There is a big difference in the potential for errors between no-thumb and thumb-in drilling operations. By introducing a thumb, you create the potential to err on span to either finger, bevel preferences, oval angles, pitch errors, oval dimension errors, top-to-bottom taper errors, smoothness inconsistencies, and more.
Furthermore, the tooling and inventory commitment necessary to drill thumbs is much larger than drilling finger holes -- expanding your bit carousel from the two sizes we use to 40+ sizes, including many specialty bits necessary for each of the various switch-grip systems from Vise, Turbo, Ultimate, JoPo, and more. This is a business decision and as a part-time pro-shop operator, it would not be cost-effective for us to offer this service. If you need a thumbhole I would recommend visiting Rusty Bryant at Winnetka Bowl.
.png)
%20(2).png){kind=small}