Topics

2465 Fan Collet Thingy


Chuck Harris
 

It should be pretty clear that even plastic works very
well.

The only broken collets were broken by people that didn't
read the manual, and guessed wrongly about how to remove
the impeller... Usually their wrong guess involved what
the slot on the threaded shaft was for.

If you hold the shaft by the slot in the screw, loosen
the nut with a wrench, and then give the end of the shaft
a tap with the butt of your screwdriver's handle, you
will never break another collet.

-Chuck Harris

GerryR wrote:

I'm pretty sure that the slots can be done, too, but from the drawing, it looks like
the part is a perfect candidate for a Swiss Screw Machine. If I was to make this
part, I actually would try making it in two pieces, the main body and I would insert
a threaded stud into the base, thereby giving threads all the way up to the body and
not having to thread it on the lathe. Loctite on the approximately 4 threads in the
body would hold it. Any reason it can't be made from steel; brass would be fine, as
well, but aluminum might be a little fragile for my liking. Just a thought.


----- Original Message ----- From: "Renée" <@rjdeeter>
To: <TekScopes@groups.io>
Sent: Monday, November 11, 2019 11:29 AM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy


I forgot....sorry
Renée

On 2019-11-11 7:55 a.m., Chuck Harris wrote:
Attachments are not allowed on this group.

The collet is in the files section. Log on to groups, and
search collet. It will come right up.

-Chuck Harris

GerryR wrote:
I can't see any attachment. If you have the drawing, can you email to
totalautomation1 at gee mail dot com. Thank you.

GerryR
KK4GER






Tom Gardner
 

On 11/11/19 18:19, Chuck Harris wrote:
It should be pretty clear that even plastic works very
well.

The only broken collets were broken by people that didn't
read the manual, and guessed wrongly about how to remove
the impeller... Usually their wrong guess involved what
the slot on the threaded shaft was for.

If you hold the shaft by the slot in the screw, loosen
the nut with a wrench, and then give the end of the shaft
a tap with the butt of your screwdriver's handle, you
will never break another collet.
Not entirely :(

I was well aware of that, and have removed a small number successfully using that technique.

Nonetheless, the last one fell apart: all four parts of the tapered section fractured at their base and, as they say,  "it just came away in my hand".


Chuck Harris
 

Hi Tom,

If you didn't buy the scope new from tektronix,
you have no idea what it has been through since
it was made.

I think a probable scenario is the last person that
removed the fan turned the screw slot, and heard a
cracking sound, quickly stopped turning, and went off
to read the manual...

I have also heard of people breaking the collet, and
"repairing" the break with crazy glue. Once you get
the collet to pull up, it doesn't matter if all of the
collet's jaws are broken.

Except to the guy that got stuck holding the bag.

But we will never know for sure.

-Chuck Harris

Tom Gardner wrote:

On 11/11/19 18:19, Chuck Harris wrote:
It should be pretty clear that even plastic works very
well.

The only broken collets were broken by people that didn't
read the manual, and guessed wrongly about how to remove
the impeller... Usually their wrong guess involved what
the slot on the threaded shaft was for.

If you hold the shaft by the slot in the screw, loosen
the nut with a wrench, and then give the end of the shaft
a tap with the butt of your screwdriver's handle, you
will never break another collet.
Not entirely :(

I was well aware of that, and have removed a small number successfully using that
technique.

Nonetheless, the last one fell apart: all four parts of the tapered section fractured
at their base and, as they say, "it just came away in my hand".




n4buq
 

It's strange to me how the stud that holds the collet tight appears to have been designed so that reversing the screw (with the screwdriver slot) would naturally push the collar on the stud against the impeller and push the collet open. The instructions don't say to do that and to simply grab the impeller and pull it but that doesn't seem to work (at least it didn't for me and, supposedly, that could easily break the impeller or strain the motor bearing surfaces, etc).

Fun stuff...

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 12:19:01 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

It should be pretty clear that even plastic works very
well.

