Adjusting speeds on COPAL MXV YASHICA shutter : Which screw?

Hi folks


Im usually a 35mm nikon shooter but I was recently given an old Yashica D that was pretty beat up. Im doing the repair work my self as I dont have spare cash to send it to a shop and these are all mechanical so in theory if you have a good head on your shoulders and all the right info at your finger tips you can crawl your way through it. Spring by spring.


Here is my main problem now, let me try and keep it simple but thorough
The shutter speeds are a bit slow BUT they are steady. They dont strat to drag or anything like that, they just seem to be too slow. This is compared to another COPAL MXV shutter and a nikon F70 (those two seem to be pretty much spot on). So instead of 1 second, I get 1.4 or something like that and so on and so on.

I have opened, jiggled and flushed out with lighter fluid - no change

I have trawled the internet looking at pictures and info and have found one page that says if your speeds are off you can adjust them via a screw and moving something BUT the picture link that accompanies the info no longer works.
the exact word were

"When you are done, check the shutter speeds. If they are way off, you can loosen the upper screw at the red arrow and move that end of the escapement closer or farther away from the lens mount to adjust speeds"

Any ideas which screw/part they are talking about? I know which area holds the gears for speeds but there are a few screws and dont want to just start fiddling with them.

Im working on this kind of shutter
http://ratfactor.com/yashica-d-tlr-copal-mxv-shutter

Cheers in advance for any ideas.

On the page you linked to, in the picture of the shutter "guts", part B is the shutter escapement. It regulates the shutter speed. Typically, one of the holes is elongated, you loosen (slightly) both screws, and move it inward to speed up, or outward to slow down.

I'm not certain that Copals have the elongated holes. Compurs, yes, but I don't find them on a Copal MXV.

Another breakdown, not specifically the Yashica version but the parts sure look the same, from Dan Mitchell-
http://daniel.mitchell.name/cameras/index.php?page=copalmxv&WEBMGR=a0b3c98cc7ff8ed20034ef1154616de7

"...Speed adjustment on Copal shutters is made by spreading or closing the gap at the pallet end of the speed governor. Spreading the gap causes the pallet to be farther away from the star wheel and thus runs faster. I have found that a thorough cleaning is usually enough to get the speeds correct. Before trying to adjust the speed setting, make sure the escapement is completely clean..."

If anyone can explain what the 'pallet' is, much appreciated.

Anyway, having cleaned a few Yashica-mat Copals, I've had good results with simple soakings. I do two or three rounds, shaking around in the naphtha. Then letting dry for a long period of time. Actually, I will put the shutter inside the gas oven after it has sat outside for half a day or so to drive all the naphtha out, letting the heat of the pilot light create some extra warmth. I have never adjusted the speeds.

By the way, if you study the shutter you should figure out which part is engaged for the slow speeds. As you turn the cam plate, a secondary lever is cut moved in or out as you reach the cross-over point (1/30 to 1/15 second, maybe? This will show you which gear and escapement is dragging. Maybe one drop of oil on just this gear? Really small drop, more a light touch with a small brush.

Sans my copy of "Time and Timekeepers" (packed away somewhere....), the pallet is the piece that swivels back and forth, see the illustration of a deadbeat escapement here: http://en.wikipedia.org/wiki/Anchor_escapement

Wow allot of responses already. Firstly epatsellis thanks for that, now I know exactly which part/end they are talking about when they say 'pallet'. Very helpful.
Dan: I had also found that page you linked but could not quite figure out what the author meant. Now I know what he means by pallet I shall have another read and another look at the mech. I have given it a good flushing drying flushing drying and a little bake in the oven but the times seem to be the same so I think i will need a fiddling with.

If anymore info is thought of feel free to add

I'd be hesitant to start adjusting(bending) things for a bit. Lighter fluid should work OK for flushing the thing out. but the gears need oil and 3in1 ain't gonna work.
Watch oil will do it. It's as thin as water and clear to the eye. a tiny drop is all it takes, like oil on the point of a pin touched to the gear shaft.
It may be possible to thin 3/1 with the lighter fluid. a drop o' this a drop o' that etc.

