Re: holes, collets, counterbores, guitar bridges. More

FIK,

Cheap counterbores are just that....CHEAP. Try a good one like a 2
lip Weldon brand, then compare with the 6 dollar J&L "quality
import". It shouldn't take more than a couple of holes to make you
wish you'd spent the $30 on the Weldon.

I go to Boeing Surplus almost every week. I believe what you're
referring to as counterbores are spot facers. They don't do that
good a job used as a counterbore. Besides, they aren't sized for
common cap screw sizes, so for that application they'd need a regrind
to size.

I'm the one who suggested not using endmills in a drill press. A
couple reasons why. First, most DP's don't have quill bearings to
withstand the side loads from end mills. A better reason not to use
them has to do with the chuck mount. Very few of the new DP's come
with the threaded safety locking ring to hold the chuck on in the
event it slips off it's taper mount, the safety lock ring was
standard on all older quality DP's. Taper mount chucks are not meant
to withstand side loading. In spite of the above every one of us has
used an end mill in a DP, still not a good idea.

Interesting what you say about the wave of the future and small shops
making Boeing parts in garages. Lots of us make "parts" for Boeing.
But I guarantee you no small uncertifed garage shops are making
airframe critical parts for Boeing.

thanks,

Doug

--- In CAD_CAM_EDM_DRO@y..., "FIK" <vrojas@p...> wrote:
> Blank> First off, you don't want flat bottom holes, you want
counterbores.
>
> You can but cheap counter bores with pilots from mst catlalogs, J&L
etc. $6.00 is not a lot to m,e for a hole he way want it, also if
you know anyone in Seattle ask them to go to Boening Surplus, it is
on 68th in Kent, they have bins of counterbores, pilots etc, drils
all for about a buck a piece. I use endmills in my drill press all
the time, who said you can't. Damn do I have to stop now??
> COLLETS
> sizing the collet's ID. That's "cheating", since the collet then
> > becomes spindle-dependent
>
> I use ER collets, Beall tool compnay sells a nice fixcture that
mounts on a 1 1/2 x8 spindle nose (other sizes availbale including an
adaptor for sherline. ER collets are reltively cheap, they have about
ther same TIR as anyyhing I have seen and the holder can go from
machine to machine so the error if specific to colet holder is a non
issue if spindle is faily accurate, They also have a variance per
collet of like .010 so a few go a long way.. IF you set up with a a
true dead center and check run out before you start turning, then
remover deadcenter, recheck run out and are good, hey it i sworking
for me on all my machines and I have 8 ( Fred is part right, big
commercial dedicated CNC part specific companys are in trouble, but
home shops are on the rise. to use fred's own evidence, look how much
cCNC stuff is bought on austion by guys like us, or other retired
machinists who are dpoinf small work clandestinely in their gargages,
the home shop shop machinist is the wave of the commercial future, I
know three guys who make parts for BOEING in converted wo car
garages. So Big shops, BIg machines are struggling but CNC is still
viable, has vitality and will be gorwing tremendously in all
industry)
>
>
> On CAD CAM. So far it all sucks. Not one company "imho" has yet to
figure out the basic starting point for us beginners, and believe it
or not we are the target market cince the bg companie can afford CNC
literate 20 year olds who can't turn a lathe on. That first thing
for any CADCAM is to define the unworked part and how it is oriented
on the work lane, be it lathe or mill. Until CADCAM can let us
junkststers sketch in some scrap iron treasure clamped to a milling
table, then aproach how we are going to reduce to some wonderful
creation the whole concept is lost on me. I have everyoones demo
version here and they are chapters of assumptions ahead of me. Slow,
down, let me get the "thing" on the table, let me tell the CADCAM
what drills I have and how I planned on working it. So many Caned
cycles and tool librarys don't consider or make it easy to write some
of this approach our own way. So Fred,Mike Miligan, Warren at
Surfcam, help us draw a workpiece and define it n the work table
before introducing vectors and all kinds of new stuff. All the stuff.
I do appreciate the free demos and the email helps and the support. I
am not ungrateful, I am frustrated that your assumptions that I might
be working with some industry standard mormal stuff isn't adequate
for the edge I work on.
>
>
> Someone mentionedmaking a guitar bridge, I missed the whole post. I
have made Ebon and rosewod gitar bridges for restraton work for
years. LAst year I sent two out to a gy in New Mexico. He repleied
with his check, wow these are so perfect you must use CNC can I order
2 dozen. I make them all with a bandsaw and a cabinet scraper. All by
hand and they are all identical. So just for the thought everything
does not have to be made on CNC to be great or accurate. In the final
analysys it is the human eye and feel that measures it anyway. The
old machinists said they could "feel" the difference of .004" with
their hands. That is a human hair by the way, and just about everyine
on the planet can rll a human hair between their fingers and feel it.
let alone one in their food:^) Johnno on a Sunday Rant
>
>
> . At first I thought that there is no way
> > of
> > > making my guitar bridge.
>
>
>
>
> POB 226
> Seldovia Ak 99663
> www.fossilivory.com
>
>
>
>
> [Non-text portions of this message have been removed]