possible agitation idea???

[bigbear]

I was watching a show that had a shot of a chrome plating set-up and they used a small gear driven motor to turn an offset cam to "bump" the parts in the chrome take to agitate them. I was wondering if it would be possible to create enough agitation in the ano bath to possible eliminate having to run an air line or an expensive crosive pump? I want to keep the fumes as low as possible for my set-up as it will eventually be in the same shop as my cnc equipment.

The set-up I'm thinking of doing would consist of a small gear driven motor (surplus) driving a round wheel with an offset dowell in it. Depending on the diameter of the wheel could it provide enough up and down movement to provide enough agitation to possible eliminate the airline. If not then at least keep the air agitiation to a minimum. I was thinking of having the parts physically move in the tank a few inches per revolution of the cam mechanism. Would this provide enough agitation?

The only possible downside I can see is the movement causing the connections to come loose. The bus bar I'm planing on running is a "pinch" type bar consisting of a U shaped piece of 6061 with a mathcing bar fitting into the inside of the U. The bar will be fixed on one end with a hinge screw and then the other side will have a locking mechanism to open and close it. The only place of concern would be at the part itself. If the cam mechanism was slow enough I couldn't see it really coming loose.

Any ideas? good? bad?

Thanks
Adam

[cameraman]

I've been thinking about something similar, some sort of vibration mechanism. Same first thought, that parts connections could come loose. I've also wondered about possibly one of those ultrasonic transducers like they have for ponds that generates "fog" - you'd want to set it up so that it wasn't on enough to actually get mist up off the solution, though.

I haven't talked myself into it yet. My suspicion is that without broader agitation, the heat could still 'hang' around the part and eventually cause problems.

One of the guys here, sage, is using a squirrel cage type paint mixer. He replaced its steel shaft with an aluminum one and attached it to a cordless screwdriver. The screwdriver is mounted at the top of the tank. There's pictures here:
Small tank anodizing

I think I may try something like that once all my aquarium pumps have died.

[sage]

Yes, Paint mixer - highly recommended. If you turn it with an electric drill at normal speeds you'll get the solution moving at more than sufficient speeds to keep even the most pesky bubbles off your parts, and I'm using the smallest one Richards makes ($7).

Sage

[destroyer125]

I may look into this....I have a fan motor sitting here collecting dust with variable speeds...maybe a decent sized propeller or something with a manafold to hold the motor

[sswee]

Moving the parts will do good for removing nitrogen bubbles from the parts. On the other hand, the other reason for aeration / agitation is to circulate the electrolyte to evenly dissipate the heat throughout the tank and keep a thermal pocket from forming around the parts. Anything to move the electrolyte around with out contaminating the tank.
SS

[bigbear]

yes I saw Sage's idea quite some time ago. I signed up along time ago but I never really had a chance to contribute to the forum. My set-up is still far form being finished.

Yes I do believe that there using the bumping to help remove the bubbles from the plating process. The other idea which may help would be to supt weld the wire to the part to help prevent the loss of the connection. That combined with the pinch bar may be enough to keep a strong connection.

I can definitly see the down side of this ideaas well. I mainly wanted to see if it would be plausable. I'm going to be in a confined spaced so I want to try and keep any air-born acid to a minimum without having to build a bulky enclosure/vent.

I was also thinking along the line of a surplus wiper motor to slowly agitate the parts and if the cam mechanism didn't move the parts enough to create enough agitation to remove the nitrogen bubbles (and prevent hot spots) then I would make the cam mechanism a larger diameter. The idea is to move the parts 2-3 inches in the solution which I think should agitate it enough to prevent nitrogen or hot spots. I wouldn't think this would work for a larger tank but smaller batches (1-3 items in a tank) should be enough. I want to supplement my larger color batches with custom color choices so this idea would only be for 1-3 items at a time.

Keep the ldeas coming.

Thanks
Adam