The only broken collets were broken by people that didn't
read the manual, and guessed wrongly about how to remove
the impeller... Usually their wrong guess involved what
the slot on the threaded shaft was for.

If you hold the shaft by the slot in the screw, loosen
the nut with a wrench, and then give the end of the shaft
a tap with the butt of your screwdriver's handle, you
will never break another collet.

-Chuck Harris

GerryR wrote:
I'm pretty sure that the slots can be done, too, but from the drawing, it
looks like
the part is a perfect candidate for a Swiss Screw Machine. If I was to
make this
part, I actually would try making it in two pieces, the main body and I
would insert
a threaded stud into the base, thereby giving threads all the way up to the
body and
not having to thread it on the lathe. Loctite on the approximately 4
threads in the
body would hold it. Any reason it can't be made from steel; brass would be
fine, as
well, but aluminum might be a little fragile for my liking. Just a
thought.


----- Original Message ----- From: "Renée" <@rjdeeter>
To: <TekScopes@groups.io>
Sent: Monday, November 11, 2019 11:29 AM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy


I forgot....sorry
Renée

On 2019-11-11 7:55 a.m., Chuck Harris wrote:
Attachments are not allowed on this group.

The collet is in the files section. Log on to groups, and
search collet. It will come right up.

-Chuck Harris

GerryR wrote:
I can't see any attachment. If you have the drawing, can you email to
totalautomation1 at gee mail dot com. Thank you.

GerryR
KK4GER








Chuck Harris
 

Hi Barry,

The screw threads do NOT engage the impeller body. It is
a tight through hole. So, if you turned the screw slot,
all you would be doing is torquing the screw free of the
collet body. Which breaks the head of the collet, freeing
the collet's jaws.

When the collet is new, simply loosening the nut will allow
it to relax enough to be pulled off of the shaft... especially
given that pulling moves the collet in the direction of
release.

When the collet has been tightened for 2 or 3 decades, the
plastic of the impeller stretches out a little bit and
relaxes, leaving a pit for the collet to get stuck into.

That is why you need to loosen the nut, and give it a tap.

-Chuck Harris

n4buq wrote:

It's strange to me how the stud that holds the collet tight appears to have been designed so that reversing the screw (with the screwdriver slot) would naturally push the collar on the stud against the impeller and push the collet open. The instructions don't say to do that and to simply grab the impeller and pull it but that doesn't seem to work (at least it didn't for me and, supposedly, that could easily break the impeller or strain the motor bearing surfaces, etc).

Fun stuff...

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 12:19:01 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

It should be pretty clear that even plastic works very
well.


Bruce Griffiths
 

On 12 November 2019 at 04:34 Chuck Harris <cfharris@...> wrote:


I have a CD stud welder that can weld a 3/8" threaded stud onto
a piece of heavy sheet metal without burning the paint on the
other side... takes about 5ms to do the weld. Clearly a much
smaller "weld" would take less time and less energy.

I have thought that using a CD method to fuse the stock metal onto
the part being made might be effective. The big problem is avoiding
fusing the feedstock metal to the electrode.

A pulsed laser to a bed of powdered metal granules is probably
an ideal way of avoiding that issue... and avoiding metal distortion
due to the heat of fusion.

-Chuck Harris

EricJ via Groups.Io wrote:
It's out there now, but it's not trickled down to the hobbyist level yet. May be a while.

https://gpiprototype.com/metal-3d-printing

--Eric

On Nov 11, 2019 8:09 AM, Chuck Harris <cfharris@...> wrote:




Very cool, but not useful as the strength of these composite
filaments is entirely in the plastic binder.

-Chuck Harris


Chuck Harris
 

Looks like a MIG welder without the argon.

The vacuum would certainly reduce the power requirements for
the melt.

I wonder how warpage is managed?

