I manufacture a growing line of dirt bike protection products....radiator guards, skid plates, etc. using a CNC router as my main workhorse.
My volume has gotten to the point where I spend half my waking hours deburring stuff. As we all know, deburring sucks. Here's what I'm doing about it.
Web research led me to vibratory tub finishers, like the BurrKing, etc. These machines have a big tub which holds a finishing media and the parts to be finished. There is a mechanism attached to the tub which shakes the hell out of the tub and all within it. These machines usualy have a sprayer and recirculation system to wash the media as it runs as well.
A machine with a tub in the 6-7 cubic foot range seems to be selling for around $5000 new.
So what I needed was a tub, a base and something to shake the hell out of it.
I made the base out of 2"x3" mild steel tubing. Just a simple box, aprox 3'L x 2'W x 15" tall. It's got a couple cross members to provide a mounting location for the motor.
For the tub, I got a plastic 55 gal barrel laid over on it's side. I cut it open so that the barrel is like a big blue trough.
To support the tub, I made a cradle out of 2"x2" angle, 1.5" box and a bit of 1.5" flat mild steel. The cradle has 4 ribs that hug the barrel. The ribs are attached to a rectangular frame that has the same outter dimesions as the base. It all sort of looks like a nuclear beer keg.
The cradle/tub assembly sits on top of the base, supported by 8 springs. I'm using 4 pieces of angle iron bolted to the outter corners of the base to act as guides to prevent the cradle/tub assembly from bouncing off of the springs.
To shake the hell out of it, I am using a 1" steel axle supported by 4 pillow block bearing bolted to the bottom of the cradle. The axle has 2 aluminum weights at either end, and a drive pulley in the middle. It's all driven by a 220v (221, whatever it takes) motor sourced off of an old air compressor.
I'm using plastic media, v-cylindrical shaped that I got from McMaster Carr. Right now, I'm just using water. I may throw in some mild soap just to see what it does.
I need to sink some anchors and bolt this thing to the floor. With 150 lbs of sand bags on the base, sitting on a rubber mat and a carpet, it walks 3' in 30 minutes. I would imagine the finishing time should decrease if it was bolted down as well.
It's pretty loud to operate at this point. I think the bolting to the floor will help this a bit. Improving the guide system should help too. I need to get a better material for the guide surfaces. I'm using some thin plywood glued to the inside of a piece of angle. The plywood rubs against the cradle's frame to keep it centered over the springs. I think I am going to try some Delrin strips in place of the plywood, and bolt them in place instead of glue. I think I can close up the gap between the cradle and the slider surface as well. Less friction and less distance for the cradle to travel before it hits a slider should cut down on some of the racket. I'm giving some serious consideration to building an enclosure to put around this thing to try to control the noise as well.
There are a couple different variables to play with. I can change the frequency of the shake by changing out pulleys on the motor or the axle. I can change the size of the shake by adding or removing weight from the axle. I could also change the springs to provide more or less action. I could also probably affect the movement pattern inside the tub by playing around with different rate springs in different locations on the base.
In addition, there are lots of different media and washes to try. I will most likely be sticking to the media from McMaster Carr for the time being. 50lbs of media is around $135 shipped. My tub could hold 400 lbs if I filled it all the way up. Kind of an expensive variable to be playing with.
With 50 lbs of media and 2 gallons of water in the tub, the crappiest aluminum part I had in the scrap bin took about 45 minutes to get all the burrs knocked off and finished to a reasonably even finish. The media flows around inside the tub, carrying the part around with it. The water gets agitated enough that I don't think I need a circulation pump, not until I run a bigger load of media anyway.
Pics will follow soon.