Segmenting. The sky is the limit. Segmenting is used in turning far more than pens by the most talented people you would ever meet. I could never even carry the scraps that they drop for what they do. One of my all time idles is Malcolm Tibbetts . He is a master when it comes to segmenting and his tools are a Festool Kapex miter saw. But he also uses the table saw and has many jigs to work with each. Rarely does he use bandsaw because accuracy is limited even with the best of jigs because the blade is not as stout as a fixed blade. But his other tool that is important in his line of segmenting is a true disc sander with jigs to hold pieces in proper alignment.
I bring this up because they may work with larger segmented pieces at times than we do when making a small round pen blank but the ideas are basically the same and can be carried over. Just look up the name and see the beautiful work that he does. There are many more true turners that do things like he does.
But to address the OP questions, as mentioned bandsaw, tablesaw of any size, and also chop saw along with the lathe and router, can be used. Jigs are made to both safely cut small pieces and to be able to repeat the cuts with accuracy. Knowing your tools plays a big role and tuning the saws so they do what they were designed to do. Having jigs that have hold downs is important for both safety and again accuracy. Myself I love to use a tablesaw and will never use a chop saw. My thought here is I want to be able to see and control the blank or wood I am working with. I want to be able to see the entire cut all the way through. With a chop saw you are blinded when that blade is pulled down so it would not be my choice. As I said I do not make fine cuts on a bandsaw because no matter what you do the accuracy needs to be tuned after the cut. For some of the segmenting I have seen here such as celtic knots the cut is not that important when done for clean cutting. Just infill and it is good to go. A tablesaw will give you a cleaner cut. Now I have done many segmented blanks using my lathe and a router platform. When you get into this line more you too will find what works best for you because there are many ways to get the same results. I have to say one of the most important tools I use when working with small pieces is doublesided tape.
Tablesaw blades --- I use 1/8", mostly 3/32" and also 1/16"
Bandsaw I use mainly 3/16" and also metal cutting blades.
Jigs I brought this thread back to life the other day hoping others would contribute but seems not many segmenters on this site. but Ken started it and he shows some of his jigs. There are also articles in the library showing jigs for cutting blanks.
https://www.penturners.org/threads/shop-built-jigs.164721/
