The inflation calculator says the new Jobo I bought in 2000 cost $1500 in todays dollars with no drums or reels. It seems to me almost all the units I have seen on ebay go for less than that. I'd just look for another Jobo. If I were going to put together R&D resources, I'd work on making spare Jobo parts.
I agree with ic
I just went through the process of resurrecting a Jobo CPE-2. Considering my electronics knowledge boarders on "Just enough to get me in trouble, hardly enough to fix anything", I would have to say that I would try and fix an keep a jobo going, even if it means gutting out all the electrics/mechanicals and starting with an empty bath.
In the end, building a circuit that will turn and reverse the motor is not that difficult (& you can get kits that would suit off the shelf), the motor is nothing more then a 24v (running at 18v) motor and reduction gearbox (you build the circuit right and you could have it infinitely variable below the max RPM).
Yes, the heating circuit would be harder, but certainly no harder then trying to build a new unit from scratch.
Maybe I am looking at it too simplistic (the issue on mine was a simple fried power supply).
In 1985 a CPE2 cost $450.00, in 1995 a CPE2 Plus cost $600.00.
Originally Posted by ic-racer
In today's dollars that works out to be $885.00 & $836.00 respectively. and that is for brand spankin' new.
If the units on eBay were brand new, I could see your point, but they are far from it. Most of them are in horrid condition, and have seen a lot of use. Still, try to get one for much less than $600.
Too difficult to make spares for the original JOBO's. Most of the failures are motors (and there is absolutely no substitute, or injection molded plastic, which would be cost prohibitive to produce in small quantities.
My design criteria will eliminate most of the problems associated with the JOBO flaws, and will have a much longer service life, with easily replaceable parts.
Tony, I suggest trying to design a machine that can be sold and shipped without the water basin. This would make the machine much smaller and lighter to ship anywhere in the world. When buying a Jobo, weight and shipping costs are an obstacle.
Most anybody can find some kind of big water basin, plastic or metallic according to taste. The ideal solution would be something that you put inside this large basin. It will rotate the tank, warm the water, circulate it and maybe provide some kind of rapid change like the "lift".
If you go for this solution (i.e. only selling the complicated parts, not the basin) I suggest considering two separate units: the "baths" unit and the "tank" unit. The first unit, the "baths" unit, serves to keep chemicals and water at the right temperature. You provide thermostat, heater, pump and the user provides the basin.
The second unit has the motor for the tank rotation, and also keeps the tank at constant temperature. That means two heaters and two pumps, but the cost overall (for not having to buy a specific basin, and for saving on shipping) will probably be less. Much greater flexibility would be achieved.
Separating the two units has several advantages:
- No need to design a two-level basin (like the Jobo); users can use common plastic basins;
- Much less problems in regulating the water level around the tank;
- Anybody can adopt it better to the space he has in his darkroom. One could even keep the chemistry behind his back if need be;
- People who need 7 or more baths (including rinsing water) will have a big basin for their "baths" unit. I use 7 chemical baths plus 6 litres of warm water in my E6 processing. People who only need 3 or 4 baths will use a smaller basin and will save space.
- The same gear can be used when people shifts from B&W only to C41, and then from C41 to E6.
- By the same token, if you use a powerful enough motor (don't save on that), people can use it in a little basin if they only use a 1-roll tank or 2-roll tank, and save space. When they decide that they want to try with 6-roll tanks, they will just move the unit in a larger basin.
I also suggest the heating to be made with a digital and precise thermostat, like the Jobo CPP2.
Personally I prefer plastic. It takes more time to go in temperature but, once there, it is easier to keep it at a stable temperature.
I'm too far away from you to be of much help but I will keep looking to see how you are getting on. I regularly cut PVC sheet using our CNC drill/router which was intended for PCB manufacture (see my 6x12 camera link). Something like this would be easy to make parts for on the CNC machine we have.
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.
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Maybe these will help.
This was done for less than $200. It does, however, use Jobo tanks and their magnets for driving. It does not have a lift. I built it so that I would not have to worry about replacing specialized parts. It uses a synchronous motor that runs at around 75rpm and uses cheap timer relays for reversing. I have a little .avi clip but I couldn't upload it.
Please keep me updated, because I've wanted to look into home E-6 for a while but without the soon-to-be-defunct Jobo equipment. And let me know if there's any way I can assist you. I work primarily in vibration and acoustics, but they did give me an M.S. in mechanical engineering. (Suckers...)
Neal, thanks for sharing. I may be "picking your brain" about this sometime in the near future (if you don't mind...).
Originally Posted by Neal
Updates will be forthcoming...
Originally Posted by yeknom02
If you are interested in getting involved, leave a comment on my site. this is where I'm trying to keep everything together.
There are some pretty inexpensive Chinese made temperature controller in evilBay. I just bought one, and it looks good so far, but I haven't given it a thorough workout yet. My gut feeling, however, is that it's going to be able to provide dead on accurate temperature control. Most items like this seem to be rock solid, and the technology is old enough that it's not hard to get right.
Originally Posted by tonyjuliano
If you aren't comfortable with the electronics PM me and I'll try to work out some details for you, so long as you promise to return the design for my part to the community. Kind of a Hardware Open Source design. I'll put this on your site, too.