Re: Repair of a broken camera lens


from "David"

Had a few probs that I had to iron out, but I suppose that is the
prototyping.

I had to skim more of the inside of the thin wall, then turn more off the
hieght of the thick piece (after filing the spigot lower due to it
interfering with the inner barrel.)

Just goes to prove that no matter how much you think you've researched a
reverse engineering project you never get all the details right first
time!



Still having to mod it... (done now). I had to shave some off the height to
fit the cover with the orange band on. I then forgot about the chamfer. The
lens became really tight to turn when that cover was screwed down. This
morning, I discovered that the cover actually has a machined / moulded
chamfer, so I had to strip the lens again to chamfer the ali ring. It is
MUCH better now. Still a little tight, but nowhere near like it was before.



I also had to trim the inside of the zoom barrel to fit the piece into.

The screws, I couldn't get hold of an M1.6 tap so used 10BA instead.
Screws
fit quite tight and well. (see pic 19)

Looks as if you had to make a packing piece as well - why are the
two screws different?



No, that is actually from the original piece. The spigot on my piece is
effectively the black broken piece in photo 1. That has a small steel 'arm'
that is screwed to the spigot. Is that what you mean by a packing piece?

All I made for it was the aluminium ring. (I had to make some clamps
(basically just a lump of metal with a hole drilled in) in order to fasten
my lathe chuck to the rotary table)

If you look at photo 19, the inner ring where the actual lens is, you can
see a slot. That piece where the screws are rides into that slot, so when
the ring rotates, it drives the slot round which has a (VERY) course thread
to drive the lens forward (downward in this photo) to zoom..

The two screws were like that when I took the lens apart. Because of the
head size, I had to measure both screws just incase they were different
threads. They are both the same thread, just different sized heads. (I
thought it was odd as well.)

I quite pleased with it. I only bought the rotary table a few weeks ago.
That has just paid for itself. The only real cost was my time. (At my hourly
rate as a computer programmer, I could have bought two lenses, but what I
thought to myself is why waste a perfectly good piece of equipment due to
the failure of something I could very easily manufacture to fix it.) It is
just a shame that the cost to have something fixed by the manufacturer is
almost the same as the cost to buy a new item, which makes such things now
just throw away.

Best regards,
Dave Colliver.
http://www.AshfieldFOCUS.com
~~
http://www.FOCUSPortals.com - Local franchises available


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Relevant Pages

  • Re: Repair of a broken camera lens
    ... lateral force that the spigot needs to apply forced it off again. ... drives the zoom on the lens so there is a reasonable force there. ... The spigot itself is level with the top of the ring rather than the bottom. ... Then I would machine a mandril at 63.85mm dia. ...
    (uk.rec.models.engineering)
  • Re: Disassembling Rubinar 10/1000
    ... unscrew the 3 screws inside the "mounting ring", ... lock the inner ring of the mounting ring so one hole for the ... the holes on the oposite side of the lens where the focusing line is ...
    (sci.astro.amateur)
  • Re: Disassembling Rubinar 10/1000
    ... I left 10mm of space to use the m6 screws. ... flattener lens, otherwise I'm not sure I could focus to infinity. ... That's not enough distance to mount any 1.25" diagonal. ...
    (sci.astro.amateur)
  • Re: Disassembling Rubinar 10/1000
    ... I left 10mm of space to use the m6 screws. ... flattener lens, otherwise I'm not sure I could focus to infinity. ... That's not enough distance to mount any 1.25" diagonal. ...
    (sci.astro.amateur)
  • Re: Disassembling Rubinar 10/1000
    ... I left 10mm of space to use the m6 screws. ... flattener lens, otherwise I'm not sure I could focus to infinity. ... That's not enough distance to mount any 1.25" diagonal. ...
    (sci.astro.amateur)