed and can rotate so make sure you have some reference to keep it in the right place, or the voltage selection will be out or register.
Re-assembly is a matter of patience to line everything up, and manoeuvre the spacers into position, and then test before fitting the switch assembly back to the projector bulkhead. Make sure the switch is in the off position when refitting, to ensure the pin locates in the correct place to engage the lever on the bulkhead for the slow running clutch.
If the nylon blocks flip-flop across snappily and all contacts are clean and shiny, including the ones on the paxolin plate, all should be good. I did not want to take the glowing knob off the shaft, and disassemble the switch mechanism and I could see springs and tiny parts flying into space never to be found.
The first problem was the lamp failed to light in either the forward or reverse positions.
The second problem was the shutter blades were stuck, and the clever mechanism to swap nine to three blades failed to work, the three weights were stuck.
Also the metal ring behind the airflow cowl had got unstuck sometime, and collided with the fan and thus distorted some blades.
Otherwise generally tidy and working. The foam sealing round the plug sockets at the rear had disintegrated and were replaced with draught excluder after some treatment to the rust residue, access for this task is easier after the removal of the cowl. The belts are in good condition. The fuse needed a clean to remove oxidation.
The shutter blades were flushed with some lighter fuel to dissolve the sticky substance holding everything solid. It looked as though it might have been WD40, or some other spray lubricant. My guess is that the shutter runs dry, with some tiny trace of lubricant at the centre – (Happy to be corrected here). Pleased to hear the familiar tick of the shutter weights flying out when the motor starts up at 18 fps, and retreat to the ‘parked’ position when the projector runs at 5 fps. A clever solution to change the shutter for flicker-free projection at 18 and 5 fps.
The bulb still failed to light after the contacts on the bulb holder were cleaned, and of course the bulb tested on the Cinovid. The switch is not easy to see inside, and the soldered wire connections on the back face visible to the extent of the short wiring looked clean and tidy. I could hear the switch blocks flipping over as the switch was moved. Time to take it apart…
It is possible to separate the front part of the switch from the rear paxolin plate carrying the wire connections, held in place with 5 screws (with 5 short spacers), and then possible to get to the plate with the mechanism that flips the contact blocks over from one side to the other, (from one set of contacts to the other) and it was possible to investigate the problem with the lamp contacts. These pairs of contacts are paired with the 'room lamp connection' (provided the right adaptor plug is available!) and I discovered one of the small contact pieces was stuck fast to the nylon block and this tiny lack of movement was enough for the contact piece to fail to meet the contact pin on the round paxolin piece where the wires are soldered. Also the general assembly was thick with some sticky lubricant (WD40?) that seemed similar to the stuff holding the shutter stuck. After cleaning with cotton buds and topical application of lighter fuel to carefully un-stuck the contact strip, and so allowed it to feel and behave like the other strips on the other nylon contact 'flippers'.
The working of the switch ‘flippers’ can be checked with the switch plate separated from the back plate. Care needed to ensure the lamp and room light set of contacts lines up to the top of the switch and the aluminium face plate, and note the circular printed plate with the voltages is not fixed and can rotate so make sure you have some reference to keep it in the right place, or the voltage selection will be out or register.
Re-assembly is a matter of patience to line everything up, and manoeuvre the spacers into position, and then test before fitting the switch assembly back to the projector bulkhead. Make sure the switch is in the off position when refitting, to ensure the pin locates in the correct place to engage the lever on the bulkhead for the slow running clutch.
If the nylon blocks flip-flop across snappily and all contacts are clean and shiny, including the ones on the paxolin plate, all should be good. I did not want to take the glowing knob off the shaft, and disassemble the switch mechanism and I could see springs and tiny parts flying into space never to be found.
Comment