I was going to make a quick and dirty dividing head to use with my
Taig chucks on my X2 mill.

I thought I would basically run a shaft through a block of aluminum
with 3/4-16 thread on one end and a dividing plate on the other. Then
I thought: What shaft? What bearings?

Primary concerns here are not the rotation loads but absence of radial
and axial movement of the shaft.

I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?
Presumably a steel shaft would wear out the aluminum. Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Thanks,

Michael Koblic,
Campbell River, BC

On Mar 9, 3:47*am, wrote:
I was going to make a quick and dirty dividing head to use with my
Taig chucks on my X2 mill.

I thought I would basically run a shaft through a block of aluminum
with 3/4-16 thread on one end and a dividing plate on the other. Then
I thought: What shaft? What bearings?

Primary concerns here are not the rotation loads but absence of radial
and axial movement of the shaft.

I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?
Presumably a steel shaft would wear out the aluminum. Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Thanks,

Michael Koblic,
Campbell River, BC

I like these:
http://www.kalamazooind.com/products...exing-fixture/
I bought two used ones for ~$50 each and mounted one on an angle plate
with the axis vertical. If necessary the second can serve as a
tailstock to steady a long shaft, like the splined pulley broach I
have to make soon.

The Spin Indexer is less rigid but can be set to 1 degree with the
vernier holes on the top:
http://www.phase2plus.com/details.as...IN_INDEX&id=58

A chuck for them:
http://www.tools4cheap.net/proddetail.php?prod=5c3jaw

Then there's this:
http://www.harborfreight.com/3-inch-...kit-98077.html

The rotation load is VERY important when milling if the work diameter
is larger than the shaft clamp. You can arrange a clamp that secures
the work directly to the mill table at the cost of inconvenience.

jsw

On Wed, 9 Mar 2011 04:59:33 -0800 (PST), Jim Wilkins
wrote:

On Mar 9, 3:47*am, wrote:
I was going to make a quick and dirty dividing head to use with my
Taig chucks on my X2 mill.

I thought I would basically run a shaft through a block of aluminum
with 3/4-16 thread on one end and a dividing plate on the other. Then
I thought: What shaft? What bearings?

Primary concerns here are not the rotation loads but absence of radial
and axial movement of the shaft.

I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?
Presumably a steel shaft would wear out the aluminum. Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Thanks,

Michael Koblic,
Campbell River, BC

I like these:
http://www.kalamazooind.com/products...exing-fixture/
I bought two used ones for ~$50 each and mounted one on an angle plate
with the axis vertical. If necessary the second can serve as a
tailstock to steady a long shaft, like the splined pulley broach I
have to make soon.

The Spin Indexer is less rigid but can be set to 1 degree with the
vernier holes on the top:
http://www.phase2plus.com/details.as...IN_INDEX&id=58

A chuck for them:
http://www.tools4cheap.net/proddetail.php?prod=5c3jaw

Then there's this:
http://www.harborfreight.com/3-inch-...kit-98077.html

The rotation load is VERY important when milling if the work diameter
is larger than the shaft clamp. You can arrange a clamp that secures
the work directly to the mill table at the cost of inconvenience.

jsw

I have looked at all of those at one time or another. I rejected the
spin indexer because of the 5C collets. The chuck adds $100 to the
cost. The rotary tables have the same problem.

Right now the job is to drill several cross holes in round stock at
precise but not necessarily outlandish angles. I was also trying to
use what was in the drawer. Maybe even learn how to thread on a lathe
:-)

I was going to buy the Grizzly rapid indexer but both Grizzly and Busy
Bee are out of stock. Also at 6" it would probably bee a tad too big
for my X2.

I suppose an option would be a spin indexer, a 3/4" collet holding a
short shaft with 3/4"-16 thread and a Taig chuck. Now that you made me
look at things again I should consider it.

Michael Koblic,
Campbell River, BC

On Mar 9, 1:47*am, wrote:
I was going to make a quick and dirty dividing head to use with my
Taig chucks on my X2 mill.

I thought I would basically run a shaft through a block of aluminum
with 3/4-16 thread on one end and a dividing plate on the other. Then
I thought: What shaft? What bearings?

Primary concerns here are not the rotation loads but absence of radial
and axial movement of the shaft.

