Gunco Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
247 Posts
Discussion Starter · #1 ·
Hey all, still really enjoying the Mini Mill, but the more I use it, the more questions rattle around.
On the subject of End Mills, the only ones I have at the moment are HSS Center Cutting.
What is the correct method of getting optimum performance from this type of End Mill.

Is it better to drill a hole (using a drill bit), then use a non- center cutting End Mill, to just cut side ways.

Reason I ask, is that the center cutting end mills don't seem to drill so great (without complaining). Side ways cuts are fine though.
 

·
Registered
Joined
·
2,071 Posts
PullThru 1948 said:
Hey all, still really enjoying the Mini Mill, but the more I use it, the more questions rattle around.
On the subject of End Mills, the only ones I have at the moment are HSS Center Cutting.
What is the correct method of getting optimum performance from this type of End Mill.

Is it better to drill a hole (using a drill bit), then use a non- center cutting End Mill, to just cut side ways.

Reason I ask, is that the center cutting end mills don't seem to drill so great (without complaining). Side ways cuts are fine though.

First thing. There's a tool for everything when it comes to machining. I dont know a lot about machining but I'm always finding about some other tool that is used for this or that. What you described will work. It also depends on how much it bothers you to swap from from the drill chuck back to the collet. Plunging with a center cutting end mill doesn't always work the greatest, though, especially if the end is dull. Sometimes I'll use some cutting fluid to help plunge with a center cutting end mill. In many cases you'll have to use the center cutting end mill to achieve the cuts you want without using a drill bit. Yes, the non-center cutting end mills are generally used for cutting on the sides of the end mill, or roughing out an area.
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #3 ·
Thanks. Not a bother to drill before Milling, thought I might save a step, seeing as the little starter kit End Mills had the capability of drilling down.
Think I'll go ahead and order up some plain , non centre cutting End Mills.
 

·
Premium Member
Joined
·
5,980 Posts
From a position of incompetence, the two flute work for plunging, addition flutes make for better side cuts.
 

·
tired of idiots
Joined
·
2,276 Posts
1948, where are you ordering end mills? I generally use enco, stay away from the cheapest end mills because you generally get LESS than you pay for. Also find a tool sharpener company in your area to resharpen your decent end mills.
I experienced a vast improvement in tool life by switching from sulpher oil to a coolant flood.
You can do a coolant flood cheap by getting a pan from an HVAC company ($18), a cheap walmart aquarium pump ($12), some vinyl tube, a cheap boat bulkhead ($5) and a spare 5 gallon bucket. this modest investment tripled/quadrupled my tool life and increased the load I could put on my mills.

As for the center cutting a machinist told me they work to drill but drilling is for drills. I usually buy centercutting so if I need it I have it, usually they are practically the same price as noncenter cutting
 

·
Registered
Joined
·
247 Posts
Discussion Starter · #6 ·
The little set of End Mills came from Little Machine shop.com (Chinese). They seem fine apart from the "groaning "noise during the plunge/drill cycle prior to the sideway cut.
I've ordered some from ENCO and some from Wholesale Tool.

For Lubrication, presently using a straight mineral cutting/broaching oil. Applied manually and keeping it wet.
 

·
Registered
Joined
·
14,032 Posts
vz58 said:
Will do when I find the camera..

Well think of the last place you'd look, then start there. :rofl:

Sorry had to type it. :D
 

·
Registered
Joined
·
49 Posts
You can plung with a center cutting end mill but they are not designed for drilling. The chip clearances are wrong. They are fine for shallow plunging but if you try and drill to deep you'll bust them. Even when pocket milling it's better to ramp down. Then again I have drilled a hell of a lot of holes with end mills to save tool changes. they just don't last as long.
 
1 - 10 of 10 Posts
Top