I spent some time over the weekend delving into the world of kitless and closed end pens. One issue I ran into is getting the drilled blank to turn true on the pin chuck - I keep getting a wobble. The blank is well seated on the pin and it turns fine, but results in a slightly out-of-round condition. Is there a trick to mounting the blank on the pin chucks?
If it's rod, insert as close to the check as can get, I have a small chuck with center drill that I placed a wobbler on to make sure concentric then marked the MT with marker as to fit in rail stick same place each time
Once the rod spins at high RpM the center is clear , I sit in a chain so eye level and make sure nail center
The switch chuck to drill
Best to drill small the step up to size as can get chamfer with larger bits and first few mm of bore may be larger , another tip is drill 2mm in reverse as slow speed to start the bore then switch back
Different materials drill best at different speeds some need some lubricant that part is trial and error but don't force ease in, take out cool lubricant , brush off swarf the. Drill again
Should hit center every time
Otherwise your chuck is not true , a dial indicator will help, more then .0002 you got an issue , maybe bent pin jaw or simply chuck or insert not threaded complete to lathe stock
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