If yo can find a watch repairman that still works on real watches you might ask if he could give you a couple of drops, maybe in a film container?

I just CLA'd my first Yashica D. a few weeks ago. The speed adjustment is made by moving the bar on the end of the pallet assembly (it's perpendicular to the pallet and pointing towards the center of the shutter) ever so slightly away from (faster) or towards (slower) the main body of slow-speed escapement. Mine was running about a whole stop slow and I only widened the gap about 1/3 to 1/2 of a millimeter. If you're going to make those kind of fine adjustments I highly recommend getting a shutter tester. Less than a millimeter changed the speed from 2 secs to 0.8 secs.

I have one the inexpensive ones below and it works great.

http://cgi.ebay.com/Camera-shutter-...138?pt=LH_DefaultDomain_0&hash=item23071f5492

right? iv got a good idea what im after. Sadly my tools are not quite fine enough for the inner workings of these puppies so I need to grab some new screwdrivers. When I get a moment out from the wedding planning that is also going on I will upload a labeled photo of the mech to make sure Im reading from the same page as you.
On another note did you clean out and re grease the focus mechs/arms on your yachica kerne? Mine have some slack when you jiggle the knob back and forth and I have heard that it can be due to springs getting gummed up with old oil. Just a bit terrified of all those cogs and springs.

Fortunately, my Yashica was pretty clean to begin with and the focus/film advance mechs didn't really need internal cleaning or lubing. The focus knob on mine has almost no slack and the film advance knob just has a few millimeters of slack.

This site (at the bottom) has exploded diagrams of the Yashi D - http://www.kyphoto.com/classics/repairmanuals.html

This site has a great disassembly tutorial for the Copal MXV - http://ratfactor.com/yashica-d-tlr-copal-mxv-shutter

Btw, I also removed the entire self-timer assembly since accidentally arming it with the flash contact set to "M" will damage the shutter. The downside of removing it is you loose the shutter speed cam detent spring (the spring that snaps into depressions each time you change shutter speeds), so you have to double check that the shutter speed setting is lined up correctly in the window before cocking it. Looking at the second website again, I see the rat factor guy (Dave) removed the guts of his self-timer and put the frame back in just so he could still use the detent spring.

Here's a photo with the guts labeled for you.

Dead Link Removed

The way I deal with the M/X problem on the Copals is to remove the lever that makes the actual change. On your photo, kerne, it is on the edge of the frame just above the red' Slow speed' text. If you hold it tight to the main shutter body and then bend the lever at the point where it bends 90 degrees for its main length, rock it up and down and the metal will snap.

Be sure that it is in the X postion when installing the lens shroud.... oh heck, wait a minute. One of the points of this is that I can still switch it to M if come across a stock of bulbs and want to expeirment. I can slide a skinny screwdriver in the mM/X slot and move it back and forth.

(uh, be sure to slide it to the lower-X position!!)

GFC, here's a link to exploded drawings of the D- http://www.kyphoto.com/classics/repairmanuals.html
Enter the ID and password they list at the top of the page.

The hardest part I find working on Yashicas is getting the coverings off. If yours are coming off ok, it might be worth going inside the body to tighten up the focus. There are two smalls bearing pieces at the end of small tubes with springs behind them. But you might find that what you need to do is loosen the plate holding the back one in place and press it forward to take up slack.

The big thing to watch out for is pushing on the focus axle after removing the focus knob and nut on that side. Because if you push on it, the cams might pop out of place and the whole axle slides towards the other side of the camera. Now you have two loose focus rails- I always like having one 'master' on any mechanism repeated just for reference. On a Yashica-Mat, having the axle slide away from the focus knob means removing the whole wind and shutter-cocking mechanism, not difficult but tedious.

