The Black Mamba lightsaber, a joint Orbital Machining/Slothfurnace endeavor, is arguably the most intriguing custom saber ever produced. The custom saber is an extremely detailed and complex, reveal lightsaber. The entire Black Mamba lightsaber project took a grueling five years to complete.
Orbital Machining (aka Acerocket) initially approached Slothfurnace asking him to “help me get my [lighstaber] ideas on paper to give me a frame of reference to work with and model from” . Slothfurnace agreed. After the pair exchanged ideas through series of emails, Slothfurnace sketched out an initial concept of the Black Mamba lightsaber hilt, a reveal lightsaber with an industrial, skeletal appearance.
Next, Orbital Machining spent a year painstakingly designing, tweaking, exchanging ideas with Slothfurnace, and ultimately modeling the lightsaber. Finally, Orbital Machining machined and prepared a real life lightsaber. Only 8 Black Mamba lightsabers were ever made.
Orbital Machining accepted pre-orders for the extremely limited Black Mamba lightsaber run in 2013, requiring an initial deposit of $500. The completed project was priced at $3200 per unassembled empty lightsaber hilt, plus Paypal fees and shipping.
The Black Mamba empty hilt consists of 224 separate parts, including 167 machine parts, 63 hardware parts (12 of which were modded after purchase), 12 pieces of stainless steel braided wire, 1 piece of stainless steel conduit and 1 crystal. Orbital Machining warns that Black Mamba lightsaber “[i]nstalls are not for the faint of heart” and “[t]his is not a saber you will install in a few hours – it will take planning and thought.” 
Brad Lewis, the owner and operator of Slothfurnace, also worked as a video game developer for Star Wars: The Old Republic (SWTOR). Lewis developed an in-game model of the Black Mamba lightsaber in SWTOR called the Twisted Fang lightsaber.
RELATED LIGHTSABER SELLERS affiliate links
If you purchase an item through these links, I receive some money at no cost to you.
Slothfurnace, operated by Brad Lewis, is a custom saber company that specializes in lightsaber clamp cards. Lewis, a video game developer, has designed lightsabers and objects for the video game Star Wars: The Old Republic (SWTOR).
Orbital Machining, also known as Acerocket, is a custom saber company known for creating the Cobin Das’s Killer Penny lightsaber and releasing limited runs of customs sabers including: a TFUII lightsaber run, Obi ROTS lightsaber run, Skinnyflex lightsaber run, Obi TPM lightsaber run.
REFERENCES AND RESOURCES
1. Black Mamba Lightsaber Pictures
2. The Black Mamba – a joint Wat Tambor/slothfurnace endeavor
[Original Black Mamba project thread on FX-Sabers]