90 degree grooves, 1/4 Deep

desim

Aluminum

Joined

Apr 23, 2013

Location

tennessee USA

• Jun 15, 2015

• #1

This is another simple easy item. I searched and did not find a good answer.
I have a job that involves a lot of grooves on a flat plane. The grooves are 90 degrees x 1/4" deep. The material is 3" thick 4140PHT HRc 27-32.
I ask because while we easily do this I think we should be able to do this much faster than we are. What tooling to you recommend for a VMC to install these? We use syn. coolant and have thru spindle cap.

Thanks in advance guys!

 

Mtndew

Diamond

Joined

Jun 7, 2012

Location

Michigan

• Jun 15, 2015

• #2

Something like this?
LakeShore Carbide.com Carbide End Mills-Carbide Thread Mills - AlTiN COATED DRILL/CHAMFER MILLS

Or do you need a side cutter?

 

G

grbl

Aluminum

Joined

Nov 18, 2014

Location

California, USA

• Jun 15, 2015

• #3

Related question: when using a drill mill like in the link, how do you need to change feeds and speeds? Do you need to change them for each pass as you cut deeper and a larger radius is engaged in the metal? Does it behave like a regular 1/2" end mill when it's engaged at 1/2" width?

Thanks in advance.

 

R

Rstewart

Stainless

Joined

Jun 14, 2006

Location

Huntsville Alabama

• Jun 15, 2015

• #4

Pretty sure the fastest way your gonna get those grooves cut is by placing the part @ a 45Deg angle and use a regular endmill.

Those drill/mills are great for chamfering but the tip WILL break when you run it through 4140.

 

Bobw

Diamond

Joined

Feb 8, 2005

Location

Hatch, NM Chile capital of the WORLD

• Jun 15, 2015

• #5

Rstewart said:

Pretty sure the fastest way your gonna get those grooves cut is by placing the part @ a 45Deg angle and use a regular endmill.

Those drill/mills are great for chamfering but the tip WILL break when you run it through 4140.

Click to expand...

What he said... I can't buy the jaws for my Mazak lathe, some old bastard chuck... Mixture of imperial and metric..
It has 90 degree grooves on 1/16 spacing instead of 60 degrees on 1.5mm...
Anyways.. I have a soft jaw that holds them at a 45 degree angle and I use a regular old endmill... A simple little sub
program, down and over and they are done in no time.

And those mill/drills... They don't drill so good, the tips are fairly fragile. And I certainly wouldn't want to try
any serious milling with the tip, though I have used the tip to engrave occasionally, but only in aluminum, and not very deep.

 

Mtndew

Diamond

Joined

Jun 7, 2012

Location

Michigan

• Jun 15, 2015

• #6

Rstewart said:

Pretty sure the fastest way your gonna get those grooves cut is by placing the part @ a 45Deg angle and use a regular endmill.

Those drill/mills are great for chamfering but the tip WILL break when you run it through 4140.

Click to expand...

Yes that is the fastest way.
BUT
I if you use the chamfer mill in this fashion you CAN break the tip, it's all on how you approach it.
I just did a job where I had a 90deg slot closed ends on both sides so I had no choice. It was in 4340pht and it ran like a dream. I just slowed down the feed a little bit, and had the rpm a little higher than normal.
I also ramped into the cut instead of plunging.
But if you can approach from outside the stock, go full depth, or take about a .01" finish pass for tool deflection depending on your tolerance.

 

Mtndew

Diamond

Joined

Jun 7, 2012

Location

Michigan

• Jun 15, 2015

• #7

Bobw said:

though I have used the tip to engrave occasionally, but only in aluminum, and not very deep.

Click to expand...

For engraving I use these:
Engraving Tools and Cutters, Diamond Engraving Tools
Great price and they last quite a while.

 

R

RJT

Titanium

Joined

Aug 24, 2006

Location

greensboro,northcarolina

• Jun 15, 2015

• #8

If you can stand a small flat in the bottom of the groove (.090 wide) put a flat on the bottom of the V cutter. We did this in 17-4 stainless and it worked fine. Sharpen the .090 flat like an end mill with appropriate clearance.

 

curtis r

Aluminum

Joined

Nov 8, 2007

Location

northeast,ok.

• Jun 15, 2015

• #9

Harvey tool makes two different style drill mills. They call them Mill Style and Drill Style. The drill style has a split point. Just an FYI.

Harvey Tool - Carbide Drill/End Mills - Drill Style 2 Flute

Curtis

 

desim

Aluminum

Joined

Apr 23, 2013

Location

tennessee USA

• Jun 19, 2015

• #10

Thanks guys, yea the drill point mill is what we have been using. They don't hold up well. The 45 degree thing would be good but our grooves run both ways at 90 degrees to each other.
Guess I'm stuck.

 

Mtndew

Diamond

Joined

Jun 7, 2012

Location

Michigan

• Jun 19, 2015

• #11

desim said:

Thanks guys, yea the drill point mill is what we have been using. They don't hold up well.

Click to expand...

If you can dial the speeds and feeds in they should hold up pretty well.
Is it a closed groove or is it open on an edge to where you can approach from outside the part?
You might also try roughing it in as much as you can with something like a small ballnose endmill and finishing with the 45degree chamfer mill.

 

W

wesg

Titanium

Joined

Nov 4, 2004

Location

Cedar Park, TX - Boulder Creek/Redwood City, CA

• Jun 19, 2015

• #12

Fast = right angle head and a 90° double angle milling cutter. But you can buy a carload of pointy endmills for the price of that.

 

Krovvax

Hot Rolled

Joined

Mar 5, 2012

Location

Quebec, Canada

• Jun 19, 2015

• #13

Look at nine9 they make a great 90 spot drill that you can groove with and its a insert cutter might work best for your job anf last longer.