On Sun, 27 Dec 2020 10:07:42 +0000 (GMT), "Dave Liquorice"
wrote:

On Sun, 27 Dec 2020 06:39:01 -0000, Brian Gaff \(Sofa\) wrote:
snip
... but cannot design a set of universal nut crackers.

Or a toaster that can produce consistent toast slice after slice
without adjustment or needing a pre-heat.

Yeahbut I think dealing with all the different thickness and densities
and moisture content of bread you are trying to toast is actually way
more complicated than cracking a range of nuts (with the right
approach).

Eg, as long as you (can / do) apply enough force then every nut *will*
crack. So as long as you have more power than you would ever need then
that's that box ticked.

As long as there is the minimum of elasticity in the mechanics, it
should 'just' crack the nut and no go further, eg. damaging the nut
itself.

So, say you had a pistol grip like a battery drill with a square
hopper at the front providing the anvil and an electrically driven
'ram' that could be driven onto the nut via a drill like trigger ...
you drop the nut in (orientating it if you prefer), pull the trigger
and a clear / mesh guard 'flap' flips down that both stops any bits
flying out and acts as a safety interlock to stop you leaving your
finger(s) in there ... and then the ram is wound forward quickly till
it senses the increased load of the nut and then slower as it breaks
the nut.

It could either cut off after a further distance traveled (say 1mm) or
waits till you let go of the trigger (so you could crush the nut flat
if you chose to).

Let go the trigger and it (quickly) unwinds the ram and when you press
a second trigger (maybe like a drill Fwd / Rev button or a second /
integral trigger) the lower hopper flap(s?, like bomb doors) opens and
drops the nut / shell into your hand.

Or it could be designed for (/also) table-top use with a shallow tray
under the hopper an on top of the battery to catch the nut / shell
instead.

With PWM and micro controllers the speed / torque thing should be easy
and current sensing should be able to measure the increased load on
proper contact with the nut and then how long you would need to run
the motor at slow speed / high torque to get the nut to fully crack.

You could even have a selector knob for the nut type (as each might
need slightly different treatment) and maybe a user adjustable knob
for whatever turns out to be the most important function.

You could set the prototype up to be learning assisted like running a
PID Tuning on a 3D printer.

With a potential 'world wide' gadget obsessed market, it could be a
good seller. ;-)

Cheers, T i m

p.s. There are several 'bulk' nut crackers but they 1) take some of
the fun out of doing them one at a time and 2) need to be 'set' for a
specific size / type of nut each time / run.

https://youtu.be/hHlsL8pGk-g?t=459

This would be one for our Mr Rumm: ;-)
https://www.youtube.com/watch?v=yhSzfre8Kn0