Core size effect on machine?

That is a good question that i would like to know about as well.

there are basically 3 types of wraps:
8
10
12
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8 wrap coils are by far the cheapest, they are smaller, the heat dissapates less making them run hotter and are generally run at a lower voltage due to them using smaller needles.
10 wrap coils are kinda the middle norm, they work well for a variety of jobs and uses and can be run at moderate speeds using a wide variety of needle groupings from the smallest to about 9 mag effiecently.
12 wrap coils are monsters sort of. Most tattoo artists that I have met use 12 wraps for large jobs using large needles, I personally only use my 12 when I have to load up 11 liners, or 15 mags or larger. This wrap I also have to run at about 10-11 volts sometimes as high as 13. I cannot stress enough though that IF you use such a set-up you have to pay VERY close attention to the area in which you are working as you can chew up the skin in seconds. Again, LARGE AREAS!!
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I have always referred to 8’s as minis. Just habit for me. Out of my 7 running machines 1 is an 8 and one is a 12. Yes I run 7 machines in my booth and on average set up 3-4 ata time when I ink with different needle set-ups and tubes. Which allows me to switch to a different “brush” for my canvas without having to take a long break. Needles are cheap and if I don’t end up using one or two then whatever, needles are cheap!
I have heard that you MUST run your power supply at this speed or that speed. When in reality you have to figure out what works. My power supply runs anywhere from 6.75 all the way up to 13.45 at times, depending on what I am doing, what effect I am going for and the detail of the area. I get very little if any blood flow, most work I put out has very little scabbing at all and my colors are full and my blacks solid. There are as many ways to tattoo as there are tattoo artsists out there. What works for Megan Massacre doesn’t work for Paul Booth, and what works for Dmitry Vision will not work for you maybe. There is no set gospel on how to tattoo except that the lines have to be straight and solid (solid not gouging deep!) and the colors have to be full and vivid. Learn your equipment, learn your set-ups, use different inks and mixes, try rose water, try witch hazel, use glycerin! Use thick in, use thin ink, use curved mags, use flats, use 1 liners, use 11 liners! These are all things you should learn in a shop or from a mentor. But no matter how you ink it up, always remember to strive for better, to be better, to learn and to grow! Always…..

Thanks for the input. I was more referring to core size and not wrap but that was a great analysis that we all need to hear! My wall in my booth is lined with machines! I think i have over 30. I use at least three machines ,sometimes four depending on the design. I will set up one machine with a 7liner, one with a 5liner, then a mag, and then a 7rs or 9rs. There is nothing worse than having to stop during a tattoo and take off gloves, change to new gloves,and get a new needle and tube. I use a wide variety of needles and groupings. Thats what works well for me