Ideas for takeup spool winding mechanism?

[apocaplops]

Hey all. I've finally started to modify my Polaroid 110A. I'm not going the 4x5 route because I currently have absolutely no way to process that format. I'm not going the polaroid packfilm route because I have plenty of packfilm cameras. What I'd really like is a large medium format rangefinder, so I'm building myself one.

I'm doing as little as possible to the camera to maintain a stock appearance and the possibility of later conversion to 4x5.

I've got the supply-side pretty well done already, but I'm having trouble making a takeup side winding mechanism. I took apart an old Autographic Kodak to use its winder, but it won't reach all the way to the spool. I need something with a longer shaft, or maybe modify the shaft of this one somehow. Oh, and it spools the wrong damn way.

I figure there's pretty much no way to configure a red window frame counter to work for this contraption, as it's gonna be a 6x10.5cm frame. If anybody has any ideas on the winding mech though, let me know.

[Don Day]

I had to come up with something for a pinhole body I'm working on. Here's my approach:

Installed views, inside and out:


Pulling up against the tension:


Basic parts:


To make the slot end, I trimmed a picture nail to length and whacked it into the slotted screw head with a hammer--its in there for good.  Better would be a sliver of bar stock or rectangular chunk of steel, but I went with what I had at the time--it's replaceable if necessary.

I drilled out the 6/32 T-nut so that the 6/32 screw now just slides in it.  The spring came from a hardware store assortment package--it just happens to fit over the neck of the T-nut, and the head of the screw just happens to compress the other end. A small washer could be used as a stop if the head is too small for the spring you find.

The hole in the body is just large enough to admit the assembly. This T-nut came from a hobby shop and it had the 3 flange holes in it already. Three small brass screws finished the assembly. The knob was from my junk box, and has a setscrew on one side to keep it from unscrewing when winding the film.

This winder works great.  As you can see, the length of the T-nut neck basically sets how much you can pull up on the head. I had to file a bit off the end of the T-nut to enable the head to be retracted fully out of the cavity, no big deal.  It was just lucky that the wood was thick enough for the assembly to fully retract into.

For my "red window" plastic supply, I bought a box of red hanging folders from the office supply. It has a set of red plastic tabs for labeling the folders. Drop a tab into a cup of water and put it into the microwave. When the water boils, the plastic will flatten out by itself. Quickly set it on a cool surface to set up flat. I can get 4-5 windows from each tab.  While the folders were extraneous, I can use them just fine with clear tabs that you can buy.  The hard part was finding the right kind of plastic--durable and decently deep color (not cellophane, as I've seen pasted into many old cameras).

[ImageMaker]

I've used red window on the 6x4.5 track to get 6 frames of 6x11+ on a roll of 120.  The trick is that you have to wind 2 1/2 frames for each exposure.  Place the window near the supply side corner on the 6x4.5 edge, and wind to 2.5, 5, 7.5, 10, and 12.5 on the numbers, and all is well.  The 6x4.5 works well for this because the first warning mark, or the start of the text on Kodak film, is just about exactly halfway between numbers (and there's plenty of space between frames to take up a little error with this format or 116/616 cameras converted to 120).

BTW, to correct the spooling direction, put the winder on the bottom instead of the top, as Kodak did originally.  

[apocaplops]

I still don't think I can swing a red window on it because of its double-door mechanism. There's another door underneath the first door. Are all 120 films a standard length between takeup and film? I was going to just count the number of turns to the first shot, and then the number between each shot thereafter.

Still not sure exactly what I'm gonna do with the winding mech. I'm gonna see if I can find some stuff to try out Don's method, but I need a rather long shaft to turn the spool as it's quite a ways into the body - about 3cm from the outer body of the camera to the spool.

I wanted to put the kodak winder on the bottom of the body, as the top is all plastic rangefinder bits. unfortunately it won't wind that way. Here's a picture:

[ImageMaker]

The position of the film start and first frame (for each format) is specified in the ANSI spec for 120, in reference to the double-headed start arrow.  The problem is, the backing thickness isn't, so you might well see a half inch variation if you count turns after setting the start arrow at a reference mark.  It shouldn't be difficult to drill through both doors (just like drilling through back and pressure plate) if you want to use a red window.

