Drilling & bushing questions

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BlackGoatWW

Member
Joined
Apr 11, 2021
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20
Location
NCR
So I have searched through and I think I am on the right track with both of these questions but I wanted to throw these out to see if anyone had any sage advice.

1) When I am turning on my mandrel with bushings. Is it common to somtimes have just a little scrape of the bushing as you finish shaping up the end? Its never much but I always seem to have just a few flakes as I try to get the barrel of the pen nice and tight to the tolerance of the bushing.

Background:
Generally I turn down to close to the bushings and sand my first few grits. Then I pull the bushings off and put on plastic non stick bushings and finish sanding to include making sure I get the edges nicely. Then I go into finishing from there.

Any problem with this process or suggestions?

2) I am looking at making a vessel or some other items on my lathe. I have a Laguna Revo 1216 (Midi). Great lathe so far, but the quill throw is only approximately 2.5". If I need to drill something deeper what is the best way to go about doing this? Should I drill to depth shut everything off. Move the tail stock in, and then drill again? Sorry if this is a silly question, but I havent quite been able to wrap my head around the best way to do this.
 

jttheclockman

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Feb 22, 2005
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19,082
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NJ, USA.
Lets start with question #2 The answer is YES. That is common with just about any drilling on the lathe.

The first question is subjective. First the bushings are only a guide. They are never the exact same dimension as the kit parts. Could be over or could be under. This is why a good set of digital calipers is a must if you want to get good at making a good quality pen. Measure the parts and right them down. Now measure the bushings and write them down and you will see which way the bushings are made, over or under. what I do is always trim some metal off bushings so they are always under. Now when I turn the blank down I measure the ends with calipers and it gets me to exact measurement that is needed to math components. No need for sanding. But if I need to sand I take blank off those bushings and use plastic cone shaped and turn between centers. This way no metal sanding dust corrupts the blank and ruins it. just my way of doing this. But to your question, never use bushings as exact measurement for kit parts.
 

penicillin

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Feb 27, 2019
Messages
1,036
@jttheclockman's answer above is exactly what I would have said. Allow me to add:

If you sand with the plastic bushings as JT and I do, be careful to keep your sandpaper flat on the outside of the pen blank. Do not allow the sandpaper to curl over the ends, or you will round over the ends and reduce their size, just after you spent all that time and work with the digital calipers to get the size and shape just the way you wanted it.
 

monophoto

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Mar 13, 2010
Messages
2,542
Location
Saratoga Springs, NY
#1. Bushings are ultimately 'expendable' meaning that they will eventually need to be replaced. The diameter slowly shrinks as you use them while turning, but sanding probably causes more rapid wear.

2. That's everyone's experience. Stop the lathe,
withdraw the drill bit, clear the swarf (very important - if you allow swarf to build up, that increases friction and heating and can damage both the blank and the drill bit), advance the tail stock to move the bit into the hole, and resume drilling
 
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