Fig. 1 Animation showing rotating cams and cam followers producing reciprocating motion.

A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice-versa.^[1][2] It is often a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the follower, which is a lever making contact with the cam.

Overview[link]

The cam can be seen as a device that translates from circular to reciprocating (or sometimes oscillating) motion.^[3] A common example is the camshaft of an automobile, which takes the rotary motion of the engine and translates it into the reciprocating motion necessary to operate the intake and exhaust valves of the cylinders.

Cams can also be viewed as information-storing and -transmitting devices. Examples are the cam-drums that direct the notes of a musical box or the movements of a screw machine's various tools and chucks. The information stored and transmitted by the cam is the answer to the question, "What actions should happen, and when?" (Even an automotive camshaft essentially answers that question, although the music box cam is a still-better example in illustrating this concept.)

Displacement diagram[link]

Fig. 2 Basic displacement diagram

Certain cams can be characterized by their displacement diagrams, which reflect the changing position a roller follower (a shaft with a rotating wheel at the end) would make as the cam rotates about an axis. These diagrams relate angular position, usually in degrees, to the radial displacement experienced at that position. Displacement diagrams are traditionally presented as graphs with non-negative values. A simple displacement diagram illustrates the follower motion at a constant velocity rise followed by a similar return with a dwell in between as depicted in figure 2.^[4] The rise is the motion of the follower away from the cam center, dwell is the motion where the follower is at rest, and return is the motion of the follower toward the cam center.^[5]

Plate cam[link]

Fig. 3 Cam Profile

The most commonly used cam is the plate cam which is cut out of a piece of flat metal or plate.^[6] Here, the follower moves in a plane perpendicular to the axis of rotation of the camshaft.^[7] Several key terms are relevant in such a construction of plate cams: base circle, prime circle (with radius equal to the sum of the follower radius and the base circle radius), pitch curve which is the radial curve traced out by applying the radial displacements away from the prime circle across all angles, and the lobe separation angle (LSA - the angle between two adjacent intake and exhaust cam lobes).

The base circle is the smallest circle that can be drawn to the cam profile.

History[link]

An early cam was built into Hellenistic water-driven automata from the 3rd century BC.^[8] The use of cams was later employed by Al-Jazari who employed them in his own automata.^[9] The cam and camshaft appeared in European mechanisms from the 14th century.^[10]

See also[link]

Other mechanisms that convert between translates between circular and reciprocating motion:

• The crank can be used in either direction, from reciprocating motion to circular or vice versa.
• Scotch yoke
• Swashplate
• Trip hammer

Other mechanisms named "cam" or similar:

• Dwell cam (used in pairs in sewing machines)
• Binary cam (for compound bows)
• Spring-loaded camming device (rock climbing equipment)

References[link]

External links[link]

• Cam design pages Creates animated cams for specified follower motions.
• How round is your circle? Contains various linkages.
• Kinematic Models for Design Digital Library (KMODDL) - Movies and photos of hundreds of working mechanical-systems models at Cornell University. Also includes an e-book library of classic texts on mechanical design and engineering.
• Introduction to Mechanisms - Cams Classification, nomenclature, motion, and design of cams; information for the course, Introduction to Mechanisms, at Carnegie Mellon University.

Juelz Santana
Santana in July 2005
Background information
Birth name	LaRon Louis James
Born	(1983-02-18) February 18, 1983 (age 29) Harlem, New York, United States
Genres	Hip hop
Occupations	Rapper, record producer, actor
Years active	1999–present
Labels	Skull Gang, Def Jam, E1
Associated acts	Skull Gang, The Diplomats, Jim Jones, Lil Wayne, Cam'ron, Chris Brown, Lloyd Banks
Website	www.myspace.com/juelzsantana

LaRon Louis James (born February 18, 1983),^[1] better known by his stage name Juelz Santana, is an American rapper, producer, actor and member of group Dipset. He appeared on Cam'ron's 2002 singles, "Oh Boy" and "Hey Ma". In 2003, his debut album From Me to U was released by Def Jam Recordings; his next album What the Game's Been Missing! contained the top-ten single "There It Go (The Whistle Song)". He is currently working on his long awaited third studio album Born to Lose, Built to Win set to be released in the 4th quarter of 2012.^[2]

