On Friday 26 April 2019 03:13:37 Marcus Bowman wrote:
> On 26 Apr 2019, at 06:58, Gene Heskett wrote:
> > a tooth style called ATBF, where a flat topped
> > tooth is fitted between the angled teeth.
>
> I use a table saw fitted with an ATB blade for cutting sheets of
> aluminium up to 16mm thick. It works a treat, and gives a pretty fair
> cut, even on angled cuts. The ATB blade came with my old DeWalt radial
> arm saw, which I got second hand from a chap who use to make flight
> cases for musicians (ali panels, angle corners, etc). Cutting thick
> sheet, the blade has remained tolerably sharp for a long time. It's a
> bit larger than the 9 inch blade on the table saw, so there is very
> little clearance, but just enough to work safely. I cut blocks on my
> ancient reciprocating ('donkey') saw, and it is accurate but slow.
>
> I cut Acetal and Delrin bar on the reciprocating saw, with a very
> sharp and relatively coarse-pitched blade. It's accurate but a bit
> slow. I'm too scared to cut it on the radial arm saw, but I would
> welcome ideas as to how to cut fast but accurately through Acetal bar
> from 32mm up to 75mm diameter, holding a tolerance of +/- 0.5mm. The
> bar lying on the workshop floor is ready to be cut into approximately
> 1000 slices, so any time saving would be valuable. It's the old story:
> I turned a specimen on the spindle of the vertical mill, partly as a
> demonstration of LinuxCNC, but the job has grown a thousandfold, and
> the order keeps repeating - larger every time. But the sawing takes
> most of the time.
>
> Marcus
>
>
This could go 30-45 seconds a slice on a 12" chop saw. I have an old
dewalt that has provisions for clamping the workpiece down, and with the
chop saws mostly downward cut it should be ok, shim it away from the
backstop fence to reduce any potential lift from the blade and clamp
tight enough it won't roll. You are shimmed about right when the end of
the cut is centered on the bottom of the rod so the saw blade almost
doesn't enter the slot. The shim, maybe a 2x2, should be clamped
separately, as should the length stop, then a toggle or maybe 2 to clamp
the delrin. You may need to drill the saws bed for the toggles to put
them in the right place, but they clamp and unclamp in a second, so you
spend most of your time actually sawing. Paramount is clamping tight
enough to make sure the blades torque as it cuts can't move the plastic.
It will want to roll forward at the top of the cut, and backwards for
the last inch.
You couldn't pay me enough to try that on a radial arm, so leave it
unplugged.
>
>
>
>
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Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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