You are not taping the bearing for a 1-72 screw , you are cleaning out the bearing hole.  There is material from the printing process fowling the bearing surface in the side-frames that once removed allows for a smooth rolling truck. The end of a 1-72 tap works well.

 Bill Miller

-----Original Message-----
From: Mark Lewis <narrowrails12@...>
To: HOn3@groups.io
Sent: Fri, Sep 25, 2020 4:51 pm
Subject: Re: [HOn3] Is there market "demand" for 3D printed HOn3 trucks?

Bill Miller,

I'm with Bruce and Bill....please explain!

Mark Lewis 
Narrow gauge modeling in N.C.