(written from a Production point of view)
Jay Curtis Crimp (9 April 1951 – 28 February 2011; age 59) was a dancer, singer, and actor who portrayed a Vulcan electrician in Star Trek IV: The Voyage Home and later a Starfleet officer from the USS Stargazer in the 1987 Star Trek: The Next Generation episode "The Battle". He received no credit for both appearances. His Vulcan costume was sold off on the It's A Wrap! sale and auction on eBay. 
Crimp was born in Ellensburg, Washington and attended the Ellensburg public schools and geaduated from Ellensburg High School in 1969. During his high school time he built a passion for theatre and film. He attended the Central Washington University and then the University of Washington but left and moved to New York where he was cast as a dancer for the stage tour of "Applause" in 1973. In the late 1970s he moved to Hollywood, California and was further seen in stage plays such as "Godspell", "Jesus Christ Superstar", "Grease", and "Hello Dolly". Crimp also worked as choreographer on some of these plays.
Also in the late 1970s he started to work in film and television and was cast to dance in the musical dramas Saturday Night Fever (1977) and Grease (1978). Crimp's first credited appearance was in the 1985 Academy Award-nominated thriller Jagged Edge (alongside Michael Dorn, Bruce French, Louis Giambalvo, Leigh Taylor-Young, and Karen Austin). In 1992, Crimp appeared in an episode of the short-lived comedy Tequila and Bonette entitled "Fetch This, Pal" (directed by Rob Bowman). In 1997, he portrayed a Yoga student in "Instant Dharma", an episode of the sitcom Dharma and Greg (alongside Mitchell Ryan) and in 2006 he appeared in a Still Standing episode, entitled "Still Flunking". Other acting appearances include the comedy Junior (1994, with Frank Langella, the mystery sequel The X-Files (1998), and the comedy The Bucket List (2007).
For the last twenty years, Crimp mainly worked as stand-in on comedy series such as Cheers, Coach, Wings, News Radio, Dharma & Greg, Will & Grace, Still Standing, That '70s Show, and as stand-in for Jim Parsons on The Big Bang Theory. He also worked as stand-in for David Duchovny on the 1997 crime thriller Playing God. Crimp also worked as choreographer for several stage plays and founded the troupe "A Chrous Line for Care" which raised money for AIDS victims.