After over a year of shaking and learning, I've developed some ideas for improvement on my vibratory finisher. When the drive pulley on my axle came apart a week ago, I decided now was the time for some upgrades.
I would often use a ratchet strap to restrict the movement of one side of the tube to help get the media to move in a cylindrical tumbling fashion. With this in mind, I got rid of the springs along one side and replaced them with an axle and bearing setup.
I think this setup offers several advantages over the old style in that it gets rid of the guides (and the noise they created) that were used to keep the tub centered over the base, it makes emptying the media from the tub very easy, and it allows for easy access to the drive axle and weights.
On the original design, the drive axle was located just off of center on the bottom of the tub. I moved the drive axle further outboard to increase the effect that the spinning weights will have in creating up and down motion, and to create a bit more space for my drain upgrade. I also shifted the drive pulley over a bit, and relocated the motor, again to make space for the drain. The motor was relocated closer to the tub pivot axles in order to decrease the side loads on the motor created by the tub's up and down movement.
For drains in the original version, I had been using 3 brass fittings that are threaded on one end with barbs on the other with 1/2" ID vinyl tube running to the puke tub. When the media is new, these worked ok. But as the media wears and gets smaller, it would get down into the fittings and plug up the drains. Then you would have to remove the drain lines and unplug the drains with a punch. As you can see in the pics, this makes quite a mess.
To improve this, I switched to a bath tub style drain. This drain has a metal plate with lots of tiny holes that should prevent the line being clogged by media. The larger diameter of the tubing also helps keep things moving along nicely.
My original barrel had started wearing away at the contact points and I wanted to change the drains. Instead of patching the old one, I splurged and spent $15 on a new barrel. A lot of the noise on the old design came from various parts of the rack smacking into the barrel. To help this area, I cut several strips of 3/8" plywood to act as shims between the rack and the barrel. The strips were slid into place, with a bead of liquid nails securing each strip to the next. The barrel is bolted to the rack using stainless steel hardware. I lucked out and found some oak trim pieces that were just the right shape to act as spacers between the rack and barrel at the bolting areas.
Here she is sitting in the sound resistant box ready for action.
The above changes all have helped increase the effeciency of the machine, as well as reduce the noise output by half. The cycle time is 20-30 minutes, depending on the shape of the objects. This load had 8 pieces and ran for 30 minutes. The number of parts varies depending on the shape of the parts. Some of my larger guards can only be run 4 at a time. I make a lot of 5" long x 7/16" rods and run them through hundreds at a time.
I'm in the process of trying different size pulleys on the motor to vary the speed of the axle. I've done one change so far, and it tells me faster is better.
I need to take some shots of my stuff before and after finishing, and after they come back from anodizing so you'll have an idea of the finish quality I'm getting.