Great idea. If you put the resin cup on one side of the beam 43 units from the fulcrum and put the hardener cup 143 units from the fulcrum on the other side of the beam and adjust your clamp weight so the beam levels with the cups empty, then all you would have to do is put any amount of resin in the first cup and then pour resin in the second cup until the beam levels.

: This is one of my new inventions -- a Balance for easily acheiving the
: correct mix ratio for epoxy. (I've never posted with a picture before, so
: I'm really hoping my picture will be included here as pictures are
: generally worth somewhere in the vicinity of 1000 words.)

: The basic process is: a) Hang empty (& clean) cups from both cup hangers
: b) Pour the desired amount of hardener in the outer cup
: c) Adjust the counterbalances to balance the scale
: d) Switch cups (i.e., the one with the hardener to the inner hanger, the
: empty one to the outer hanger)
: e) Pour in the Resin until the scale balances
: f) Mix & use your epoxy
: g) Throw the empty cup away (they're only ~$0.03 when bought in bulk at
: Costco)

: The ratio by weight for the Raka 127/350 I'm using is 43:100 -- to achieve
: the correct mix, I put the outer cup hanger 17.875 (143/8) from the pivot,
: and the inner cup 5.375 (43/8) from the pivot. The pivot is made from a
: piece of hacksaw blade riding on brass rods. Before I used it, I checked
: it with the best scale I had available, but I still would like to run it
: against one with finer resolution. Maybe I'll bring it along with me to
: R2K2 and see if Pete Roszyk has a scale like he used in his glassing
: demostration last year, and do a little stastical anaysis of the weight
: ratios that this contraption really gives.

: So, I'm putting this up for peer review -- Whadd'ya think?

: -John D.