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Deburring steeply sloped cross holes

Finegrain

Diamond
Joined
Sep 6, 2007
Location
Seattle, Washington
I need to deburr/chamfer a 6mm bore, ~40mm deep, intersecting 2x .386" cross holes. I looked at EZBurr, BurrAway, and Heule COFA. The Heule COFA seems well-suited to steeply sloping surfaces, while the EZBurr and BurrAway are more for flat or slightly sloping surfaces.

Material is mild steel, quantity is high enough to justify the best-suited tool.

Any first-hand experiences that you can share?

Thanks, and regards.

Mike
 
Maybe not as sturdy as what you mention, but I've been using these for all my off axis weird angle stuff. They've also been helping me bone up on my arcs in XZ and YZ plains programming.

Couple of Harvey numbers to look up that might work. Fragile for sure and takes some dead on programming, especially in the situation described, but they will chamfer and debur. I will admit that these two length to diameter ratios are a bit more then I've tried.

270 degree undercutting carbide balls.

3/16 ball 0.117 neck 1 3/4" neck length - 929612


Not sure you could sneak this down the hole or not. 6mm ball 0.148 neck 2.0" neck length - 96066M
 
Maybe not as sturdy as what you mention, but I've been using these for all my off axis weird angle stuff. They've also been helping me bone up on my arcs in XZ and YZ plains programming.

Couple of Harvey numbers to look up that might work. Fragile for sure and takes some dead on programming, especially in the situation described, but they will chamfer and debur. I will admit that these two length to diameter ratios are a bit more then I've tried.

270 degree undercutting carbide balls.

3/16 ball 0.117 neck 1 3/4" neck length - 929612


Not sure you could sneak this down the hole or not. 6mm ball 0.148 neck 2.0" neck length - 96066M

Yes, that's a long reach with a .117" neck. Might work though. Doesn't need to be pretty, just absolutely positively no burrs allowed

I can do it with a lollipop going down the .386" holes, but that would add an op. That's my backup if I can't get it done in the same op as drilling the 6mm hole.

Regards.

Mike
 
I don't think an abrasive will remove the sort of burrs a drill breakthrough makes in steel.

How big are the burrs? We use flex-hones in larger sizes to knock down the exit burr when mag drilling into large HSS tubes. It won't necessarily put a nice chamfer on the backside like a cogsdill will, but it's quick and easy and knocks down the burr to where we won't have coating issues and no one will slice their fingers open.

If I understand you correctly, the burrs won't be sticking out into the 6mm hole, but rather were created in the larger holes when you drilled the 6mm hole. This makes it harder to solve the problem with abrasive, but it may still be feasible. If it's feasible, it's a dead easy process. If you send a part to Brush Research, they'll figure out the flex-hone or brush to use.

P.S. I have no affiliation with Brush Research, just a happy customer.
 
I'd go with the Huele. Expensive but they are fast and work well if you follow their programming instructions. We had some manifolds (think of the air manifolds you can buy from McMaster but with J1926/J514 type ports) where we had some nasty burrs where the side ports met the main through hole, and the Huele took care of them fast, with no visible marking on the threads they were going through.

Pucker factor is high with the way they have you program rapid moves to compress the cutter...
 
Update ...

It turns out that the actual required reach is only~7/8", as there is a ~.350" entry to the first cross bore. So, I can use a 3/16" x 1" reach lollipop, which is a lot less snaky than the 1-3/4" reach would have been:

Lollipop.jpg

Regards.

Mike
 
I've tried the J.W. Done Orbitool for hole deburring, but it didn't meet the marketing hype they put up. It took some fixing to get the macro they provide to work and once I got it going it didn't do that great of a job removing the burr even rerunning it. The other problem was that with the family of parts I was hoping to use this on it needed a custom extra length tool which snapped off after a few parts.

I've been wanting to try the Heule COFA-X, but with them only making that tool custom it'll be a hard sell to my boss to just test it out to see if it'll work for our needs in the first place.

The only other thing that could work for the part would be an even more expensive electro-chemical system. Thermal deburring could work too, but with some of the monkeys working around here part of the shop is likely to get blown away.
 








 
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