I have looked at a couple rotary tables on-line, but have not looked at one
in person. Are they designed so that they can be rotated continuously 360
degrees or do they have a travel limit? It seems obvious to me that they
should be designed for 3060 travel, but I have learned better than to assume
anything with metal working tools.

Bob La Londe
www.YumaBassMan.com

Bob La Londe wrote:

I have looked at a couple rotary tables on-line, but have not looked at one
in person. Are they designed so that they can be rotated continuously 360
degrees or do they have a travel limit? It seems obvious to me that they
should be designed for 3060 travel, but I have learned better than to assume
anything with metal working tools.

Bob La Londe
www.YumaBassMan.com


Infinite rotation, no stops. The tilting models do of course have a
limited range on the tilt axis.

There is full rotation of the table, Bob, as Pete commented, and on most RTs
the screw/worm can be disengaged to allow the table to turn freely (so ya
don't need to crank the handle to get to the opposite side).

For precision positioning, turning the handle to the next position would be
the most accurate way to ensure that the positions are precisely spaced by
the readings on the dial.

Being able to disengage the screw/worm allows quick movements for spacing
that doesn't require seconds of accuracy.

Some small RTs I've seen advertised don't have the feature where the worm
can be disengaged.

In addition to disengaging the worm, there should also be a screw to
adjust/limit the engagement of the worm. With this adjustable stop screw,
the amount of worm engagement can be adjusted so that each time the worm is
re-engaged, it stops just short of dragging or binding. When properly
adjusted, backlash is non-existent or at least minimal.

Another adjustment, which is important for acuracy, is a method of adjusting
out end play in the worm shaft. End play in the worm shaft will introduce
backlash and could allow the table to shift when the workpiece is being
machined (even though the table locks should prevent shifting).

A feature which is probably present on all RT models except for maybe a
couple of hobby RTs, is a resettable zero indicator on the handwheel dial.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Bob La Londe" wrote in message
...
I have looked at a couple rotary tables on-line, but have not looked at one
in person. Are they designed so that they can be rotated continuously 360
degrees or do they have a travel limit? It seems obvious to me that they
should be designed for 3060 travel, but I have learned better than to
assume anything with metal working tools.

Bob La Londe
www.YumaBassMan.com

On Mar 31, 12:51*pm, "Wild_Bill" wrote:
There is full rotation of the table, Bob, as Pete commented, and on most RTs
the screw/worm can be disengaged to allow the table to turn freely (so ya
don't need to crank the handle to get to the opposite side).

Mine has a separate 24 position hole circle and index pin for use when
the worm is disengaged.

In addition to disengaging the worm, there should also be a screw to
adjust/limit the engagement of the worm. With this adjustable stop screw,
the amount of worm engagement can be adjusted so that each time the worm is
re-engaged, it stops just short of dragging or binding. When properly
adjusted, backlash is non-existent or at least minimal......
--
WB

It doesn't quite work on mine, when tight on one side there is
backlash on the other, as though the 40 tooth gear isn't quite
centered on its bearings.

Some have graduated degree wheels, others a set of index plates which
are more precise and easier to use when you need to index some large
number of identical spaces, like cutting a gear. I think the degree
wheel might be easier to figure out if you had to rotate by one large
angle, such as making a plate cam or a smooth curve between protruding
arms, like this:
http://picasaweb.google.com/KB1DAL/T...75471032901730
Either way, they are tricky to use unless you are comfortable with
math and geometry.

Jim Wilkins

All the rotary table I know about continuously rotateable.

Bob Swinney
"Bob La Londe" wrote in message ...
I have looked at a couple rotary tables on-line, but have not looked at one
in person. Are they designed so that they can be rotated continuously 360
degrees or do they have a travel limit? It seems obvious to me that they
should be designed for 3060 travel, but I have learned better than to assume
anything with metal working tools.

Bob La Londe
www.YumaBassMan.com

Usually they can rotate indefinitely in one direction.

I have a Troyke DMT-15 for sale. This one, has a cross slide on top of
rotary, which makes it convenient to use, but very heavy. 12" top.

i

On 2009-03-31, Bob La Londe wrote:
I have looked at a couple rotary tables on-line, but have not looked at one
in person. Are they designed so that they can be rotated continuously 360
degrees or do they have a travel limit? It seems obvious to me that they
should be designed for 3060 travel, but I have learned better than to assume
anything with metal working tools.

