How to drill faster in brass

[ptjw7uk]

You should also check the drills geometry as a normal drill used on brass can break as it will pull into the hole, possibly not that relevant on a cnc machine as the drill will be restrained by the z axis.
Normally if you drill a lot of brass you can remove the cutting edge with a 'stone'.

Peter

[Boyan Silyavski]

I had a talk with the HSMadvisor maker, so it seems i had that functionality but did not know how to find it.

So according to the calculator it seems drill / HSS/ or mill/carbide/ is almost the same feed rate. But if drill is cobalt or carbide then 1.5x faster. 1000mm/min and 1500mm /min respectively.

I use the general option " Other non ferrous alloys" in stead of "low lead brass " or similar as the latest give me too slow feed , slower than aluminum. So it seems my brass is different, as i know for a fact that it machines and drills much faster than aluminum.

Will experiment tomorrow to see how fast it could go in real life and report back.

[magicniner]

Boyan,
I'd definitely use a drill bit, not a milling cutter,
Regards,
Nick

[sinnsvak]

And pecking could be reduced to short-stops to just break the chips.

[Boyan Silyavski]

Boyan,
I'd definitely use a drill bit, not a milling cutter,
Regards,
Nick

I will buy, but unfortunately have to order from the net and wait for them, as i live in a very small tourist town . So from calcs it seems carbide drills would be best. Even faster with parabolic ones, whatever that is.

And pecking could be reduced to short-stops to just break the chips.

I was thinking something similar. Though at the end decided to use no peching following the HSMAdvisor prescription, see snip above where says " pecking not necessary.



So instead of wasting more time thinking, today i tested the HSMAdvisor suggestions. 18000rpm, 3mm 2 flute carbide end mill, ~40IPM or 1000mm/min. I started reducing to 30% the feed to see what happens, then raised slowly to 70 , then 100%.




Hat down to the HSMAdviser. Drilled like cheese. At the suggested speeds and feeds all noise disappeared. You could see from video how smoothly all went. I think for DIY machine to drill 15 holes 9 mm deep in metal for <20 seconds all, is a quite an achievement. At least in my world.


I would use the chance to recommend again HSMAdviser. The support is great. I have the 3 year subscription. The guy updates the program constantly and every 2 updates or so resets the trial counter, so it could be used almost on trial. Plus i see now that he decided to let you have full functionality once a subscription expires . With some HP restriction. I am not affiliated in any way, just think that its a great tool worth the money.

[Clive S]

Boyan Very nice. Does the brass bar bend at the ends as you are drilling? On the last hole! as that could snap the bit.

[Boyan Silyavski]

Boyan Very nice. Does the brass bar bend at the ends as you are drilling? On the last hole! as that could snap the bit.

You have really sharp eyes Clive! i see what you meant. In reality - i don't think its a problem. I believe that was some artefact from the video. If you note at the beginning it does not happen, having in mind the distance is the same both sides.

By the way i just realised that HSMAdvisor did recommend peck drilling, i just have missed before to fill how deep my hole is. Fortunately this brass is a very nice material to work with, that's why on first place i abandoned aluminum for the bridge of the instrument i make.