Untitled Document

To begin with, I started to disassemble the upper portion of the enlarger. Here you see most of those parts strewn on the floor.

Here are the dirty gear drive parts, covered in old grease and years of cat/dog fur (my cats and dogs have always enjoyed spending time with me in the darkroom, it is the coolest room in the house).

A close up of the 45 degree bevel drive gear. This is the business end of what moves the rail rider up and down the column. In a fully loaded, condenser version of the L184 with a color head can weigh several hundred pounds. This finely machined gear, in other words, can have some serious stresses on it. Normally this is covered with axle grease, here it has been cleaned using paint thinner and an old tooth brush.

Another view of the same part, only from the other side. The tolerances on this part are real tight. I felt no slop in the bearing, and it is probably 40 years old!

The Worm Gear Pinion No 2(AB33520) is driven by the Hand Wheel (AB33511) and Pinion No. 1 (AB33518). This gear is threaded on the inside, which interfaces with the Spindle Screw Shaft (AB33527). When you turn the handle, it rotates the Pinion Gear and in turn, rotates the threads inside, which moves the whole Carriage Assembly (AB33403) up or down. Worm gears are a great way to make movements like this happen. The Beseler 45 enlargers use worm gears too. They have a pulley driven by a small motor, which in turn rotates worm gear that drives a pair of gears that move the head assembly up or down. The problem, in my mind, is that the gears are very small and the belt tends to get old and loose. Also, if you are not careful, the head assembly can easily become out of level either because of one side of the gear drive slipping a notch, or the frame of the enlarger not being properly aligned. The big Durst enlargers were built to support heavy color heads AND condenser lenses. All combined this weight could add 150 pounds to the top of the enlarger. Soooo - the gears that move the head around had to be sturdy. Here are the Worm Gear Pinion and the Spindle Screw shaft together. These are both very finely machined, a real handsome piece of work. Also - a counter balance system was built into the L184 and L138 enlargers. More about that HERE.

This is called the Yoke (AB33603). It fits between the Left Hand and Right Hand Columns (AB33600 & AB33601). It also is the place where the Spindle Shaft rests.

Even though I have the Worm Gear Pinion installed for display , this illustration shows how the gear threads onto the shaft and how the two components fit into the yoke.

The Screw Shaft was caked with 40 years of grease and cat hair, so I cleaned it. The quickest way was to soak a rag in paint thinner and wipe it down. I clamped the shaft into my cordless drill and ran it one direction, then in reverse. Two passes with the rag and I was done.

Looking inside the carriage you can see Pinion Number 1 (AB33518). This is the gear which is attached to the end of the Hand wheel (AB33511). I've seen some of these made out of nylon. Mine was made out of metal (not sure if it was steel or brass, I didn't take it out).

Bushing installed. Note the flat spot in the mounting ring. That cutout is necessary to allow room for the neighboring Lower Bronze Ring (AB33406).

The Spindle Screw Shaft (AB33527) is held in place at the top of the Column Hood (AB33701) by the Retaining Ring (AB33528) which is held in by three screws (1128299 or 8). There is a steel Round Pin (1241451) which is inserted at the top of the shaft which actually anchors the Spindle in place - it also keeps the shaft from rotating. In order for the pinion gear to work properly - the Spindle shaft has to remain stationary.

Here is the partially assembled upper assembly. Note that I have not yet attached the Retaining ring. I don't know why this photo was taken without it. Must have been in a hurry.

On the bottom and top of the carriage you will find a set of Bronze Rings. They are called the Upper and Lower Bronze Rings (AB33405 and AB33406). There is a set on the left and on the right. Each are slightly different. One set has a small scallop carved out - this allows room for a thin ruler that is attached to the column shaft to pass thru the carriage assembly. More about that little detail later. The rings are unique to each spot where they attach. Thee is no mistaking where they belong.

The carriage assembly is equip with a break. Once you have the enlarger camera set to a desired elevation, you can lock the whole thing in place via this break. The break is comprised of a Clamping Cheek (AB33414) and a Clamping Shaft with Knob (AB33412). As you see in the left hand photo, there are two rectangular divots in the face of the clamping cheek. There is also a threaded hole. If you look inside the carriage assembly, you will see two threaded studs. Now I don't know why they are threaded, but I do know that the divots in the cheek plate have to line up with the studs. Soooo - follow my illustration and place the plate inside as shown. Then, carefully insert the Clamping Shaft thru it's hole and then thread it into the hole mad for it on the cheek plate. When the carriage assembly is again mounted on it's shafts, this cheek plate is used as a primitive break. As you tighten the knob, the cheek plate is pressed against the column shafts, thusly securing the carriage assembly.

Follow my guide here to insert the cheek plate. You can see the bright marks on the front of the plate caused by years of rubbing against the columns. It would be a good idea to make sure the carriage break is fully released before moving it up or down.

Here I am insertion the knob and shaft assembly. It is real simple - just be sure to thread it into the cheek plate (don't make it too tight, it will get in the way of installing the carriage assembly onto the vertical columns).

The finished upper assembly. I didn't photography getting the carriage installed because it took both hands. Basically you slide the carriage up from the bottom just until the lead screw (spindle shaft) passes thru it's hole at the top of the carriage Then carefully continue sliding the whole thing up till the lead screw comes in contact with the threads inside the pinion gear. Once they meet, slowly turn the handle until the threads catch. Now your home free. Mount the Yoke and that's it.

At the bottom of the Spindle shaft everything is held in place by the Yoke (AB33603). The Yoke is a resting place for the Spindle Shaft and is held in place by 4 screws (1128568). These screws are inserted thru 4 small holes which are drilled thru the columns shafts. It is kind of tricky getting these back in - but a magnetic tip screwdriver and a flash light really helps. Make sure not to fully tighten the screws until all 4 are in place.

