I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

Make a couple of flats! They won't compromise the strength, and will
ensure (if the screws are gum-locked) that there's no slippage.

If you 'dimple' instead of flatting, there also will be no longitudinal
play.

They make shaft-mounted stones for a reason! G

Lloyd

Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

PS... I missed the part about adjusting it.

Get a Climax coupling. They do NOT slip, period!

Lloyd

On 9/10/2013 0:47, Tom Gardner wrote:
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

Some locking arrangement with tapered parts comes to mind.

A couple of bolts to pull the taper tight, a couple of threads
at other end to release the taper. Quite standard arrangement
for pulleys, and handles lots of torque. "Taper lock" is one
trademark. You can get them as separate parts so you can use
your own cam follower, just bore the middle to match the OD
of the taper lock sleeve. Cost is quite low, around 20usd..
Untightening it is surprisingly easy with the bolts at the
opening threads, pushing the tapered parts apart.

"Tom Gardner" Mars@Tacks wrote in message
...
I have an application where a 1" dia. shaft is hard to R-62 and a part is
attached with two opposing 3/8" cup-point set screws. The part has a cam
follower on it and rotating the part on the shaft then locking it with the
set screws is a positioning adjustment. There is about 75 pounds of force
on the part. I hate this set-up! I just don't trust it not to slip but I
can't think of a better way of locking the part on the shaft yet be able to
adjust it easily.

Split ring clamp?

If you like set-screws, you can use a conical tipped screw in an off-center
hole so the side of the cone engages the side of the shaft.

You can also grind a shallow groove in the shaft where the screw makes
contact and leave it with a rough finish. Then use a brass-tipped screw
that would bite into the finish.

Kristian Ukkonen fired this volley in
:

Some locking arrangement with tapered parts comes to mind.

Climax coupling... G
Lloyd

On Mon, 09 Sep 2013 17:47:47 -0400, Tom Gardner Mars@Tacks wrote:

I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

Google "adjustable cam gears" and see if they give you any ideas.

Maybe.

--
Ed Huntress

On Mon, 09 Sep 2013 17:47:47 -0400, Tom Gardner Mars@Tacks
wrote:

I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.
====================

Although this will require a new hub and increase cost, one
of the best solutions is what is called a split cotter [not
cotter key] Very compact and has tremendous grip. Another
possibility is the commercial tapered collet and hub which
is tightened and removed with set screws. Also very compact
and strong but $$$.

http://bbs.homeshopmachinist.net/thr...-cotter-design
http://www.cnccookbook.com/MTMillKurtViseStop.htm
http://www.frets.com/HomeShopTech/Pr...longknurl.html

http://www.grainger.com/Grainger/wwg...130909222421:s
http://www.grainger.com/Grainger/wwg...rue&sst=subset

Tom Gardner wrote:

I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

How much adjustment range and how fine an adjustment is needed? A
splined setup comes to mind, 36 spline, 10 degree adjustments. How about
pinning the shaft connection and making the adjustment offboard in the
cam follower arm with a threaded adjustment?

On 9/9/2013 5:59 PM, Lloyd E. Sponenburgh wrote:
Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

PS... I missed the part about adjusting it.

Get a Climax coupling. They do NOT slip, period!

Lloyd



Good idea, I should have room.

On 9/9/2013 6:26 PM, F. George McDuffee wrote:
On Mon, 09 Sep 2013 17:47:47 -0400, Tom Gardner Mars@Tacks
wrote:

I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.
====================

Although this will require a new hub and increase cost, one
of the best solutions is what is called a split cotter [not
cotter key] Very compact and has tremendous grip. Another
possibility is the commercial tapered collet and hub which
is tightened and removed with set screws. Also very compact
and strong but $$$.

http://bbs.homeshopmachinist.net/thr...-cotter-design
http://www.cnccookbook.com/MTMillKurtViseStop.htm
http://www.frets.com/HomeShopTech/Pr...longknurl.html

http://www.grainger.com/Grainger/wwg...130909222421:s
http://www.grainger.com/Grainger/wwg...rue&sst=subset



Good solution!

On 9/9/2013 6:07 PM, anorton wrote:

"Tom Gardner" Mars@Tacks wrote in message
...
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has
a cam follower on it and rotating the part on the shaft then locking
it with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust
it not to slip but I can't think of a better way of locking the part
on the shaft yet be able to adjust it easily.

