Bouncing Pen Blanks leading to a bad times

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concelor

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Jul 7, 2022
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Finally getting set up in the world of pen turning

I find myself with an odd issue, and looking through the forums here I see a few things I've tried but still no good

To save shop space the wife ended up me getting Jacobs drill chuck for the lathe to drill blanks based on the recommendation of the Rockler staff and local turning club

Combined with the Nova G3 lite jig with pen jaws I figured I would be all set and wouldn't need a drill press

That said the drill bit and barrel trimmer oscillated as I try to drill into a blank for the tube hole that's not a huge deal

But for the barrel trimmer (she ended up getting "sold" the woodpecker ultra shear set) it has shattered/chunked out my blanks depending if its acrylic/wood

Thinking the chuck and end stock wasn't aligned I bought an alignment bar and its super level

For my wood pens, I can just chuck the blank up and spin by hand for the pen mill, it's crazy sharp but can't do that with acrylics

Not sure what could be causing the bounce and unalignment as the blank spins, so looking for some direction that I may not be thinking of

I do know from forum diving barrel trimmers seem to be in two camps (love em, ditched them lol) and have seen the sanding jig

That said I can't justify buying anything else right now, lathe, nova lathes, hand tools, woodpecker pen mandrel, wood peck ultra-shear, and a tormek T-8 sharpener on the way, my wife's surprise present (she was so happy she got the lathe for 600) is costing us a few thousand bucks…Luckily I got her to stop adding onto the lathe "bundle" gift, but that means a sanding jig/drill press will need to wait

So hoping the experts have some tricks that can help me use what I have to get some acrylic blanks spun up

As always thanks for all the responses
 
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monophoto

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That said the drill bit and barrel trimmer oscillated as I try to drill into a blank for the tube hole that's not a huge deal
- - -
Not sure what could be causing the bounce and unalignment as the blank spins, so looking for some direction that I may not be thinking of

How are you using the jacobs chuck? Are you mounting it in the headstock, and the pushing the blank into the spinning drill bit/trimmer, or are you mounting it in the tailstock and pushing a stationary bit/trimmer into the rotating blank?

The normally recommended approach is to mount the blank in your scroll chuck on the headstsock, and spin at 300-600 r/min, and the have the drill bit in the jacobs chuck mounted in tail stock and stationary. Before starting to drill, use a skew to cut a dimple in the end of the spinning blank, and then align the drill bit with that dimple before locking down the tailstock and starting to drill. That should eliminated any wobble.

You can mount the jacobs chuck in the headstock, and there may be situations where that's appropriate. However, that's potentially dangerous because the morse taper can decouple and allow a spinning jacobs chuck to fly across the shop. As a minimum, whenever the jacobs chuck is mounted in the headstock, it should be held in place with a drawbar. That's still not a perfect solution because the arbor on a jacobs chuck often has two tapers - a morse taper that mates with the lathe, and a J-33 taper that mates with the chuck body. A drawbar will hold the morse taper in the headstock, but it would prevent the J-33 from decoupling with the chuck body. DAMHIKT
 

MPVic

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Dec 23, 2011
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Hamilton, ON, Canada
Welcome to the world of pen turning! This is just my personal experience, for what it's worth. I ditched the pen mills some time ago & purchased Rick Herrell's sanding jig which was a real game-changer for me. I have also heard that the Woodpecker pen mill is very aggressive, especially with any non-wood blanks.
I use a Oneway Stronghold chuck for drilling blanks - with the 4 jaws I have not had any problem drilling. But as far as the mis-alignment you mention, I can't help you there. But stick with it, there is a huge knowledge base here at IAP so I'm certain you will get more feedback from others.
P.S. Your wife sounds like a sweetheart with all the lathe gifts!!!!! ;)
 

concelor

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Jul 7, 2022
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Location
Michigan
How are you using the jacobs chuck? Are you mounting it in the headstock, and the pushing the blank into the spinning drill bit/trimmer, or are you mounting it in the tailstock and pushing a stationary bit/trimmer into the rotating blank?

The normally recommended approach is to mount the blank in your scroll chuck on the headstsock, and spin at 300-600 r/min, and the have the drill bit in the jacobs chuck mounted in tail stock and stationary. Before starting to drill, use a skew to cut a dimple in the end of the spinning blank, and then align the drill bit with that dimple before locking down the tailstock and starting to drill. That should eliminated any wobble.

