Submitted 01.18.23

“[15:26] So Bog, I would basically define as the speed of the machine slowing down…resistance, load, torque. That resistance of the skin is transmitted through the needle bar up to the cam or mechanism driving it.  And, that in turn is torque or demand on the motor. ”

— Aaron Williams

Let’s Define Some things here. Resistance is the opposition that a substance offers to the flow of electric current. Load is the force exerted on a surface or body. Torque is a measure of the force that can cause an object to rotate about an axis. Torque relates to the rotational force of an electric motor while speed refers to the rate that the motor can rotate.

The needles puncturing the skin creates resistance, causing strain on the components of a tattoo machine, this is called "bog" or "give". That being said, coil tattoo machines produce a particular type of “bog” or “give” that tattoo artists worldwide say is particularly useful for reducing trauma to the skin.

In many pen style machines and Rotary machines the cam needs to complete a full rotation in order to penetrate and exit the skin. There isn’t a lot of “natural” resistance from the pushing back on the needle so in many cases this can be more traumatic or damaging to the skin. Many rotary machine manufacturers add different mechanisms and membranes to attempt to induce this same effect.

Check out Power Supplies and Needle Depth | Aaron Williams | Ep 262

By Jake Meeks —

Topics: tattoo science, ink in skin, Tattoo Science, Tattoo Physics, Machine Building, Tattoo Machine Power Supplies, Coil Tattoo Machines, Rotary Tattoo Machines, Tattoo Needle Cartridges, High Speed Camera, Tattoo Technology

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