Huh? Not sure what you are asking, or implying. Badger has made their brushes since the 60's with a teflon needle packing pressed in from the front. They periodically fall out, or more often start allowing paint back into the brush body, and trigger area. The Sotar needed to have a removable head, so that the teflon packing could be replaced from the front. The packing has nothing to do with centering the needle, or controlling runout. In the removable head design, you then needed to have a seal around the threaded head post to keep air from entering the paint path and bubbling the cup. You also wound up with a potential air leak around the circumference of the head where it meets the body. By brazing the head base to the body, they address all of these situations. No air leak possible around head base, or into the paint path at head base, and no possibility of the packing seal falling out. A bonus, and to me it is a big one, is that it gives the end user the ability to actually adjust or replace the packing. It used to be required to send the brush back to Badger to have a packing replaced. Long overdue upgrade on these brushes.
