I'm working on a piece of pharmaceutical equipment that has a minor mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2" that fits on a steel shaft. The aluminum is split and tightened with a set screw. The problem is that the hole in the AL is somewhat buggered, and I can't tighten the setscrew enough to get a really solid grip.

I can't shut the machine down long enough to do a proper repair, so I was thinking that I could just glue the sucker in place. Ordinarily, I'd think that even green loctite 290 would do the job without any disassembly, or even just some "Crazy glue". The problem is that neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have curing times measured in tens of hours. The most they'll tolerate here is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

On Sunday, October 25, 2015 at 4:06:18 PM UTC-4, rangerssuck wrote:
I'm working on a piece of pharmaceutical equipment that has a minor mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2" that fits on a steel shaft. The aluminum is split and tightened with a set screw. The problem is that the hole in the AL is somewhat buggered, and I can't tighten the setscrew enough to get a really solid grip.

I can't shut the machine down long enough to do a proper repair, so I was thinking that I could just glue the sucker in place. Ordinarily, I'd think that even green loctite 290 would do the job without any disassembly, or even just some "Crazy glue". The problem is that neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have curing times measured in tens of hours. The most they'll tolerate here is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

I assume that taking it apart to put in a helicoil or Keensert takes too long.

What about making a replacement part complete with keensert and just remove and replace. Might be faster than putting a keensert in the existing part..

There is crazy glue used in place of stitches in surgery. Don't know if it is food safe, but I would think it is. Maybe contact your local emergency room to find out if the stuff used for surgery is food safe and where to get it.

And then there is something like putting a wooden match stick in a stripped out screw hole. Maybe aluminum wire or wood from a wooden dowel.

I expect none of the above is possible, but they might give you an idea of something that is possible.

Dan

On Sunday, October 25, 2015 at 4:24:09 PM UTC-4, wrote:


I assume that taking it apart to put in a helicoil or Keensert takes too long.

What about making a replacement part complete with keensert and just remove and replace. Might be faster than putting a keensert in the existing part.

There is crazy glue used in place of stitches in surgery. Don't know if it is food safe, but I would think it is. Maybe contact your local emergency room to find out if the stuff used for surgery is food safe and where to get it.

And then there is something like putting a wooden match stick in a stripped out screw hole. Maybe aluminum wire or wood from a wooden dowel.

I expect none of the above is possible, but they might give you an idea of something that is possible.

Dan

Oh yes , filing a flat or drilling a dimple so the set screw is not trying to grip a smooth shaft.

Dan

rangerssuck wrote:
I'm working on a piece of pharmaceutical equipment that has a minor
mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2"
that fits on a steel shaft. The aluminum is split and tightened with
a set screw. The problem is that the hole in the AL is somewhat
buggered, and I can't tighten the setscrew enough to get a really
solid grip.

I can't shut the machine down long enough to do a proper repair, so I
was thinking that I could just glue the sucker in place. Ordinarily,
I'd think that even green loctite 290 would do the job without any
disassembly, or even just some "Crazy glue". The problem is that
neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have
curing times measured in tens of hours. The most they'll tolerate
here is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

If the hole is already bad how about removing the current set screw and
replacing it with a different size? IE if it's a metric size - find an
SAE that is a bit larger but a close thread and screw that in. Or
reverse that if it's SAE. Should work and give you some time.

--
Steve W.

"rangerssuck" wrote in message
...
I'm working on a piece of pharmaceutical equipment that has a minor
mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2"
that fits on a steel shaft. The aluminum is split and tightened with a
set screw. The problem is that the hole in the AL is somewhat
buggered, and I can't tighten the setscrew enough to get a really
solid grip.

I can't shut the machine down long enough to do a proper repair, so I
was thinking that I could just glue the sucker in place. Ordinarily,
I'd think that even green loctite 290 would do the job without any
disassembly, or even just some "Crazy glue". The problem is that
neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have
curing times measured in tens of hours. The most they'll tolerate here
is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

=============

Stainless shim stock?

This is great thin, stiff material if you can find a small piece:
http://usaknifemaker.com/knife-makin...-to-2240f.html

I've used aluminum auto body tape for shimming, to fit a Morse #2
arbor snugly into my B&S #7 mill spindle for instance, but it might
shed particles.

-jsw

On Sunday, October 25, 2015 at 4:28:49 PM UTC-4, wrote:
On Sunday, October 25, 2015 at 4:24:09 PM UTC-4, wrote:


I assume that taking it apart to put in a helicoil or Keensert takes too long.

