Thank you. But for this purpose, I am going to go with graphite, as graphite migration out onto the aperture blades could actually logically be beneficial. The way the assembly is made, the ends of the blades are jut stamped indentations that are trapped in their slots in the aperture plate. Now, the stampings have gotten sloppy and allow the blades to slip under their slots and out of place, jamming the stack and bow outward causing more damage. CRC won't work on this as I've tried a similar aerosol manufacture by my big customer locally. Lithium grease--no. Oil--not very good. I think this calls for graphite.
Graphite- shutter and aperture blades, NO OIL or GREASE!
Oil- trace on pivots and shafts for gears and levers only.
Grease- spring ends especially where they slide on other surfaces; levers where they slide against other surfaces. A dab about the size of a straight pin head or less is all that is needed. Trace on gear teeth.
The CRC is excellent the other manufacturers stuff may be garbage.
"the ends of the blades are jut stamped indentations that are trapped in their slots in the aperture plate"
Insert an ice pick or similar instrument into the center of the blade end and spread the stampings. The edges of the stamped protrusion can break off, extreme care must be taken.
Want to rent my sledge hammer if all else fails?
Last edited by shutterfinger; 08-06-2013 at 01:54 AM. Click to view previous post history.
Hey, I'm telling you what--that graphite's the stuff. Go ahead and slather it on there, work it in, and what's not needed will just dump out. Yessireebob. Now we're cooking.
Once you get the shutter back together and working set it to its fastest speed and set and trip it 10 to 20 times with no lens elements attached to dislodge any loose graphite that did not shake off.
Well I've got this thing back together. I might add that is was no small feat. At first the shutter would not trip. Some BOOB had been tinkering with it and had bent the long trip arm that extends from 11 o clock to 4 o clock on the right side, and it was not catching the little trip dealie at about 3:30 o clock.As it turns out that long arm is VERY important to be bent just so, as it has a lot to do with accuracy.
Now that the whole thing is nice and clean and wrokd like a new one, I have a question because I have no shutter checker. There are only 5 speeds on this thing--50, 25, 10, 5, 2. But I can barely tell any difference between 1/10 and 1/25. Or is this normal for us human beings? I wish I could get my hands on the technique for tuning shutter accuracy. It seems it would have lot to so with spring bending or lever bending, or both to fine-tune this shutter.
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Well, in editing my first post and attempting to get rid of the incorrect photo the link to the simple shutter speed tester got deleted so here it is:
read through the entire post first as the latter posts are the most up to date.
When checking a shutter by eye position the shutter so that you can see the shutter blades and the second hand of a watch or clock. A clock with a sweep hand is best.
Set the shutter to the 1 second setting, set the shutter, trip just as the second hand is in line with a second mark. The shutter should open and close just as the second hand gets to the next second mark.
Set the shutter to the 1/2 second setting and repeat. The shutter should open and close just as the second hand reaches the mid point before the next second mark.
Set the shutter to the next higher speeds in sequence and verify that the speed increases until you get to the 1/50~1/60 then set to the next slowest speed and verify it is longer than the previous.
Normally if the 1 and 1/2 second speeds are correct the rest will be reasonably correct up to 1/100 second. Speeds faster than 1/100 use a booster spring and the condition of that spring and wear on the shutter determine if the fast speeds are good.
Last edited by shutterfinger; 08-07-2013 at 03:42 PM. Click to view previous post history.
A little problem
I'm sort of hoping von Hoegh will click on and chime in on a little situation I'm having to deal with. Lacking illustrations, this question can be described adequately verbally. Specifically I'm inquiring about a proper glue for a purpose. What I have here is the shutter-close spring has gotten weak over the years. Lacking any small gauge spring-steel stock I'm forced to go with the original spring. Because of this I cannot tighten down the 5 shutter hinge screws that hold down the top shutter plate. I have to leave the screws a bit on the loose side to keep from squeezing the shutter blades between the top and bottom plate. No real matter, but I think I ought to paint on some sort of glue to keep the 5 shutter blade screws from backing out any more than they are. But what kind of glue can you paint on these screws and the surrounding flat surface to keep the screws in place? Of course, the best remedy is to obtain some proper spring-steel stock and make a new spring, which wouldn't be all that difficult. Then I could snug up the shutter-hinge screws and end the matter. Thanks.
Originally Posted by shutterfinger
It is possible the shutter pivot posts have been compressed from overtighting the screws in the past or the shutter blade retaining plate has become deformed resulting in the plate putting too much pressure on the shutter blades.
as for holding the screws in place Locktite 242 threadlocker will work or any non expanding glue that will stick to metal should work.
Somebody Tell Me What I've Got Here.
The above EBAY listing now over on about 8-3-13 was the lens I've bought. That's what this whole thread is about--following me through a first time Betax procedure. Never again to be a self-proclaimed expert of naptha-dipping boobs. Each repair that isn't like the repetitious ones of the past; is refreshing. This one was an discovery adventure to un-doing the effects of age and part-bending tinkerers to get it to work. What they were fighting was a worn-out shutter-return spring, and their own inability to unscrew a screw without chewing it up. In 101 years since the engraved 1912 dating, I figure about 5 different guys had been into this. I do thank god they managed to pass on perfect glass without so much as a cleaning mark. And now the shutter is back to Stage 1 cancer. Still needs me to find a piece of spring steel wire and twist up a quick shutter-return spring. I can now lay that thing out on a table and have it back together like a new one lickity-split. Look at the ad. Is this any good? Thanks.
Revisiting this thread after conducting speed tests and attempting to correct, I've reached a dead end for now. There is no real way provided on this shutter for meaningful timing adjustments. This leads me to ask a question of perhaps some clock people (of which I am not one). Specifically my biggest question is: over 90 years time, how much spring strength typically gets lost? There are not really many springs in this simple Betax shutter, but I am just about convinced it will never be possible to make the adjustments needed without my fabricating new springs. Would you agree? Here is what I have now: 1/2 ok, 1/5 ok, 1/10=11.5, 1/25=1/33, 1/50 does not exist. Nothing past 1/33. And believe me, I've done a lot of spring bending to get this compromise. The simplistic clockwork-and-escapement mechanism only has one spring and I highly suspect it has no strength remaining to hold against the big hairpin spring that drives the whole shutter.