-Chuck Harris

Bruce Griffiths wrote:

You mean something like this?:
https://www.sciaky.com/additive-manufacturing/electron-beam-additive-manufacturing-technology

Bruce
On 12 November 2019 at 04:34 Chuck Harris <cfharris@...> wrote:


I have a CD stud welder that can weld a 3/8" threaded stud onto
a piece of heavy sheet metal without burning the paint on the
other side... takes about 5ms to do the weld. Clearly a much
smaller "weld" would take less time and less energy.

I have thought that using a CD method to fuse the stock metal onto
the part being made might be effective. The big problem is avoiding
fusing the feedstock metal to the electrode.

A pulsed laser to a bed of powdered metal granules is probably
an ideal way of avoiding that issue... and avoiding metal distortion
due to the heat of fusion.

-Chuck Harris


n4buq
 

Hi Chuck,

That's not what I meant. When the stud is turned CCW, provided the collet doesn't break first, the threads in the collet itself would push the flanged part of the stud against the inside surface of the impeller. Of course, 10 times out of 9, the collet breaks before the threads allow the stud to turn because the stud is locked somewhat tightly against the back face of the collet.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 2:16:22 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

Hi Barry,

The screw threads do NOT engage the impeller body. It is
a tight through hole. So, if you turned the screw slot,
all you would be doing is torquing the screw free of the
collet body. Which breaks the head of the collet, freeing
the collet's jaws.

When the collet is new, simply loosening the nut will allow
it to relax enough to be pulled off of the shaft... especially
given that pulling moves the collet in the direction of
release.

When the collet has been tightened for 2 or 3 decades, the
plastic of the impeller stretches out a little bit and
relaxes, leaving a pit for the collet to get stuck into.

That is why you need to loosen the nut, and give it a tap.

-Chuck Harris

n4buq wrote:
It's strange to me how the stud that holds the collet tight appears to have
been designed so that reversing the screw (with the screwdriver slot)
would naturally push the collar on the stud against the impeller and push
the collet open. The instructions don't say to do that and to simply grab
the impeller and pull it but that doesn't seem to work (at least it didn't
for me and, supposedly, that could easily break the impeller or strain the
motor bearing surfaces, etc).

Fun stuff...

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 12:19:01 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

It should be pretty clear that even plastic works very
well.



Bruce Griffiths
 

Hybrid laser sintering and machining:
https://www.lumex-matsuura.com/english/about
N.B. for Titanium powder an inert atmosphere is required to avoid catastrophic fires.

Bruce

On 12 November 2019 at 10:46 Chuck Harris <cfharris@...> wrote:


Looks like a MIG welder without the argon.

The vacuum would certainly reduce the power requirements for
the melt.

I wonder how warpage is managed?

-Chuck Harris

Bruce Griffiths wrote:
You mean something like this?:
https://www.sciaky.com/additive-manufacturing/electron-beam-additive-manufacturing-technology

Bruce
On 12 November 2019 at 04:34 Chuck Harris <cfharris@...> wrote:


I have a CD stud welder that can weld a 3/8" threaded stud onto
a piece of heavy sheet metal without burning the paint on the
other side... takes about 5ms to do the weld. Clearly a much
smaller "weld" would take less time and less energy.

I have thought that using a CD method to fuse the stock metal onto
the part being made might be effective. The big problem is avoiding
fusing the feedstock metal to the electrode.

A pulsed laser to a bed of powdered metal granules is probably
an ideal way of avoiding that issue... and avoiding metal distortion
due to the heat of fusion.

-Chuck Harris


Chuck Harris
 

Hi Barry,

Ok, I see what you are saying.

What we don't know is how the average person
will respond when they see a tiny shaft going in,
and a screw slotted thread coming out.

I think most folks are not used to seeing a collet
in that context... but are pretty familiar with how
a screw works.

I suspect that most would observe the threads, and
intuit that the skinny shaft grows to be a threaded
shaft somehow inside of the hub of the impeller.