What about making a replacement part complete with keensert and just remove and replace. Might be faster than putting a keensert in the existing part.

There is crazy glue used in place of stitches in surgery. Don't know if it is food safe, but I would think it is. Maybe contact your local emergency room to find out if the stuff used for surgery is food safe and where to get it.

And then there is something like putting a wooden match stick in a stripped out screw hole. Maybe aluminum wire or wood from a wooden dowel.

I expect none of the above is possible, but they might give you an idea of something that is possible.

Dan

Oh yes , filing a flat or drilling a dimple so the set screw is not trying to grip a smooth shaft.

Dan

I appreciate the suggestions, but I guess i wasn't clear. The part does not have a setscrew to hold it on the shaft, it has a clamping screw to squeeze its split hole onto the shaft, and it can't squeeze tight enough.

I have thought about running a hacksaw blade through the slot to allow for more squeeze, but the hole itself is pretty well buggered, and squeezing tighter will make for less contact area, I think.

Surprisingly, the cyanoacrylates used in surgery are not designated food safe, neither are the UV curing acrylics used in dentistry. Apparently something has changed recently about this, as I see many references on the web to adhesives that are food safe, and then checking the manufacturer's sites, see that they specifically point out that they are NOT food safe. Rhino glue is one example. Lots of references in various forums, but manufacture is very specific in saying that it is NOT food safe.

while I agree that this is an example of too much government (actually, it's just two parts of the same agency (FDA) not being on the same page), I can't use anything that isn't documented food safe on these machines.

what I may try is drilling the hole round again, and then making a sleeve of shim stock to snug it up. What do y'll think about that?

On Sunday, October 25, 2015 at 5:33:11 PM UTC-4, Jim Wilkins wrote:
"rangerssuck" wrote in message
...
I'm working on a piece of pharmaceutical equipment that has a minor
mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2"
that fits on a steel shaft. The aluminum is split and tightened with a
set screw. The problem is that the hole in the AL is somewhat
buggered, and I can't tighten the setscrew enough to get a really
solid grip.

I can't shut the machine down long enough to do a proper repair, so I
was thinking that I could just glue the sucker in place. Ordinarily,
I'd think that even green loctite 290 would do the job without any
disassembly, or even just some "Crazy glue". The problem is that
neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have
curing times measured in tens of hours. The most they'll tolerate here
is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

=============

Stainless shim stock?

This is great thin, stiff material if you can find a small piece:
http://usaknifemaker.com/knife-makin...-to-2240f.html

I've used aluminum auto body tape for shimming, to fit a Morse #2
arbor snugly into my B&S #7 mill spindle for instance, but it might
shed particles.

-jsw

We just posted pretty much the same idea at the same time as you. I'm thinking that I might drill the hole out to make it round and then add some shim stock to make it fit. In this particular case, it doesn't have to be SS, as this machine is wiped down to clean it, rather than washed with a hose.

On Sunday, October 25, 2015 at 5:39:03 PM UTC-4, rangerssuck wrote:
On Sunday, October 25, 2015 at 4:28:49 PM UTC-4, wrote:
On Sunday, October 25, 2015 at 4:24:09 PM UTC-4, wrote:


I assume that taking it apart to put in a helicoil or Keensert takes too long.

What about making a replacement part complete with keensert and just remove and replace. Might be faster than putting a keensert in the existing part.

There is crazy glue used in place of stitches in surgery. Don't know if it is food safe, but I would think it is. Maybe contact your local emergency room to find out if the stuff used for surgery is food safe and where to get it.

And then there is something like putting a wooden match stick in a stripped out screw hole. Maybe aluminum wire or wood from a wooden dowel.

I expect none of the above is possible, but they might give you an idea of something that is possible.

Dan

Oh yes , filing a flat or drilling a dimple so the set screw is not trying to grip a smooth shaft.

Dan

I appreciate the suggestions, but I guess i wasn't clear. The part does not have a setscrew to hold it on the shaft, it has a clamping screw to squeeze its split hole onto the shaft, and it can't squeeze tight enough.

I have thought about running a hacksaw blade through the slot to allow for more squeeze, but the hole itself is pretty well buggered, and squeezing tighter will make for less contact area, I think.

Surprisingly, the cyanoacrylates used in surgery are not designated food safe, neither are the UV curing acrylics used in dentistry. Apparently something has changed recently about this, as I see many references on the web to adhesives that are food safe, and then checking the manufacturer's sites, see that they specifically point out that they are NOT food safe. Rhino glue is one example. Lots of references in various forums, but manufacture is very specific in saying that it is NOT food safe.

while I agree that this is an example of too much government (actually, it's just two parts of the same agency (FDA) not being on the same page), I can't use anything that isn't documented food safe on these machines.

what I may try is drilling the hole round again, and then making a sleeve of shim stock to snug it up. What do y'll think about that?

