just so I can get a better picture of what you and your engineer friend are going to do, could I show you something I was thinking of when I first read this post? I'm drawing it up now as I type this, so I'll post it here as soon as I got it done.
are you set up for the magnetic bases for your tanks, or the cog heads?
EDIT: i mean, are you wanting to use the cog heads for your tanks when you have the new machines, or the magnetic bases like for the CPE/A's?
Last edited by DanielStone; 12-14-2009 at 02:29 PM. Click to view previous post history.
here's some rough sketches of what I was thinking..
technical details are a little sketchy, since I'm not that sure about electronics, others here will know much more than I. I'm coming from more of a purely design view...
..ill have to look up his contact info, but I have communicated often with Rodger King in the past. He is well into his 80s, but if you don't know who Rodger King is, he is likely "THE" authority on rotary processing. His company, 'King Concept' was the 1st real rotary processor. Every drum processor was modeled from his machines. Though he is retired Ill bet he'd be interested in this project.
If you'd like his email contact me.
Originally Posted by Bob Carnie
Your usual woodworking lathe turns pretty quick unless you rework the drive pulleys and you really don't have a good idea of the real speed on most.
Problem is most have a bottom speed from 250 to 600 rpm. For instance the Delta lathe is reversible and has a range down to 250. You would need to replace the drive motor with a 10:1 reduction geared motor to get into the right range of speeds. In this case you would be building a control unit for the reversing with relays and timers to run the motor.
Sounds like you have the techs for that.
I would think the best bet would be to get a second hand lathe bed, strip it down and rebuild it to suit. Some of these old rigs are barebones enough to start with that they can be modified easily with an outboard motor and a coupler made to fit the headstock that the tanks can hook up to. Most of them has a morse taper in the headstock that a chuck can be mounted into that will grip a shaft pretty easily.
Just a few observations.
1. With a micro-controller and enough servos, you can automate almost any process.
2. The 24V motors are likely because of DIN regulations. Higher voltages than that involve mega safety considerations. German process equipment often operates at 24V, as it is cheaper than using wall voltages (120 to 240V). The power supply can be country-specific, and can be located far away from the wet stuff.
3. This sounds like a fun project.
4. Sourcing the electric motors (servos) is going to be harder than designing the mechanical devices.
5. Sourcing reliable pumps will be harder than finding good servo motors.
You might consider a non-electric motive power source, like compressed air or a hydraulic pump. The compressor or pump costs some money, but the servo cylinders can be relatively inexpensive. One compressor can supply more than one process machine.
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Have you ever thought of fish tank pumps?
When I took mine apart (Jobo), I was struck with the similarity to a fish tank pump.
that's what I was thinking, with simple hot/cold water hookups directly to the bottom of the basin, and a drain valve for when not in use...
a big, industrial grade one though. most I've found top out at like 95deg F though, so not hot enough for C-41 or E6.
Just looking through eBay there are lots of electric bicycle motors that might be suitable. The output RPM is way too high but as it already has a cog on the shaft ready for a bicycle chain it should be relatively easy to gear it down to an appropriate level. Another possible option would be the old singer style external sewing machine motors although I don't know whether they would have enough torque.
Ok now we are smoking, the brainiacs are coming out of the woodwork with some great Ideas.
Water Pump is a no brainer or at least I think so, I just bought a bosch motar at my local Volkswagen garage that is part of the Alt2300, $250 but it is brand new with no wear or tear.
As long as they make volkswagens I think this part is safe.
As I have pointed out this is for long term operation and I am not budget driven on this machine. My business partner would kill me for saying this. But from the sounds of things parts should not be the problem for the mechanical side of things, Richard has a complete shop to manufacture in plastic, wood and stainless steel.
I am wondering now ideas on a programable timer, controller that stores the different processes and starts the whole process.
Would we think of monitoring the water bath with temp probes to assist the opreator in bringing every thing up to temp?
Would we have the tanks rotate over a dry platform or would we want the tubes rotating in tempered water?
If you look at the Jobo tanks they are odd shaped and would not lie flat on the rollers, could we use very large rollers and lathe down spots for the hoods of the tanks?
If so would we make separate rollers for different size film so we can process more than one tank at a time?
Enquiring minds need to know,
Just to say I appreciate the responses and actually have not gone backwards over the suggestions as I want to keep the ideas coming and Richard and I are not meeting until the end of the month.
How will you control the RPM?