I'm about to take the plunge, but the Aloris catalog only lists specific
lathes, not a way to calculate which toolholder one needs for a particular
compound height.

Does anyone know the formula, or how much a (say) BXA allows one to adjust
the holders vertically once on the post?

LLoyd

In article ,
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

I'm about to take the plunge, but the Aloris catalog only lists specific
lathes, not a way to calculate which toolholder one needs for a particular
compound height.

Does anyone know the formula, or how much a (say) BXA allows one to adjust
the holders vertically once on the post?

Aloris has in their catalog a form one fills out, from which they
compute the necessary spacer height. I bet they would also just tell
you the needed dimensions, given the form.

I bought my BXA toolpost directly from Aloris, and the package included
the custom machined spacer. Unlike MSC et al.

Joe Gwinn

On 2011-06-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
I'm about to take the plunge, but the Aloris catalog only lists specific
lathes, not a way to calculate which toolholder one needs for a particular
compound height.

Does anyone know the formula, or how much a (say) BXA allows one to adjust
the holders vertically once on the post?

The first thing is whether it will go low enough. To determine
that, measure the distance between the top of the compound and the
center height.

Next -- measure from the bottom of the tool holder to the top of
the tool slot (thus for the largest tool which will be held in there).
If this is less than or equal to the center height above the compound,
you are probably fine. Pick the largest which will fit, as this gives
you the most rigid setup.

Have you downloaded the Aloris catalog in PDF format? I've got
one which I downloaded n 2 January 2006, and b clicking on the index
item "Quick Change Shank Tool Holders" I get dimensions of AXA holders,
and the next page (page 7) ahs the dimensions of BXA CXA, CA, DA, and EA
series. Dimension "A" is the dimension from the bottom of the tool
holder to the top of the slot. For the AXA #1 tool holder (square shank),
it is 15/16" for the AXA, BXA is 1-1/8", CXA is 1-7/16" and you can
download the catalog and look up the larger ones if it matters.

Figure at least 1/2" height adjustment range for the BXA. I
don't have an AXA, and have never used one, so I can't give you a feel
for that range.

Page 5 (on this older catalog) gives you most of the dimensions
of the toolposts.

Good Luck,
DoN.

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The dimensions for toolpost tool holders are published in catalogs, so the
lathe user can compare the dimensions to the lathe dimensions.

If one chooses a QCTP series/size that's too large for a particular lathe,
then the setup may not accept suitably sized cutting tools for that lathe.

A small QCTP will have an advantage of allowing the user to use larger
cutting tool sizes, in some cases.

Taking the TOC top of compound (plinth) distance to the lathe spindle
centerline height will show which particular QCTP series/size will be best
suited to that lathe.

The important dimension is the height of the tool holder's shelf/cutout for
the cutting tool to rest on. This dimension determines how large the cutting
tools can be, by adding the desired cutting tool height to that dimension,
before the top of the cutting tool can no longer be adjusted down to the
spindle's centerline.

All the common dovetailed QCTPs allow the holders to slide to the bottom,
stopping on the TOC.

If one chooses a B or 200 series QCTP for a small lathe, the holders may
prevent 3/8" cutting tools from meeting the spindle centerline (tool tip too
high).. since the holder may come to rest on the TOC. Then the user would
need to use smaller cutting tools (possibly 5/16 or 1/4").
Choosing a toolpost series that's too small could prevent the cutting tool
tip from reaching the spindle centerline (without adding a riser block).

The primary consideration, IMO, is scale.

Choosing a B/200 series for a 9" lathe doesn't guarantee more rigidity. One
wouldn't expect to run 1/2" or 3/4" cutting tools on a 9" lathe, and they
likely wouldn't fit due to the limited spindle centerline height over the
TOC.
Considering other factors such as motor size and the lathes's overall
rigidity, should determine which size cutting tools are appropriate for a
specific size of lathe.

Choosing a B/200 series for a 12" lathe is generally more reasonable.
Using an A/100 series on a 12" lathe may be completely satisfactory and
perform just as well, depending upon the usual chip loads and type of
workpieces.

Reviewing the dimensions of tool holders will be the determining which
holders are going to be suitable for future purchases, but also for the
initial QCTP choice.

Some other factors might be which sizes, and how much existing tooling one
already has in the shop, and perhaps a less common need to use some unusual
sized tooling such as a large boring bar that was only $5 at a garage sale.

--
WB
..........


"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
I'm about to take the plunge, but the Aloris catalog only lists specific
lathes, not a way to calculate which toolholder one needs for a particular
compound height.

Does anyone know the formula, or how much a (say) BXA allows one to adjust
the holders vertically once on the post?

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
I'm about to take the plunge, but the Aloris catalog only lists specific
lathes, not a way to calculate which toolholder one needs for a particular
compound height.

Does anyone know the formula, or how much a (say) BXA allows one to adjust
the holders vertically once on the post?



http://i1188.photobucket.com/albums/...hinist/bxa.jpg

"PrecisionmachinisT" fired this volley in
news:9qOdndk70pu8GGvQnZ2dnUVZ_oqdnZ2d@scnresearch. com:

http://i1188.photobucket.com/albums/...hinist/bxa.jpg

Perfect! It positions the tool bottom .5" above the plinth, and has one
inch of vertical adjustment.

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
"PrecisionmachinisT" fired this volley in
news:9qOdndk70pu8GGvQnZ2dnUVZ_oqdnZ2d@scnresearch. com:

http://i1188.photobucket.com/albums/...hinist/bxa.jpg

Perfect! It positions the tool bottom .5" above the plinth, and has one
inch of vertical adjustment.


http://www.industrydepot.com/DorianToolToolHolders.htm

--

On 2011-06-13, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
"PrecisionmachinisT" fired this volley in
news:9qOdndk70pu8GGvQnZ2dnUVZ_oqdnZ2d@scnresearch. com:

http://i1188.photobucket.com/albums/...hinist/bxa.jpg

Perfect! It positions the tool bottom .5" above the plinth, and has one
inch of vertical adjustment.

With the height of the *top* of the tool being the important
point. BXA handles up to 5/8" shank tools, and at least Carbide insert
tools tend to have the cutting edge at the same height as the top of the
shank, so you need to have your center height at least 1-1/8" (ideally a
little higher) above the top of the compound.

Enjoy,
DoN.

--
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"DoN. Nichols" fired this volley in
:

With the height of the *top* of the tool being the important
point. BXA handles up to 5/8" shank tools, and at least Carbide insert
tools tend to have the cutting edge at the same height as the top of
the
shank, so you need to have your center height at least 1-1/8" (ideally
a
little higher) above the top of the compound.


Yeah, but hand-ground HSS tools often have the cutting edge depressed
from the top edge. You have to know all the dimensions -- the highest
the top edge might ever be, and the lowest that the (say) middle of the
tool might ever be.

LLoyd