BTW, see he http://www.permabond.com/blog/2015/0...ves-permabond/ for permabond's reasoning. I will contact them in the morning to find out about heating epoxies to speed them up, but I don't hold out a lot of hope for making them really fast.

"rangerssuck" wrote in message
...
On Sunday, October 25, 2015 at 4:28:49 PM UTC-4, wrote:
On Sunday, October 25, 2015 at 4:24:09 PM UTC-4,
wrote:


I assume that taking it apart to put in a helicoil or Keensert
takes too long.

What about making a replacement part complete with keensert and
just remove and replace. Might be faster than putting a keensert
in the existing part.

There is crazy glue used in place of stitches in surgery. Don't
know if it is food safe, but I would think it is. Maybe contact
your local emergency room to find out if the stuff used for
surgery is food safe and where to get it.

And then there is something like putting a wooden match stick in a
stripped out screw hole. Maybe aluminum wire or wood from a
wooden dowel.

I expect none of the above is possible, but they might give you an
idea of something that is possible.

Dan

Oh yes , filing a flat or drilling a dimple so the set screw is not
trying to grip a smooth shaft.

Dan

I appreciate the suggestions, but I guess i wasn't clear. The part
does not have a setscrew to hold it on the shaft, it has a clamping
screw to squeeze its split hole onto the shaft, and it can't squeeze
tight enough.

I have thought about running a hacksaw blade through the slot to allow
for more squeeze, but the hole itself is pretty well buggered, and
squeezing tighter will make for less contact area, I think.

Surprisingly, the cyanoacrylates used in surgery are not designated
food safe, neither are the UV curing acrylics used in dentistry.
Apparently something has changed recently about this, as I see many
references on the web to adhesives that are food safe, and then
checking the manufacturer's sites, see that they specifically point
out that they are NOT food safe. Rhino glue is one example. Lots of
references in various forums, but manufacture is very specific in
saying that it is NOT food safe.

while I agree that this is an example of too much government
(actually, it's just two parts of the same agency (FDA) not being on
the same page), I can't use anything that isn't documented food safe
on these machines.

what I may try is drilling the hole round again, and then making a
sleeve of shim stock to snug it up. What do y'll think about that?

===========================

I did that a few days ago to replace a missing and out-of-dealer-stock
Nyliner bushing on my new-to-me 1995 snowthrower. The job took much
longer than 10 minutes, mostly in setup, as in locating the center of
the worn original hole. Had it been more precise machinery I would
have single-point bored the hole because drill bits follow what's
there.
http://www.marcospecialties.com/pinball-parts/20-8790-5

There's a metal version meant to repair worn shafts. The local bearing
supply store has one displayed in their lobby but I don't remember who
makes them.

-jsw

On 10/25/2015 5:38 PM, rangerssuck wrote:

what I may try is drilling the hole round again, and then making a
sleeve of shim stock to snug it up. What do y'll think about that?

Can you re-thread it in a bigger size? Can you centerpunch all around
the hole? Can you squeeze the piece with a vise-grip and cave in the
threads a bit? Can you slice the screw down the middle a bit with a
thin blade and wedge the screw?

"rangerssuck" wrote in message
...
On Sunday, October 25, 2015 at 5:33:11 PM UTC-4, Jim Wilkins wrote:
"rangerssuck" wrote in message
...
I'm working on a piece of pharmaceutical equipment that has a minor
mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2"
that fits on a steel shaft. The aluminum is split and tightened with
a
set screw. The problem is that the hole in the AL is somewhat
buggered, and I can't tighten the setscrew enough to get a really
solid grip.

I can't shut the machine down long enough to do a proper repair, so
I
was thinking that I could just glue the sucker in place. Ordinarily,
I'd think that even green loctite 290 would do the job without any
disassembly, or even just some "Crazy glue". The problem is that
neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have
curing times measured in tens of hours. The most they'll tolerate
here
is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

=============

Stainless shim stock?

This is great thin, stiff material if you can find a small piece:
http://usaknifemaker.com/knife-makin...-to-2240f.html

I've used aluminum auto body tape for shimming, to fit a Morse #2
arbor snugly into my B&S #7 mill spindle for instance, but it might
shed particles.

-jsw

We just posted pretty much the same idea at the same time as you. I'm
thinking that I might drill the hole out to make it round and then add
some shim stock to make it fit. In this particular case, it doesn't
have to be SS, as this machine is wiped down to clean it, rather than
washed with a hose.

