I tattoo practice skin and when I make a line I end up with too much ink on the skin, how can i cut down on excess ink getting all over the skin and therefore ruining the stencil?

I have ran it to this my self. What I did is ajust my gap between my contact screw and my front spring. By doing this it will slow it dowh and speed it up. So find a gap that suits you. Also if you ajust your power supply that to will speed it up or slow it down. So get real familar with your machines and find a speed that works for you. Good luck.

The power supply has ABSOLUTELY NO !!!! part in speeding the machine up in any way (i am about to kick the apprentice in the head) his other facts are correct, the power supply simply increases the power or force behind the punch into the skin ie you use a lower voltage for lining as its single or groups of ready made needle sets for lining which dont need to much power punch to break skin, but when shading with rounds flats and mags you need more punch other wise the needles would just bounce off the skin, but do adjust your contact screw and often the puddle is to many volts but each machine is different

could sticking the needle a bit more out of the tip help out at all ?

From what I have read and have heard, is that sticking the needle out farther than the tip allows the artist to see the needle move about also known as floating the needle. But, this should only be tempted by a more exsperiance artist sence depth is so important. 1/16 for your liner and 1/32 for your shader is just a good rule of thumb,and will allow you to maintane an even and smooth depth.

if you have just started do not DO NOT !!! try to float the needle no way, try coming down in voltage and adjust your turn screww until it stops

In addition to what Dave said, practice skin is very messy to work with and hard to clean.

If your machine is splattering ink, I would try to bend the needle backwards - meaning, if the open end of the needle loop is facing your left, bend the needle back quite a bit so that when your machine is fully set up (w/ tube and rubber bands), the needle rides the bottom of the tube. This means when looking at the tube w/ the armeture bar pushed down, there is NO gap between the needle and the underside of the tube.

Additionally, you can protect your stencil with a&d and also remove excess ink from the practice skins this way...it takes some elbow grease.

Hope that helps.