The creation of a knurl without a knurling tool
For very limited production or prototype, there is an alternative for creating a diamond or diagonal knurl without the use of a knurling tool, even on a 2 axis OmniTurn lathe or attachment. While never as efficient as the use of a knurling holder and knurls for production, when in a jam for a prototype or very short production run when you do not have the proper knurls available, the use of OmniTurn’s very efficient and versatile threading cycles can be used to produce a knurl.
The tooling for a knurl can be as simple as using OmniTurn’s Multibar with a threading insert. In the case of a diamond or left-handed diagonal knurl, either a left-handed Multibar or a large Multibar turned upside down (and a spindle drive on an attachment) will be needed.
In programming the knurl, you must calculate how many knurls will fit around the diameter to determine how many starts to make. The smaller the diameter and the coarser the knurl, the less starts you need. For example, a coarse diamond knurl on a .750” OD requires 40 starts in each direction with a pitch of .05”. That equals a 2 IPR feed rate, the maximum allowed by the OmniTurn. Refer to the coarse pitch threading codes of G35 and G36 in the programming manual or on the website under “Programming Help” for an example of multiple start coarse pitch thread.