Drilling a .12 hole 4.15 deep in 15-5 RC42

[JakeL]

I'm guessing (almost certain) that the holes in the video are piloted. 

This makes way more sense. Don't know why I didn't think about that.

My little brain said "they didn't show the pilot drill so they must not have pilot drilled" 

[neurosis]

My little brain said "they didn't show the pilot drill so they must not have pilot drilled"

In my opinion, the video is a little misleading without showing the prep/pilot operation.

They probably think we're smart enough to know that the holes need piloted?  

I totally blame that on them. 

[CNCAppsJames]

My typical process for these deep holes is as follows;

• Mill/Drill pilot hole between 1.5xD and 2xD
• Call long drill/gun drill to spindle
• Start spindle in M04 @ 50ROM
• Position to hole
• Feed into hole to 1xD
• Stop spindle
• Turn on CTS
• Turn on spindle M03 @50RPM
• Ramp up spindle to drilling RPM
• Once at speed, begin feeding to depth
• Turn off spindle
• Turn off CTS
• Turn on spindle  @ 50RPM in M04
• Retract from hole

[JParis]

My typical process for these deep holes is as follows;

• Mill/Drill pilot hole between 1.5xD and 2xD
• Call long drill/gun drill to spindle
• Start spindle in M04 @ 50ROM
• Position to hole
• Feed into hole to 1xD
• Stop spindle
• Turn on CTS
• Turn on spindle M03 @50RPM
• Ramp up spindle to drilling RPM
• Once at speed, begin feeding to depth
• Turn off spindle
• Turn off CTS
• Turn on spindle  @ 50RPM in M04
• Retract from hole

That's the exact process I have coded in my post for gundrilling ops

[Flycut]

Not sure I like the M04 but yes to the rest.

[JakeL]

Not sure I like the M04 but yes to the rest.

I was wondering the same thing.

Why M04 instead of M03?

[JParis]

I was wondering the same thing.

Why M04 instead of M03?

You don't want to front cutting lip of the gun drill to catch the edge of the hole while feeding in....

To prep a gundrilled hole, you mill the very top portion of it to size or just a few tenth's over...spinning in M04 protects the part, the machine and the drill

[CNCAppsJames]

Not sure I like the M04 but yes to the rest.

The purpose of the M04 is so the drill doesn't catch if there is any runout. If I went M03, it could catch and SNAP off. Ans if you're running a gundrill, it WILL catch.

[__]

Tell your boss he needs to be sharing that crack pipe

Sometimes I forget your from Cali

[champshire]

We run Nachi, Guhring and OSG for our long (25xD) drills. We drill oil holes in cranks from the pins out the mains. I start the hole with an endmill, then use a stubby drill then drill to china with the long drill.

One little added bit of advice to add what John and James shared, I slow ours down to 70% speed and feed on the exit of the hole as well. I think I have it slowing at something like .200 before the exit.

Also slow the rpm and retract rate out of the hole to keep any chips from binding up on retract. I'm not sure the slow exit thing needs to happen, but that's how I set it up back in 2016 and I have never changed it.

For the record, this is a MQL setup, not a Thru coolant.

[neurosis]

Ok, revisiting this.

We have these coming up in a few weeks.  Recommended tool holders?

We're going to get some new holders for this job.  Most of our ER holders are 10 years old.

[CNCAppsJames]

Without through spindle coolant, find a new place to work because you're gonna lose your ass.

[CNCAppsJames]

Get a quality ER holder. You want the holder to have near no influence on it. 

[neurosis]

Without through spindle coolant, find a new place to work because you're gonna lose your ass.

we have through spindle coolant. 

[kccadcam]

Nikken SK series holders are awesome.
Nikken SK Collet Holders