Rewinding mechanism stuck on Praktica?

I recently acquired a significant collection of gear from an estate, most of which was in excellent working condition, but one camera that has me a bit stumped is a Praktica Nova B. Now, I know this is not a particularly exciting item, but I like fiddling with things nonetheless. What happens is that when you wind it, the shutter curtain moves, then snaps back and stays open. The mirror sticks in the up position as well; it can be moved down by pushing a small spring loaded lever out of the way but snaps back up immediately.

 

Fiddling around with this and thinking about it, I decided to see if I could spin the take-up spool. It moves with little resistance in both directions. It also does not move when winding the camera. So I am thinking that perhaps it's somehow stuck in rewind mode? The little chrome button you push when you want to rewind feels suspiciously mushy.

 

Anything I can do short of taking the top cover off to further troubleshoot this?

Pressing down on the rewind button does not disconnect the shutter, which can be wound and released on my Praktica Nova with the button pushed down.

Hmm, that blows my theory out of the water then. I'll put it aside for now until I can find the time to remove the top cover and investigate.

I've no specific knowledge of the Nova but it's invariably easier to remove the base plate of an SLR rather that the top cover to reveal at least some of the "works". You may find the problem under there.

I think I'd be tempted to try a little 'percussive maintenance', giving it a moderate thump on the workbench. Just once mind. If you're not used to doing such things, don't try, knowing the amount of force is an art in itself.

 

Otherwise, I'm not familiar with the Nova, but try removing the base plate before taking the top off. It's far easier and a lot of cameras hide film advance and shutter related stuff down there, not up top as you might expect. Praktica may be different though.

Please note that in the above post, I said 'workbench', I didn't say 'your wife's solid wood kitchen worktop'.

 

Being a fine example of East German engineering, it will most likely leave a mark (on the surface, not the camera).

In the base of the Praktica, is the slow speed escapement, and the flash synchronising contacts. The wind mechanism is under the top cover. The film gate is removeable, which exposes the shutter shafts. The mirror box is not removeable, on these older Prakticas - to get to the mirror cocking mechanism involves removing the the sprocket shaft, and lifting out the plate behind it.

I'll remove the film gate then, maybe that will give a hint as to what is occurring. Thanks!

 

Right now winding spins the shutter speed dial and you can see the shutter curtain close, but the take up spool does not move and when you release the lever everything snaps back to where it was. Mirror remains in up position. Everything moves smoothly and looks to be in fine shape so hoping it's just something that got stuck due to old grease or something along those lines.

 

For removing the top plate it looks like I need to remove the screw on the shutter dial, then possibly release a pin holding the lower part of the dial in place. Been trying to find a repair manual for this one but no luck so far.

 

But I shall not complain if this one doesn't work out as I got a mint Olympus 35RC, Minolta XE-5, Praktica LTL and a bunch of other older cameras in the deal. The 35RC is such a lovely little piece of gear and I much look forward to shooting it.

In the base of the Praktica, is the slow speed escapement, and the flash synchronising contacts. The wind mechanism is under the top cover. The film gate is removeable, which exposes the shutter shafts. The mirror box is not removeable, on these older Prakticas - to get to the mirror cocking mechanism involves removing the the sprocket shaft, and lifting out the plate behind it.

Thanks, I had a feeling Praktica were going to be different, just because they could be.

Thomas Tomosy has a couple of pages on the Praktica Nova in his Camera Maintenance and Repair book 1. To remove the shutter speed dial, take off the upper dial by removing the screw. You then need a special tool to unscrew the lower dial, which unscrews clockwise. I use a modified screwdriver - pictured below.

 

Looks like maybe a small spanner wrench might work? If not I have plenty of flathead screwdrivers to sacrifice! :-)

Rick Oleson has an exploded view (sketch) of the Nova somewhere online. Search for his site or on Flickr.

I think I'd be tempted to try a little 'percussive maintenance', giving it a moderate thump on the workbench. Just once mind. If you're not used to doing such things, don't try, knowing the amount of force is an art in itself.

 

 

An art indeed. Seldom cures the problem in question and gives you several others. (although I confess, when all else fails, I've done it myself!)

Sometimes winding on the 'film' knob will reset.

 

The Praktica film advance did not improve as the series evolved, so winding the film is best done carefully and deliberately, just as a general rule.

Hi! I do not fully understand your problem. However, you had mentioned that one of the curtains gets stuck open. This can happen due to dust or dried up lubricant in the curtain spindle. Try cleaning the spindle's pivots with Petrol [Gas] or Naphtha and work the shutter a few times. Then lubricate with fresh oil drops. Also check for tension in the curtain springs. These are adjusted easily from the bottom with rachets that control the curtain tension. I hope this helps. Best, SP.

Filing a perfectly good screwdriver to fix an old Praktica Nova - sacrilege!

Filing a perfectly good screwdriver to fix an old Praktica Nova - sacrilege!

It fits the older Prakticas as well!

So I've popped off the film gate and a small metal plate inside below the winding mechanism. Attaching photos. One of the shutter curtains seems to be stuck open. When I wind the second one slides across nicely but never catches and snaps back.

 

I see no movements in the gears/cogwheels that appear attached to the film takeup spool when winding.

 

Interesting: the rewind button popped up at some point during this operation, however it made no difference in functionality. I pushed it back down and now I can't convince it to pop up again (closing / reopening back, wiggling button while doing so etc).

 

 

Progress has been made! I recalled reading somewhere that on some old Prakticas you could "unstick" things a bit by winding while pressing down the shutter.

 

Now the winding mechanism turns the take up spool, the second curtain locks into place nicely, rewind button pops right back up when you start winding.

 

However! The right side curtain doesn't want to move further than to the edge of the opening, and the mirror doesn't want to come down. However unlike before where it refused to move down, now it'll snap down if you carefully poke a little lever out of the way. I imagine this lever is tied to the shutter curtain mechanism in some manner.

 

Anything I can try before attempting to pop the top off at this point?

 

 

edit:

 

So, it appears "fixed"! I noticed when firing it over and over that each time the shutter curtain crept a millimeter or so further. Just kept at it while switching between fast and slow shutter speeds. Suddenly it went all the way across and the mirror popped down.

 

Could it be that the shutter curtain was just sticking to itself on the spool?

 

Either way, works nicely now, even the slow speeds look just fine.

Edited August 4, 2020 by christer_medin|1

Well done! I wouldn't use it for anything important though ...

Well done! I wouldn't use it for anything important though ...

 

No worries, I was mostly interested in finding out whether it just needs a CLA or if something was actually broken.

Could it be that the shutter curtain was just sticking to itself on the spool?

 

Now that you mention it, that does sound rather familiar.

Filing a perfectly good screwdriver to fix an old Praktica Nova - sacrilege!

 

It’s a flat head screwdriver, Joe. They actually were out of vogue ahead of film cameras! :)

 

Perhaps even more notably, film cameras are “back”- but nobody is trying to “bring back” the flathead screw, or the driver for it. :D