Slitting film precisely (lengthwise)

[Simon R Galley]

Our ( second stage slit ) lengths for 120 are 610 m long.....

Simon. ILFORD Photo / HARMAN technology limited :

 

[Steve Roberts]

I made a slitter to cut 35mm down to 110 with no problems. It only really amounted to making a jig that holds a cassette with a couple of guides to locate the film and two sharp blades spaced appropriately. The cassette is loaded with film as per usual, placed in the slitter in the light and the hinged back closed, which initially causes the blades to pierce the film. A leader is left hanging out the end to catch hold of. Anywhere that the film may be subject to scratching is covered in felt or something similar. Out with the light, pull on the leader in the centre and out comes a strip of film that you want from the middle and one each side that you don't. This can then be placed in something light-tight pending loading it into a 110 cartridge (not forgetting to chop off the leader which has been exposed to light. It's worked very well for me for my experiments with 110 cameras but I don't see why it shouldn't work in a suitably modified form for larger sizes. As I recall, the main problem I had was getting the spacing of the blades right, which needed some careful shimming. The results may not be perfect, but are better than consigning a camera to "exhibition only" for the want of film, especially if you enjoy the challenge of a bit of mechanical engineering!

Steve

 

[Mike Wilde]

I have slit 70mm down to get 120. The motivation was a great deal on 100' of 70mm portra 160NC. It is a pain in the ass, both the slitting and the re-loading the salvaged backing papers.

I used a 4 ply matt board channel that was hinged with sides of the hinge 120 film wide, and it was about 3.5' long. I would spool the right length off the reel (notches cut in the hinge edge as a length guide) and cut off squarely wuth a surgical blade, then slit the edge off.

I would then re-load the backing paper and spool it up again, securing it with painters masking tape.

I have done it twice to make about 12 rolls as I recall. Results were ok in some cameras (older red window sort). My mamiya c330 got very annoyed with this, and woud not sense the next frame when cranked forward. I did not try switching it to 220 setting, but that is in the plans for the next time I need to use this film.

Presently I have a large stock of NPC and NPS that I am working through before I go back to slittig the Portra.

 

[Reinhold]

Let's see...

610 meters would yield about 375 rolls of 220 film...
I'm a part-time machinist and have a small machine shop...
I like designing and making things...
Like a spooling station...

Now, if I could only find a use for 375 rolls of FP4...

It would take me a few years to get to the bottom of that pile.

Oh well...

Reinhold

www.classicBWphoto.com

 

[brucemuir]

Let's see...



Now, if I could only find a use for 375 rolls of FP4...

It would take me a few years to get to the bottom of that pile.

Oh well...

Reinhold

www.classicBWphoto.com

I'll buy some.
I REALLY miss 220 and just purchased a decent A24 'blad back.
Hate to think I wont be able to use it much longer.

Luckily my 645AFD has a back that will run both 120/220 but I have a pile of RZ and 'blad 220 backs.

 

[Nicholas Lindan]

Our ( second stage slit ) lengths for 120 are 610 m long

I'll wager a pint of bitter you are shortchanging your customers by 40cm, and in reality the rolls are 609.6 meters long.

At one time the US government decided to change over to metric - they decreed that everything they bought would be in mm, cm and meters (and kg and ...). As a result the government would buy 215.9 x 279.4 mm typing paper. For some reason the dimensions 25.4 mm, 30.5 cm and 1,609 meters were inordinately popular when it came to government purchase orders.

A4 paper made for tractor feed is actually 296.333 mm rather than 297mm. And were in blazes did 297mm come from in the totally metric world of DIN standards - well American typewriters type at 6 lines / inch. 70 lines * 1/6 of an inch * 25.4mm/inch = 296.333 mm, rounded up gives 297 mm.

 

[cmacd123]

This thread makes for a related question for the film making experts. When the factory is slitting the film from the master roll, can they mix the widths or must the whole roll be cut the same, for example can one slit a dozen rolls of 35mm and also make some 70mm, or 16mm? or would they have to make say 70mm and then re-slit some of those rolls to 35?

As far as DIY slitting beside the submini folks you might want to try to find a LOMO Regular 8 slitter. Two rollers that slice the film like scissors. I got mine a while ago and hope to use it one of these days when I get brave enough to try B&W reversal.

 

[michaelbsc]

Here's a slitter from one of the sub-mini guys I bought specifically for making 127.

It works fine.

http://cgi.ebay.com/Al-Spoil-film-s...ViewItemQQptZFilm_Cameras?hash=item25596a1eb5

 

[mgb74]

Here's a slitter from one of the sub-mini guys I bought specifically for making 127.

It works fine.

http://cgi.ebay.com/Al-Spoil-film-s...ViewItemQQptZFilm_Cameras?hash=item25596a1eb5

You can get it direct from him here (as well as film): http://www.subclub.org/sponsors/goathil2.htm

I suspect Ilford's splitters are a bit more automated.

