Need help figuring out how to build a roller base for a Jobo 3005

Nobody likes long postings so in keeping this somewhat brief I’m needing some help building a motor base for a large Jobo film processing drum.

I have some ideas in mind and a rough design. A professional machinist I was working with just hasn’t had the time so I’ve finally realized I will just have to build it myself.

What I’m after is a portable and extremely quiet motor base for my Jobo drums. I want to emphasize the quiet part. I’m surrounded by vibrating and otherwise noisy objects and I don’t want this motor base to be another one.

When it comes to electronics I know just enough to be aware I know nothing. I could use really use some help understanding what kind of torque I should be looking for and what kind of voltage I should be looking at. As the motor will be running for about thirty minutes per film run the duty cycle could be important so the motor doesn’t get overworked.

On the mechanics side, I’m looking at a multitude of bearings, rollers and drive pulleys and some pointers would be really useful.

Before it’s mentioned, please, I do not want to buy an old Beseler motor base. I’ve already done that. It’s too narrow for the drum and the drum also walks off the motor. Similarly, I do not want to buy a huge Jobo CPP/CPA processor as I have no need at all for the temperature control (I’m processing black and white film) and no room to store one of these machines.

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Originally Posted by konakoa

On the mechanics side, I’m looking at a multitude of bearings, rollers and drive pulleys and some pointers would be really useful.

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All of the mechanical stuff you would ever need is at McMaster-Carr Supply Co:
http://www.mcmaster.com

They've been in business over 100 years, and carry everything.

You want to use a DC motor, not AC.
AC motor speed can be adjusted but it requires special circuitry.

DC motor speed is adjusted just by changing the applied voltage.
That's why railroad engines use DC motors rather than AC.

The support wants to have three feet, not four.
Two are on one side of the tank and one on the other side.

One of the feet on the two-side should be adjustable in height.
That lets you adjust the support perfectly level so the tank won't walk.

- Leigh

I use a Uni-color or Beseler base for the large end and a separate set of idler rollers at the neck. I added a third idler roller wheel perpendicular to the cap end to hold it in place. Or you could put one on each end to hold the tank in place. Works fine but my tank is smaller than yours.

DC motor speed is better controlled with a PWM controller - constant voltage, variable on-periods - which provides better torque, and thus control, at low speeds. Controllers for 12 and 24v motors are all over the bay, and are inexpensive - a few pounds/dollars. I'm *guessing* here, but a suitable motor to turn, say, a kilo of tank and chemistry would probably need no more than a watt or so; there will likely be a mechanical advantage with the drive system. Belts are significantly quieter than gears. Making sure you have no hard coupling to resonant surfaces - the case of the unit, the work top - will keep things quieter. Rubber feet and mounts are your friend.

Neil

Something to think about.

Quiet rock tumblers.

https://rocktumbler.com/tips/how-muc...-tumbler-make/

The drums kept walking off my Beseler base and it ran a little slow so that was no good. I'm actually using that exact rock tumbler as a motor base now Randy. I had to swap out a set plastic rollers it came with on one side as the rollers really banged and ratted around, but works very well with a smaller Jobo 3006 drum. It runs nice and quiet now. Been using it for two years. The rock tumbler is meant for heavy loads going 24/7 for months so the motor is strong. The problem is it's the biggest model they make. No way the 3005 Jobo will fit on it.

So it looks like I definitely need a brushed DC motor on the base I want to build. 12 volt is very common. I see 24 volt too.

Attachment 171978

Your projects are always very nice.

Your next iteration may even get me rolling.

Updating this thread. It took me nine months however I finished everything I set out to do. After going through small mountain of parts and a equal amount of trial and error I have a purpose made roller system for large Jobo drums and tanks. This is for 4x5, 5x7 and 8x10 film. Works wonderfully!

Very cool.

I knew you would make something nice.