Pen Turning Issue

[professorgt]

In trying to drill pen blanks by using this innovative chuck I have had little success because of the lack of being able to keep the tailstock on center. The Aluminum bushing in the tailstock fixture is sloppy, and the set screw digs into it such that it will not allow proper adjustment. This coupled with the inherent flex of the fixture itself causes the hole drilled in the blank to be larger than it should be, and then the pen tube becomes too loose a fit in the blank. Does anyone have a reasonable solution to this issue?

Thanks,
ProfessorGT

[JPG]

In trying to drill pen blanks by using this innovative chuck I have had little success because of the lack of being able to keep the tailstock on center. The Aluminum bushing in the tailstock fixture is sloppy, and the set screw digs into it such that it will not allow proper adjustment. This coupled with the inherent flex of the fixture itself causes the hole drilled in the blank to be larger than it should be, and then the pen tube becomes too loose a fit in the blank. Does anyone have a reasonable solution to this issue?

Thanks,
ProfessorGT

Try filling the 'depression' in the 'bushing' with jb-weld, then smooth it back to 'round' and start over, but do not force the set screw.

[nuhobby]

FYI also,
You can get a new aluminum center-adjust piece for not a lot of cash:
http://www.shopsmith.com/ownersite/item ... =Find+Item
Newer Mark V's use 2 setscrews (one on each side), compared to older ones with 1 setscrew. You may be able to drill and tap a second hole.

I've been trying to find an old posting where a lot of ways to reduce the tailstock flex were discussed. Making sure the accessory-lock handle has the 2 threaded bolts equidistant from center when tightening it up can help. Also, a couple years ago on http://www.ssug.org somebody reported that slightly sanding/leveling the Base Arm where the tailstock's 2 lock collars sit upon it can reduce how much the tailstock rocks on the Base Arm.

Drilling into a rotating workpiece isn't trivial. In metalworking an accurate finish-diameter job is done with boring (single cutting edge) or reaming operations (a drill-bit is only accurate enough for the initial bulk material removal; it follows a path of least resistance and can deflect from center).

[pennview]

I just drill the blanks in the drill press mode, holding the blanks in a wooden hand screw clamp with a scrap of wood underneath to prevent drilling into the table. If I get flexing because the blank is dense or because the bit is slightly dull, I use a length of 4x4 (or 2x4) from the floor to the bottom of the table that prevents the flexing. (Such a brace works well when using the mortising attachment.)

[fjimp]

I just drill the blanks in the drill press mode, holding the blanks in a wooden hand screw clamp with a scrap of wood underneath to prevent drilling into the table. If I get flexing because the blank is dense or because the bit is slightly dull, I use a length of 4x4 (or 2x4) from the floor to the bottom of the table that prevents the flexing. (Such a brace works well when using the mortising attachment.)

I personally agree with Art. Drill Press Mode is the superior method for pen blank drilling. Woodcraft, Penn State Industries and Rockler all offer excellent pen blank drilling rigs that are superior to the horizontal jig you are using. Fjimp

[jimthej]

Ditto on the JB Weld to fill the depression in the tailstock center. I drilled and tapped the back side of my tailstock a couple of years ago. Works well.
Had the same problem though a couple of weeks ago. Problem was, the blanks were not really square, even after I rechecked the alignment, the blanks were wagging the drill bit around.
Solution for that day was to mount my Talon chuck to the tailstock and the drill to the quill. Zammo, perfect holes.

[JPG]

Hey Y'all, he wants to use his 'innovative chuck. He needs a solid tailstock to do so.

IMHO the tailstock could be much improved. The insert is a sloppy fit which causes one to over torque the set screw that then in turn distorts the soft insert.

Shimming the insert helps a little, and adding additional set screws should help also(but not convenient when needing to adjust it).

The use of stop collars helps the wiggle and as has been mentioned proper adjusting of the clamp makes it more rigid.

It is the drilling of rotating work pieces that brings the short coming(sloppy tail] to the forefront.

[dusty]

[quote="nuhobby"]FYI also,
You can get a new aluminum center-adjust piece for not a lot of cash:
http://www.shopsmith.com/ownersite/itemfind.htm?item=5014379&Submit=Find+Item
Newer Mark V's use 2 setscrews (one on each side), compared to older ones with 1 setscrew. You may be able to drill and tap a second hole.

I've been trying to find an old posting where a lot of ways to reduce the tailstock flex were discussed. Making sure the accessory-lock handle has the 2 threaded bolts equidistant from center when tightening it up can help. Also, a couple years ago on www.ssug.org somebody reported that slightly sanding/leveling the Base Arm where the tailstock's 2 lock collars sit upon it can reduce how much the tailstock rocks on the Base Arm.

Drilling into a rotating workpiece isn't trivial. In metalworking an accurate finish-diameter job is done with boring (single cutting edge) or reaming operations (a drill-bit is only accurate enough for the initial bulk material removal]
Is this the thread you are looking for? If not, there is still another thread referenced within this one.

I was scoffed at for this earlier but I use a wooden wedge to stabilize the tailstock whenever I do not want 'any uncontrolled movement'. I do this everytime I set up in drill press mode too. The wedge, in the images here, is installed to stabilize the right side extension table.

[ATTACH]14853[/ATTACH] [ATTACH]14854[/ATTACH]

[anmius]

In trying to drill pen blanks by using this innovative chuck I have had little success because of the lack of being able to keep the tailstock on center. The Aluminum bushing in the tailstock fixture is sloppy, and the set screw digs into it such that it will not allow proper adjustment. This coupled with the inherent flex of the fixture itself causes the hole drilled in the blank to be larger than it should be, and then the pen tube becomes too loose a fit in the blank. Does anyone have a reasonable solution to this issue?

How about just drilling the blank in the horizontal boring mode using either the rip guide and/or cross cut guide to guide and hold the blank?

[kalynzoo]

I just drill the blanks in the drill press mode, holding the blanks in a wooden hand screw clamp with a scrap of wood underneath to prevent drilling into the table. If I get flexing because the blank is dense or because the bit is slightly dull, I use a length of 4x4 (or 2x4) from the floor to the bottom of the table that prevents the flexing. (Such a brace works well when using the mortising attachment.)

Me too. Except I always use a sharp drill.