 

[largeformat pat]

Why not a hot wire? like what they use to cut foam. The only thought I'd have would be that the plastic film base is a thermo setting plastic.

 

[richard ide]

A hot wire might cut triacetate film but would leave a ridge of melted plastic on the edge if it did. Polyester base would not work at all.

 

[Simon R Galley]

Our master slitters ( we have several ) cut a whole master roll at one go, and the slits can be any width
and we can have any number of different slit widths on the same slitter at the same time.

We would not do that though, as the time taken to reset the machine ( + or - .5 of a thou per slitting ) would be many hours.

One machine is for 35mmm, one for 120 and one for sheet and specials.

Simon. ILFORD Photo / HARMAN technology limited :

 

[steven_e007]

I made a slitter using some cheap kraft knives. There is a type of disposable craft knife that uses a blade that you can snap off 5mm or so every time it gets blunt. I bought a handful of these and removed them from the plastic holder. To keep the blade in place they had a handy hole in the end. I got a bice long brass bolt with plenty of nuts and washers and used them to position the blades on the bolts. I can set up any width I like with several blades as required to slit different sizes or combinations of sizes. The bolt is supported over a block with two brackets and a wooden block rests on top of the blades to keep everything flat and level. The blades blunt quickly - so keep snapping.

Problems are keeping the film running straight and not letting it wander (I use two 120 plastic core reels as guides) and not scratching it. It works.... after a fashion. Dust and scratches are always a problem, though...

What we need is to persuade Simon to let Ilford sell us that old slitter which I'm sure is sitting in the store-room. We could then crank it up in someone's garage on a not for profit enthusiasts basis and repack Ilford's films for them in lots of weird and wonderful sizes ;-)

 

[Simon R Galley]

Dear Steve,

Unfortuanately its bigger than a garage......

Simon. ILFORD Photo / HARMAN tcehnology Limited

 

[Steve Smith]

Unfortuanately its bigger than a garage......

You haven't seen his garage!!!


Steve.

 

[Simon R Galley]

You haven't seen my slitters......!!!

Simon. ILFORD Photo / HARMAN technology Limited :

 

[Chris Livsey]

Put up or shut up

Let's see the photos of garage and slitter. But wait, won't the slitter be in a darkroom :rolleyes: and won't the garage be blackout :rolleyes: ?

 

[michaelbsc]

Our master slitters ( we have several ) cut a whole master roll at one go, and the slits can be any width
and we can have any number of different slit widths on the same slitter at the same time.

We would not do that though, as the time taken to reset the machine ( + or - .5 of a thou per slitting ) would be many hours.

One machine is for 35mmm, one for 120 and one for sheet and specials.

Simon. ILFORD Photo / HARMAN technology limited :

I've never seen Ilford's facilities, but I was once in an AGFA slitting plant. And it was pretty impressive. I've also done work for Fuji, but on the metal plates for print presses, nothing with film.

MB

 

[viridari]

Simon, thanks for putting up with us and our redundant "helpful suggestions" on how to run your business. Some of us get the hint when you tell us it's not in ILFORD/HARMAN's best business interests to handle a microniche market.

 

[Photo Engineer]

A hot wire might cut triacetate film but would leave a ridge of melted plastic on the edge if it did. Polyester base would not work at all.

The glow from a wire hot enough to do this job would fog film.

Give Simon a break. He knows what he (and Ilford) are doing!

PE

 

[Simon R Galley]

Dear All,

I enjoy everything about APUG, all opinions, all the ideas, everything... and I always try and remember that 'not all the best ideas have been thought of yet' ....

Simon ILFORD Photo / HARMAN technology Limited

 

[viridari]

Here's an idea: JOBO is ripe for acquisition, and would nicely round out HARMAN's analog product offerings.

 

[MattKing]

Here's an idea: JOBO is ripe for acquisition, and would nicely round out HARMAN's analog product offerings.

After all, I'm sure Simon has lots of free time .

 

[Chazzy]

Dear All,

I enjoy everything about APUG, all opinions, all the ideas, everything... and I always try and remember that 'not all the best ideas have been thought of yet' ....

Simon ILFORD Photo / HARMAN technology Limited

Thank you for saying that.

 

[steven_e007]

Dear All,

I enjoy everything about APUG, all opinions, all the ideas, everything... and I always try and remember that 'not all the best ideas have been thought of yet' ....

Simon ILFORD Photo / HARMAN technology Limited

Here's the best idea, then...

Maybe, at the weekend when the factory is shut, Ilford could just chuck us the keys and we can slip in and run off a few 'interesting' sizes and maybe coat a few glass plates whilst were at it? Always wanted to be let loose with that machine!

As long as we promise to tidy up the mess afterwards, eh?