Exakta and film advance, or not

I started collecting Exaktas a few years ago and have a complete collection of the 35mm SLRs from the Kine 1 to the VX500. With some duplicates I have a total of 16 Exaktas. Using Miles Upton's book I have disassembled, cleaned and lubed 9 of the Exaktas. I have put film through most of my collection.

 

The film advance function is, IMO, not one of the strong features on these Exaktas. The film advances exclusively by the sprocket gear and it has been my repeated experience that about 1 in 30 shots will not advance a full frame. I am at a loss how this happens. This has happened in Exaktas I have disassembled and verified everything is in good order and in Exaktas I have not disassembled. Any suggestions?

 

As long as I am on the subject of Exaktas:

If you purchase an old Exakta with bad curtains which you intend to replace make sure you are able to remove the two spanner nuts on the camera. The curtains cannot be removed with either spanner nut in place. One of the spanner nuts is in the advance lever mechanism and I have yet to see this spanner nut frozen. The other spanner nut, in the slow speed mechanism, I have found frozen solid on two cameras: a Varex and a VXIIa. Nothing would free it up. I couldn't apply sufficient torque with a regular adjustable type of spanner wrench. I tried soaking the nut assembly in Kano Kroil for days - nothing. Tried applying heat via an industrial soldering iron - nope. The only thing that might work is a custom made spanner wrench with a long handle but I am not going to spend that kind of money.

I have a total of 16 Exaktas

 

Counting Exas, I only have 14 Exaktas, and I don't even "collect" them:rolleyes:

 

 

However, I haven't had any problem on any of them with the film advance. I only got them to start with because of my obsession with KW and Zeiss "Ossis".

 

I thought that some of them were non-functional until I discovered that people (not knowing what they were doing) had overwound them. A little jostling and they came back working.

I have two Exakta cameras. One is an EXA Version 1 that is stamped "Made in USSR occupied Germany". The other is a Varex IIa. I have shot a roll through the Varex with no advance problems. The only problem was the holes in the curtain I discovered. I shined a light through the EXA and found its curtain has holes also. I plan to replace the curtains in both. I'll post something on this forum when I do.