Jobo 2502 adapter for 70mm

[polyglot]

I've been saying for ages that I'll make up an adapter to more-easily allow development of 70mm in 2502 spirals. I finally pulled my finger out this afternoon and made up a design in OpenSCAD, see the attached renders. The idea is that the adapter goes between the two halves of the spiral, causing it to be 9mm wider than on the 120/220 setting.

The Adelaide City Library has 3D printers (a couple Makerbots) that are free to use, so I hope to get a prototype made up this week.

Edit: I just noticed that the teeth on the spirals are not 120-degree symmetrical. A bit more adjustment required...

 

[gorbas]

Nice work Polyglot! Good luck! What is capacity of the reel?

 

[polyglot]

Well it's still a 220 reel, so about 20 frames on 6x7 or 24 on 6x6. I think you can fit an extra 2 frames or so due to less leader wastage.

Turns out the library printer is all booked out for a week or two, so it'll be a little while until I get a print.

 

[munz6869]

That's smashing!!!

Marc!

 

[polyglot]

Progress is being made: my first prototype was too small in the female side due to a bad measurement I made, so it didn't fit over the male spiral. The second prototype fits both spirals, though it is a little too long and the throat is too narrow to fit the central core that holds all the spirals. I didn't realise that 120 sits so loosely in the spiral with about 3mm clearance on each side, so this adapter causes there to be that much clearance. I think it's a bit too loose for the wider format, so I've made the adapter a bit shorter to see if that works better - it might have been an error to do so though, I'm not sure.

Fingers crossed for a 3rd prototype to be printed tomorrow morning before the loaned printer is returned. See attached phone-photos, showing the two prints and a bit of scrap 70mm 2415 Tech Pan on a Jobo 2502 spiral. Edit: ew my mousepad.

 

[belichten]

if your next prototype is sucessful will you be sharing the cadfile. a friend of mine has a 3d printer

 

[polyglot]

Revision C works perfectly! I'll try to get another couple of copies printed off today and I'll be doing a biiiiig batch of 70mm tomorrow; I have about 50 feet of it sitting in the cupboard, exposed. Being able to develop more than one spiral at a time will be a godsend!

I plan to check that it prints OK in an SLS printer (these tests are FDM ABS of course) and make it available for purchase through Shapeways or Ponoko or some similar online service, depending on what their prices look like.

Update: looks like FDM is still the cheapest way to print it online, and the total cost will be on the order of $50 plus shipping if people are interested. I hope I can get them drop-shipped directly from manufacturer to buyer but am not sure yet. I'll try and get some more printed on friends' printers first as I reckon they'll be cheaper

 

[Dr Croubie]

Did you tell me that you were doing this, or did I independently have the same idea? (although, I think my idea was more along the lines of dremeling some PVC pipe and gluing one end).

Anyway, looks good, I've just scored an RH50 to use my very-cheap 100' of Aviphot, so I'll probably need one of these eventually (as soon as I find another canister for the film), give us a yell when they're ready (or I'll have to borrow one of those printers myself).

With roughly the same design you could probably make a 3" long version to turn a 4x5 2509n reel into a 7x5" (not that I shoot 5x7, but some do).

 

[polyglot]

Richard: I reckon I told you about these when we were visting Alex at his new digs.

Anyway, I finally got off my lazy arse and used them to process about 3 months of 70mm backlog: about 6.2m (80 frames) of 2405 in one batch through the Jobo. You can see them all stacked up here on the core, with a scrap of film in one spiral for width reference.

 

[polyglot]

Hey all,

The 70mm adapters are now for sale! If you're outside the USA though, shipping from Ponoko is a killer.

 

[munz6869]

wow! (and wow, double and a bit for shipping!!!)

Marc!

 

[polyglot]

Yeah, they don't hold back. I suspect that if a bunch of Australians wanted some we could combine shipping and save.

Sadly I don't have access to the printer I made mine on anymore, so I can't just run off a few here.

 

[munz6869]

I'll put my hand up, because I'd definitely use it - I'm all JOBO 25xx'd up and have a number of rolls of aerographic Plus-X to get through... and meanwhile, plan B can be dipping into the retirement fund for solo shipping

Marc!

 

[Oxleyroad]

I got a 3d printer coming in the post as I type here. Expect it to arrive late July/early August. William / Marc After my back log of bits and bobs I can help out with parts if needed for material cost and postage.

 

[munz6869]

That's great Andy!

Marc!

 

[polyglot]

Pretty sure I can license you to manufacture 'em, Andy. No downsides to a second source...

 

[polyglot]

Hey everyone,

So obviously ponoko is a bit of a ripoff; I think I sold a grand total of one adapter through there. I have decided to open-source the design so if you have access to a 3D printer, you can print it yourself.

Files are up on github. You can download the STL if you just want to print one, or the full OpenSCAD source is there if you wanted to modify it for whatever reason.