Head Button Machining

[Mike Rappold]

For those that are making their own head buttons, how are you machining the combustion chamber? Are you using a custom ground form tool or a ball end mill on the lathe? Or something else?

Thanks in advance.

Mike Rappold

 

[dave roach]

Mike

I use a ground form tool for the 21,45,67 You can use a ball end mill but it will have it be ground to the form you need.

Dave Roach

 

[Marty Davis]

I also use a ground form tool that Norris Sparks made for me. It is contoured from an existing head button (Nova Rossi or MAC 21). He coats the combustion chamber with Dykem and then grinds the tool and then scraped the dykem to see if it is correct.

I tried to use the ball mill but it didn't work well. With the form lathe tool, you can work to .001" easily.

 

[steve wood]

i use ball endmills. carbide works best.give it a shot of wd-40 when cutting,and don't dwell long or you can get chatter,and don't turn too many rpm.try 400 and work from there. the nova factory button has a 2.5 mm radius, so a 5 mm diameter ball mill works great for them. i want to have a 9 mm 2 flute with a 2.5 radius made up,so i can use the tailstock, but haven't done it yet

 

[dwilfong]

The tool at the bottom of the page works wonders for the corner radius in the chamber. Dive strait in and cut to the center. Perfect flat sides and flat bottom.

http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=669&PMCTLG=00

David

 

[glenng]

The tool at the bottom of the page works wonders for the corner radius in the chamber. Dive strait in and cut to the center. Perfect flat sides and flat bottom.

http://www1.mscdirec...E=669&PMCTLG=00

David

Thanks David, Just completed my tour of duty as a machinist(1972- 2010) and never noticed the single edge tools you posted- always ground our own from HSS- works fine on Alum. Alloys with WD-40 like Steve said- or A-9 or just plain Isopropyl Alch. as a lube. Also agree with the lower speeds-depends on how rigid the machine is.

 

[Mike Hughes]

I use ball end mills. It works for me.

Mike

 

[jetpack]

If they make HSS blanks such as those carbide ones, I would get the steel ones. If your machine isn't totally rigid and you setup isn't perfect, you will break or chip out your blank. HSS can be bench honed or ground, carbide only ground using a green wheel.

Those type of blanks that David's link shows are common in mold shops in the CNC machines to detail carbon blocks that will be going into the EDM as electrodes to burn cavities or details into mold halves.

 

[dwilfong]

Yes the carbide ones are prone to breaking if not used right. but the finish is perfect. I use them for all the chamber work. Just go slow and don't cut to much at a time. The radius is more precise than any thing you can grind by hand. It is a perfect radius that is the key to the hole thing. If you like the hemispherical chamber a perfect radius is what will make it a hemi.

David

If they make HSS blanks such as those carbide ones, I would get the steel ones. If your machine isn't totally rigid and you setup isn't perfect, you will break or chip out your blank. HSS can be bench honed or ground, carbide only ground using a green wheel.

Those type of blanks that David's link shows are common in mold shops in the CNC machines to detail carbon blocks that will be going into the EDM as electrodes to burn cavities or details into mold halves.

 

[Sean Bowf]

No expert here, but I use a ball end mill clamped in my tool rest (so it is NOT spinning...the button is).

Sean