Cleaning swarf off of drill bits

[PhoenixMetal]

Hi,

I'm making of parts on a Vertical Machining Center that involve drilling and tapping a bunch of holes in steel.

The drill bit is getting a lot of swarf (long curls of metal) wrapped around it such that the swarf isn't coming off the tool on its own. Is it important that I clean this tool off between parts, or is it a situation that kind of takes care of itself?

I'm new to this, so but I want to hear how you deal with this so that I don't either waste a bunch of time cleaning the tool, or find out the hard way that bad things happen when I don't clean it off...

What are your thoughts? To clear the swarf or not to clear the swarf?

Thanks!

[LeeWay]

Some of my bits will do this as well. I find if I just peck drill, the shavings break off shorter and much more likely to self eject.
It is kinda dangerous if manual drilling. The long curls can swing out and slice the crap outta you. BTDT
It is never a good idea to use gloves around a drill press either unless it ain't running. DAMHIKT.
I don't reckon it would matter though doing this on cnc. I do generally peck drill with it too. It takes a little longer, but seems easier on tools and machinery.

[dertsap]

if your spindled runs around 10000 rpm then after drilling run the spindle at the high rpm for a second in reverse, most times it will fly off easily ,

do not do this with the door open or your face will be the next thing you'll be trying to remove swarf from

[Geof]

An idea I had one time but never tried was to clamp a small section of wirebrush somewhere clear of the work piece. Then before changing away from that tool put the spindle in reverse and stroke the drill up past the wirebrush.

[vlmarshall]

Originally Posted by dertsap ...after drilling run the spindle at the high rpm for a second in reverse, most times it will fly off easily...

When I'm having trouble getting a drill to break chips, and the resulting "chipicopter" is leaving a wire-brushed finish around the drilled holes on my parts, I'll add an M04 to the end of that tool's cycle, right after the G80. To allow the spindle time to get up to speed, but not add much cycle time, I'll g28 the Z to get it up to tool change height without actually commanding a tool change yet. That lets the chip spin off on the way up, (usually) and I'll call a tool change as normal in the next block.

[sti2011]

You did not mention what alloy steel you are cutting but, in most common steels chips break readily. If you are drilling in a CNC as you said use G73 cycle, if you are less than 4X the dia of drill deep and if more use G83 (both with a Q value (peck dist)) in steel I would use (drill dia./3) for your Q value.
Most likely of all though is you are not feeding fast enough. As a general start point for drill feed with standard twist drills use....dia of drill / 62.5 x rpm = ipm
Also be sure to check your SFM as this also has to do with chips breaking well. If your rpm is too low then there is not enough velocity to the chip to break it or get it out of the hole....
General guidlines not Mat. specific.....Hope this helps

[PhoenixMetal]

Thanks guys - the wire brush and reversing ideas are interesting. Sti2011, thanks for the advice on feed speed. You very well may be right about my RPM being too low. I am using GibbsCam and have been allowing the software to suggest speeds and feedrates based on my tool and workpiece materials, however I have found (with the endmills at least) that its numbers are way way slower (sometimes half) than what are recommended by the tooling manufacturers. I'll check what rpm and feedrates it was using for the drilling, and I wound't be surprised if an adjustment makes a big difference in the swarf coming off.

The material I am cutting is 1080 steel. I have been peck drilling (with the drill coming fully out with each peck), but was using drill diameter as my peck distance... I'll try diameter / 3 next time and see if that helps as well. Previously, I had tried peck drilling (with the bit not coming fully out), and I found it left a bunch of long stringy swarf sticking out of the hole, which caused me to break a tap in the next operation. The full-out setting solved that problem, and now I'll try your suggestions to try and completely get rid of my swarf problem.

Thanks guys!

[sti2011]

"The absolute best way to get rid of chip nests is not to make them in the first place"
I too have found most CAM sytems to be not extremely efficient as to speeds ands feeds. Unless you actually go into them and edit the individual parameters for each material. It takes a few more minutes to program each tools speed and feed "manually" but in the end, when you have optimized each tool to the specific application, the cycle time and tool wear savings more than make up the "extra" couple of mins. in programming.
Try to leave your peck at full dia with optimized feed and speeds. If you still have probs just keep decreasing peck value until the chips get short enough to "fly" off.

[PhoenixMetal]

Originally Posted by sti2011 "The absolute best way to get rid of chip nests is not to make them in the first place".

Wise words my friend, wise words.