I've had and mostly played Kiesel headless guitars since 2015. In that time, they've been fantastic, with some minor issues. The growing one has been wear-in on the tuning screw friction surfaces. This is particularly true of my Z6X, as I've had to be very careful in how I adjust the tuners, as they were hard to turn. The Z5B bass was even more difficult to turn. A secondary issue are that my fingers are just darned big and I have to finger-tip grip the tuners. Initially it wasn't a problem, until things wore in, and even with teflon grease, I still had struggles tuning quickly.
I had a "doh" moment when remembering thrust bearings. Why didn't I remember them years go? I don't know. But I saw something that jogged a memory, and I went in search of bearings that would work.
Early headless guitars have square-cut thumb screws, and at some point it was changed to a rounded shoulder facing the bridge. The thrust bearings I tried work for both. No longer screws are needed - there is so much extra length on my guitars that I still have some left despite the new bearings. Only a #1 or 2 Philips screwdriver is needed to break the screws free.
For guitar, I used F3-8M bearings, which have 3mm center holes, 8mm outer diameter, and 3.5mm thickness total.
For bass, I went with F4-10M size - 4mm center hole, 10mm outer diameter, 4mm thickness. The tuner screws are shorter than on guitar, so about 1/4" longer ones are needed. I have not yet sourced these, but once I do, I plan to edit this with dimensions and thread type/pitch.
Here's how they look compared to the stock setup. They stick out slightly farther, easier for me to get a grip on them, and they turn easily now, even for bass. Below is how they look. I bought my bearings off Amazon, but didn't want to put in links, just in case. However, overall current cost is $8.50 for bass, and about $6 for guitar. Super cheap modification. I can provide links if people want to send me a PM.