Biography[link]

1983-2001: Early life and early career[link]

LaRon James was born in New York City and raised in the Manhattan neighborhood of Harlem. He is of African American and Dominican descent. He began rapping at the age of five and at age twelve started duo Draft Pick, which was signed to Priority Records.^[3] In 2000, at the age of 17, he made a guest performance on a track on Cam'ron's album S.D.E. and eventually joined The Diplomats.^[4]

[edit] 2002–2004: From Me To U

After the signing of The Diplomats, also known as Dipset, to Roc-a-Fella Records in 2002, there was an influence of mixtapes, features on other artists' records, television and radio interviews, in which Juelz achieved mainstream recognition not previously gained through the various Diplomat mixtapes, and his solo mixtape Final Destination, that was sold in late 2002. After being featured on fellow Diplomat member Cam'ron's two singles, "Hey Ma" and "Oh Boy". Juelz started working on his debut album. In the summer of 2003, Santana released his debut album, From Me To U, which peaked at #8 in the Billboard 200. "Dipset (Santana's Town)" peaked #70 in the U.S. Billboard.

[edit] 2005-2006: What the Game's Been Missing!

What the Game's Been Missing! followed in 2005 with the singles "Mic Check", "There It Go (The Whistle Song)", "Oh Yes", "Clockwork," "Shottas", and "Make It Work For Ya" Feat. Young Jeezy and Lil Wayne. "There It Go" reached #6 on the Billboard Hot 100 and #3 on the Hot Rap Tracks charts; "Oh Yes" reached #56 on the Hot 100 and #8 on the Rap charts. "Mic Check" reached 35 in the Billboard Hot 100.^[5] Both this album and single "There It Go" were certified Gold by the Recording Industry Association of America.^[6]

[edit] 2007-present: Born to Lose, Built to Win and Dipset reunion

Since 2007, Santana has been recording material for his third album, Born to Lose, Built to Win. Shortly after recording began, Santana released a promo single, "The Second Coming", produced by Just Blaze.

After a two year hiatus, he released a new song, "Days of Our Lives", with two accompanying music videos featuring cameos from Skull Gang. In late 2009 he released the first single off Born to Lose, Built to Win, "Mixin' Up the Medicine" featuring Yelawolf.

In 2010, he released the second single titled, "Back to the Crib" featuring Chris Brown. In April 2010, Cam'ron and Jim Jones announced they ended their feud.^[7] In June 2010, the Dipset reunion began with a teaser titled "Under Construction" and a street single, "Salute" produced by Araabmuzik. The song features Jim Jones, Cam'ron, and Juelz Santana. The remix features new Diplomat artist Vado with a verse added. Since the reunion it is not yet known if or when Juelz will release the album.

But it is known that he is working on a new album with The Diplomats. Recently Santana tweeted "I will give people that people wants Reagan Era in the studio" so that means that we can wait a new album for 2011.^[8]

In 2012 Juelz stated he is still working on his third studio album Born to Lose, Built to Win & is Set To Be released in the 4th quarter of 2012 but before then he will release two mixtapes entitled Reagan Era & Reagan Era Pt. 2.^[9]

Legal Issues[link]

In January 2011 Juelz Santana's Bergenfield, New Jersey Recording Studio was raided, after a 10-month investigation by the Bergen County Prosecutors Office and Gang Unit.

