Checking a tight tolerance chamfer

[Rstewart]

Have some aluminum parts I'm going to machine; about 24 of them.  The print has a 15deg chamfer ± .002" on a through bore (.750").

 

We're kind of a mom and pop shop without a CMM or a whole lot of gauging. 

 

What's my bet on checking these Before I send them out for inspection?

[themachinist]

Do you have an optical comparator? Some clay or putty might be useful depending on your tool set.

[cncchipmaker]

Have some aluminum parts I'm going to machine; about 24 of them.  The print has a 15deg chamfer ± .002" on a through bore (.750").

 

We're kind of a mom and pop shop without a CMM or a whole lot of gauging. 

 

What's my bet on checking these Before I send them out for inspection?

Is this a lathe part or a mill part? Have you considered using a ball bearing?

[The Cathedral]

Ball bearing would only be good to check size after you've verified it's cutting to the right angle.

 

Old school method? Machine a blank and saw it in half. Measure.

[Del.]

Ball bearing would only be good to check size after you've verified it's cutting to the right angle.

 

Old school method? Machine a blank and saw it in half. Measure.

Excellent point.

[Rstewart]

It's on the mill.  The .750" bore is +.0015 -0.  2.00" deep with a 15deg chamfer on top and bottom.  Cathedral, I think you might have the best Idea (sawing in half) with dummy stock.

[Del.]

I'd make a male gage you could verify and check it with.

 

 

You cab buy a digital chamfer gage fairly cheap accurate +/- .001 or better

[mkd]

It's on the mill.  The .750" bore is +.0015 -0.  2.00" deep with a 15deg chamfer on top and bottom.  Cathedral, I think you might have the best Idea (sawing in half) with dummy stock.

well this is what i've seen done.

it's better since it is non-destructive.

http://reprorubber.com/applications.asp

 

still need a good comparator.

 

if all else fail you can tell the designer to F.O.C.U.S.

[jlw™]

Gage ball or buy a chamfer Gage. Gage ball will be quickest and least expensive.

[mkd]

Is there a spreadsheet out in cyberspace for calculating ball height with a given chamfer angle and diameter.

[The Cathedral]

Is there a spreadsheet out in cyberspace for calculating ball height with a given chamfer angle and diameter.

 

Yeah, look up "trigonometry"

 

[Rstewart]

Out of likes for the day LOL^^^

 

Yup, I'm thinkin the ball is the way to go maybe now.   Anyone recommend a certain size of ball for a .751 hole with a .015" wide 15 deg chamfer.   I can just model it up to give me the correct height for chamfer width.

[jlw™]

Is there a spreadsheet out in cyberspace for calculating ball height with a given chamfer angle and diameter.

If the trig flips your wig you can draw it up in mcam in about 20 seconds!

[The Cathedral]

Is it 15 from the bore, or the face? 25/32 if it's from the bore

[Rstewart]

Yes, It's from the bore.  That's about what I was thinkin'   Thanks for the help guys