A-1 clean up the view.

While looking through the viewfinder I noted a lot of dust … it was between the viewfinder window and the prism (like the Olympus OM-2 that I worked on).

Ok, now we need to get the top plate off … so we start from the front.

DSC00701First push up AT dial guard, this will reveal the screw that holds to the body.

Remove screw and then remove slide, watch as the two plastic pieces may fall apart.

 

 

DSC00702Underneath is a ball bearing. Carefully put that aside.

Unscrew the metal plate, then finally the plastic cover under it.

 

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Now remove lens mount front cover. There are four screws – one on each side, one top, and one bottom … pull off.

Note the buttons on side they might … and in my case also watch out for moths. There happen to be a dead one under this cover.

This will reveal the two hidden screws that hold the top on.

DSC00704Now get to the back.

the viewfinder cover in the middle is glued on, pull off, remove screw, then remove switch lever.

Now we can start to get the top off

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DSC00706Unscrew the rewind lever , wrap a little tape, before popping off the e-ring you might want to make  deflection wall around it when the ring springs off into infinity. Then you can remove the dial and washer underneath.

 

 

DSC00707Use a rubber grip to remove the ring surrounding the shutter release button. Remove the shutter button, av/tv selector dial, and washer … do not invert camera.

Remove the winding advance cap, copper washer, spring washer, plastic washer, lever, cam

 

DSC00708There again is another spring clip, metal washer, selector switch, and finally the multi exposure switch.

 

 

DSC00709Put some isopropal alchohol on indicator light … then pop off the outer housing pull off

DSC00710The top cover … screws two side, two front, two back … wiggle and slide off, note the wire going to the PC socket.

The viewfinder is held on both sides … two screws … pull out rear finder window.

Clean up the top plate before putting it back on … something I should have mentioned some time ago.

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A(-1) shutter problem

Well, I got a hold of a Canon A-1 … not surprising since I just posted a historical note about it … anyway, this camera came with a shutter problem. It appears that it does not trip. For an electronic camera, that is not a good thing since there could possibly be one or more of sooooo many components that is the issue … why I prefer the older mechanical cameras.

OK, so first thing, battery … check camera with fresh battery. Battery check shows good power. I noticed the light meter is working and displaying exposure information in the viewfinder, OK so power is getting through some of the circuit. I noticed that as soon as I pressed the shutter button to take a shot the LED display goes out … hmmm.

OK, now it is time to hunt around the web … well, it appears that there is something obvious to check out … an electromagnet.

Take off the bottom plate.

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There are two electromagnets down there … one large one hiding under a plastic cover, and another smaller one on the other side (just follow the red/black wires). The large one is in charge of releasing the mirror and shutter. When the shutter is charged, the trapezoid magnet is pushed against the two metal posts on the electromagnet, where it gets stuck … when the shutter button is pressed, it will send power through the electromagnet that will repulse the magnet and thus release the mirror/shutter mechanism.

You can manually pull them apart to clean out anything that could be causing stickiness between them … but I think the more typical problem is that the electromagnet is not working.

You can electrically short the circuit to send power through the electromagnet, bypassing any electronic issue that is occurring before this in the circuit.

If you look at the flexible printed circuit board, there are two large solder posts beside a screw.  If you short the upper post with the screw (or the contact on the board under it), it will complete the power circuit and should trip open the magnetic contact … if it does not, then the electromagnet needs replacing. In my case that appeared to be the case.

DSC00699 1With a handy-dandy soldering iron you can detach it from the flexiboard. I pulled it out and took a look at it (the plastic cover it a bit of a pain to work around, you might want to cut it.)

There were a couple of coil wires that broke … though I am not sure if I did that when trying to take it out (the coil wire is very very small gauge) … anyway, I tried to solder them together (note that coil wire is coated) … but I still do not get any continuity when checking with a multimeter. This must mean there is a break somewhere else (or my soldering skill really sucks).

A query on a forum confirmed that the A’s share the same electromagnet. Sooo, I decided to sacrifice the AE-1 that I just worked to confirm that this is the problem … the Canon AE-1 and AE-1P both (and possibly the AT-1) have the same electromagnet that the A-1 has.

After carefully swapping them out (too much heat can cause the posts to get damaged or disconnected from the coil wire) I now have a working A-1, and a non-working AE-1.

You can stand under my umbrella …

OK, so I told you that I got a Unimat … so, what do I do with it?

Well … the first thing is to fix my patio umbrella. Last year the (cheap) umbrella that I got failed. The rope broke. This was due to the wheel at the top that the rope turns on … it broke and fell out (into the post), so the rope was rubbing on the metal and well it didn’t like that.

I used a makeshift coat hanger hook to keep the umbrella open for the summer.

Now that I have the Unimat I could make a new wheel.

I got some new tool bits (Taig set from Lee Valley), an 1″ diameter acrylic rod, and new cord line rope (you can actually find “patio umbrella rope” on Amazon).

DSC00724It’s been about 35 years since I used a lathe so it took me a long time (machinist time) to replicate the broken wheel … I had to “learn” how to use such a small lathe with thick material.

… anyway, I think it turned (hmm, sounds like a pun there) out very well … though there was a lot of mess since the wheel was only about 1/2″ in diameter. One thing I noticed about the original wheel was the sides are cut through with a slot … this is actually the part that failed first. When I made the new wheel I did not slot it first before I fitted it into the umbrella … I am not sure why they did that, as the wheel spins freely.

