I was able to use a safety pin and pop off the ends of my 510 carts when I first started dripping. As I recall there is
another cap inside that can be removed also(?). Someone correct me if I'm wrong.
I also used a very sharp knife and sliced off a little bit of the sleeve part that goes inside the atty so that nothing was close to the heat source, this also makes it easier to remove the cart.
When I started getting lazy and not wanting to take the cart off, I looked inside and noticed that there was some plastic construction inside. Had read that you could still drip around it but I wanted a clear unhindered path, empty tube. I ended up having to firmly hold the cart with a pair of pliers and used a hand drill to gut the tube out.
Now it is a straight shot for the
juice to the coil, but the cart got roughed up and is not smooth anymore, not a big deal but a personal preference, I could see where some people wouldn't like it.
I've had two drip tips, a long one with narrow hole that looked like a T-Tip, and a short barrel shaped tip with a wide mouth I got from Goodprophets.com.
I prefer the short wide mouth. I also like the delrin as from past experience (holding tools/flashlights in my mouth while working) I cannot stand my teeth biting on metal.