Since the threads of the slotted shaft are clockwise,
you would then need to turn the threaded shaft in the
clockwise (tighten) direction to move the shaft out of
the back of the impeller.. which will only serve to
further tighten the threaded stud into the threaded
insert, and break the collet.

If they were to turn the threaded shaft in the CCW
direction, it would likely do what you suggest, and
push the collet out.

But as you also say, 9 times out of 10, the plastic
is already full of small cracks from the stress risers
caused by the extreme diamond knurling on the brass insert,
and will simply shatter before the steel stud will break
free in the threads of the brass insert.

Of course a combination of tightening the threaded
shaft (and finding it didn't help), and then loosening
the threaded shaft would be fatal to the decades old
plastic.

-Chuck Harris

n4buq wrote:

Hi Chuck,

That's not what I meant. When the stud is turned CCW, provided the collet doesn't break first, the threads in the collet itself would push the flanged part of the stud against the inside surface of the impeller. Of course, 10 times out of 9, the collet breaks before the threads allow the stud to turn because the stud is locked somewhat tightly against the back face of the collet.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 2:16:22 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

Hi Barry,

The screw threads do NOT engage the impeller body. It is
a tight through hole. So, if you turned the screw slot,
all you would be doing is torquing the screw free of the
collet body. Which breaks the head of the collet, freeing
the collet's jaws.

When the collet is new, simply loosening the nut will allow
it to relax enough to be pulled off of the shaft... especially
given that pulling moves the collet in the direction of
release.

When the collet has been tightened for 2 or 3 decades, the
plastic of the impeller stretches out a little bit and
relaxes, leaving a pit for the collet to get stuck into.

That is why you need to loosen the nut, and give it a tap.

-Chuck Harris

n4buq wrote:
It's strange to me how the stud that holds the collet tight appears to have
been designed so that reversing the screw (with the screwdriver slot)
would naturally push the collar on the stud against the impeller and push
the collet open. The instructions don't say to do that and to simply grab
the impeller and pull it but that doesn't seem to work (at least it didn't
for me and, supposedly, that could easily break the impeller or strain the
motor bearing surfaces, etc).

Fun stuff...

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 12:19:01 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

It should be pretty clear that even plastic works very
well.





Chuck Harris
 

Milling the surface flat after several layers of metal
are deposited, and suddenly this is becoming very
complicated and expensive...

Though it would take care of the warpage.

-Chuck Harris

Bruce Griffiths wrote:

Hybrid laser sintering and machining:
https://www.lumex-matsuura.com/english/about
N.B. for Titanium powder an inert atmosphere is required to avoid catastrophic fires.

Bruce
On 12 November 2019 at 10:46 Chuck Harris <cfharris@...> wrote:


Looks like a MIG welder without the argon.

The vacuum would certainly reduce the power requirements for
the melt.

I wonder how warpage is managed?

-Chuck Harris


Siggi
 

On Mon, Nov 11, 2019 at 4:55 PM n4buq <n4buq@...> wrote:

When the stud is turned CCW, provided the collet doesn't break first, the
threads in the collet itself would push the flanged part of the stud
against the inside surface of the impeller.
I don't have much experience with this other than my own scope and
machining some replacement collets, but when I inspected my own scope, I
figured this is exactly what the stud is for. This is a very gentle way to
separate the two, as the thread's quite fine (32TPI). I can't see any
reason why Tek would have gone to the trouble of using this
double-threaded, collared stud, if not for this very purpose. It would have
been less expensive and simpler for sure to mold the collet around a
threaded stud that protruded out through the impeller.
On my scope, the collet was fractured all around the insert, while the
tapered end looked just fine. This commonly happens with parts molded
around inserts, over time the plastic wants to shrink, while the metal
insert is unyielding.


n4buq
 

That's exactly where mine broke but since it broke so cleanly, it provided a relatively smooth, flat surface to which the CA glue could adhere.

