From: "gkricorissian" <gregg-k@...>
To: "tekscopes" <TekScopes@groups.io>
Sent: Tuesday, September 13, 2022 9:15:34 AM
Subject: [TekScopes] Fan collet for the 2465

I mentioned in my intro that I had made a new collet to replace the one
which secures the fan impeller on my 2465, which is the same as those found
on many Tek scopes. I tried sending a picture of the broken/black plastic
collet and the replacement I machined from 6061-T6 alloy bar, but the
Tekscopes site bounced it because attachments are not allowed.



So, in a "second-best" effort, here are some notes about machining a new
collet from round bar stock:

1. The double-ended metal adapter simply unscrews from the old plastic
collet, and can be re-used on your new collet

2. The tapped hole in the new collet for that adapter is threaded 4-40

3. The male thread at the other end of the adapter is 8-32, in case you
need a new nut for it.

4. The new collet could be machined from alloy or brass bar depending on
what you have available.



Dimensions of the new collet are simple:

- over-all length: 0.730"

- diameter of the cone (the large end): 0.344"

- diameter of parallel shank (the small end): 0.291"

- axial length of taper, from the large end of the cone to the start of the
parallel shank: 0.344"

- angle of taper: 4.4 degrees

- hole for motor shaft: 2mm

- collet slots are not critical, but should be narrow as practical. I used
a 1/32" slitting saw on mine.



Feel free to ask for any clarifications you may need.

.. Gregg