>- How about a TP holder that measures the weight? Or a spring loaded
>arm, that contacts a switch when it get near empty. With a wheel at the end,
>you can also have it provide drag on the roll, for spin control. Then it
>won't be so easy for my cat to run all around the house with it...
You read my mind... I was going to suggest a spring arm pressing against
the roll. The further the arm travels, the lower the roll. This should
also take very little adjustment since you are looking for % left.
Actually, since rolls all share a common spindle diameter... it would be
easy to have this auto adjust for good thick rolls vs, cheap economy
paper. You know the end location, so add a sensor to know when the roll
has been changed. When the "new roll" sensor is tripped, take the current
reading, that is max size. Now you can calculate the difference from
there to empty, and relay a % left no matter what the initial thickness
is. (the only time this would start to be off is on roll "reloads" of
partially used rolls)
Two problems with the earlier mentioned rotation counter... 1: you need
to deal with vastly different sheet counts (Scott will turn WAY more
times than Charmin will, but both are roughly the same diameter, just
Charmin is thicker so has fewer sheets per roll, thus fewer turns till
empty).
And of course, a turn based counter needs to subtract for roll
re-rolling... for the times the cat decides to use it as a batting toy,
and unrolls half of it onto the floor. The counter has to subtract turns
as you spin the paper back onto the roll.
Oh yeah... and a spin counter would be throw off by those 4am "where did
the end of the roll go blind half asleep multiple rotations trying to
find the start" situations.
Nah... a simple spring arm reading resistance based off roll diameter
would probably work best.
-chris
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Received on Wed Mar 20 2002 - 13:04:56 GMT