Santana was arrested February 2, 2011, and charged with possession of a firearm, possession of a handgun without a permit, possession of a controlled dangerous substance and possession with intent to distribute a controlled substance within 1,000 feet of a school. Santana posted $125,000 bail.^[10]

On March 22, 2011, Juelz Santana missed a performance at Chris Brown's record release party for his album F.A.M.E., New York Police stopped the rapper and searched him for guns and drugs. While no one was arrested, Santana was not allowed to enter the building during the search. This caused him to miss his entire performance with Chris Brown. Juelz' lawyer Joe Wunstop told The New York Post that police stopped Santana because members of his entourage "might be affiliated, friends bring friends and he's really friendly"^[11]

Discography[link]

Filmography[link]

• State Property 2 (2005)
• Killa Season (2006)
• Kiss and Tail: The Hollywood Jumpoff(2009)^[12]
• The Project (2011)^[13]
• Video Girl (2011)

References[link]

External links[link]

• Official site

Wiz Khalifa
Wiz Khalifa in Brooklyn, New York in August 2009.
Background information
Birth name	Cameron Jibril Thomaz
Born	(1987-09-08) September 8, 1987 (age 24) Minot, North Dakota, United States
Genres	Hip hop
Occupations	Rapper, singer, songwriter, actor
Years active	2005–present
Labels	Rostrum, Taylor Gang, Warner Bros., Atlantic
Associated acts	Snoop Dogg, Rick Ross, Curren$y, Big Sean, Chevy Woods, Mac Miller, Juicy J, Tinie Tempah, Yelawolf, Maroon 5, Big K.R.I.T.
Website	wizkhalifa.com

Cameron Jibril Thomaz (born September 8, 1987), better known by the stage name Wiz Khalifa, is an American rapper. He released his debut album, Show and Prove, in 2006, and signed to Warner Bros. Records in 2007. His Eurodance-influenced single, "Say Yeah", received urban radio airplay, charting on the Rhythmic Top 40 and Hot Rap Tracks charts in 2008.^[1] Khalifa parted with Warner Bros. and released his second album, Deal or No Deal, in November 2009. He released the mixtape Kush and Orange Juice as a free download in April 2010; he then signed with Atlantic Records.^[2] He is also well known for his debut single for Atlantic, "Black and Yellow", which peaked at number 1 on the Billboard Hot 100. His debut album for the label, Rolling Papers, was released on March 29, 2011.^[3]

Early life[link]

Khalifa was born on September 8, 1987 to a mother and a father serving in the military.^[1][4] His parents divorced when Khalifa was about three years old. His parents' military service caused him to move regularly: Khalifa lived in Germany, the United Kingdom, and Japan before settling in Pittsburgh where he attended Taylor Allderdice High School.^[1][4]

His stage name is derived from khalifa, an Arabic word meaning "successor", and wisdom, which was shortened to Wiz when Khalifa was a young boy .^[5] Khalifa stated to spinner.com that the name also came from being called "young Wiz 'cause I was good at everything I did, and my granddad is Muslim, so he gave me that name; he felt like that's what I was doing with my music." He got his stage name tattooed on his 17th birthday.^[6][7] He includes Jimi Hendrix, Camp Lo, The Notorious B.I.G. and Bone Thugs-n-Harmony among his influences.^[8]

Career[link]

[edit] 2005–08: Early mixtapes and Show and Prove

Rostrum Records president Benjy Grinberg first heard about Wiz Khalifa in 2004 when the rapper's contribution to a mixtape of various new Pittsburgh artists attracted his interest.^[9] When Grinberg finally met the 16-year-old artist, he immediately decided he wanted to work with him, later telling HitQuarters: "Even though he wasn’t all the way developed you could just tell that he was a diamond in the rough, and that with some polishing, guidance and backing he could become something special."^[9] Khalifa signed to the label shortly after and began a seven year period of artist development.^[9]

Khalifa released his first mixtape, Prince of the City: Welcome to Pistolvania, in 2005. The mixtape paved the way for his first full length album entitled Show and Prove in 2006. Khalifa was declared an "artist to watch" that year in Rolling Stone magazine.^[10][11]

