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Looking for fan impeller fastener for 2465

Jonathan.yaeger@...
 

Does anyone have or sale or a source for the impeller fastener, Tek P/N: 343-104-001?

Thanks in advance.

Jon

 

Parts for the "original" 2465 fan (motor, impeller, collet) are near impossible to find.  Even when found, they are old and made from plastic that does not age well.  Most people make substitutes or convert to muffin fans as used in the later model 24xx scopes.  You can search the group archives with the term "impeller" and spend an afternoon learning all the ways others (including me) have been frustrated with this part.  I ended up using a collet from my collection of Dremel tools to replace the collet.  (Re: Removing a 2465 Squirrel cage fan).
A more elegant solution can be found in the pictures archives.  Search for "2465 fan collet repair"Or, if you have access to a machine shop there is a drawing for making one:  https://groups.io/g/TekScopes/files/Fan%20Collet%20-%20Tek%202465%20O-scope.pdf

On Tuesday, April 30, 2019, 12:55:51 AM CDT, Jonathan.yaeger@... <Jonathan.yaeger@...> wrote:

Does anyone have or sale or a source for the impeller fastener, Tek P/N:  343-104-001?

Thanks in advance.

Jon

Siggi
 

On Tue, Apr 30, 2019 at 10:11 AM machineguy59 via Groups.Io <machineguy59=
yahoo.com@groups.io> wrote:

Parts for the "original" 2465 fan (motor, impeller, collet) are near
impossible to find. Even when found, they are old and made from plastic
that does not age well. Most people make substitutes or convert to muffin
fans as used in the later model 24xx scopes. You can search the group
archives with the term "impeller" and spend an afternoon learning all the
ways others (including me) have been frustrated with this part. I ended up
using a collet from my collection of Dremel tools to replace the collet.
(Re: Removing a 2465 Squirrel cage fan).
A more elegant solution can be found in the pictures archives. Search for
"2465 fan collet repair"Or, if you have access to a machine shop there is a
drawing for making one:
https://groups.io/g/TekScopes/files/Fan%20Collet%20-%20Tek%202465%20O-scope.pdf

I machined a small number of replacement collets from delrin and shipped
one to Jon. On pulling the collet from my own 2465 to get measurements, I
found that it was due for a replacement also. The plastic had started
cracking around the threaded insert, so I've replaced mine too.
The collets I machined are a direct replacement for the original part,
which means they're tapped #4-40 on the narrow end to fit the original
stud. The delrin will hold the thread just fine, the only reason there's an
insert in the original is for production expediency as they're injection
molded.
Now, the original double-threaded stud is #4-40 on one end and #8-32 on the
other with a "9/32 collar in between. The #8-32 side sticks out from the
impeller and serves to pull the collet into the impeller and clamp it on
the shaft. The #4-40 threads go into the collet, but the purpose of those
threads and the "9/32 collar is to push the collet out of the impeller.
So to remove the impeller, start by removing the nut, then use a regular
screwdriver on the slot in the stud while holding on to the impeller. As
you turn the stud counter-clockwise, the "9/32 collar will eventually
contact the inside of the impeller and (gently) push the collet out of the
impeller.

In any case, if anyone finds themselves needing one of those collets for a
repair, send me a message (off-list) and I'll ship you one for postage - so
long as my supply lasts at least.