Oh, and when you use the vac to clean up the workspace make sure to keep important things away from the area … I almost “lost” an important hex screw that secured the tool post.

Now one thing I will say about repairing a patio umbrella … it’s a pain in the ass if you haven’t done it before.

I should have stated at the beginning … when you take apart the crank, make sure you document. In my case I should have taken off the cover on the other side of the handle and really looked at the latching mechanism … make sure to document what place everything is, otherwise you end up scratching your head and cursing for half an hour … and possibly (like me) end up with some extra washers. Also, melt the ends of the rope to a nice point as you may have to thread them though some small holes.

The Universal Machine

Back in my youth I made a hammer entirely of metal. This was in grade 9 machine shop course.  I have kept the memory of machines ability to shape material (metal and also wood) … so when a friend of mine offered me his old metal lathe, I jumped on it.

622px-HwacheonCentreLathe_460x1000

NOOOOOOOO !!!

Now, I will have to say that my friend is a skilled metal/wood worker … and he also does have a metal lathe like that (I even helped moving it out of the basement of his house when he moved … he had to use a block/tackle to get it down there and assembled). When I told my wife our friend was giving me a lathe she wondered how it was going to fit in the car … but that is not what he was offering me.

So here is the primer …

Maier & Company in Austria introduced a machine in 1953, called the Unimat. This was a multi-purpose device aimed at hobbyists making small things. Some of their first ads were presented in model train magazines. The advertisement states it is 8 tools in 1 – lathe, drill press, table saw, surface grinder, mill sander, screw cutter, portable drill. It was also known as the Emco Unimat, though I am not sure where the Emco name came from.

It was made with die-cast ZAMAK and offered all the mechanisms that you would expect from a metal lathe, including the ability to change the layout to do other jobs, but was made on a scale so small it would fit in a small box. The wood box with all the accessories packed in it.

Sometime after 1956 Simpson-Sears Ltd. started distributing it in Canada. This Unimat, I suspect, came from the original owner to his son (who was another friend of mine) and was given to my machinist friend as he had no use for it. He was using it for very small metal work, but he needed to upgrade for his clock repair … so now it has been passed down to me.

This is the Unimat DB 200 … light ZAMAK with the green tone, made sometime after 1965.

It still had some of the accessories to change it up like for milling, table saw, and also had the auto feed … but no original box. It needed a cleaning, new belts, and bearings (Doug has parts) … also it was missing the pinion lever. Since replaced the headstock bearings, we took parts of it off … and so we forgot to put the tailstock back on before I brought it home.

Did I mention it is small ?

DSC04673

To give you a better idea of scale vs. my Dremel drill press.

DSC04680

… and vs. a Canon AE-1

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Now I have to figure out what to make with it … hmm, off to watch youTube videos.

You will find that the Unimat lathe is still sold new … this is not the same as the early models … the Unimat 1 is considered a “toy” lathe.

… every act has a closing curtain.

Shutter curtains … hmm. I like leaf shutters cause they are easy to restore. Focal plane shutters, well that is a different story.

leafshutter
Leaf shutter

Leaf shutters have blades (though sometimes there is only one) that opens and then closes to expose the film.

Easy peasy. Kinda like taking off the lens cap and then putting it back on.

When you encounter these that don’t work, it usually just takes a cleaning of the blades to get them back in working condition.

Sometime in 1883, a guy named Ottomar Anschütz invented the rouleau shutter in order to take high speed images, as the leaf shutter was not fast enough. This roller shutter became the focal plane shutter that we know today.

horizontalshutter
Horizontal focal plane shutter

One shutter opens and the other follows it … this is like have two lens caps, one you take off the lens with one hand and then with the other hand you put the other cap on.

The timing of the two creates a slit that passes in front of the film to expose it for x number of seconds. The early focal plane shutters were horizontally traveling … and eventually became vertical using metal blades that could move faster.

Each curtain is connected to two rollers, one to set the shutter and the other attached by ribbons that are pulled by a spring loaded roller when the shutter mechanism is released.

Leica started using rubberized cloth focal plane shutters to achieve higher speeds in their infamous Barnack cameras, this was very helpful for an interchangeable lens systems as it didn’t require every lens to have a shutter built into it. Now of course everybody else had to copy this.

Over time, problems appeared with cloth shutters on old Barnack type cameras … or in many old cameras that used rubberized cloth … the type of problem that I have encountered most commonly is a deteriorated rubber on the shutter curtain(s). The Minolta-35 is famous for it. Another is the glue holding the ribbons has let go of the cloth or from the rollers … then there is the issue of degraded rubber causing light to leak through …

In the image below,  it is one of the ribbon tapes (top left) that pull the second shutter curtain that has come off of the spring loaded roller.

s-l1600_1Here is the crooked shutter … telltale angled wrinkles. The top is leaning because the curtain ribbon tape is no longer pulling the curtain.

In my case the ribbon was torn just after the point where it was glued to the roller, so it needed to be replaced. So I would need to get inside this thing to replace it.

You might want to read over Rick Oleson’s doc on a Leica shutter repair first … just to give you an idea. You can even watch Nobbysparrow do a replacement.

DSC00680Now wait till you get a hold of a multi-bladed vertical focal plane shutter !!

That’s another story to tell …

 

The adventures of this guy who tries to restore and repair vintage photographic equipment … and wins (most of the time).

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