In 2007, Khalifa signed to Warner Bros. Records and released two mixtapes through Rostrum Records: Grow Season, hosted by DJ Green Lantern and released on July 4, 2007, and Prince of the City 2, released on November 20, 2007. His debut Warner Bros. single "Say Yeah" reached number 25 on the Billboard Rhythmic Top 40 music chart and number 20 on Billboard's Hot Rap Tracks. The song samples "Better Off Alone" by Alice Deejay. Khalifa's vocals from "Say Yeah" appear near the end of Pittsburgh mash up producer Girl Talk's 2008 album, Feed the Animals, over music from Underworld's "Born Slippy", Usher's "Love in This Club", and the Cure's "In Between Days".^[12] Khalifa appeared with The Game, David Banner and Play-n-Skillz at U92's Summer Jam at the USANA Amphitheatre in West Valley City, Utah on August 2, 2008.^[13] Khalifa released the mixtapes Star Power in September 2008, and Flight School in April 2009 on Rostrum Records.

Khalifa parted ways with Warner Bros. Records in July 2009 after numerous delays in releasing his planned debut album for the label, First Flight. Khalifa stated to the Pittsburgh Post-Gazette that, "I learned a lot during my time there and matured as an artist during the process. I'm happy to be moving on with all of my material and having the chance to be in control of my next moves".^[14] Khalifa appeared with Girl Talk, Modey Lemon, Donora, Grand Buffet, and Don Caballero at the Amphitheatre at Station Square in Pittsburgh on July 31, 2009, where he announced that his relationship with Warner Bros. was over.^[15]

Wiz Khalifa performing at Columbia University in New York City in April 2010.

[edit] 2009–10: Deal or No Deal

Continuing his association with Rostrum Records, Khalifa released the single "Teach U to Fly", and the mixtape How Fly, a collaboration with New Orleans rapper Curren$y, on August 9, 2009.^[14] Khalifa introduced a more melodic style on the mixtape, alternating between singing and rapping. He opened for Wu-Tang Clan member U-God at the 2009 CMJ Music Marathon in New York City.^[16] Khalifa released the mixtape Burn After Rolling on November 2, 2009, where he raps over familiar beats from other artists, including the songs "If I Were A Boy" and "Diva" by Beyoncé, "Walking on a Dream" by Empire of the Sun, "Luchini AKA This Is It" by Camp Lo, and "Best I Ever Had" by Drake.^[17] Khalifa released his second album, Deal or No Deal, on November 24, 2009.^[18]

Khalifa performed at Emo's in Austin, Texas in March 2010 as part of the 2010 South by Southwest Music Festival.^[19] He appeared on the cover of XXL magazine that same month, for the magazine's annual list of Top 10 Freshman, which included Donnis, J. Cole, Pill, Freddie Gibbs, and Fashawn. Wiz Khalifa was named 2010 "Rookie Of The Year" by "The Source", with alongside Rick Ross, "The Man Of The Year".^[20] He toured with rapper Yelawolf on a 20-date tour, the Deal Or No Deal Tour.^[21] Khalifa released the free mixtape Kush and Orange Juice for download on April 14, 2010. Due to Khalifa's devoted grassroots fan base, the mixtape became the No. 1 trending topic on Twitter with the hash tag #kushandorangejuice, and "Kush and Orange Juice download” ranked No. 1 on Google’s hot search trends.^[22]

2010: Signing with Atlantic Records[link]

Citing music industry insiders, New York magazine wrote that Khalifa signed with Atlantic Records in April 2010, although the rapper did not confirm it.^[23] He stated to AllHipHop in June 2010 that he was working on a new album, but was weighing his options and had not yet decided on a label to distribute it.^[24] Khalifa confirmed to MTV on July 30 that he was signing an Atlantic Records deal.^[25]

Wiz Khalifa on stage in Boston in August 2010.

