Re: Creating long straight edges (and big squares)

Hi Les,

Very well written and very clear. It comes at a great time for me.I
think I am going ahead with 3" square tubing for the table and plan
on mounting rails to that. I had given thought to using the table
as the rails, and just run bearings on that. Seems to get it level
is one thing, to get it flat is another, and to get two sides flat
and perpendicular would be prohibitivly hard with hand tools.


When thinking about how to do it faster, easier, better, or some way
change it, I thought about making a beam of some sort with screw
adjustments. Then bolting on the linear rails one would be using
anyway. Then with your measurement technique, one could run an
indicator up and down the length of the part to be straightened.

Seems the jig would cut a lot of time off and be worth the effort.

Even seems that one could use that jig for a finish grind of a few
tenths to get the whole length with a even finish.

Dave

ps: This sentence could be mis-leading to a novice.

>Sometimes I grind an area that feels high with the plate.

This is about halfway down, immeadiatly before "A note about
grignding technique..."

--- In CAD_CAM_EDM_DRO@y..., "Les Watts" <leswatts@r...> wrote:
> Ok, as the web site is still down I have uploaded the write-up into
the
> group
> files section as STRAIGHTEDGE.txt.
>
> Carlos, you asked about squaring ways... well the easiest way for
medium
> size stuff is just a big square. I know they are usually very
expensive,
> but I got mine from a little place in illinois called SHARS.
> http://WWW.Shars.com (I think)
> They sell a nice 12x24" square in a wooden case for $100!
> They claim it is accuracy class N (0.0002" +L/500,000).
> I checked mine with granite square and surface plate and
> it was in spec.
> You can also make large squares in sets of three with no standard...
> but that is another story!
>
> Les
>
> Leslie Watts
> L M Watts Furniture
> Tiger, Georgia USA
> http://www.rabun.net/~leswatts/wattsfurniturewp.html
> engineering page:
> http://www.rabun.net/~leswatts/shop.html