Here you see the insertion of one of the Yoke screws, and another shot looking up a columns shaft illuminated by a mouth-held flashlight. A little note here - when I was a small boy, my mother would clean the wax out of my ears. She would hold me down on the bed, hold our silver and red flash light in her mouth and carve the wax out of my nasty little ears with a hair pin and Q-Tips. To this day, whenever I am out of hands trying to get light on something I am working on, and I place the flash light in my mouth - I think about my dear mother. There you have it. My life's childhood memories laid out for the public on this forum. I hope you sleep well.

As soon as I had the upper assembly together I tried raising and lowering the carriage the full length of the rails. Near the top I felt friction and then it stopped. I backed it down the tried again, same thing. Something was in the way. After a little looking I realized that the columns were installed backwards. On the left tube there is a Scale (AC33217) held in with tiny little screws (1128176). The bushings have a little scallop just for clearing this Scale. I got them in backwards, so when I lowered the carriage, I was hitting this scale. In the process I sheared off on of the screws. I decided that I never used the scale and did not feel like taking the whole thing apart to fix. So I just removed the scale. Anyone out there want it, e-mail me and I'll ship it to you (you pay the shipping). The photo on the left shows the sheared off screw. Photo on the right shows the scallop designed for scale clearance.

Attaching the CB7 camera to the L184 chassis was accomplished by a bracket that I designed and had fabricated by a machine shop. In the first photo I have laid the T-Bracket next to the CB7 camera. The T-Bracket is a slug of steel machined to precisely fit into the mounting channel on the L184. In order to keep everything exactly parallel and square, the machinist first turned the metal shaft down to the proper size (each end is a different diameter). Then he used a Mill to cut out a key-way (needed to provide clearance for the lead screw - remember the earlier photo showing how the lead screw bisects the opening?) Finally a flat plate of steel was pinned and screwed to the face of the shaft. Pinning (see my finger in the middle photo) allows for the removal and precise replacement of this plate. Some additional milling was required to ensure the shaft did not get in the way of the moving parts of the enlarger (namely the focusing motor). A note: After the key way was cut out, the metal wants to bend slightly outward, like a tuning fork. To fix this, and to make sure the rear clamp of the enlarger mount did it's job, an end-cap was built with two machine screws. Once the T-Bracket was inserted into the enlarger, this cap was screwed into place. It held everything tight and together.

A close up showing how metal was milled away to make room for the focus motor box (gray box on the left). There is also a limit switch finger that pokes out near here - it shuts to motor off once the lower standard is at the lower limit of travel. I had to make sure it was not obstructed.

This shows the long key way, and the basic shape of the T-Bracket shaft. At the very top you see the end plate I mentioned before. You remove it before instillation, then replace after it is fully inserted.

I did not take the bottom section apart, the gear drive for the easel base was just too much work. I did give the whole thing a good cleaning. I also tried to reform the Pleated Screening Panel (AC33218). It looks like a bellows and mine has several spots where it does not fold properly. I carefully refolded the whole thing then clamped it together with a C-Clamp for a few hours. I didn't work. As soon as the clamp was released, the whole thing went back to it's old shape. You really don't see this part, it is hidden by the easel base.

On both sides of the enlarger base are a pair of guide rails which keep the pleated screen panels in place. These are called the Left Hand / Right Hand Guide with Rail (AC33213 & AC33215). One has a ruler on it for measuring the height of the table. The top of these slips under the Guide Panel (AC33205). Once set you only need a little tap with a rubber mallet to secure everything in place. Screws in the top and sides hold everything secure. Careful not to tighten the Clamping Screw Levers (AC33206) - they need to be loose when you install the upper assembly.

There are a pair of screws that hold the lower assembly easel bed in place. Along with the big screws are a pair of set screws. From what I can tell, the set screws are used to prevent over tightening of the main screws. If those are too tight, you'll have a hard time adjusting the height of the easel bed.

Here I am trying the first instillation of the upper assembly. This part went fine. When I tried to insert the camera and T-Bracket I ran into trouble. It would slide in about 4 inches, the stopped. I was hitting something, again. Now it is worth mentioning the camera weighs about 45 pounds, and the T-Bracket weighs almost as much. Holding the damn thing gets tiring. I looked around for the trouble and found it. The vertical columns were in the way, by about 1/8 inch on both sides. The only fix is a trip back to the machinist.

Photo on the left is the T-Bracket shaft as first created. The second photo is after the sides were each milled down about .0094". Before I went to the shop I carefully cut a block of wood so that it would barely fit in between the top vertical columns This would be a guide to the machinist, so he would know just how much metal to remove, in turn allowing the T-Bracket shaft proper clarence.

Second attempt to mount the camera. This time is all fit, like a glove. I was sooooo happy to see this part finally together. Some careful leveling is in order, but for now I'll just take pictures. I set my D200 on interval timing. Had it take a photo every 4 seconds while I installed the camera. I'm such a geek.

This shows the rear of the mounting assembly for the shaft. The bolt on the upper left is a clamp, this is what helps keep the head from rotating. On the left you see the nice fit job the machinist did. Flush mount - baby!

Finally a side shot of the mounted Beseler CB7. The middle shot give a clear look at the spine of the CB7 and it;s mounting bracket. Then, on the right - DURSTZILLA !!

My next phase will be dealing with the electrical system. I have already started on making a schematic of the CB7. There are only a few switches I want (focus up/down, focus speed and the on/off switch). Everything else can go. I will need to decide which transformer box I need to keep and trash the rest (like the enlarger timer and power regulator - I already have one of those, it weight nearly 100 pounds).

Stay Tuned !!

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