Re: Lighted edge finder

---Making an accurate center punch mark is very difficult, I have
always used a small pin with a very sharp point and a lump of
modelling clay as already suggested. It is very easy to pick up lines
that have been scribed with a height gauge using the pin and a loup.
Terry Ackland
In CAD_CAM_EDM_DRO@egroups.com, ballendo@y... wrote:

> Jon Elson wrote:
> <snip>The edge finders are much better (and safer, too) for

locating

> >edges,but they don't do as well on punch marks.
>
> Had one of my machinists show me how to use the "pointy end" of an
> edge finder. This would be the combo kind w/ a .2 cylinder at one

end

> and a cone on the other.
>
> To use, prick or punch the hole location. Do this carefully and
> accurately(punch held vertical), the center finder will EXACTLY

find

> the bottom/sides of this punch mark.
>
> Now jog the axes 'til edge/center finder is neatly above the

punched

> mark. With the spindle about 5-800 rpm, use a fingernail(hey,

that's

> what the old guy used!)or something else to "true" the

cylinder/cone

> joint.
>
> Then bring the point down into the punch mark and the center finder
> will DEFLECT the amount you are off the punched location. So you

can

> adjust the axes until the cylinder runs true again; or you can stop
> the spindle with the quill down and "mike" the major cylinder dia.
> across the joint(cylinder typically is .375 or .500) If the
> measurements are taken in line with the axes they will show the

EXACT

> distance the spindle is "off" from the punch mark.
>
> This works really well! I use the scribe from an old Starrett combo
> square to make the original mark. It can be a really small mark and
> still work, you just have to be careful (if it's small) to be

WITHIN

> the punch or you may make a NEW punch "mark" WITH the center finder!
>
> Hope this helps.
>
> Ballendo