8mm Forum: Specto 9.5 gearbox overhaul

This is topic Specto 9.5 gearbox overhaul in forum 9.5mm Forum at 8mm Forum.

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Posted by Vic Newey (Member # 5181) on November 03, 2017, 04:54 AM:

I recently made a thread regarding the rewind lever causing the gearbox to jam, this got slowly worse and the whole mechanism eventually became rather stiff.

Although not recommended by others I decided to open the gearbox as otherwise the projector would be unusable.

After removing the screws it was quite a struggle to loosen the lid by working round it with a knife & flat screwdriver blades to ease it gently upwards and it slowly began to lift, seemingly the static spindles that pass through from side to side are not a reasonable push fit but are fitted under pressure

When at last I got it off I was surprised to see how clean it was inside, I had read of others discovering congealed grease inside which had to be scraped out but this one has never been greased so some confusion there unless later years altered how they were lubricated. I notice on the advertising literature that it boasts an 'oilbath gearbox'

The big gold coloured gear is for the rewind, when you twist the knob it lifts a big flat spring which raises the gear to connect with the rewind pulley via a dog clutch.

The dark red gear is the one that caused the jam as it was exceedingly stiff & took quite some time to free it.

Whilst it was apart I examined it to see how the oil dripped in via the rewind hole would lubricate the entire mechanism, it would fall onto the small helical gear on the shutter spindle directly below and then accumulate at the bottom but unless the oil was around 20mm deep it would not create an oil bath to lubricate the lower gears and this most certainly is what happend in this gearbox

The lower two gears have alignment marks to keep the two cams of the claw mechanism in order

As the paper gasket had disintegrated I used a tube of liquid gasket to reseal, getting it back together however was very difficult due to the tight fit of the non rotating spindles but after a considerable struggle and a bit of reaming it finally closed up with a satisfying snap.

I'm pleased to say the projector now runs perfectly & the troublesome rewind is fixed

[ November 08, 2017, 10:38 AM: Message edited by: Vic Newey ]

Posted by Dominique De Bast (Member # 3798) on November 03, 2017, 05:19 AM:

Well done ! Another 9,5 projector fixed 😀

Posted by Clinton Hunt (Member # 2072) on November 03, 2017, 07:44 PM:

Well done Vic,I own the Specto and it runs like a charm,and I hope it always will [Smile]

It was good reading how you fixed the problem and that it will guide many others in the future [Smile]

Posted by Vic Newey (Member # 5181) on November 04, 2017, 04:36 AM:

Thank you,
I'm thinking it's difficult to know just how much oil might be in many of these projectors.
Seeing the importance of the oil bath perhaps it would be a good idea to remove the gearbox unit which of course is easy enough & then leave it upside down to see if a reasonable quantity of oil drains out.
Then pour back in around 30 mil and then hold your finger over the rewind hole & turn the unit in different angles to spread the oil to parts that might be bone dry as they were in mine

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