hi Dave!
thick wall.. yes maybe, i will check.
i tried to flex a 4 meter piece, it is sturdy enough on 1 meter length for
anything i can imagine.
NO i want not to use aluminium.
i don't have it and don't want it.
i think if i want to make a mill which can also mill aluminium it has to be
steel.
that's my opinion, i know this is wrong in principle but i want it so.
( ;-) this is the advantage of building it from scratch)
i think about your method of straightening...
but i found a huge supply of this tubes and maybe i can select pieces which
are already perfect (for me).
the surface is pretty fine and i think they are straight...
i have used this measuring tools before (i had a very classic electrical
engineering education including machinist
work like milling, using a lathe, welding etc. as well as programming
microcontrollers.....)
so i would be able to do this but i don't have this measuring tools at
home, neither do i have a flat steel table.
thanks for the suggestions but i really have to inspect this stock closer
before i can do anything...
you know a lot of other work now....
regards
stefan...
only another thougt:
if you use two of this "rails" in parallel and put a toolpost on it and
construct a lathe head on the end........
hmmm..... maybe in ten years i have enough time for this ;-) i ever wanted
to have a lathe..
On Sat, 02 Aug 2003 01:01:13 -0000, Dave Mucha <
dave_mucha@...>
wrote:
> Hi Stefan,
>
> from what you describe, you are talking about square steel tubing.
> probably pretty thick wall.
>
> this is common for HEAVY duty router tables, depending of the size of
> course. I was looking at 2 inch x 2 inch square with a 0.187" wall for a
> 4 foot x 8 foot (1.2 meter x 2.4 meter (just guessing)) table.
>
> to check accuracy, this can be complicated. and getting really high
> accuracy will take lots and lots of time.
>
> If you are only looking for a PCB table, considder making a frame with
> aluminum as extruded aluminum is usually pretty darn straight.
>
> or, attaching a rail to the top (or bottom) and one side. all you need
> to do is make the rail accurate and you can bolt that in the middle
> pretty easily. your bearings would ride on the rail.
>
> If you want to true up the steel box, get a machinests level, and a small
> grinder. level the table at best you can taking measurements so you know
> all the lowest points are at the same level, check them a fet times to be
> sure.
>
> then mark the height of the high spots with a feeler gauge and chaulk.
> think topographical map here.
>
> then grind off the high spots. one note is that grinder wheels are
> cheaper in the 10 pack.
>
> additional notes,
> wear hearing protection
> wear eye protection
> wear breathing mask of some sort
> get wifie to rub your poor aching back.
>
> Once you get the thing close, start checking side to side. then mark it
> all over again.
>
> lotta work, but a really great result.
>
> Dave
>
> above is synopsys of a proceedure written by Les Watts
> http://home.alltel.net/leswatts/straightedge.html
>
>
>