Being a little picky, but the other end of that stud is 40 t.p.i. so an even finer pitch (#4-40 on one end and #8-32 on the other).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Siggi" <siggi@...>
To: TekScopes@groups.io
Sent: Monday, November 11, 2019 5:18:10 PM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

On Mon, Nov 11, 2019 at 4:55 PM n4buq <n4buq@...> wrote:

When the stud is turned CCW, provided the collet doesn't break first, the
threads in the collet itself would push the flanged part of the stud
against the inside surface of the impeller.
I don't have much experience with this other than my own scope and
machining some replacement collets, but when I inspected my own scope, I
figured this is exactly what the stud is for. This is a very gentle way to
separate the two, as the thread's quite fine (32TPI). I can't see any
reason why Tek would have gone to the trouble of using this
double-threaded, collared stud, if not for this very purpose. It would have
been less expensive and simpler for sure to mold the collet around a
threaded stud that protruded out through the impeller.
On my scope, the collet was fractured all around the insert, while the
tapered end looked just fine. This commonly happens with parts molded
around inserts, over time the plastic wants to shrink, while the metal
insert is unyielding.




Siggi
 

On Mon, Nov 11, 2019 at 9:00 PM n4buq <n4buq@...> wrote:

Being a little picky, but the other end of that stud is 40 t.p.i. so an
even finer pitch (#4-40 on one end and #8-32 on the other).
So it is, thanks for the correction.


 

That might become a "#me too" issue.

I add myself to the list of those that tried to turn the screw... I was too eager to get the PSU out after one of the RIFAs went up in smoke.

I found the drawing in the files section, but do not have the tools do work on such a part. Does someone has a model for a 3D-printer yet?

Anyone around Stuttgart / Germany with the proper tooling who might help me?

cheers
Martin


DaveC <davec2468@...>
 

Martin,
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.

Thanks,
Dave

On Aug 7, 2020, at 12:07 AM, Martin <@musaeum> wrote:

That might become a "#me too" issue.

I add myself to the list of those that tried to turn the screw... I was too eager to get the PSU out after one of the RIFAs went up in smoke.

I found the drawing in the files section, but do not have the tools do work on such a part. Does someone has a model for a 3D-printer yet?

Anyone around Stuttgart / Germany with the proper tooling who might help me?

cheers
Martin



n4buq
 

When mine broke, it sheared the cylindrical part cleanly where the brass insert stopped (approximately where the taper begins). I was able to drill and tap a very short (maybe three or four threads deep) 4-40 hole in the tapered end and with a very short length of 4-40 threaded rod and ca glue, put the pieces back together. I had to remove a few threads from the stud as well since it bottomed out on the threaded rod, but it has all held for about a year now.

Just a thought in case you don't find a replacement.

BTW, that may have been broken before you tried to turn that shaft. In my case, I know I did not apply very much torque at all before I noticed it was just spinning and I'm pretty sure mine was already broken.

An alternative (if you have access to a lathe or someone who could make it for you, would be to make a replacement for that threaded, shouldered, stud but make the 4-40 end just a bit longer. Drill and tap the end of the tapered piece and then screw the entire length of the new stud in to both pieces and affix it all with ca glue. It won't twist as before (due to the glue) but it would be a stronger way to go. Just a thought.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Martin" <@musaeum>
To: TekScopes@groups.io
Sent: Friday, August 7, 2020 2:07:56 AM
Subject: Re: [TekScopes] 2465 Fan Collet Thingy

That might become a "#me too" issue.

I add myself to the list of those that tried to turn the screw... I was too
eager to get the PSU out after one of the RIFAs went up in smoke.

I found the drawing in the files section, but do not have the tools do work
on such a part. Does someone has a model for a 3D-printer yet?

Anyone around Stuttgart / Germany with the proper tooling who might help me?

cheers
Martin




 

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin


Raymond Cote
 

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin




Dave Daniel
 

On Aug 8, 2020, at 12:10, Raymond Cote <@Bluegrass> wrote:

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin