Drilling holes on cnc

**dfox1787** · 23-05-2018

Originally Posted by Wal

>I know my spindle has certain collet sizes so standard bits are unlikely to fit.

Why not - you're using an ER system, aren't you?

Anyway, as m_c said, there are plenty of options out there - a cursory search brought this up:

https://www.cadem.com/single-post/cn...l-helix-angles

Not a bad place to start. As per Chaz's advice - yep, it can be a bit hit and miss with the 2.2kw Chinese spindles - you don't want to go too fast and burn up the drill, but you really don't want to drop much lower than 9krpm as you risk stalling the spindle...

One thing I would say: make sure you spot drill first..! If you're using standard drill lengths then you can expect a bit of a squeal on the first peck, but that should disappear once the drill gets a bit deeper... Here's a vid of my machine drilling out a section so that I wouldn't have to deep slot (fast forward to about a minute in). I'm sure I could've gone a bit quicker, but you know - when you find something that works you tend to keep it that way..!

https://www.youtube.com/edit?o=U&video_id=uwDesJPd6a0

Good luck.

Wal.

Hi Thank you for this.

Ill take a look into those bits. My spindle is the ER system. The min rpm i can get is 10000.

The link you sent me takes me to the video edit part on my youtube. Id love to see the video though

**Wal** · 23-05-2018

Originally Posted by dfox1787

The link you sent me takes me to the video edit part on my youtube. Id love to see the video though

Ah - I copied link from my creator page - here you go (not that interesting, to be honest..!):

https://youtu.be/uwDesJPd6a0

All the best.

Wal.

**wiremonkey** · 24-05-2018

Wal, what are you using for coolant and how are you catching it? Would be cool to see a wide shot and overall setup view of your CNC.

**Wal** · 24-05-2018

Originally Posted by wiremonkey

Wal, what are you using for coolant and how are you catching it? Would be cool to see a wide shot and overall setup view of your CNC.

Here's a link to a handful of pics on an old thread. Added a couple of extras since, but the machine itself remains the same...

http://www.mycncuk.com/showthread.php?p=55068

Sent from my HTC One M9 using Tapatalk

**Wal** · 24-05-2018

Oh - and coolant wise: WD40

I do my best to avoid it like the plague nowadays. Useful, but once it atomises and hangs in the air it's nasty stuff. Instead I try to plan better, use decent materials that cut well and as much air as I can get on the part...

Wal.

Sent from my HTC One M9 using Tapatalk

**A_Camera** · 24-05-2018

dfox1787,

Perhaps I missed something, but I don't see any reference to the material you want to drill. That is very important in my opinion. The fact that you have ER collet is not a problem, you just need to buy a set of collets since those are not like a drill chuck, you need a number of those. I have ER11 so I can't drill anything larger than 7mm with drill bits, which is OK for my needs, but of course, even I must have a large number of collets. I am drilling holes from 0.3mm up to 6mm with different drill bits, depending on the material I need to drill in, which can be PCB, aluminium or plastic. Of course, wood and similar is also OK. I also don't know why you feel you are limited to 10k rpm. The recommended lowest rpm for high speed 24k rpm spindles is 6k rpm but I have absolutely no problems to go below that as well.

Drilling starts at 2,5 minute mark.

In that clip I am drilling with different, standard (I think Cobalt) spiral drill bits, from 1.5mm to 5mm and in that video the lowest rpm is 5800rpm, but in aluminium I went as low as 3800 rpm also and that caused no issues at all. What is important is to use sharp and good quality bits. I use no liquid cooling at all and have no issues with welding, but if I have to drill many holes I let the bit to cool now and then.

**dfox1787** · 24-05-2018

Originally Posted by A_Camera

dfox1787,

Perhaps I missed something, but I don't see any reference to the material you want to drill. That is very important in my opinion. The fact that you have ER collet is not a problem, you just need to buy a set of collets since those are not like a drill chuck, you need a number of those. I have ER11 so I can't drill anything larger than 7mm with drill bits, which is OK for my needs, but of course, even I must have a large number of collets. I am drilling holes from 0.3mm up to 6mm with different drill bits, depending on the material I need to drill in, which can be PCB, aluminium or plastic. Of course, wood and similar is also OK. I also don't know why you feel you are limited to 10k rpm. The recommended lowest rpm for high speed 24k rpm spindles is 6k rpm but I have absolutely no problems to go below that as well.

Drilling starts at 2,5 minute mark.

In that clip I am drilling with different, standard (I think Cobalt) spiral drill bits, from 1.5mm to 5mm and in that video the lowest rpm is 5800rpm, but in aluminium I went as low as 3800 rpm also and that caused no issues at all. What is important is to use sharp and good quality bits. I use no liquid cooling at all and have no issues with welding, but if I have to drill many holes I let the bit to cool now and then.

Drill aluminium mainly. However i would need collets that would fit say 2.5mm drill bits so the hole can be tapped. Myabe i just need some high quality bits for the cnc. Its just the high speed of the spindle that concerns me.

**A_Camera** · 24-05-2018

I have a set of collets and 2.5mm is one of them. Drilling in aluminium it is important to spot drill first. I normally use a 6mm 90 degree spot drill for that purpose, and after spot drilling (not resetting the machine so that I keep the zero positions) I just change to the right bits and start the drilling. Just make sure the spindle can't start spinning when you are changing bits so that you are safe.

**magicniner** · 24-05-2018

Originally Posted by dfox1787

Drill aluminium mainly. However i would need collets that would fit say 2.5mm drill bits so the hole can be tapped. Myabe i just need some high quality bits for the cnc. Its just the high speed of the spindle that concerns me.

You don't need to Drill to get accurately sized and positioned holes, you can mill with an interpolated spiral tool path, a 2mm endmill will suffice for a 2.5mm hole, with air and lube it may be the ideal solution with a spindle with only high speed capability.

**dfox1787** · 24-05-2018

Originally Posted by magicniner

You don't need to Drill to get accurately sized and positioned holes, you can mill with an interpolated spiral tool path, a 2mm endmill will suffice for a 2.5mm hole, with air and lube it may be the ideal solution with a spindle with only high speed capability.

nice ill give that a go on some scrap aluminium.