Bob La Londe
www.YumaBassMan.com



--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

You could probably correct the loose/tight from one side to the other
problem, Jim.

The horizontal RT I bought used, had a couple of snug spots as the table
made a full rotation, I was able to get a completely uniform engagement by
gently scraping a couple of "gear teeth" spaces.
Then the entire rotation was silky smooth with essentially zero backlash. No
perceptible backlash can be felt by trying to force the table by hand,
anyway.

I bought a set of plates a while back, and yourself and a few others
answered my questions regarding the number of holes and the potential
applications.
I will definitely need to refer to Machinerys Handbook to be able to use
them with any degree of confidence.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Jim Wilkins" wrote in message
...
On Mar 31, 12:51 pm, "Wild_Bill" wrote:

In addition to disengaging the worm, there should also be a screw to
adjust/limit the engagement of the worm. With this adjustable stop screw,
the amount of worm engagement can be adjusted so that each time the worm
is
re-engaged, it stops just short of dragging or binding. When properly
adjusted, backlash is non-existent or at least minimal......
--
WB

It doesn't quite work on mine, when tight on one side there is
backlash on the other, as though the 40 tooth gear isn't quite
centered on its bearings.

Some have graduated degree wheels, others a set of index plates which
are more precise and easier to use when you need to index some large
number of identical spaces, like cutting a gear. I think the degree
wheel might be easier to figure out if you had to rotate by one large
angle, such as making a plate cam or a smooth curve between protruding
arms, like this:
http://picasaweb.google.com/KB1DAL/T...75471032901730
Either way, they are tricky to use unless you are comfortable with
math and geometry.

Jim Wilkins

Infinite rotation, no stops. The tilting models do of course have a
limited range on the tilt axis.

Tilting models: Not if they're on a hill and not anchored to the floor
somehow...
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Flagship Site: http://www.Drill-N-Tap.com

V8013-R

On Tue, 31 Mar 2009 08:05:50 -0700, "Bob La Londe"
wrote:

I have looked at a couple rotary tables on-line, but have not looked at one
in person. Are they designed so that they can be rotated continuously 360
degrees or do they have a travel limit? It seems obvious to me that they
should be designed for 3060 travel, but I have learned better than to assume
anything with metal working tools.

Bob La Londe
www.YumaBassMan.com

=============
While rotary tables in general have continuous rotation, you may
be better off with a dividing head. It all depends what you are
doing. Indeed it is possible that an inexpensive "spindex" (TM)
will be adequate if what you're machining will fit a 5C collet
and you only need integral degrees.
http://www.shars.com/product_categor..._Index_Fixture
http://www.penntoolco.com/catalog/pr...ategoryID=1464


Can you give us more information on the type of work that you
anticipate doing?

FWIW -- I bought a rotaty table and indexing plates [which is a
dividing head] from WTTOOL. I have no complaints, and it works
well, but is rough in operation and required some
cleaning/rework.
http://www.wttool.com/product-exec/product_id/20850
and
http://www.wttool.com/product-exec/p...Set_WT_Import_
also available
http://www.harborfreightusa.com/usa/...ateg oryName=
you can download instructions in pdf.

Unless money is exceptionally tight, and you can spend the time,
I suggest YUSA or HHIP. Note that even these dividing heads will
not cut gears with some prime numbers such as 127 teeth [metric
change gears] without a 127 tooth index plate, although you can
make your own 127 hole plate using the verneer dials. [Send me an
email if you want an excel spreadsheet to calculate the
degrees/min/sec for a given number of divisions.]
http://hhip.com/products/product_vie...ctID=3900-2308
http://hhip.com/products/product_vie...ctID=3900-2401
http://www1.mscdirect.com/CGI/NNPDFF...2468&PMCTLG=00
http://www1.mscdirect.com/CGI/NNPDFF...2468&PMCTLG=00


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).

On Tue, 31 Mar 2009 14:31:34 -0400, "Wild_Bill"
wrote:

I will definitely need to refer to Machinerys Handbook to be able to use
them with any degree of confidence.
--------
Also see

http://lindsaybks.com/dgjp/djgbk/series/index.html
{#1153 -- build your own dividing head -- good information on how
these work}
also see
http://lindsaybks.com/bks/mmindx/index.html
MM Indexing 23578 $8.95
and
Indexing 869 $4.00


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).