Making and tying Tzitzis on Chol Hamoed:[1]

It is permitted for one to weave Tzitzis strings [and tie the Tzitzis] onto one’s garment [i.e. Tallis Gadol or Tallis Katan] on Chol Hamoed. [This may be done even without an irregularity.[2] However, one may not weave the strings using a sewing wheel or other machinery.[3] Likewise, one may only make/tie the strings on Chol Hamoed for the sake of wearing it on Chol Hamoed.[4] Likewise, one may not make/tie strings on behalf of others, even for the sake of the Moed, unless he does not take payment.[5]]

____________________________________________________________

[1] Michaber 545:3; Rebbe Yehuda in Mishneh Moed Katan 3:4 [18b]

[2] M”A 545:7; Beis Yosef 545; Tur 545; Rambam; See Taz 545:4

Other opinions: Some Poskim rule that one may only tie the Tzitzis with an irregularity. [Implication of Michaber and Mishneh ibid, as understands Taz 545:4; Rashi Moed Katan ibid]

[3] M”A 545:8

[4] P”M 545 A”A 7 “Specifically when its needed for the Moed…as Tzitzis is not so much a Chovas Gavra”; See also P”M 545 M”Z 4 [in initial ruling, as opposed to the implication of his conclusion]

[5] P”M 545 M”Z 4