[mowbot] testing terminator blades

DON AUTRY (Don.L.Autry nospam at msfc.nasa.gov)
21 Oct 1996 13:41:24 -0500

I talked with the folks at the RC hobby shop here today and found out that
the small motors used in the RC cars should be of use for our purposes. They
have speeds of from 15000 to 40000 rpm and are fairly high torque. Although
most of the time they use them for only 6 minutes at a time, the fellow
I spoke with had just helped a guy build a blimp which used a custom built
set of two 8pack batteries and he said it runs with the motors running full
tilt for about 2 hours. The recharge time using a peak charger was less than
a half hour, but this is rough on the batteries. He expected the packs
would only last a couple of months with our duty cycle, but they should last
a mowing season if a 2:1 charge cycle was used. In addition he gave me one
of his old electric motors to play with to test the feasability of the
weed terminator blades. I hope to fashion some sort of test platform within
a couple weeks and will let everyone know what happens. These motors range
in price from US $20-75 dollars. The nicad packs are about $3 a cell thru
his store, but I am sure they can be purchased cheaper elsewhere. I would
also like to know if any of you can give me sources for supply of better
larger battery cells than are used by the RC hobbiest. I believe we can
safely double the size of the batteries used in that blimp for a longer run