You can mount the jacobs chuck in the headstock, and there may be situations where that's appropriate. However, that's potentially dangerous because the morse taper can decouple and allow a spinning jacobs chuck to fly across the shop. As a minimum, whenever the jacobs chuck is mounted in the headstock, it should be held in place with a drawbar. That's still not a perfect solution because the arbor on a jacobs chuck often has two tapers - a morse taper that mates with the lathe, and a J-33 taper that mates with the chuck body. A drawbar will hold the morse taper in the headstock, but it would prevent the J-33 from decoupling with the chuck body. DAMHIKT
Took me a few rereads, but I'm doing it the recommend way, drill bit not spinning and being pushed into the spinning blank around 400 RPM
Not sure i understand the comment about using a skew to center mark, I use a center punch and have been aligning off that
 

concelor

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Jul 7, 2022
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4
Location
Michigan
Welcome to the world of pen turning! This is just my personal experience, for what it's worth. I ditched the pen mills some time ago & purchased Rick Herrell's sanding jig which was a real game-changer for me. I have also heard that the Woodpecker pen mill is very aggressive, especially with any non-wood blanks.
I use a Oneway Stronghold chuck for drilling blanks - with the 4 jaws I have not had any problem drilling. But as far as the mis-alignment you mention, I can't help you there. But stick with it, there is a huge knowledge base here at IAP so I'm certain you will get more feedback from others.
P.S. Your wife sounds like a sweetheart with all the lathe gifts!!!!! ;)
I have seen the Rick sanding jig, it's on the list, but will be a few months need to recover for the Tormek lol
 

AllanS

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Jun 13, 2022
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New Mexico
... use a skew to cut a dimple in the end of the spinning blank, and then align the drill bit with that dimple before locking down the tailstock and starting to drill. That should eliminated any wobble.

I've found that brad point drill bits have generally done that for me. But I may be in the wrong on that.
 

KenB259

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One of the inherent problems with barrel trimmers lies in the fact that you are trying to square the ends to the brass tube, not the blank. Anytime the drilled hole is not perfectly straight and you are holding the pen blank in any sort of vise, whether that is pen jaws attached to a chuck or a vise on s drill press, you will will have problems and lackluster results. The drill bit can cut its way through, the pen mill is going through a brass tube and can easily bind and do all sorts of bad stuff. You're better off sanding them square, and you can easily make you're own setup for pennies. In addition, center finding stubby bits are your friend.
 

wouldentu2?

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Oak Creek WI
Use a center drill before drilling with your drill bit, it's sturdy with a short point to mark the center and aid the drill bit entry. Really cheap online or harbor freight.
 

AllanS

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New Mexico
To save shop space the wife ended up me getting Jacobs drill chuck for the lathe to drill blanks based on the recommendation of the Rockler staff and local turning club

Just to ask, what is your lathe sitting on? One thing (among many) I was doing wrong was an inadequately stable table.

and/or perhaps a few pics of your setup may help.
 

monophoto

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Took me a few rereads, but I'm doing it the recommend way, drill bit not spinning and being pushed into the spinning blank around 400 RPM
Not sure i understand the comment about using a skew to center mark, I use a center punch and have been aligning off that
I presume that you use the center punch to mark the physical center on the blank before mounting it in the scroll jaws. However, that doesn't guarantee that the axis of rotation will pass through those marked centers.

My suggestion is to mount the blank in the scroll chuck, spin it, and use a skew to mark the center of rotation on the end of the blank. Then, align the drill bit in the tailstock to that center.

Alternatively, you could loosely place the blank in the headstock-mounted chuck, and then bring up the tailstock to make sure that the center you have marked on the blank aligns with he tailstock before tightening the jaws on the scroll chuck. That approach will work as long as the tailstock remains exactly in alignment when the jacobs chuck is installed and the tailstock is moved into position. However, on some lathes, the tailstock can rotate a fraction of a degree before it is locked down to the bedways, and if the drill bit isn't exactly aligned with the axis of rotation of the blank, the bit will wobble

