this is my solution for an adder-subtractor. it took me actually building one and using it to figure out how it actually worked

i have seen some that are useful but not what i was looking for, most were very tall and didn't have the center of gravity that i wanted.

this solution is based on one that i found on the net (sorry i forgot the owner but these are the pictures -adder-subtractor/adder1.jpg adder-subtractor/adder2.jpg ) an elegant solution but not my favorite... (these files do not exist cause i forgot them at home)

this is the newer mechanism, it is one brick higher but with one motor on each end it can fit into the space of a 16 stud beam.  this picture has two for driving note:pov-ray email me for the mlcad dat http://odin.prohosting.com/mrplanet/adder-subtractor/add-sub2.jpg	here is a render of the older one.  again email me for the mlcad dat http://odin.prohosting.com/mrplanet/adder-subtractor/add-sub1.jpg

what i did was match the differential gears with their respective counterparts and link them that way with two (2) sixteen (16) tooth gears on the smaller side, and one twenty-four (24) on the other side.

the differentials themselves are driven directly (which i shouldn't do for the steering gear because of torque loss)

you will notice that the drive gears have two motors on them, if it was done with one motor it could be placed inline with the other motor. the bottom view (bottom right) gives the best comparison of the geartrain.

i did use a few different colors in this setup so the different beams would show up better in the pictures.

i may work with this a little while more to get the gearing better.

any questions mailto:mikefusion@hotmail.com