I got my tumbler the other day and started doing some tests. I wasn't keen on buying some of the tumbling media as it can get a bit pricey. A friend who's Mum lives in France has vast quantities of walnuts, so it looks like I will be getting a sack of shells to play with at some point...
Hmmmm, crusher is going to be on the ever increasing list of projects. I went to the local pet shop and picked up two bags of Aquarium gravel, not really knowing how much I would need, one bag would have done twice over. Hey only wimps read the manual first !!! I did surprisingly read the packet for the gravel and washed the first 2kg as instructed. Then couldn't wait for it to dry, thinking it will self lubricate wet. Tumbling was not a success with twice the amount of wet media it rolled about in clumps. Open the second bag, dry the drum and try that... Much better and started thinking about different grades of media and getting some spares bowls so I didn't contaminate the media. That was when I found out you add upto 2lbs (about 1kg) of dry media. Soooooooo, weighing out the correct amount I went on my way with a few more tests. Finally doing some serious work with snap rings I make here. These are stainless steel, heat treated and sized in a die. Previously they have gone into the ultrasonic tank for cleaning, but this time into the tumbler. It did a similar job on removing the scale, however the ring ends had the sharp edges knocked off from shearing the wire, and they work hardened a little better after 2hrs in the tumbler. This isn't conclusive proof your old fish tank gravel will work wonders, but it was cheap per kg. I did try tumbling some plastic parts, and they didn't float about as I thought they might, but the fine gravel didn't really have much mass to rub down the PLA. I think heavier media and possibly sharper media would work better.
With more experience I am sure this will become a valuable tool for the workshop and provide surface finishes, deburr of small metal components I make here. This model of tumbler runs about 60w, so a few hours tumbling won't really impact my parts electric cost. Tumbling isn't fast, but it's a lot less hassle than deburring by hand and you can be getting on with other work. My only caution would be using gravel, lay some paper towel over the tumbler to stop gravel dust getting into the shop/lungs. I sift the gravel after use and discard the material that falls through the sieve as it does get broken up during use. Plug any holes or gaps you don't want jamming with media in items for tumbling.
