How many tools can you use to make a groove

If you're an experienced enough spinner, you can spin fiber with anything, even a rock. That's why my pickiness with spindles, weight, shape and material can be completely subjective. But one thing is for sure, working with a good tool is more pleasurable and makes the work feel more like an extension of your own body, instead of an external effort.
For me, since I became confident enough about my spinning to evolve from the way I was taught to spin to the way I really want to spin, there are small details that make all the difference.
Alongside with balance and weight, the helical groove on top of the spindle is the more important detail. I like it to be deeply carved and for it to form a perfect hook on top. I believe that this groove is one of the things that differentiates the "portuguese spindle" from other similarly shaped spindles from around the world, like the russian spindle. If the russian spindle has to be used with support, our spindle, when it has a well carved top screw can even be used as a drop spindle, although that depends a lot on individual techniques.

The first spindles I got made for me, were made by Zé Manel, in Bucos. In the end, he would sculpt the screw with a pocket knife and that was it. When I had to have these spindles made here in Porto, with a slightly different size and shape, not one of them came with a decent groove. So I though that if Zé Manel could do it, so could I. The pocket knife wasn't enough, but with the help of a nail file and a knife file, I got the job done.
Since then, I ask for all the spindles to be hand turned, but delivered without the helical groove and then I sculpt them one by one, with the shape I feel they should have for the spindle to spin properly. You see, sometimes it's very difficult to explain to someone that doesn't spin why such a small detail makes such a big difference, so I prefer spending my time making the grooves myself, instead.