Split ring clamp?

If you like set-screws, you can use a conical tipped screw in an
off-center hole so the side of the cone engages the side of the shaft.

You can also grind a shallow groove in the shaft where the screw makes
contact and leave it with a rough finish. Then use a brass-tipped screw
that would bite into the finish.

No, I don't like set screws for this. I like the different clamp style
parts!

On Mon, 09 Sep 2013 19:13:48 -0400, Tom Gardner Mars@Tacks wrote:

On 9/9/2013 5:59 PM, Lloyd E. Sponenburgh wrote:
Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

PS... I missed the part about adjusting it.

Get a Climax coupling. They do NOT slip, period!

Lloyd



Good idea, I should have room.

My mind must be in the gutter, thought I was missing a love position.

I looked it up. I call these locking collars and use them to time cup
conveyors on my packing line. They have never slipped.

Karl

Say I have a place where apples are transferred from singular cups to
wieght cups and the timing must be perfect.

The chain between the two makes a U around an idler sprocket. This
sprocket can be quickly rasied/lowered with a threaded bolt and
handweel, changing the length of chain between the singulator and
weight cup conveyors and thus the timing. Quick and accurate to change
while the machine runs.

may not fit your application, but one clever idea.

Karl

Tom Gardner wrote:

I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.
You need a collet setup. It sounds like you have a hub on the
cam where the setscrews are. Turn the OD of the hub to a
smooth, constant diameter. Slot across the hub, probably twice
at right angles. Then, make a snug-fitting collar that goes around the
hub. Make one slit in the collar and cross-drill for a setscrew that
will close up the slit. (Easier to drill and tap first, then saw-cut
the slit.) When this is clamped firmly over the hub, it forms a
collet that can be VERY tight.

Jon

On 2013-09-09, Tom Gardner Mars@Tacks wrote:
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

Hmm ... A cup-head won't do much for you unless it can deform
the shaft -- which then makes subsequent adjustments more difficult.

Instead -- there are setscrews with a soft ball end (something
like silver or aluminum in a cup point) so it deforms and grips the
shaft without deforming the shaft.

Or consider putting annealed copper slugs turned to be the
minor diameter of the thread or a bit smaller under the cup-point (or
better, flat-point) setscrew. Every so many re-adjustments, pull out
the copper slugs and replace with fresh ones, as they will work harden.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) 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 ---

Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.


Right up my alley, Tom..

--but you're so much of a jack ass that I'm not going to offer you help with
this one, or with anything else, for that matter.

On 10/09/2013 8:03 AM, Karl Townsend wrote:
On Mon, 09 Sep 2013 19:13:48 -0400, Tom Gardner Mars@Tacks wrote:

On 9/9/2013 5:59 PM, Lloyd E. Sponenburgh wrote:
Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

PS... I missed the part about adjusting it.

Get a Climax coupling. They do NOT slip, period!

Lloyd



Good idea, I should have room.

My mind must be in the gutter, thought I was missing a love position.

I looked it up. I call these locking collars and use them to time cup
conveyors on my packing line. They have never slipped.

Karl




My mind must be in the gutter, on my side of the pond we call cup
conveyers brassieres.

On Tue, 10 Sep 2013 16:03:18 +0800, Scromlette
wrote:

On 10/09/2013 8:03 AM, Karl Townsend wrote:
On Mon, 09 Sep 2013 19:13:48 -0400, Tom Gardner Mars@Tacks wrote:

On 9/9/2013 5:59 PM, Lloyd E. Sponenburgh wrote:
Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

PS... I missed the part about adjusting it.

Get a Climax coupling. They do NOT slip, period!

Lloyd



Good idea, I should have room.

My mind must be in the gutter, thought I was missing a love position.

I looked it up. I call these locking collars and use them to time cup
conveyors on my packing line. They have never slipped.

Karl




My mind must be in the gutter, on my side of the pond we call cup
conveyers brassieres.

Poor Karl. From this day hence, he'll be thought of as

The Apple Brassierier.

Or should that be The Apple Bra Bro? snort


(Sorry, Karl.)

--
[Television is] the triumph of machine over people.
-- Fred Allen

"PrecisionmachinisT" wrote in message
news:H_ydncQ00b1oXrPPnZ2dnUVZ_uednZ2d@scnresearch. com...

Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.


Right up my alley, Tom..

--but you're so much of a jack ass that I'm not going to offer you help
with this one, or with anything else, for that matter.


You're the jackass . Opinionated , rude , and often just plain mean .
Bubbye
--
Snag

On 9/10/2013 4:03 AM, Scromlette wrote:
On 10/09/2013 8:03 AM, Karl Townsend wrote:
On Mon, 09 Sep 2013 19:13:48 -0400, Tom Gardner Mars@Tacks wrote:

On 9/9/2013 5:59 PM, Lloyd E. Sponenburgh wrote:
Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part
on the
shaft yet be able to adjust it easily.

PS... I missed the part about adjusting it.

Get a Climax coupling. They do NOT slip, period!

Lloyd



Good idea, I should have room.

My mind must be in the gutter, thought I was missing a love position.

I looked it up. I call these locking collars and use them to time cup
conveyors on my packing line. They have never slipped.

Karl




My mind must be in the gutter, on my side of the pond we call cup
conveyers brassieres.

Do they use "Cup-Point" set screws?

On 9/9/2013 8:47 PM, Karl Townsend wrote:
Say I have a place where apples are transferred from singular cups to
wieght cups and the timing must be perfect.

The chain between the two makes a U around an idler sprocket. This
sprocket can be quickly rasied/lowered with a threaded bolt and
handweel, changing the length of chain between the singulator and
weight cup conveyors and thus the timing. Quick and accurate to change
while the machine runs.

may not fit your application, but one clever idea.

Karl


I use that method on auto wire cutters where the cut bundle fits in a
trough on a chain.

Tom Gardner Mars@Tacks fired this volley in
:

Do they use "Cup-Point" set screws?

Nope... 'called "pointed tit" screws.

Lloyd

On 9/9/2013 10:22 PM, Jon Elson wrote:
Tom Gardner wrote:

I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.
You need a collet setup. It sounds like you have a hub on the
cam where the setscrews are. Turn the OD of the hub to a
smooth, constant diameter. Slot across the hub, probably twice
at right angles. Then, make a snug-fitting collar that goes around the
hub. Make one slit in the collar and cross-drill for a setscrew that
will close up the slit. (Easier to drill and tap first, then saw-cut
the slit.) When this is clamped firmly over the hub, it forms a
collet that can be VERY tight.

Jon


Yep, I agree.

On 9/10/2013 1:03 AM, DoN. Nichols wrote:
On 2013-09-09, Tom Gardner Mars@Tacks wrote:
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has a
cam follower on it and rotating the part on the shaft then locking it
with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.

Hmm ... A cup-head won't do much for you unless it can deform
the shaft -- which then makes subsequent adjustments more difficult.

Instead -- there are setscrews with a soft ball end (something
like silver or aluminum in a cup point) so it deforms and grips the
shaft without deforming the shaft.

Or consider putting annealed copper slugs turned to be the
minor diameter of the thread or a bit smaller under the cup-point (or
better, flat-point) setscrew. Every so many re-adjustments, pull out
the copper slugs and replace with fresh ones, as they will work harden.

Good Luck,
DoN.


I only have about 7/16" thread to work with.

Maybe a small point, but having the set screws opposite each other would be
the worst way to use set screws, wouldn't it? If you have to use two of
them, shouldn't they be 90 degrees from each other so they are both pulling
the part toward the same side of shaft?

Pete Stanaitis
---------------

"Tom Gardner" Mars@Tacks wrote in message
...
I have an application where a 1" dia. shaft is hard to R-62 and a part is
attached with two opposing 3/8" cup-point set screws. The part has a cam
follower on it and rotating the part on the shaft then locking it with the
set screws is a positioning adjustment. There is about 75 pounds of force
on the part. I hate this set-up! I just don't trust it not to slip but I
can't think of a better way of locking the part on the shaft yet be able
to adjust it easily.

"Snag"
wrote in message

"PrecisionmachinisT"
wrote in message

Tom Gardner
fired this volley in

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way
of locking the part on the
shaft yet be able to adjust it easily.


Right up my alley, Tom..

--but you're so much of a jack ass that I'm not
going to offer you help with this one, or with
anything else, for that matter.


You're the jackass . Opinionated , rude , and
often just plain mean .
Bubbye
--
Snag

Yup, hacksaw is a jackass.... must be hard to work
with him, eih?
He thinks he is the boss, but is really just a
frustrated worker.