Its fine to mark the physical centers on end of the blank, but those physical centers do not necessarily have to coincide with the axis of rotation of the blank when it is turned. The axis of the hole you drill in a pen blank becomes the center of rotation of the blank when you eventually turn that blank. Unless you are working with a segmented blank where pattern symmetry is important, the axis of the hole doesn't have to join the physical centers on the two ends of the blank. Instead, the only requirement is that there must be enough 'meat' around the entry and exit holes to turn the desired shape; as a result, it's OK if those holes aren't exactly centered on the ends of the blank.
 

jttheclockman

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Alex, you got alot of real good advice and from there you should be able to correct the problem. Now I maybe repeating things that were said but will chime in. First things first because you use the term bouncing pen blanks and it is throwing me a little. So we begin with the scroll chuck with the pen blanks jaws. Take the chuck and close the jaws by hand all the way and see if they meet the entire way from top to bottom. If they do not that is the beginning of your problem but if they meet properly you are set there. Do not mark any centers because it is a waste of time. Set the blank in the jaws so that the 2 corners of the blank line up in the grooves of the jaws. Does not matter which corners you use. Just nestle them in there and lock the chuck closed. The blank may spin offcenter but do not worry about it. Blanks can be out of square when you buy them or cut your own.

Now with your jacob chucks firmly installed in the tailstock get yourself some centering bits. (you can use a skew but do not recommend for a beginner) These are cheap short bits and they are designed to make starting holes in end grain of blanks. (https://www.amazon.com/Center-Drill...hvlocphy=&hvtargid=pla-4584070156680349&psc=1) Drill a small hole and remove bit. Now chuck up whatever bit you want to drill tube hole. I suggest you stay away from brad point bits. They can present other problems. When drilling put lathe on slow speed. Hold the jacobs chuck to get the bit started or it can bounce around on you a bit. After you get hole started you do not have to but most people continue to hold it because when pulling the bit out it is possible for the chuck to get dislodged from tailstock ways and become loose. By holding the chuck you stop from happening. You will get the feel for this procedure quickly. It is safe to do and easy. Clean the hole out every so often and also keep the bit cool when drilling.

I won't go into all the other steps but glue your tube in and let dry. Now as most people mentioned it is best to sand the ends flush using a set of transfer punches in the jacobs chuck and a makeshift sand disc in the headstock. Now there is so much to write here but if you want to know more about this process you can do a search for it or just ask as a separate question so things do not get mixed up. Using a barrel trimmer in a jacobs chuck mounted on a lathe is not a good idea in my opinion. You would have better control if you chuck the blank in a vice and use a hand drill to trim if you are set of using them. I did away with them years ago. Good luck.
 

monophoto

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Agree with everything John says, but I would add that I have learned (the hard way) that it's important to hold that Jacobs chuck with your left hand while drilling. It's entirely possible that one of the morse tapers on the chuck will decouple when you start to withdraw the drill bit, allowing the chuck body to spin. The milling on the outside of the chuck body can be painful, so wearing a glove on the left hand is prudent. I use a kevlar carver's glove - the kind that fits on either hand.
 

monophoto

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I'm interested in your experience regarding this.
There's nothing inherently bad about brad point bits, but under some circumstances, they can lead to problems.

One of the issues you face when drilling, especially on the lathe, is keeping the bit aligned with the turning axis of the lathe. If the wood you are drilling has a pronounced grain pattern, it is possible for that grain to deflect the direction of the hole. Remember that what we perceive as grain (changes in the color of the wood) represent growth during different seasons - growth that takes place in the summer is faster than growth that takes place in the winter, so the wood that developed during summer months is softer than the wood that grew during winter months. So what can happen is that the bit can deflect along the boundary between hard winter wood and soft summer wood - the bit wants to stay in that softer wood where less effort is required to drill. The result is a hole that is no longer straight, or that is straight, but through the side of the blank. Since thicker bits are less likely to bend, this problem is more pronounced when drilling smaller holes.

The problem with brad point bits is that the direction of the hole is heavily determined by the spur at the end of the bit - if that small spur is deflected, it can lead the entire bit off course, especially when drilling into end-grain where the hole is roughly parallel with the direction of those grain boundaries. Standard twist drill bits don't have a spur, so the entire bit has to be deflected before the hole can change direction. Brad point bits are fine when drilling in face grain since the direction of the hole is roughy perpendicular to the grain boundaries. So the bottom line is that brad point bits are fine for face grain, but twist drill bits are preferred in end-grain.

