On Sat, 03 Mar 2012 21:26:32 -0500, Bob S
wrote:

This seems a little more complicated. Everything that I read and the
people that I talk to say that a quick-change toolpost is more of a
necessity than a luxury.

Choices seem to be:

Buy the Proxxon one

Buy the A2ZCNC 60% of AXA one

Build one, probably of the circular post plus split-bushing type


The Proxxon version costs about $115 with two holders, plus $21 from
another holder. It replaces the existing toolpost, which is a
rectangular chunk of aluminum with a dovetail slide on the bottom and
a threaded hole in the side; it doubles as the top slide! It thus
retains all of the flexibility and deficiencies of the current
slow-change toolpost, but tools get changed quickly.

The primary deficiency seems to be that the tools are fixed at the
same angle as the top slide. One cannot (for example) set the top
slide to 29 degrees and then set the tool perpendicular to the work.


The A2ZCNC version costs about $100 with four holders. It completely
replaces the top slide, mounting to the slot in the cross slide.
Reports are that it is a quality product. It apparently allows you to
set the tool at any angle to the work by loosening the mounting screw,
rotating, and re-tightening. However, there is no top slide with this
unit in place. That means no 29-degree threading (which apparently
cannot be done with any other option either). It also means using the
current slow-change toolpost for tapers. I don't know of any other
function of the top slide, but I am a beginner so I am probably
missing something.


Then there is the DIY option. The advantages are probably educational
value and low monetary cost (but high time cost). It would probably
consist of a circular post mounting to the slot in the cross slide,
plus holders consisting of rectangular blocks with a hold up the
middle with a slot and a clamping screw. The tools could be set at any
angle, but again there is no top slide.


Any other good options?

Any advice?

Bob
Shop around for the best price on the AXA toolpost. The quick change
toolpost is a big time saver, meaning more time spent making chips.
It's also easier to use which means less aggravation, which saves
time, time you can spend making chips. When you do get the AXA size
toolpost, make sure to get the wedge type instead of the piston type.
The wedge type repeats better. At least in my experience they do. I
make my living as a machinist. Have been doing so for the last 35
years or so. My opinion is that if you can afford it buy the tools
which will enable you to cut metal the fastest. After you have some
experience you can decide if making your own toolpost for special work
is something you want to do. In the meantime you can learn about
turning, facing, boring, threading, and parting off while you make
your lens parts. You will be using, most likely, a turning/facing
tool, a boring bar, internal threading tool, external threading tool,
and a part off blade. That's 5 tools used to make one part. Get those
tools set and then it is much easier and faster to make your lens
parts. And since the tools are each in a separate, quickly changed
tool holder, you only need to set each tool once.
Eric