Some advance units can be reversed by disassembling the stem and then reassembling it the other way to in the housing (which contains a one-way mechanism, either a ratchet or, more commonly, a silent ball bearing overrun type clutch).  Question is, did Kodak leave a way to separate the winding knob/key from the inside stem?  Otherwise, you might look for a folder with a bottom advance to donate the advance unit -- my Voigtlander Rollfilmkamera and Wirgin Auta both have this, but the Moskva parts I have here are top advance, so they rotate the wrong direction.  Top advance on the left side would work, too, of course...

[Diwan Bhathal]

Apocaplops,

Just saw your photo.  Yes, you got it, that is the way it should go.

The Pola 110A has all that Pola junk inside that should be removed.  Get rid of all of it, but, keep the film pressure plate.

Then follow your drawing as how to mount the spools.  Use only 120 spools, do not use the original Pola spools unless you want to complicate your life.

The spools are to be spring tensioned, you have the springs in the right locations.  For the tops of the spools, that is, the one closest to the RF casing, use L brackets with an Allen screw that fits into the hole of the 120 spool.

These L brackets are to be placed in a location that allow you to center the film on the film gate.  Sand the L bracket location, clean with denatured alcohol and glue with epoxy, the brackets will stay there forever.

The bottom spool sides are spring loaded, as you indicate.  One of them has the knurled knob used to advance the film.  The other one can be built with another L bracket with an Allen screw and a washer and a nut and spring loaded to allow you to insert the film.

Remove all the junk in the back of the camera unless you want to have some muscle strain after 30 seconds of holding it.  It is useless anyhow if you plan to do the conversion to 4x5, and it will give you more room inside the camera body to do the mod.

You have now the film pressure plate separate.  You need to remove the flat spring attached to it (drill the small rivets out).  This flat spring is right smack in the center of this plate!

Then drill a big hole in the center of the pressure plate, aligned with the film back paper, where the numbers are.  With a ruler measure the relative positions of everything, and drill a big hole in the back door of the camera.  This is where the film advance peep hole will be.

I do not recommend to use the 645 film indications to drill the ruby window, this will destroy the back for future use.  Drill the back for the 6x6 film numbers on the film backing paper.

Find some transparent plastic of the color of your choice to make up the ruby window.  Find something somewhere to put in there to cut down on the light.

Then, get a piece or pieces of thick mouse pad (neoprene), cut them to the size of the film pressure plate, make a hole into this neoprene and glue them to the back of the pressure plate, this is your film pressure spring.

Now you need to get some thin self-adhesive felt (Michaels or AC Moore) and cut a small ribbon of this felt that you will paste all around the lip of the back of the camera for a light seal.  This camera leaks like a sieve, that is why all the "armor" inside.  Thin felt does the job.



Seems confusing, but you are 75% there.  Just use the 120 spools, this will save you lots of trouble in the future.  Again, this is simple surgery and the intent is not to complicate life.

Congratulations and best of luck.  Please post results of the modified camera.

[apocaplops]

L brackets! Those would work great. The only thing I still don't know is what to use for the film advance though. I just can't find anything that will reach all the way to the spool to turn it. I think I can use my Kodak advance on the top right of the camera, but I need to lengthen the shaft about 3cm. Hmm... I'll think about it.

[Diwan Bhathal]

Apocaplops:

Don Day just gave the solution for this, see his photos above.

You can get a longer screw to do what he has done.  Still, use your configuration with the film advance on the bottom of the camera.

To maintain the longer screw from shifting, make it go through a small block of wood as a guide.  Suit the thickness of the wood to your dimensions.

Ace Hardware has all kinds of knobs and screws and anything that you may need.  Go see what they have.

It is not needed to have a ratchet mechanism of something like that to advance the film, a simple screw with a head that fits the slot of the 120 spool and a knob on the other end is all you need.

Best,