The usual advice is to keep the lathe speed low when drilling; the theory behind this advice is that higher speed causes more friction which causes more heat, and more heat can cause the wood to actually crack - moisture trapped in the wood is converted to steam which expands and cracks the wood. Or if you are drilling plastic, heat will melt the resin. In general, I agree with this but with two minor qualifications:
1. The friction that is most harmful results from swarf buildup in the flutes of the drill bit rubbing against the side of the hole. So it's important to periodically stop drilling and clear that swarf.
2. Bit deflection is more likely to occur if the bit is forced into the blank. Therefore, it's safer to advance the bit very slowly. Having the discipline to frequently stop and clear swarf also helps slow down the rate of advance.

My belief, based on my anecdotal experience rather than rigorous scientific testing, is that when using standard twist drill bits, it's not only OK to run the lathe faster, but it may actually be helpful to do so if the bit is advanced slowly and swarf is cleared frequently. The reason for this is that this approach allows the cutting edge at the tip of the bit to actually cut a hole in the wood before the bit is forced into that hole.
 

jttheclockman

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I'm interested in your experience regarding this.
My friend Louie explained this and even more so I will not repeat but all he said is true and you read many times here people having problems with brad point bits when drilling. There are vendors that sell brad point bits with their kits and it is a choice for those that buy but from experience I stay away. I use brad point bits in my flat work many times because I am not drilling into end grain. Good luck.
 

AllanS

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There's nothing inherently bad about brad point bits, but under some circumstances, they can lead to problems.
Appreciate the detailed breakdown. I knew they were tough to sharpen, but the endgrain issues - well - seems obvious now in hindsight.
 
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For the Woodpecker ultra sheer tool set, if the you have the right sized trimmer on it and the trimmer slides into the barrel without friction but is destroying blanks then you are either being too aggressive with the flush trimming or haven't glued the blanks well enough.

I have that set and haven't had these issues with flushing blanks up either they were wood, acrylic or hybrids. On a project for a kids class I was working with a guy to prep blanks and he was using my Woodpecker ultra sheer but was destroying blanks, wood and acrylic, because he was being too agressive with the flushing of tubes. When using the ultra sheer start really slow as you get a feel for how aggresively it can cut.
 

mark james

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There's nothing inherently bad about brad point bits, but under some circumstances, they can lead to problems.

One of the issues you face when drilling, especially on the lathe, is keeping the bit aligned with the turning axis of the lathe. If the wood you are drilling has a pronounced grain pattern, it is possible for that grain to deflect the direction of the hole. Remember that what we perceive as grain (changes in the color of the wood) represent growth during different seasons - growth that takes place in the summer is faster than growth that takes place in the winter, so the wood that developed during summer months is softer than the wood that grew during winter months. So what can happen is that the bit can deflect along the boundary between hard winter wood and soft summer wood - the bit wants to stay in that softer wood where less effort is required to drill. The result is a hole that is no longer straight, or that is straight, but through the side of the blank. Since thicker bits are less likely to bend, this problem is more pronounced when drilling smaller holes.

The problem with brad point bits is that the direction of the hole is heavily determined by the spur at the end of the bit - if that small spur is deflected, it can lead the entire bit off course, especially when drilling into end-grain where the hole is roughly parallel with the direction of those grain boundaries. Standard twist drill bits don't have a spur, so the entire bit has to be deflected before the hole can change direction. Brad point bits are fine when drilling in face grain since the direction of the hole is roughy perpendicular to the grain boundaries. So the bottom line is that brad point bits are fine for face grain, but twist drill bits are preferred in end-grain.

The usual advice is to keep the lathe speed low when drilling; the theory behind this advice is that higher speed causes more friction which causes more heat, and more heat can cause the wood to actually crack - moisture trapped in the wood is converted to steam which expands and cracks the wood. Or if you are drilling plastic, heat will melt the resin. In general, I agree with this but with two minor qualifications:
1. The friction that is most harmful results from swarf buildup in the flutes of the drill bit rubbing against the side of the hole. So it's important to periodically stop drilling and clear that swarf.
2. Bit deflection is more likely to occur if the bit is forced into the blank. Therefore, it's safer to advance the bit very slowly. Having the discipline to frequently stop and clear swarf also helps slow down the rate of advance.

