Measuring the diameter of 3-flute/sided tooll

Awl--

Iny trad'l methods? idears?

Here's my 2c:

A triangular insert is circumscribed by a circle whose diameter is 1.15 x the length of an edge of the insert. Or, if measuring perpendicularly from an edge to a vertex, mult. by 1.33. Barring faulty algebra. :)

Along those same, uh, lines, a triangular endmiill should obey the same relationship, *even tho* the corners are rounded--I think.

With endmills, it's def'ly easier to measure flat-to-vertex, and for a 10 deg conical 3-flute em, a .110 measurement indicates about a .147 diam tip. It's a "Conical" conical 10 deg (# J203, USA made), if anyone has any data to perhaps verify this.

If anyone wants the derivation, ax or email.

Reply to
Proctologically Violated©®
Loading thread data ...

Stick the cutter in your mill, start the cutter turning, and edge it up to a piece of stock of known length. Make note of the digital read out's X (or Y depending on which way you decide to traverse) position. Then traverse the mill to the other side of the stock and edge the mill up to it. Some simple addition or subtraction should give you the cutter's diameter. Dave

Reply to
dav1936531

Do a cut across a piece of scrap.

Reply to
Tid Bit

PV:

If you're going to be doing a lot of measuring of 3 flute end mills you might invest in an anvil micrometer:

==================================================================

formatting link
I believe Harbor Freight has some cheap non-digital ones that work fine. I've got a couple. ==================================================================

Otherwise, you can use a V-Block and a height gage. Set zero on the shank, then measure the flute diameter (rotating the cutter to get the highest reading. Calculate from there.

The suggestion by Tid Bit , to just take a pass in a piece of scrap (use the same material you're going to machine your part out of) is quick, easy, and accurate.

Reply to
BottleBob

See, this is what happens when you sit around goddamm pyooters'n'shit all day--you lose yer common sense!

Great idear! Which can be used to determine the multiplier for caliper-measuring as well. Actually, I thought of this this morning, and was going to post it, but not after frittering away boucou time yesterday on an effing spreadsheet, thinking I was a shop bad-ass.

Reply to
Proctologically Violated©®

PV:

formatting link

Or how about putting a gage pin in a V block and comparing the endmill with an indicator.

Best, Steve

Reply to
Garlicdude

BottleBob wrote in news: snipped-for-privacy@earthlink.net:

It's actually more accurate, since you can measure what the cutter actually _cuts_ instead of it's diameter.....there can be a considerable difference in the two.

Reply to
Anthony

They sell v-anvil micrometers designed for the measuring of 3- and 5- fluted tooling.

Reply to
woodworker88

A drill sizing plate - an array of holes - would size it.

A draftsman circle template is the say concept.

Rather than milling a block of Al or steel - how about wax.

Mart> See, this is what happens when you sit around goddamm pyooters'n'shit all

Reply to
Martin H. Eastburn

Read what it says on the shank

Bob

Reply to
bob_1fs

Along the same lines...Drill an undersize hole and bore with the endmill then measure the hole diameter? Randy

Reply to
Randy Replogle

But if it's been sharpened............. Randy

Reply to
Randy Replogle

But if it's been sharpened _properly_.........

LLoyd

Reply to
Lloyd E. Sponenburgh

I meant to say re-sharpened. Randy

Reply to
Randy Replogle

I meant to say "re-sharpened properly".

LLoyd

Reply to
Lloyd E. Sponenburgh

Bob is a good example of why I have to work alone.

Reply to
Proctologically Violated©®

LOL

Reply to
brewertr

I trusted a resharpened endmill (1) time. It was .01 smaller than the etching on the shank. So it had been resharpened at least twice.

Now I measure.

Gunner

This Message is guaranteed environmentally friendly Manufactured with 10% post consumer ASCII Meets all EPA regulations for clean air Using only naturally occuring fibers Use the Message with confidance. (Some settling may occure in transit.) (Best if Used before May 13, 2009)

Reply to
Gunner

How about reading what is written on the shank?

Bob

Reply to
bob_1fs

According to woodworker88 :

Yes -- the one for three-flute (and also six-flute if you want to measure other than across two opposite flutes) has a V of 120 degrees, while the one for five-flute tooling is 72 degrees. I've got an example of each -- from eBay auctions over the years.

Enjoy, DoN.

Reply to
DoN. Nichols

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.