"Phil Kangas" wrote in message
...

"Snag"
wrote in message

"PrecisionmachinisT"
wrote in message

Tom Gardner
fired this volley in

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on
the
shaft yet be able to adjust it easily.


Right up my alley, Tom..

--but you're so much of a jack ass that I'm not going to offer you help
with this one, or with anything else, for that matter.


You're the jackass . Opinionated , rude , and often just plain mean .
Bubbye
--
Snag

Yup, hacksaw is a jackass.... must be hard to work with him, eih?

All I've ever done with Tom, and you, Phil, is to respond in kind.

He thinks he is the boss, but is really just a frustrated worker.

On 9/10/2013 11:05 AM, Pete S wrote:
Maybe a small point, but having the set screws opposite each other would
be the worst way to use set screws, wouldn't it? If you have to use
two of them, shouldn't they be 90 degrees from each other so they are
both pulling the part toward the same side of shaft?

Pete Stanaitis
---------------
"Tom Gardner" Mars@Tacks wrote in message
...
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has
a cam follower on it and rotating the part on the shaft then locking
it with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust
it not to slip but I can't think of a better way of locking the part
on the shaft yet be able to adjust it easily.


Yep, but no room at 90. I figure that oposing is better than 1 screw.

On 9/10/2013 8:59 AM, Snag wrote:
"PrecisionmachinisT" wrote in message
news:H_ydncQ00b1oXrPPnZ2dnUVZ_uednZ2d@scnresearch. com...

Tom Gardner Mars@Tacks fired this volley in
:

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way of locking the part on the
shaft yet be able to adjust it easily.


Right up my alley, Tom..

--but you're so much of a jack ass that I'm not going to offer you help
with this one, or with anything else, for that matter.


You're the jackass . Opinionated , rude , and often just plain mean .
Bubbye
--
Snag



Watch out! He's got clips full of bullets for a handgun. He always has
on opinion that nobody wants...because he's usually wrong and since I
started calling him on his lack of knowledge he's pouting.

On 9/10/2013 1:14 PM, Phil Kangas wrote:

"Snag"
wrote in message

"PrecisionmachinisT"
wrote in message

Tom Gardner
fired this volley in

I hate this set-up! I just don't trust it
not to slip but I can't think of a better way
of locking the part on the
shaft yet be able to adjust it easily.


Right up my alley, Tom..

--but you're so much of a jack ass that I'm not
going to offer you help with this one, or with
anything else, for that matter.


You're the jackass . Opinionated , rude , and
often just plain mean .
Bubbye
--
Snag

Yup, hacksaw is a jackass.... must be hard to work
with him, eih?
He thinks he is the boss, but is really just a
frustrated worker.




He signs pay checks on the back, always has, always will.

On Tuesday, September 10, 2013 9:46:17 PM UTC-4, Tom Gardner wrote:




Yep, but no room at 90. I figure that opposing is better than 1 screw.

Actually it is not much better. Think of having two men pulling against each other on a rope. Now tie one end of the rope and just have one man pull. The tension in the rope is the same in both cases.

Is the part long enough that you can put two set screws both at the same degree.?

Dan

On 09/10/2013 08:46 PM, Tom Gardner wrote:
On 9/10/2013 11:05 AM, Pete S wrote:
Maybe a small point, but having the set screws opposite each other would
be the worst way to use set screws, wouldn't it? If you have to use
two of them, shouldn't they be 90 degrees from each other so they are
both pulling the part toward the same side of shaft?

Pete Stanaitis
---------------
"Tom Gardner" Mars@Tacks wrote in message
...
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has
a cam follower on it and rotating the part on the shaft then locking
it with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust
it not to slip but I can't think of a better way of locking the part
on the shaft yet be able to adjust it easily.


Yep, but no room at 90. I figure that oposing is better than 1 screw.

No. The action of the set screw pulls the opposite side of the part
against the shaft, and that is where most of the torque resistance comes
from, not from the screw itself. Two screws at 90 degrees assist each
other in pulling the part against the shaft. But, two opposing set
screws will fight each other. The part is not pulled against the shaft
anywhere, and the tiny tips of the screws are doing all the work.

Opposing sharp point set screws digging into a soft shaft might behave
the way you expected, but that's not what you have.