My belief, based on my anecdotal experience rather than rigorous scientific testing, is that when using standard twist drill bits, it's not only OK to run the lathe faster, but it may actually be helpful to do so if the bit is advanced slowly and swarf is cleared frequently. The reason for this is that this approach allows the cutting edge at the tip of the bit to actually cut a hole in the wood before the bit is forced into that hole.
This is a superb master-class on drill bit info. Cannot agree more. Well done!
 

grpass

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Grants Pass, Oregon
For the Woodpecker ultra sheer tool set, if the you have the right sized trimmer on it and the trimmer slides into the barrel without friction but is destroying blanks then you are either being too aggressive with the flush trimming or haven't glued the blanks well enough.

I have that set and haven't had these issues with flushing blanks up either they were wood, acrylic or hybrids. On a project for a kids class I was working with a guy to prep blanks and he was using my Woodpecker ultra sheer but was destroying blanks, wood and acrylic, because he was being too agressive with the flushing of tubes. When using the ultra sheer start really slow as you get a feel for how aggresively it can cut.
I find when using a trimmer that the secret is to take small bites at a time. I am constantly taking a bit off then backing out a little. It definitely takes practice.
 

Paul in OKC

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Lots said here. My question is are you drilling and then squaring with the pen mill, or putting the blank back in after gluing in the tube? I always use a pen mill (with sleeves made from slim line tubes and scrap wood turned to size needed to fit the tube used), but I use it in a hand drill and either hold the blank or put it in a vise. The point is to square the blank to the tube as this will be the center axis of the blank when turning. The drill bit will usually always wonder a bit gong through the blank, so trying to follow with the mill in the lathe I think would not work very well.
 

grpass

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I find when using a trimmer that the secret is to take small bites at a time. I am constantly taking a bit off then backing out a little. It definitely takes practice.
My procedure is as follows: Cut the blank to length. I use a chop saw with a special fence that keeps the blank supported. I drill the blank on a drill press, using a vise that keeps the blank square. Test fit the tube. If it fits snugly rough up the tube with 180 grit sand paper. Put CA on the tube and rotate the tube as you install it. When you are ready to square the ends, use a trimming mill on the drill press. Note: if it is more then 1/4 inch between tube end and the end of the blank I go back to my chop saw and cut it closer. Then to the trimmer with the blank secured in the pen vise. Take small bites at a time on each end till flush. Make sure the trimmer is kept sharp. Easy to sharpen yourself.
 

BULLWINKLE

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Nov 8, 2010
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Winder Georgia
Finally getting set up in the world of pen turning

I find myself with an odd issue, and looking through the forums here I see a few things I've tried but still no good

To save shop space the wife ended up me getting Jacobs drill chuck for the lathe to drill blanks based on the recommendation of the Rockler staff and local turning club

Combined with the Nova G3 lite jig with pen jaws I figured I would be all set and wouldn't need a drill press

That said the drill bit and barrel trimmer oscillated as I try to drill into a blank for the tube hole that's not a huge deal

But for the barrel trimmer (she ended up getting "sold" the woodpecker ultra shear set) it has shattered/chunked out my blanks depending if its acrylic/wood

Thinking the chuck and end stock wasn't aligned I bought an alignment bar and its super level

For my wood pens, I can just chuck the blank up and spin by hand for the pen mill, it's crazy sharp but can't do that with acrylics

Not sure what could be causing the bounce and unalignment as the blank spins, so looking for some direction that I may not be thinking of

I do know from forum diving barrel trimmers seem to be in two camps (love em, ditched them lol) and have seen the sanding jig

That said I can't justify buying anything else right now, lathe, nova lathes, hand tools, woodpecker pen mandrel, wood peck ultra-shear, and a tormek T-8 sharpener on the way, my wife's surprise present (she was so happy she got the lathe for 600) is costing us a few thousand bucks…Luckily I got her to stop adding onto the lathe "bundle" gift, but that means a sanding jig/drill press will need to wait

So hoping the experts have some tricks that can help me use what I have to get some acrylic blanks spun up

As always thanks for all the responses
Drilling on the lathe is much better than a drill press. I’ve used both. If you have problems, I’d think that either the drill bit, or the squareing jig is dull. I recommend using carbide for both. Also, if the blank is stabilized, know that stabilization doesn’t fill voids that may be present in the blank. That too causes blowouts. The other possibility is you went too fast drilling or squaring off on the lathe. Take your time.
 
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