If you go inside the focus knob side. might as well clean and lube the winding mechanism. Probably some dried out grease and dirt and bug pieces in there.

I

Let me just clarify this. Dose the arm on the slow speed assembly need bending? do you need to loosen any screws? One write up i was reading was describing loosening a screw and pushing the assembly towards the shutter but now it seems that is not the case, you just bend the arm either way depending on slow or fast.

Thanks for the heads up on the focus cam Dan. The covering came off fine when I first checked this camera over. I would love for the focus arms to run smooth so I think I will have another look at them and try to fiddle with the bearings/springs before doing a whole clean and re-lube. See if it works by keeping it simple. If not, and I have the whole lens board, hood and mirror already removed wold a good flushing be a viable idea. Anyone done this? (can you tell that I really dont want to take out all those cogs?)

You cannot write up a repair ticket if it says "bent or bending" it's "reforming" costs more.

I don't see any elongated holes that allow for repositioning the escapement. Leave the screws alone. Bend (uh, reform) the arm as shown in kerne's photo. Was just fixing a D for someone today and this method works like a charm. I put a small screwdriver in the slot and twisted it ever so slightly to move it out. Needle nose pliers to bring it closer. Very slowly, softly.

Loosening a screw and sliding the escapement back and forth is standard technique for Compur shutters.

Looking at the drawings referred to yesterday reminded me- there is only one adjustable bearing on the focus system for Yashicas. Open the non-wind/focus side first and you'll see that on the front side of the focus rail is a tab of a red material that rides on a cam. On the other cam, it is a small 'dot' of red material emerging from a small tube formed in the end of a small bracket. This is to the back side of the cams.

See if this is the source of the slop. When I have reinstalled focus rails in the past, I have ended up pushing that bracket for the back bearing hard forward. There is a spring in the tube pushing the bearing material, so maybe there is more adjustment room than I realize.

Vertical motion, hard to imagine it going out.

The grease can become quite a challenge to clean out. And on the focus axle, there is a grease groove at each 'end' where it goes through the mirror chamber. Yould need to remove the axle to clean this and replace it. The one time I did that with a 1950s Yashica-Mat, things got worse so I don't bother any more.

Right, iv done it!!!!!!!!!
With the aid or a small pair of pliers I just bent the little arm slighty in the 'faster' direction to enlarge the gap. You could also use a small screwdriver if you were to place it in the groove and twist. You dont need to bend it much to hear the results and after bending it back a tiny smidge, the shutter is firing at the same speeds as the other MXV/Nikon.
I had a bit of trouble fitting the shutter unit back together but that was mainly caused by not understanding how the speed cam detent spring was supposed to sit. Also that the pin for the 'bulb' setting has to sit in its groove. Anyway after a bit of fiddling and figuring its all sorted.

Thanks for that picture Kerne, it really helped.

Now I think it would be rude to not clean out and re-lube the whole focus mech as it could be a whole lot better. Im doing a run through on my spares/repair Yashica that I got for a fiver. So far so good, I have the focus knob side all out and soaking in lighter fluid before wiping off the caked on grease. The other side looks even simpler. The cogs just seemed scary but did have much to say when it came to taking them out.

Thanks for the help folks. Your amazing. With an extra bit of luck and elbow grease I might even get my spares model to become a fully working Yashica. Mark Hama very kindly sent me some new screws for the focussing arms. The man is a saint. My hat goes off to him

need sleep. just re read that post and didnt notice the screwdriver tip had been mentioned. Plus il look out for that red tab thing Dan.
Right, bed time

Hey Dan it sounds like you have cleaned out quite a few Yashicas. I wanted to ask about re greasing the focus mechanisms. Where should I be greasing or dose everything need a little dose? Also what is the basic procedure for re-setting calibrating the focus rails. I have a few ideas on how it should go but a bit of your knowledge to fill in the blanks would be great.
Cheers