Re: Nice replacement knob for FDM-DUO #fdm-duo


John Fell
 

Yes ,the new version knob looks nice and screw retention is improved from what you say .

The original knob has a recessed rear which allows you to add some low density foam (6mm thick is optimum) .This in conjunction with the locking screw allows you to set the knob so that it can be turned easily but adds a slight drag force , which prevents inadvertent frequency changes from slight finger contact when working very narrow bandwidths .The foam density allows the knob to be depressed when required and removes all traces of shaft wobble .

All you need is a 1/16"/1.55mm A/F Allen Key and a sharp craft knife to cut out the annular foam insert and  if you don't like the mod , it comes off the same way .

73
John
G0API


On Sun, 19 Sept 2021 at 13:38, G8NRY <info@...> wrote:

[Edited Message Follows]

Nice. My only concern would be that the new all metal knob is much heavier than the original so will put even more stress on the already very weak encoder shaft leading to even more wobble and failure. Maybe look at adding some bracing e.g. felt washer?

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