I have 2 drill holes (3/32") into the side of 6061-T6 tube, and don't have easy access to deburr them. I've been sort of "carving" a chamfer with a small utility knife to remove the burr, but I will have to do this on 500-1000 pieces, so I need something more productive. Any recommendations on drill bits that can will create a burr-free hole? Or any other recommendations on limited-access deburring tools?

Thanks,
-Neil.

Are you doing this on a drill press or a mill. Sometimes to minimize the burr it is best to use an endmill to drill the hole but this is not possible on a drill press.

An alternate approach which can minimize the burr is to have a mandrel that the aluminum tube slides over. There has to be a hole in the mandrel, of course, for the drill to enter when it passes through the wall of the tube. The burr gets pushed down into this hole and mostly gets pinched off by the drill as a it goes through the tube and into the mandrel; then when the tube is pulled off the mandrel most of the remaining burr is sliced off.

On a drill press, and a cheapo one at that. Works great for this application, but I agree that it's not the correct thing for an endmill. If an endmill does solve the problem though, I'd be happy to move the operation to the mill.

The problem with the mandrel is that the ID will have a significant tolerance, but you've given me an idea that I can make a "part mandrel" that will act like a "shelf" onto which the ID of the tube with rest, and that will serve as the backing for the drill bit. I can run a test of this pretty simply to see if the theory proves correct. I'll be back...

Thanks,
-Neil.

try using a brad point drill

Perhaps a Cogsdill type "spring loaded flag"deburring tool would work.

Google found me Cogsdill, and I'm very impressed with the tool. They're a pain to get in touch with (they don't return messages it seems), but I managed to get pricing -- the 3/32" tool costs US$49.35 ea. and spare blades cost $9 ea. But I still haven't heard back from any tech so I can find out how far the blade protrudes (for clearance reasons), and what sort of life I can expect from it.

LeftCoastCNC, have you actually used one of these? And if so, does it really work as advertised?

Cheers,
-Neil.

I used the "Burraway" model years ago on one project and can't for the life of me, remember what it was. I do remember the tool working well.

The blade is HSS (they might offer carbide?). In 6061 I would think the HSS would last your entire batch.

As far as the cutter protruding, it seems it could be ground to reduce the protrusion. Care would need to be taken as this is the portion of the blades that drags in the hole as it passes through. If the hole is critical the ground surface might need to be polished.

One more side note that came to mind... there is Cogsdill Tool and Cogsdill Enterprises. They both make similar products. The tool I used was Cogsdill Tool. One might have better service than the other...

... Unless the your tubes are too long, there is alway vibe deburring too...

Hope this helps,
Kris

might check J&L I think they carry one thats called Debur Master. same thing dif name.

I did find a separate company called Cogsdill Enterprises in MI. They claimed to be the original, and that Cogsdill tool copied theirs after the patent expired. Much more helpful, and they recommended a slightly different tool with fixed lobes, rather than a retractable blade. All dimensions work well for my app, and I should expect 3k-5k holes from one of these. HSS = $50 or TiAlN coated = $56. So I ordered a TiAlN unit, and I'll report back here after I try it.

Cheers,
-Neil.

I have used the "burraway" also. Works well using it in the spindle after the drill, or it can be used as a manual deburring tool. Just watch the small diameter ones as they are easily damaged.

Okay, so the tool came in. Specifically, I got this type (3/32" dia)... http://www.cogsdillenterprises.com/BurrZit.html.

I've tried it on about 20 holes so far, and I must say it works beautifully! ... with a couple caveats though...

First, I noticed that the purple-black coating (TiAlN) came off after just 3 holes (it became silver colored again, and looks like the coating came off, rather than just having some aluminum stuck on it etc.) I need to ask them if this is normal, as I've never used any type of TiAlN tool bit before.

Second, if the inner face of the drilled hole is not completely perpendicular to the hole, it will leave a burr on one size of the hole. However, retracting the bit a little slower takes care of that (by lengthening the chamfer).

Overall I am *very* happy with this tool, and somewhat ticked off at myself for not knowing about this before! :) Thanks for this info guys!

Cheers,
-Neil.

Glad to hear it has worked well for you. That is strange with the coating coming off, maybe they had a bad batch of coatings...

I am sure you tried adjusting the inner pin to get more "bite" rather than having to spend more time in the hole...?

The smaller sizes (like my 3/32" dia) don't have the adjustment device. I'll find out about the coating this week and post back.

I am very surprised that the coating came off. We use TiAIN coated drills in steels and stainless steels without this occurring. I have a strong hunch that is the aluminum coating the drill.

Can't be sure, but I think it was TiAIN that a drill manufacturer told me needed to get hot. This caused the finish to get harder. Could have been BS. Not that knowledgeable on the subject.

I did speak with them about it, and they assured me (without seeing any photos of it) that it's not the coating coming off, but just a build-up on the edge. Although the silver section looks to me like the coating is coming off, I will take their word for it for now, since this is the first time I've used a TiAlN tool. And also because it works beautifully and I don't want to part with it right now.

Cheers,
-Neil.