==============================
Thin brass stock is much easier to find, at a hobby store.

I have aluminum pulley wheels with brass center bushings on my TV
antenna guy lines and they haven't corroded.

-jsw

"Jim Wilkins" wrote in message
...

There's a metal version meant to repair worn shafts. The local
bearing supply store has one displayed in their lobby but I don't
remember who makes them.
-jsw

http://www.skf.com/us/products/vehic...its/index.html

http://www.timken.com/en-us/products...disleeves.aspx

http://daemar.com/shaft_repair_sleeves_17.html

If you split it with a Dremel it should slide onto the shaft.

If that solves the problem do I get (would I want?) a free sample of
the product?
-jsw

On 10/25/2015 4:06 PM, rangerssuck wrote:
I'm working on a piece of pharmaceutical equipment that has a minor mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2" that fits on a steel shaft. The aluminum is split and tightened with a set screw. The problem is that the hole in the AL is somewhat buggered, and I can't tighten the setscrew enough to get a really solid grip.

I can't shut the machine down long enough to do a proper repair, so I was thinking that I could just glue the sucker in place. Ordinarily, I'd think that even green loctite 290 would do the job without any disassembly, or even just some "Crazy glue". The problem is that neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have curing times measured in tens of hours. The most they'll tolerate here is more like ten minutes, during a lunch break or shift change.

So... any suggestions?



Put a hose clamp around it. They are made in stainless.

On Sunday, October 25, 2015 at 5:39:03 PM UTC-4, rangerssuck wrote:


what I may try is drilling the hole round again, and then making a sleeve of shim stock to snug it up. What do y'll think about that?

I think I would make a new part with a keensert. The thread should be a fine thread to get more clamping power.

I assume that you can not also make a shaft with a keyway in the shaft and the aluminium part. But maybe you could make a sleeve to fit on the shaft to increase the size of the shaft where the part is clamped on. It could be keyed or silver soldered on or set screw with dimple on shaft. I am assuming the shaft is something like a 1/4 inch dia. So with a sleeve increasing the diameter to say 3/4 inch , it would be much less inclined to slip.

Dan

On 2015-10-25, rangerssuck wrote:

I'm working on a piece of pharmaceutical equipment that has a minor
mechanical problem.

[ ... ]

I can't shut the machine down long enough to do a proper repair, so I
was thinking that I could just glue the sucker in place. Ordinarily, I'd
think that even green loctite 290 would do the job without any
disassembly, or even just some "Crazy glue". The problem is that neither
of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have
curing times measured in tens of hours. The most they'll tolerate here
is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

There are Cyano-accrilate glues which are used for surgical
sealing. I would think that they would be food safe -- but you would
have to check to be sure. Rules can be strange.

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 ---

On Sun, 25 Oct 2015 20:08:45 -0400, Steve Walker
wrote:

On 10/25/2015 4:06 PM, rangerssuck wrote:
I'm working on a piece of pharmaceutical equipment that has a minor mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2" that fits on a steel shaft. The aluminum is split and tightened with a set screw. The problem is that the hole in the AL is somewhat buggered, and I can't tighten the setscrew enough to get a really solid grip.

I can't shut the machine down long enough to do a proper repair, so I was thinking that I could just glue the sucker in place. Ordinarily, I'd think that even green loctite 290 would do the job without any disassembly, or even just some "Crazy glue". The problem is that neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have curing times measured in tens of hours. The most they'll tolerate here is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

Put a hose clamp around it. They are made in stainless.

Yeah, a hose clamp and some food-safe duct tape would be my
suggestion, too. Well, at least for him.

-
To change one's self is sufficient. It's the idiots who want
to change the world who are causing all the trouble.
--Anonymous

On 10/25/2015 6:08 PM, Jim Wilkins wrote:
"Jim Wilkins" wrote in message
...

There's a metal version meant to repair worn shafts. The local
bearing supply store has one displayed in their lobby but I don't
remember who makes them.
-jsw

http://www.skf.com/us/products/vehic...its/index.html

http://www.timken.com/en-us/products...disleeves.aspx

http://daemar.com/shaft_repair_sleeves_17.html

If you split it with a Dremel it should slide onto the shaft.

