< > [subtractive](index.html)
###[Plasma cutting](https://www.youtube.com/watch?v=Ry4kohKGAfI)
* Requires sheilding gas
<blockquote>"The basic plasma cutting process involves creating an electrical channel of superheated, electrically ionized gas i.e. plasma from the plasma cutter itself, through the work piece to be cut, thus forming a completed electric circuit back to the plasma cutter via a grounding clamp. This is accomplished by a compressed gas (oxygen, air, inert and others depending on material being cut) which is blown through a focused nozzle at high speed toward the work piece. An electrical arc is then formed within the gas, between an electrode near or integrated into the gas nozzle and the work piece itself. The electrical arc ionizes some of the gas, thereby creating an electrically conductive channel of plasma. As electricity from the cutter torch travels down this plasma it delivers sufficient heat to melt through the work piece. At the same time, much of the high velocity plasma and compressed gas blow the hot molten metal away, thereby separating i.e. cutting through the work piece." -Wikipedia</blockquote>
* Traditionally, plasma cutting was viewed as a messy and rough cut process, but improvements in control technology have tightened tolerances and made the process more precise and accessible. 0.012" accuracy is quoted from [Plasma cutting: Then and Now](https://www.thefabricator.com/article/plasmacutting/plasma-cutting-then-and-now)
* [Plasma cutting basics](http://www.lincolnelectric.com/en-gb/support/welding-how-to/Pages/plasma-cutting-basics-detail.aspx)
* Any conductive material can be cut with plasma. Steel, Aluminium, Copper, Brass, Titanium, etc.
* Precision plasma cutting is [commertially availiable](http://www.plasma-automation.com/Machinery/Plasma-Cutting/Elite-Precision-Plasma-Cutter.php) at [different scales](http://www.modernmachinerycompany.com/plasma-cutting-machines/cnc-precision-plasma-cutting-machines/)
###Oxy-acetelene
* <blockquote>"The best and most versitile tool." -Sara Falcone <blockquote/>
* [Really affordable](https://www.google.com/search?q=oxy+acetylene+cut&client=firefox-b-1-ab&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjxtP-F4MbaAhVimeAKHbUcDN4Q_AUICygC&biw=1280&bih=623)
* Can use the same cylinders with different tips to cut, heat treat, or weld.
* [Very dangerous](https://www.youtube.com/watch?v=B_mRHfz7RQk)
* Not good for Al and other very highly conductive materials because it will just melt everything...
* For mass production oxy-fuel is easy to parallelize
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