Author Topic: Mill Creep  (Read 12079 times)

Offline Mosey

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Re: Mill Creep
« Reply #30 on: January 05, 2015, 06:17:17 PM »
Why don't we rename this thread to Slot Drills and End Mills, and I can repost my question?
My question has nothing to do with either. I asked about milling cutters that creep out of their (collet)holders, and why they do.  :noidea:
I too looked at  my mills and find that flutes run from 2 to many and all are center cutting.
I gather that some prefer to talk about slotting.
Or better still, why don't we put it to rest.
Mosey

Offline Roger B

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Re: Mill Creep
« Reply #31 on: January 05, 2015, 06:37:12 PM »
I have had a quick look here and metric W20s are easy to find but I am still looking for imperial sizes. There are a couple of other places I will try.
Best regards

Roger

Offline Jo

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Re: Mill Creep
« Reply #32 on: January 05, 2015, 07:00:40 PM »
Muddled Engineer had a large ice cream tub full of them thrown in for free with the Schaublin 12 milling machine goodies he shipped back from the states as the guy couldn't find any one who wanted them  :shrug:

Jo
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Offline Mosey

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Re: Mill Creep
« Reply #33 on: January 05, 2015, 07:04:58 PM »
I cleaned the collet, mill shank, and spindle and retested the roughing mill with a 5/8" deep 1/16" cut, and found that the mill still creeps out of the collet. Tomorrow I will install a new collet and retest.

W-20 x 1/2" collet is now in stock in the US!!  :cartwheel:
It is on the UPS truck to me for tomorrow.
They come in Standard and Ultra Precision grades.
Mosey
« Last Edit: January 05, 2015, 07:21:19 PM by Mosey »

Offline Bluechip

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Re: Mill Creep
« Reply #34 on: January 05, 2015, 07:07:48 PM »
Why don't we rename this thread to Slot Drills and End Mills, and I can repost my question?
My question has nothing to do with either. I asked about milling cutters that creep out of their (collet)holders, and why they do.  :noidea:
I too looked at  my mills and find that flutes run from 2 to many and all are center cutting.
I gather that some prefer to talk about slotting.
Or better still, why don't we put it to rest.
Mosey

I've no real idea whether this is relevant but ...

When I first got a mill I always used parallel shank cutters in a ER25 collet holder and the larger diameters tended to walk out of the collet. Presumably because the helix tries to ' drill in' ??

A Professional geezer said to use threaded shank cutters in a suitable chuck, in my case a Posilock.

This one:

http://www.chronos.ltd.uk/acatalog/Engineering_Menu_Posilock_Collet_System_105.html

Problem goes away. Still use the ER25 for small stuff though.  :)

Dave

Offline Mosey

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Re: Mill Creep
« Reply #35 on: January 05, 2015, 07:25:14 PM »
Bluechip
I have never had a mill creep out of an ER collet on the old mill. Unfortunately, ER collet holders are not easily found for a W-20 spindle in the US, so I will make one eventually, as they are so  convenient and I like to use them.

Offline Dan Rowe

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Re: Mill Creep
« Reply #36 on: January 05, 2015, 08:12:51 PM »
If you are making holders anyway put end mill holders on the list. End mill holders with a set screw are very handy and they will not slip or creep if the set screw is tight.

When I started I used collets only for the mill then I had a job that required several tooling changes. The z height is locked with the set screw with an end mill holder so it is the same each time it is installed in the spindle. So I could alternate between two cutters and not have to reset the z every time I changed end mills.

Dan

 
ShaylocoDan

Online mklotz

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Re: Mill Creep
« Reply #37 on: January 05, 2015, 08:37:06 PM »
If you are making holders anyway put end mill holders on the list. End mill holders with a set screw are very handy and they will not slip or creep if the set screw is tight.

Remember, when you install the endmill in the holder, to pull it down against the nearly tightened setscrew before fully tightening the setscrew.  DAMHIKT.
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Arbalest

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Re: Mill Creep
« Reply #38 on: January 05, 2015, 08:51:26 PM »
I've got a small end mill with absolutely no teeth on the bottom at all, it's perfectly flat. Is this normal or has it missed a stage in production? It's brand new, never been used.

Offline Roger B

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Re: Mill Creep
« Reply #39 on: January 05, 2015, 09:03:35 PM »
I've got a small end mill with absolutely no teeth on the bottom at all, it's perfectly flat. Is this normal or has it missed a stage in production? It's brand new, never been used.

It's called a reamer  :stir:  :)  :mischief:
Best regards

Roger

Offline Mosey

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Re: Mill Creep
« Reply #40 on: January 05, 2015, 09:21:41 PM »
I've got a small end mill with absolutely no teeth on the bottom at all, it's perfectly flat. Is this normal or has it missed a stage in production? It's brand new, never been used.
Might need a picture of that

Offline PStechPaul

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Re: Mill Creep
« Reply #41 on: January 06, 2015, 05:32:42 AM »
Like this?



McMaster does not have "slotting drills", but they have planty of two, three, and four flute center-cutting end mills, and tight tolearance two-flute mills made for slotting. There are "finishing" end mills with four and more flutes, that are not center-cutting. I have some large end mills that are end-cutting but not center-cutting, because with higher flute count it becomes impossible to provide effective cutting edges at the center.

http://www.mcmaster.com/#end-mills/=vcd1rl





Some of what I have that I thought were end mills turned out actually to be counterbores with removable (and in some cases broken) pilot drills and plain pilots:


Offline Mosey

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Re: Mill Creep
« Reply #42 on: January 06, 2015, 07:18:34 PM »
To reach closure on this thread, I bought a new collet and installed the roughing mill in it today, taking a good cut of 5/8" deep by 1/16" feed. There was no creep of the mill! None.
The new standard precision Schaublin collet measures 0.505" ID at the nose, considerably larger than an old one. I suspect it holds so well because when tightened against the mill shank it contacts evenly along the length of the shank. Perhaps that is what makes it more successful than a worn collet. What Bogs  said.
I learned a lesson from this about work holding.
Mosey

Online Tennessee Whiskey

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Re: Mill Creep
« Reply #43 on: January 06, 2015, 07:36:22 PM »
So, you didn't buy the ultra precision collets,  you saving the money for "cutters :lolb: :lolb: :lolb: :mischief: :Jester:"

Cletus

Offline Roger B

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Re: Mill Creep
« Reply #44 on: January 06, 2015, 07:37:16 PM »
Glad you reached a good solution  :ThumbsUp:  :ThumbsUp: Do you think that the old collet had worn to a taper?
Best regards

Roger