Replacement of the Claw pin in an Eumig 824, i just did it

[Erik Snel]

Hello everyone, today i finished up quite a big project that was requested by Edwin van Eck. He often gets customers with 800 series projector that have their claw pins broken due to not having the correct knowledge on how to remove the film gates in these projectors. He asked me if it could be possible to replace the claw pin. So i went to work, for years now i have an 824 that was left with me by the owner with a broken pin. He didn't want it anymore and the projector was placed as a donor in the back of a shelf. It was the perfect candidate for this experiment.




first i looked into the Eumig 800 series service manual and saw that this was a problem eumig new about and distributed a special tool and replacement pins for the repair shops. they could replace it without a big disassembly job trough then lens tube.



allass, these times are gone and so are these tools. I inquired at the eumig museum if there maybe was one of these tools left so i could make a replica of it but no. fun fact, replacement claw pins are still there.

so what did i do, i disassembled the projector to isolate the claw arm and got the brass pin holder out of the arm.


First i made a Cad model (fusion 360) of the Claw assembly if i should make a complete new one on the lathe.(this was not needed now)


i then drilled with a 0,5mm drill bit under the miscroscope a tiny hole on the backside of the holder. i then pushed out the remainder of the pin.



the pin is 0,5 by 3mm, probably a hardened type of spring steel.

then, at my work (Philips Shaver plant) i got some 0,55 mm ejector pins used in an ejection mold.

i then placed this pin in the holder and soldered it into place, i then filed it to length wit a diamond file.




I riveted the pin and holder back into the claw arm and re assembled the entire projector, it had been standing a long time so it needed new caps in the amplifier and a clean of the record play switch (see an earlier how to i made about this) and a good clean of the rubber drive discs. and lo and behold, the projector works again!!

here is a YT video for proof: https://youtu.be/Bz5vAeAct3M

i am very excited to see this actually worked, as an instrumentmaker my job is working with tiny mechanical devices so this is right up my alley, and i wonder now why i haven't tried this before.

[Maurice Leakey]

Erik
Does this mean that Edwin may have these for sale soon?
It's a great pity that new owners of Eumig dual-gauge machines have no knowledge of setting the inching knob in its correct position to withdraw the single claw before gate changing, and thus subsequently braking off the tiny claw pin.

Maurice

[Russ Green]

That's an impressive description of replacing the claw pin Eric I took mine out of a donor 802 that I had but was a pain to do and the 802 is now a scrap machine so well done very informative

[Mark Todd]

Wow wel done Erik !!! amazing job.

If Van Eck are doing a replacement be worth doing a square one for the only super 8 machines as these round claws wear a semi circle seat in to the film, well into acetate certainly.

I always thought they used the round pin in the dual machines to allow for both gauges.

But do the only super 8`s have two pins ( round ? or flat ? ) and the bolex super 8`s etc

Best Mark.

[Erik Snel]

Well no, i dont think van Eck will have these in store. it could be possible but for now defective projectors he gets are going to be send to me for repair. replacement does need special tools even without the original eumig tool. i checked all my super 8 only 800 projectors and they don't have a square pin but two round pins en different sizes. the dual guage machines have just one pin. if my memory serves me well i have seen a plastic pin once but i cannot recall which type it was.

getting i claw out of a donor is certainly an option but i can imagine setting it correct is indeed a pain

[Maurice Leakey]

The dual gauge projectors only have one round claw. It's to enable it to fit both standard 8 and Super 8 perforations which differ in their size.

Maurice

[Lee Mannering]

One of the good things about the humble Eumig sound projectors is they have a simple mechanical design with no mysteries awaiting once inside. It much easier to fabricate parts than the maze that awaits in some other manufacturers machines.
Locally we had a retired projector engineer and he had many special tools. In the 70s when I stupidly broke a claw pin he had a small clamp which pushed the larger brass pin holder backwards then could slot in a new one.
I did order complete claw arms for future use tho after as precaution.

[Joseph Banfield]

Nice to see someone solving some of our problems with these machines, not to mention someone who displays a devotion to the hobby. Bravo!

[Erik Snel]

One of the good things about the humble Eumig sound projectors is they have a simple mechanical design with no mysteries awaiting once inside. It much easier to fabricate parts than the maze that awaits in some other manufacturers machines.
Locally we had a retired projector engineer and he had many special tools. In the 70s when I stupidly broke a claw pin he had a small clamp which pushed the larger brass pin holder backwards then could slot in a new one.
I did order complete claw arms for future use tho after as precaution.

That tool is the unicorn i am searching for, and probably i need to make a replica. even the museum doesn't have it

[Lee Mannering]

You inspired me Erik. Forgot I had a faulty 810D in loft with a broken claw. I got it down and without removing the claw assembly put a small nut on the back of the pin and with a micro clamp turned it forward and out.
Into workshop and struggled a bit to remove remainder of old pin but once done replaced it with.....wait for it, a stainless steel pin earing £1.99 . I did glue it in with resin to secure. Seems secure enough and a pretty easy fix.

I may have to get a ear pierced to use the other earing ee

[Brian Fretwell]

I don't thin you will have to do anything as drastic as that - I'm sure another Eumig with a broken claw pin will come up before long. 😀