FWIW Just found this on the added weight of the lumenock(not the homemade lighted nock but it would be interesting to know what they weigh), looks like they add 22 grains to the normal nock, 30 grains total.

http://www.archerysportsusa.com/store/index.cfm/c2/i6747

http://www.keystonecountrystore.com/index.html?stocknumber=ARB2828806