Khalifa was featured in a remix and video for the 2010 Rick Ross single "Super High", alongside Curren$y.^[26] He guested on the mixtape Grey Goose, Head Phones, and Thirsty Women by St. Louis rapper M.C,^[27] and was featured on the track "The Breeze (Cool)" on rapper Wale's August 2010 mixtape More About Nothing.^[28] Khalifa was named MTV's Hottest Breakthrough MC of 2010, winning with nearly 70,000 votes, and beating out finalists Nicki Minaj, J. Cole, Travis Porter, and Diggy Simmons.^[29]

Khalifa appeared at the Soundset 2010 festival in May 2010 in Minneapolis, Minnesota, alongside Method Man & Redman, Del the Funky Homosapien and Hieroglyphics, Atmosphere, Murs, Cage, and others.^[30] He also performed at the 2010 Rock the Bells festival, along with hip hop veterans Wu-Tang Clan, Snoop Dogg, Lauryn Hill, A Tribe Called Quest, Rakim, KRS-One, Jedi Mind Tricks and Slick Rick.^[31] Khalifa declined an invitation to tour with rapper Drake and launched his own "Waken Baken" tour, a 50-city national tour with rapper Yelawolf. The tour, scheduled to last from September to November 2010, has, as of October, sold out every venue.^[8] On November 2010, during his "Waken Baken" tour at East Carolina University, Wiz Khalifa was arrested for possession and trafficking of marijuana. He was then released the next morning after a $300K bail, and resumed his tour. Khalifa performed in a cypher during the 2010 BET Hip-Hop Awards. He recited his verse from the song, "The Check Point", from his mixtape with Curren$y, How Fly.^[32]

[edit] 2010–11: Mainstream success and Rolling Papers

Wiz Khalifa at SXSW in 2010

Khalifa released "Black and Yellow", his first single for Rostrum/Atlantic, produced by Stargate, which has received radio airplay.^[8][33] The single was peaked at number 1 on the Billboard Hot 100; the title of the song refers to the colours of the City of Pittsburgh.^[34] Khalifa released his debut album with Atlantic Records in 2011.^[35] He appeared with Curren$y on the track "Scaling the Building" on producer Ski Beatz' 2010 album, 24 Hour Karate School.^[36] Khalifa's record label is Taylor Gang Records, named after his love of Chuck Taylor All-Stars^[8], and Taylor Allderdice High School in Pittsburgh, PA, where he graduated from.

On March 29, 2011, Khalifa released his first studio album, Rolling Papers. The album debuted at number two on the US Billboard 200 chart, with first-week sales of 197,000 copies in the United States.^[37] Shortly afterward on March 31, 2011 Wiz Khalifa performed at Emory University in Atlanta, Georgia as part of the school's annual Dooley's Weekend.^[38] On June 26, 2011, Khalifa was nominated and won Best New Artist at the BET Awards of 2011.^[39] Khalifa collaborated with British rapper Tinie Tempah whom Tinie announced in an interview with Rolling Stone that his next single is to be called "Till I'm Gone" and would feature Wiz Khalifa and is to be produced by Stargate.^[40][41] The single and the video song were released at the end of June 2011.^[42]

Personal life[link]

Thomaz proposed to model Amber Rose on March 1, 2012 showing off the ring on Twitter.^[43] He is personal friends with Snoop Dogg, Juicy J, Yelawolf, and fellow Pittsburgh rapper Mac Miller.^[44]

In March 2012, Thomaz purchased a 2.8 private wooded acres with a 3,891-square-foot residence in Canonsburg, Pennsylvania, a small community southwest of Pittsburgh. The residence includes 5-bedroom, 4-bath eco-friendly, Brazilian Koa floors, stainless steel appliances, a separate guest house, and a lavish master suite with high ceilings.^[45] He currently resides there with his fiancée Amber Rose.

Discography[link]

Studio albums

• 2006: Show and Prove
• 2009: Deal or No Deal
• 2011: Rolling Papers
• 2012: O.N.I.F.C. ^[11][46][47]

Collaborative albums

• 2011: Mac & Devin Go to High School (with Snoop Dogg)
• 2012: TBA (with Taylor Gang)

Awards and nominations[link]

References[link]

External links[link]

Wikimedia Commons has media related to: Wiz Khalifa

• Official website
• Wiz Khalifa on Facebook
• Wiz Khalifa on Myspace
• Wiz Khalifa on Twitter
• Wiz Khalifa at MTV
• Non-commercial Wiz Khalifa mixtapes