Hasselblad 503CX/A12 winding issue

[Telecaster]

Hi . This is my very first post so i want to greet everyone here.

I recently became a medium format shooter (in my town = freaky) and bought a really beatiful 503 CX with A24 back. Soon i needed another back and bought an A12 from ebay. good news are that it give 12 frames but it seems to work in a somewhat strange. When i wind the crank (body) the last quarter of turn seems to drift (slide off) ... the first A24 has a different feeling (=working perfect) but is not very well adjusted as I get only get 10-10.5 frames

Should i send both to a technician? .


Thanks and sorry for my bad English (Im Spanish)

 

[Sirius Glass]

Welcome to APUG
I too have a Hasselblad 503 CX and use A12 backs. I am not sure what you me by "When i wind the crank (body) the last quarter of turn seems to drift (slide off)". Can you explain more clearly?

If you list your location in the profile so that it appears on the left side of the post, we might be able to direct you to someone near you to help.

 

[film_man]

I assume you mean winding the crank on the body after a shot, I sold my last Hasselblad a few months ago but from what I can remember (two 501CM bodies with various A12 backs) the last bit when winding after a shot always felt lighter. Bear in mind that the winding of the crank is not just to wind the film, it also cocks the shutter and returns the mirror so maybe not the whole turn is for winding the film.

 

[Sirius Glass]

I assume you mean winding the crank on the body after a shot, I sold my last Hasselblad a few months ago but from what I can remember (two 501CM bodies with various A12 backs) the last bit when winding after a shot always felt lighter. Bear in mind that the winding of the crank is not just to wind the film, it also cocks the shutter and returns the mirror so maybe not the whole turn is for winding the film.

If the OP is talking about what film_man, then I agree with what film_man stated.The feel of the cranking does change as the mirror is raised and the lens is cocked.

 

[bdial]

The turning effort is not the same for the full rotation, and the last part is a little tighter, as Film_man suggests, and that is normal behavior. But it shouldn't be much different than what you may notice with the a24 back. If the camera seems smoother with the 24 back, the 12 back may need some servicing.
Have you processed the film from the 12 back, if so, is the frame spacing ok? irregular spacing would be another indication the back should be services.

As for 120 in a 24 back I think 10 or 10.5 frames would be the expectation because of the thickness difference. 120 has backing paper along the whole length, but 220 only has paper at the beginning and end.

 

[mitrajoon]

Regarding 120 film in your 220 back, you should get a full 12 shots. If you search the web you will find some instructions but my recollection is that the main thing is that you advance the film about a half inch past the red mark. But you should do some research to be safe. After 12 shots you just wind the film as you would with a 120 back.

Good Luck.

 

[Telecaster]

I send them both to revision ... thanks to everyone for the tips