Minox daylight developing tank

[Ron Valdes]

I've misplaced my spacer rings for my Minox. Daylight drum. The one i need is for 36 exposures.I've considered PVC. measurements don't work out. Does anyone have one. I will gladly pay for the

 

[DWThomas]

If anyone out there could supply the numbers I would be interested in seeing the actual dimensions of an authentic version of that ring. A year back I made one out of some small scrap of plastic I had tucked in a box here. The inside and outside diameters are reasonably defined by where it has to fit, but the height was something I had to make an educated guess at and I'm really not sure how close it is to the original. Presumably the dimensions also affect the developer level in the tank, which could mean the 53 mL might not be enough if the wall thickness is thinner than the original.

This sort of problem is where you can earn your 'eccentric' badge and tour a store with your vernier calipers in hand looking at plastic juice or shot glasses, pill bottles and other sundry products with a cylindrical section trying to find a source of plastic tube of appropriate size. One might be able to buy a rectangular strip of polystyrene from those hobby shop assortments, soften it with a heat gun and wrap it around a mandrel too -- can't say I've tried that.

I have vague hope my original may be around, but it had wandered from the tank and thermometer and could be anywhere, including tossed thinking it was some sort of shipping stop from a printer or whatever. Although I tend to save odds and ends of metal and plastic that "might be useful." (That's why it's becoming difficult to walk through this house. )

 

[Ron Valdes]

Thanks for the information. I'll find something. Be Well, Ron

 

[Leigh B]

My tank set is complete and appears to be new.
There are no signs of use and no water or chemical stains anywhere.

Ring dimensions:
Length = 17,40mm +0 -0,01mm
OD = 48,82mm +/- 0,02mm
ID = 35,00mm +/- 0,04mm

The ID (inside diameter) is the most difficult to measure accurately, particularly with a plastic part that's not perfectly rigid.
All my measurements are done with properly calibrated and certified Mitutoyo instruments.

Quoting from the November 1968 manual:
"Stop ring for 36-exposure films
"Before developing a 36-exposure film, slide the enclosed stop ring over the inner tank core and let it drop to the bottom of the tank.
"After attaching the film to the drum, turn the drum into the tank slowly, until it is stopped by the ring. Do not continue to turn the drum after reaching the stop.
"With the stop ring inserted, use the normal volume of 53cc solution."

Boldface is from the original text.

I might consider selling the entire boxed set with thermometer and all, but not just the ring.

- Leigh

 

[Ron Valdes]

Leigh...thanks for the information.

 

[DWThomas]

Thanks Leigh -- I conclude my home made substitute is thinner (probably not a major issue), but it also appears my length is a few mm short. The latter I should fix.

 

[Leigh B]

Thanks Leigh -- I conclude my home made substitute is thinner (probably not a major issue), but it also appears my length is a few mm short. The latter I should fix.

Hi Dave,

The thickness (length, height) is certainly the most important dimension.

I measured that at several different locations and it was quite consistent, so they put some effort into it.

- Leigh

 

[DWThomas]

Question ... might there be a typo in that OD number? Of course it could also be there were production changes over the years too, I suppose. Anyway the ID of my tank appears to be down around 46mm, so the stop ring couldn't be fatter than that. Anyway, I stopped in Lowe's for an unrelated reason and noticed a 1-1/4 to 1 inch reducing bushing in the PVC electrical conduit section (for a mere $1.79) so I bought it:

Cut away what didn't fit withing a stop ring profile and voila!

(The white ring is the thinner shorter one I fudged back in 2015.)

An-n-nd, in the process of rummaging through stuff in the darkroom ... didn't find the original ring, but found two SS reels that may indeed be for Minox. The inner edge of that stamped ring on the non-spiral side is awfully sharp to be dragging film near; dunno.

I have no recollection of buying them -- or using them. But then I bought my Minox B and some accessories in the mid-1960s. Now that I've made the new ring, I'll probably find the original the next time I open the back closet for something ...

All of this is a delaying tactic, as based on what I saw back in the summer of 2015, I need to disassemble the camera enough to clean out the film path. I seemed to be getting longitudinal scratches on the film. And at $20 a roll, I have to do better than what I saw from that roll!

 

[MartinP]

Good luck! I had a clever plan all ready to chop down a Paterson reel and rebuild it in to a Minox reel - then I went in a local junk shop and found a Minox tank, so my problem was solved by accident. That tank is for the 36 size of film, which is ok for me as my Minox-B does not take 54 exposure lengths of film, so the camera/film matches the tank and I have no need of a spacer ring.

Edit:
The tank I found has no thermometer. There is a space in the centre of the Minox tank design which accepts a 'fat' thermometer for both temperature measurement and for agitation (via a cunning overflow-and-refill system). I use a standard thermometer size occasionally for checking the temperature and a long 8mm nylon bolt for agitation, which seems to do the job.