- I have trammed my HF 33686 Milling machine and was wondering if 1 32nd
out of tolerance is acceptable as when i have drilled into a piece of
aluminum and meadured the distance of the hole from the end and there
was a difference of 1 32nd in my measurement i squared the pice up in
my lathe before drilling and measuring
- Looks like I got's some 'xplainin' to do. The rotor I use - that i originally suggested - was a garage sale rotor.
New, clean, no rust, no hub, never installed, originally built for "maybe a Honda" according to the lady. The rotor was machined on ALL surfaces. I had previously trammed my mill. I set the rotor in the center of the table, lightly clamped, and swung the DTI. The maximum variation was less than .001, but my DTI only indicates to .0005. Good enough for me! YMMV.
There ain't no sure thing in this world, but there are ways to test what you have. If you tram your mill to the table, then, while it is presumably still in tram, you find a round surface to tram from, and that surface indicates the same accuracy as you believe your table to be, then you might reasonably assume that that round surface can be used, at a future date, to tram the machine again.
If your round (or rectangular or triangular) surface isn't parallel top side to bottom side, throw it away or make it parallel, at your discretion. And don't site maximum runout as an indication that something is junk. Maximum error dimensions may mean that a part is intended to be produced to much tighter tolerances than the worst case - and .001 worst case could mean most rotors are quite good for this purpose. Certainly, it will often be good enough, and an excellent starting point for further tramming if you need tenths.
rexarinoOn 5/7/06, mertbaker <MertBaker@...> wrote:Those Chrysler specs are maximums. Most rotors are a lot flatter.
----- Original Message -----From: "Robert George" <roberttgeorge@...>Sent: Saturday, May 06, 2006 10:18 PM
Subject: [mill_drill] Re: Mill Tramming
--- In firstname.lastname@example.org, "Glenn N" <sleykin@...> wrote:
> I have been thinking about the Brake rotor idea. It seems to me you
> could add 3 feet to one side of the rotor and lay the flat side on
> the table.
> With the table and flat surface of the rotor as reference you could
> then mill the feet so they were all exactly the same height (or as
> close as possible). Then when you want to tram the head you just
> set it under the spindle (feet down) and sweep the flat surface.
If a brake rotor was really flat, but according to the Chrysler specs,
Good idea though -- you just described the "EZ Tram." :)
There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences. P.J. O'Rourke