--
Bob Nichols AT comcast.net I am "RNichols42"

On 09/12/2013 07:03 AM, Robert Nichols wrote:
No. The action of the set screw pulls the opposite side of the part
against the shaft, and that is where most of the torque resistance comes
from, not from the screw itself. Two screws at 90 degrees assist each
other in pulling the part against the shaft. But, two opposing set
screws will fight each other. The part is not pulled against the shaft
anywhere, and the tiny tips of the screws are doing all the work.

Opposing sharp point set screws digging into a soft shaft might behave
the way you expected, but that's not what you have.

Afterthought: As a low-tech solution, put a little valve grinding
compound in the joint and use just one set screw.



--
Bob Nichols AT comcast.net I am "RNichols42"

On 9/11/2013 9:23 AM, wrote:
On Tuesday, September 10, 2013 9:46:17 PM UTC-4, Tom Gardner wrote:




Yep, but no room at 90. I figure that opposing is better than 1 screw.

Actually it is not much better. Think of having two men pulling against each other on a rope. Now tie one end of the rope and just have one man pull. The tension in the rope is the same in both cases.

Is the part long enough that you can put two set screws both at the same degree.?

Dan


I've pretty much decided to build a clamp the next time this part comes
into play. It does work OK as is, I just know better.

On 9/12/2013 8:03 AM, Robert Nichols wrote:
On 09/10/2013 08:46 PM, Tom Gardner wrote:
On 9/10/2013 11:05 AM, Pete S wrote:
Maybe a small point, but having the set screws opposite each other would
be the worst way to use set screws, wouldn't it? If you have to use
two of them, shouldn't they be 90 degrees from each other so they are
both pulling the part toward the same side of shaft?

Pete Stanaitis
---------------
"Tom Gardner" Mars@Tacks wrote in message
...
I have an application where a 1" dia. shaft is hard to R-62 and a part
is attached with two opposing 3/8" cup-point set screws. The part has
a cam follower on it and rotating the part on the shaft then locking
it with the set screws is a positioning adjustment. There is about 75
pounds of force on the part. I hate this set-up! I just don't trust
it not to slip but I can't think of a better way of locking the part
on the shaft yet be able to adjust it easily.


Yep, but no room at 90. I figure that opposing is better than 1 screw.

No. The action of the set screw pulls the opposite side of the part
against the shaft, and that is where most of the torque resistance comes
from, not from the screw itself. Two screws at 90 degrees assist each
other in pulling the part against the shaft. But, two opposing set
screws will fight each other. The part is not pulled against the shaft
anywhere, and the tiny tips of the screws are doing all the work.

Opposing sharp point set screws digging into a soft shaft might behave
the way you expected, but that's not what you have.


I see. The shaft is too hard for any setscrew to get a purchase, it's
only a pressure thing. I did notice that if either set screw is
loosened, the part will turn on the shaft. I'll build a clamping part.

On 9/12/2013 8:20 AM, Robert Nichols wrote:
On 09/12/2013 07:03 AM, Robert Nichols wrote:
No. The action of the set screw pulls the opposite side of the part
against the shaft, and that is where most of the torque resistance comes
from, not from the screw itself. Two screws at 90 degrees assist each
other in pulling the part against the shaft. But, two opposing set
screws will fight each other. The part is not pulled against the shaft
anywhere, and the tiny tips of the screws are doing all the work.

Opposing sharp point set screws digging into a soft shaft might behave
the way you expected, but that's not what you have.

Afterthought: As a low-tech solution, put a little valve grinding
compound in the joint and use just one set screw.





Yep! I've used that technique before.

On Thu, 12 Sep 2013 10:25:05 -0400, Tom Gardner Mars@Tacks
wrote:

I'll build a clamping part.
==============
Just hit my in-basket

see
http://www.industrialmachinerydigest...tp-hydropress/

On 9/26/2013 11:27 AM, F. George McDuffee wrote:
On Thu, 12 Sep 2013 10:25:05 -0400, Tom Gardner Mars@Tacks
wrote:

I'll build a clamping part.
==============
Just hit my in-basket

see
http://www.industrialmachinerydigest...tp-hydropress/




Slick device! I did make a simple split locking collar that works and
is easily adjusted. BUT...I will file away the Zero-Max! Thanks!