If it's the Joye 510 cartomizers I'm thinking of (all plastic body?) you can't use a drip tip with them, it won't fit. The body of the cartomizer tapers from the connector up to the mouthpiece. The Joye cartos can't easily be dripped on (well, you _could_ drip down the air vent I suppose but that makes it all gurgly and the
juice leaks out the bottom and it sucks), you're meant to fill them with a syringe or via dripping
through the battery connector hole, which sucks.
Boge cartomizers are the same diameter as an atty, so a drip tip would work on those.
This is what a Boge carto looks like:
FIVE (5) Joye 510 compatible e-Cigarette blank cartomizers (Manufactured by Boge) You can use a drip tip with these.
If this is what you have (the cartomizer on the left side):
http://farm5.static.flickr.com/4131/5010460413_728e427c43.jpg then you cannot use a 510 drip tip with it.