Swarf, we have two of the Mr. DeBurr machines...a couple years ago we needed to get enough aluminum parts through plastic and then through the porcelain in order to keep up, so two machines made sense, then we went to a round tub with steel media after the plastic for an almost chrome finish..much better than the porcelain. The porcelain media we have (angle cut cylinders, 3/16" dia x 3/8" long) will "brighten" up the parts after the plastic media, but certainly not "shiny", but they are smoothed out quite well - they should annodize quite well. It looks as if you have it under control pretty well...we found larger media is faster cutting and the more large, galvanized spangle look you get, small cones work quite well for an even, matte finish, but don't cut as quickly or round off corners as well. We have been using the Vibra-Finish VF-77 (Purple) that C&M sells for most eveything, we just add in some of the corrosion inhibitor on steel parts.
Funny thing, we no longer tumble the parts we originally bought the units for...they come off the machine and may need a quick knife on a cross hole, but we've covered that pretty well with a ball hone, and then they go to black annodize. We also used to engrave them in the machine...a half hour for 8 parts just in the engraving (dropped our cycle time to 1.5 hours from 2hours) but are now laser engraving them. The laser isn't too fast, although better than the machining center, but it's kind of like another spindle in a way. What's bad is we end up handling the parts too much...pack to go to annodize, unpack, laser engrave, install a fitting, bag and box.
For whatever reason - they quit sending me the purple stuff, and now I have the clear "VF 100".
We have found that the VF does a better job of no rust than the purple, and if we keep the concentration as bubbly as we can - without it getting out of control, the rust inhibitors in the soap last plenty long to git it through the tub and then into the worsh w/o much rust issue.
Have already left overnight by accident and not been the end of the world. (not as we know it)
I am Ox and I approve this h'yah post!
Am am after the matte finish, these parts get hard anodized anyway and my anodizer says that a shiny look will not make it through the anodizing process. I don't know that I will go through the trouble of a second pass through the machine with cones or balls or whatever - have to see how some turn out. This is very low volume production, so I could swipe them with Scotchbrite at the end and get the slightly grained look that I got by hand. It was a lot of work removing the tooling marks that way, but real quick to remove the galvanized "spangle".
C&M sent me the VF 77 for aluminum, and I think VF 100 for the stainless steel. Rust isn't an issue with the 316, not sure what the differences might be other than rust inhibitors.
That's the difference between a tub tumbler (like Mr Deburr) and a bowl type tumbler. The parts separation is just flat out better in a bowl type. But, ya pay for it.
Originally Posted by Lambert
One way to get a finer matte finish is to turn off/turn down the detergent/water for 1/2 an hour or so at the end of the cycle. Another is to use smaller media. For a no "galvanised" look at all, beadblast after tumbling. But it seems no matter what finish goes to the anodizer, it all disappears in a long etching cycle. An anodizer that gives you exactly what you want is hard to find. If you do, be nice to him. My favorite, unfortunately, went back to doing inhouse work only (the boat fittings business picked up again). Rats!
Yeah - a bowl type big enough to take these parts off of Ebay is $4K - 8K, and looking very, very well used. Takes more floor space as well, it appears.
We have one vote for filling the tub with water/detergent for the last few minutes and another for turning it off completely? Guess I will have to try each way...
We have a bunch of anodizers within 100 miles - but I had to call 8 or 10 of them before I found the one I use. Several did not even know what a proper hard anodize was, the rest (but one) could not tell me how much the part would grow in the process. I have some close fits (about 0.001 clearance on studs/bores spread across 8 inches) and this becomes a problem. On one part I was aiming for +0.0000/-0.0001 finished dimension and he was able to do it.
Hard anodize as in TRUE hard with 32 degree acid temp and the higher amps/sq ft? Is that what you were trying to get them to stay? A lot of anodizers use an additive so their acid tank can anodize at 50-60 degrees type-III
Originally Posted by swarf_rat
OK, that give me some questions to ask the anodizer! I don't know what temperature or current density, but the resulting oxide is .002" thick (part is .001" larger in very dimension), and are nickel acetate sealed against porosity. This is mainly for salt water corrosion protection.
Originally Posted by MBG
I recently bought there large round bowl tumbler with the circulating system and it works great for me. The parts I am doing come out like the ones in your pictures and I send them to be anodized. My parts range from 5.1" x 2.25" x 1" and some 1" aluminum shafts up to 12" long all parts are 6061 t-6. They send me the cone shaped media. the bowl holds 50#. I can run 10 parts at a time in it which is how many I machine at a time on the fixture so it works perfect by the time one batch of parts is machined the last batch are done in the tumbler. This is the one I got. Rhodes Deburring Media Equipment Used Machine Pre Owned Machines Vibratory Tumblers Tumbler
It is the one with the stand just like the bottom picture. I bought a garden hand claw made out of plastic rather than metal it makes digging through the media fast for locating the parts much faster than draining the media to find the parts it is hard on your hands digging through by hand.