Newbie mistook milling cutter bit for center drill bit...

A boo-boo with a couple of follow up questions.

Following a tutorial dvd, I was looking for a centre drill bit to do my first pilot hole using my Taig lathe.
In a yellow packet there was what looked like the bit on the dvd.
It said the dimensions & "d/e stub".
I used it to drill a pilot hole.
The result looks ok, in so far as I can judge.

later I found:
http://www.super-tech.com/root/grp.asp?p1=Taig-Products

shows part TAIG-1230D . The part I used - a milling cutter bit.

Also I found:

http://www.mini-lathe.com/mini_lathe/accessories/accessories.htm

with pics of real centre drill bits
& I had a packet of those in the drawer..

so...

1) is there an easy way to tell the difference?

2) Also on
http://www.diytools.co.uk/diy/main/...t-hand.asp?iPriceRangeID=6&iCategoryID1=10844

it refers to
Dormer A225 3/4in BS7 HSS Centre Drill Right Hand

as right handed

why would it be called right handed when you can just turn it around??

Right hand refers to the direction of rotation which is the way 99% of drills & milling cutturs turn. You can get l/H but its not something we are likely to need. BTW the No 7 refers to the British Standard size, bit big for what we need as the main body is 3/4"

A milling cutter is likely to have a "flat" end but a ctr drill will typically have a short pointed end and the flutes will cary slightly into the main body.

Jason

Don't think of it as a 'Boo-Boo' in anything more than naming convention and recognition, on your part.

There are many ways to do 'it', and if the result is OK, then you did 'it' right.


:big: :bow:

Kermit

Kermit said:

There are many ways to do 'it', and if the result is OK, then you did 'it' right.


Kermit

Click to expand...

I could not have said it better myself.

You say tomato I say and end mill can be used as a center drill.

Its just a matter of semantics.

kel

Thanks to you all for the speedy responses.

Mike

Mike, from your first post "d/e stub" means "double end, stub length" which translates to an end mill with a cutting edge on both ends. Stub refers to the length, and in this case is the shortest length of the cutting part of the end mill. There are other nondescript names for lengths of cutting edges of end mills, like "regular", "long", and the "stub" that you have.

It doesn't do any harm to make a hole with an end mill, but it's not the right tool for spotting holes. That is what center drills are for, along with another main purpose.
Also, something worth knowing; Not all end mills will make a hole. Some will not cut at the very center of the mill diameter, and if you try to plunge them as you would a drill, you will have troubles. Probably just a broken tool, but can also pull things around enough to sometimes pull the work piece from your vise.

kcmillin said:

You say tomato I say and end mill can be used as a center drill.

Its just a matter of semantics.

kel

Click to expand...

Not to quibble with Kel, but it's not really a matter of semantics. We have names for these things so we can properly identify them. If you need a center drill, that is what you should use. An end mill will not do what a center drill will, and is not made for the main purpose I mentioned above.

A center drill has a small pilot cutter on the very end, and behind that has a cutting edge that comes out at a rather steep angle. That part is specifically made for cutting center holes in stock that needs a dead or live center. An end mill is not the same thing in any way, and cannot be used for this purpose.


This is a center drill:






This is an end mill. Happens to be a d/e stub.



Dean

Dean, dont worry, no quibble taken. My bad. I was just referring to the flying by the seat of your pants type milling, wich i was, or currently am, involved in.

To show my ignorance, I used an edge finder for 3 years before I found out the machine has to be on for it to work. I always wondered why it wobbled though.
:hDe:
:noidea: :noidea: :noidea:

Kel

Dean,

Thanks for the follow up with pics - also for forcing me to go & learn the diff between a live & a dead centre! Super website BTW, one of the ones I looked at before picking a Taig.

Mike

student123

Live center point turns with the work

Dead center is just a point and will need plenty of oil when you turn

And of course you know they go in your tail stock to hold the work from wobbling
Dead
http://littlemachineshop.com/products/product_view.php?ProductID=1890&category=

Live
http://littlemachineshop.com/products/product_view.php?ProductID=2714&category=

You can also use a dead center in the head stock along with a face plate and dog

Dog, you ask??
http://littlemachineshop.com/products/product_view.php?ProductID=1149&category=

Holds work from spinning on the point. Goes around work and secured to face plate

Tony

That is assuming the endmill is center cutting and you are not planning on using the hole for a center.

Back before rocks they would drill a hole then use a 60deg tool to put in the center for the lathe... a two step process. Lot's of ways to unwrap a feline...