Paterson Orbital for processing sheet films

I would like some advice on processing 5x7 b/w sheet films in a Paterson Orbital.
I have modified the base of the processor so that the solutions can prevent the sheets from sticking to the floor of the unit.
The camera came with two boxes of film, a partially used box of FP4 Plus and an unopened box of Delta 100.

The developers I have are Kodak D76 and Adox Rodinal.

Should I presoak the sheets before development, or not? Also should agitation be continuous or intermittent?

Advice on dilutions and guide times appreciated as I have not used an Orbital before.

Hi

I've used Rodinal and PC-TEA developers with the Orbital to develop 5x4" and 9x12cm sheets. I generally use 150-200ml of solution and continuous agitation. Using 200ml you need to be careful not to slosh the solution out! So, with Rodinal you're looking at 1+25 in order to get the minimum concentrate. Having said that, I have gotten away with 1+50.

I don't pre-soak.

Given the low quantities of developer solution you need to use continuous agitation or you risk a sheet floating and being unevenly developed. Usually I slowly "wobble" it 15 seconds clockwise then 15s anticlockwise, each orbit taking about 2 seconds.

As for development times, I've not used the films you are using so can't help there other than to say I've used the MDC as a starting point.

I use the Orbital exclusively with one-shot developers like Rodinal and HC-110.
Like you, I've adapted the bottom of the tank so the film doesn't stick, but I've left the fins attached. (One suggestion was to snap them off and use longer pins as dividers)

I pre-soak Fomapan films to remove the anti-halation coloring from the film, but if you don't mind some dye getting into stuff like stopbath or fixer, don't worry about it.

I use 175ml of diluted developer, with a minimum of 5ml concentrate you're limited to 1+25 or Dilution B (1+31).
I also use continuous agitation with the motor base and reduce the developing time by 10-20% accordingly. HC-110, B would give me about 5min 15sec dev time for Fomapan 100.
Not sure if intermitttent agitation would cause problems with uneven development if the entire film is not submerged.

If you're getting 'nightmare/bright lines' on the negatives from the developer sloshing against the fins from the suggested circular motion on the base, It helps to agitate the tank left-to-right for 5-10 seconds every minute.

Another common application with the Orbital is to use it with a water bath, especially if you are doing semi-stand development. I‘ve had pretty good luck using FP4+ with Pyrocat HD, though since that developer is cheap as chips, I use a full 500-600ml of solution, and sometimes even replenish halfway through the run if I’m looking for a stronger negative. In terms of agitation, I tap each corner in turn to get the tank to bob, alternating clockwise/counterclockwise every ten seconds or so.

BTW, I picked up a lot of tips from Ed Bray—hopefully his work is still on Flickr if you care to do a search…a lovely chap from Plymouth was my impression, though we never corresponded directly.

Thank you PC Headland, Mr. Flibble and Creation Bear for your tips.

I will look into Ed Bray's photos. I also live in Plymouth, so it would be nice to meet Mr. Bray.