[GreenKeys] 28 ASR Typing Reperforator Print Hammer Replacement

[Mark J. Blair]

> On Jan 2, 2020, at 3:36 PM, Nick England <navy.radio at gmail.com> wrote:
> 
> 173979 specs
> federal stock no 5815-00-084-5008
> Overall height - 0.141 inches nominal
> Overall length - 0.391 inches nominal
> Overall width - 0.250 inches nominal
> Material - Plastic
> Special features - One slot, 0.047 in. w by 0.188 in. lg
> 
> I have a drawing somewhere.


Nice! I didn't think of looking up specs from the part number. I've often done that for things like trying to find specifications of a bolt or hydraulic fitting based on the NSN. If you can dig up that drawing without too much trouble, that would be great. Just those dimensions are a nice head start, but I'm wondering if the slot is offset a bit to make the hammer thicker on the impacting side.

Interesting that it is specified as "plastic" instead of "rubber". I plan to start looking into using elastomeric filament (typically some sort of polyurethane blend, I think?) working in my 3D printer. I wonder if something like PETG (similar to disposable water bottle plastic) might be soft enough for this application? It would probably need to be heated a bit to soften it while installing it over the end of the metal arm, but it's a lot easier to print with on most 3D printers. Getting everything dialed in right with the elastomeric filaments can be challenging, from what I've read.



-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/