I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?
Presumably a steel shaft would wear out the aluminum. Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Thanks,

Michael Koblic,
Campbell River, BC

Current Home Shop Machinist has a how-to for a cheapie indexer using
change wheels on an Atlas 6". I've seen similar using just a block of
scrapbox steel and a shaft with suitable arrangements for attaching
the gears. No bearings used besides a good running fit. A spring-
loaded plunger to fit the gaps in the teeth does the indexing.
Probably an afternoon's project. Or you can just get a 5C indexing
block set and have at it.

Stan

On 2011-03-09, wrote:
I was going to make a quick and dirty dividing head to use with my
Taig chucks on my X2 mill.

I thought I would basically run a shaft through a block of aluminum
with 3/4-16 thread on one end and a dividing plate on the other. Then
I thought: What shaft? What bearings?

Primary concerns here are not the rotation loads but absence of radial
and axial movement of the shaft.

I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?

Likely to suffer galling.

Presumably a steel shaft would wear out the aluminum.

Actually -- a polished steel shaft would be a better bearing
with the aluminum housing than an al-al interface. keep it lubed, of
course.

Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

How much load forces are you expecting?

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Or -- perhaps get an old Unimat or Emco-Maier dividing head, if
you need no more than 60 divisions.

Of course -- the Unimat ones go for crazy money these days, if
you can find them on eBay at all. People are *collecting* these things
instead of using them. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 10 Mar 2011 01:13:51 GMT, "DoN. Nichols"
wrote:

[...]


I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?

Likely to suffer galling.

Presumably a steel shaft would wear out the aluminum.

Actually -- a polished steel shaft would be a better bearing
with the aluminum housing than an al-al interface. keep it lubed, of
course.

OK, thanks, I don't have a clue about this stuff.

Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

How much load forces are you expecting?

Drilling cross holes type of forces. However, if one could make it
more versatile by simple means, why not?

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Or -- perhaps get an old Unimat or Emco-Maier dividing head, if
you need no more than 60 divisions.

Of course -- the Unimat ones go for crazy money these days, if
you can find them on eBay at all. People are *collecting* these things
instead of using them. :-)

I saw a really neat little rotary table in the Proxxon catalog. It had
an integral chuck. I have not been able to find a dealer for it so
far.

But given the principles you outlined I might be able to knock
something together.

Michael Koblic,
Campbell River, BC

"DoN. Nichols" wrote in message
...


People are *collecting* these things instead of using them. :-)

To quote:

Warren Buffett


The line separating investment and speculation, which is never bright and
clear, becomes blurred still further when most market participants have
recently enjoyed triumphs. Nothing sedates rationality like large doses of
effortless money. After a heady experience of that kind, normally sensible
people drift into behavior akin to that of Cinderella at the ball. They know
that overstaying the festivities -- that is, continuing to speculate in
companies that have gigantic valuations relative to the cash they are likely
to generate in the future -- will eventually bring on pumpkins and mice. But
they nevertheless hate to miss a single minute of what is one helluva party.
Therefore, the giddy participants all plan to leave just seconds before
midnight. There's a problem, though: They are dancing in a room in which the
clocks have no hands.
a.. Berkshire Hathaway 2000 Chairman's Letter

I don't mind dividing head but I always get the first round and then the
rest of you guys can have her after that.

------------------

wrote in message ...

I was going to make a quick and dirty dividing head to use with my
Taig chucks on my X2 mill.

I thought I would basically run a shaft through a block of aluminum
with 3/4-16 thread on one end and a dividing plate on the other. Then
I thought: What shaft? What bearings?

Primary concerns here are not the rotation loads but absence of radial
and axial movement of the shaft.

I am not sure what engineering principles apply. Would an aluminum
shaft with a slip fit through a hole in the aluminum block suffice?
Presumably a steel shaft would wear out the aluminum. Would it be
better to use a steel shaft with bronze bushings? Ball-bearings seem a
bit of an overkill.

Maybe by the time I think this through I will find it expedient to get
a Taig headstock for $60+ and use it as a base for the project (a
common approach, apparently). However, I would still like to know what
is the correct approach if building from scratch.

Thanks,

Michael Koblic,
Campbell River, BC