If that solves the problem do I get (would I want?) a free sample of
the product?
-jsw



Back in the 70's there was high quality methedrine in my neighborhood
and a pharmaceutical manufacturer less than two miles down the road.
Coincidence? No, it seems they hired the wrong person from my
neighborhood to work in the wrong area of the plant.
btw, it wasn't me.
Mikek

On Sunday, October 25, 2015 at 8:55:28 PM UTC-4, DoN. Nichols wrote:
On 2015-10-25, rangerssuck wrote:

I'm working on a piece of pharmaceutical equipment that has a minor
mechanical problem.

[ ... ]

I can't shut the machine down long enough to do a proper repair, so I
was thinking that I could just glue the sucker in place. Ordinarily, I'd
think that even green loctite 290 would do the job without any
disassembly, or even just some "Crazy glue". The problem is that neither
of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have
curing times measured in tens of hours. The most they'll tolerate here
is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

There are Cyano-accrilate glues which are used for surgical
sealing. I would think that they would be food safe -- but you would
have to check to be sure. Rules can be strange.

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 ---

Don - you WOULD think that, but you'd be wrong. That was the first place I looked. Of course, logic says that if it's safe inside your mouth, it would also be safe to get a small fraction of a microgram on a capsule, but these are approved under a different set of rules, and if the manufacturer hasn't specifically applied for a food safe rating, I can't use it.

On Sunday, October 25, 2015 at 7:08:01 PM UTC-4, Jim Wilkins wrote:
"Jim Wilkins" wrote in message
...

There's a metal version meant to repair worn shafts. The local
bearing supply store has one displayed in their lobby but I don't
remember who makes them.
-jsw

http://www.skf.com/us/products/vehic...its/index.html

http://www.timken.com/en-us/products...disleeves.aspx

http://daemar.com/shaft_repair_sleeves_17.html

If you split it with a Dremel it should slide onto the shaft.

If that solves the problem do I get (would I want?) a free sample of
the product?
-jsw

Those are a good idea, but all are too big - this shaft is less that a quarter inch. But, I think I'll drill the hole round, insert an aluminum plug, redrill the hole to proper size and then split it with a slitting saw. That ought to make a "good as new" repair. If I had a tig welder, I could just fill the hole... Yet another excuse to spend some money. But, I ought to be able to get this done under a half-hour.

I doubt you'd want anything from here. All they make is generic antibiotics.. Though, from the moment I walked in over a year ago, I thought this would make a great location for a remake of Breaking Bad Supersized. Stuff comes out of here in quantities of millions per day. Pretty cool stuff.

"rangerssuck" wrote in message
...
On Sunday, October 25, 2015 at 7:08:01 PM UTC-4, Jim Wilkins wrote:
"Jim Wilkins" wrote in message
...

There's a metal version meant to repair worn shafts. The local
bearing supply store has one displayed in their lobby but I don't
remember who makes them.
-jsw

http://www.skf.com/us/products/vehic...its/index.html

http://www.timken.com/en-us/products...disleeves.aspx

http://daemar.com/shaft_repair_sleeves_17.html

If you split it with a Dremel it should slide onto the shaft.

If that solves the problem do I get (would I want?) a free sample of
the product?
-jsw

Those are a good idea, but all are too big - this shaft is less that a
quarter inch. But, I think I'll drill the hole round, insert an
aluminum plug, redrill the hole to proper size and then split it with
a slitting saw. That ought to make a "good as new" repair. If I had a
tig welder, I could just fill the hole... Yet another excuse to spend
some money. But, I ought to be able to get this done under a
half-hour.

=============

"Less than a quarter inch" puts it into the range of hobby store
telescoping brass and aluminum tubing.

rangerssuck wrote:
I'm working on a piece of pharmaceutical equipment that has a minor mechanical problem. There's an aluminum piece about 1" x 1/4" x 1/2" that fits on a steel shaft. The aluminum is split and tightened with a set screw. The problem is that the hole in the AL is somewhat buggered, and I can't tighten the setscrew enough to get a really solid grip.

I can't shut the machine down long enough to do a proper repair, so I was thinking that I could just glue the sucker in place. Ordinarily, I'd think that even green loctite 290 would do the job without any disassembly, or even just some "Crazy glue". The problem is that neither of them is food safe, and rules are rules.

I have found several silicones that are food safe, but they all have curing times measured in tens of hours. The most they'll tolerate here is more like ten minutes, during a lunch break or shift change.

So... any suggestions?

Add some shim stock to get a tighter fit around the shaft? I use cut up
pop cans from the trash.

On 10/26/2015 9:42 AM, rangerssuck wrote:
... I think I'll drill the hole round, insert an aluminum plug, redrill the hole to proper size ...

Have you done the numbers? If you drill it to 3/8, that will only leave
1/16 on each side and the drilled-out plug will only have a 1/16 wall.