Pin chuck

[Woodchipper]

Getting back into penturning sent me to my book library. One is Turning Modified Slimline Pens by Don Ward. He shows a baseball bat pen on page 85. One part uses a pin chuck or he stated blue tape or masking tape will work. Your experience in turning such items with a blind drilled hole is most welcome. Thanks.

 

[monophoto]

There are several ways to turn closed-end pens. Pin chucks work well and are easily made in the shop - you don't have to buy them. All you need is a length of steel or aluminum rod (available at most Ace Hardware stores as well as the big-box stores). You need a rod that is very slightly smaller than the ID of the bore of the pen (or the pen tube if there is one). File/grind a flat on one side, and then cut the head off a nail whose diameter is very slightly less than the depth of that flat. Put the nail on the flat, slip the rod into the blank, and give it a quarter turn - the nail will roll to one side and wedge itself against the inside of the blank, locking the blank to the rod. Mount the rod in a collet chuck, or a Jacobs chuck, or even an ordinary scroll chuck with pin jaws. If you are using a pin chuck, you don't absolutely need tailstock support although using the tailstock is never a bad practice.

Alternatively, you can use a length of steel rod without the flat as a sort of jam chuck. This is where the article you read suggests using masking tape to pad out the diameter of the rod. However, if the rod is sized just slightly thinner than the bore in the blank, you don't need tape. However, you do want to use the tailstock to apply axial pressure on the blank while turning it to size and sanding, and then finally part off the tip of the blank. You will have to either hand-sand the end, or use a sanding mandrel to finish off the end, but that's not a big deal.

 

[Woodchipper]

Thanks for the tutorial. I'm leaning on using the tailstock to steady the end either way. I can leave material on the blank or turn/configure a piece of HDPE to fit the end of the blank. Also, duck tape will fix anything!

 

[Pierre---]

Sure, making a pin chuck is easy. I made mines from wood: boxwood or ipe (Brazilain walnut). For precise work you need the tailstock, which is not an issue if you have some mm extra. They work great.

 

[jttheclockman]

I made my pin chuck from a set of transfer punches which I get from HF and also use in my sanding of the blank ends. I have about 4 sets of those punches. They come in handy and are cheap.

 

[mark james]

With a grinding wheel, some small nails, and this transfer punch set, for $12.00 you have a plethora of pinchucks.

 

[Woodchipper]

Cheap? Now you are singing my song! I'm so cheap, they have my picture next to the word in the dictionary. Thanks as I get discount coupons from HF by email.

 

[sorcerertd]

Oh, this is good stuff. I never gave any thought to making one. Figured I'd buy some eventually. I like it. Thank you for asking and to everyone for answering.

I wonder if my Harbor Freight MT2 jacobs chuck will fit the bill as I don't have a collet chuck. Not sure how precise it is.

 

[rherrell]

The problem with using transfer punches is they aren't an exact fit. When you tighten the blank on the pin chuck it pushes the tube to one side and you end up with a tube that is not concentric with the blank. It won't be much but FOR ME it's too much.

 

[walshjp17]

I have a few of Rick Herrell's pin chucks and they work perfectly.

 

[MedWoodWorx]

There are several ways to turn closed-end pens. Pin chucks work well and are easily made in the shop - you don't have to buy them. All you need is a length of steel or aluminum rod (available at most Ace Hardware stores as well as the big-box stores). You need a rod that is very slightly smaller than the ID of the bore of the pen (or the pen tube if there is one). File/grind a flat on one side, and then cut the head off a nail whose diameter is very slightly less than the depth of that flat. Put the nail on the flat, slip the rod into the blank, and give it a quarter turn - the nail will roll to one side and wedge itself against the inside of the blank, locking the blank to the rod. Mount the rod in a collet chuck, or a Jacobs chuck, or even an ordinary scroll chuck with pin jaws. If you are using a pin chuck, you don't absolutely need tailstock support although using the tailstock is never a bad practice.

Alternatively, you can use a length of steel rod without the flat as a sort of jam chuck. This is where the article you read suggests using masking tape to pad out the diameter of the rod. However, if the rod is sized just slightly thinner than the bore in the blank, you don't need tape. However, you do want to use the tailstock to apply axial pressure on the blank while turning it to size and sanding, and then finally part off the tip of the blank. You will have to either hand-sand the end, or use a sanding mandrel to finish off the end, but that's not a big deal.

sorry i don't get it, could you please elaborate or upload an explaining picture?

 

[monophoto]

sorry i don't get it, could you please elaborate or upload an explaining picture?

Mike -

The picture that jttheclockman (John) posted earlier in this thread illustrates what a pin chuck is better than any sketch I could draw.

A pin chuck consists of two components. The first is a rod whose diameter is ever so slightly smaller than the diameter of the bore in the blank being mounted. In the case of pen making, that inside diameter is typically the inside diameter of the brass tube. There is a flat filed on one side of the rod. Then, a short length of small diameter metal rod (the pin) is placed in the flat - the diameter of that small rod must be very slightly less than the depth of the flat. In shop-made pin chucks, the pin is most often made by cutting the head off a nail. The pin chuck rod is then inserted into the bore in the blank (the brass tube). When the rod is mounted onto the lathe headstock (John shows a collet chuck, but it could be mounted using a drill chuck and the lathe is turned on, the rotation of the rod causes the pin to displace to one side where it wedges between the flat and the inside of the bore, thereby locking the blank to the spinning rod. In the picture posted earlier by Pierre, the rod is an extension of a Morse taper that he turned from wood - that's just another approach to making and mounting the pin portion of a pin chuck.

The pin only wedges between the flat in the rod and the bore when the lathe is running, so once the lathe is turned off, the blank will simply slide off the rod. Be careful when removing the blank - if the flat ends up anywhere other than 'top dead center' when the lathe stops running, removing the blank will allow the pin to drop down into the shavings under the lathe, and it will never been seen again. DAMHIKT. I try to keep one hand under the end of the blank to catch the pin when it falls out as the blank is removed.

The point that Rick made is that if the diameter of the rod is smaller than the inside diameter of the bore in the blank, the rod won't be centered in the bore and as a result the turning will be slightly asymmetrical. John mentioned using transfer punches from Harbor Freight as rods - transfer punches are metal rods that come in a set containing various diameters. John's approach is to select the transfer punch that most closely matches the inside diameter of the bore and therefore minimize any asymmetry that might result from a mismatch between the diameter of the rod and the inside diameter of the bore.

 

[MedWoodWorx]

Mike -

The picture that jttheclockman (John) posted earlier in this thread illustrates what a pin chuck is better than any sketch I could draw.

A pin chuck consists of two components. The first is a rod whose diameter is ever so slightly smaller than the diameter of the bore in the blank being mounted. In the case of pen making, that inside diameter is typically the inside diameter of the brass tube. There is a flat filed on one side of the rod. Then, a short length of small diameter metal rod (the pin) is placed in the flat - the diameter of that small rod must be very slightly less than the depth of the flat. In shop-made pin chucks, the pin is most often made by cutting the head off a nail. The pin chuck rod is then inserted into the bore in the blank (the brass tube). When the rod is mounted onto the lathe headstock (John shows a collet chuck, but it could be mounted using a drill chuck and the lathe is turned on, the rotation of the rod causes the pin to displace to one side where it wedges between the flat and the inside of the bore, thereby locking the blank to the spinning rod. In the picture posted earlier by Pierre, the rod is an extension of a Morse taper that he turned from wood - that's just another approach to making and mounting the pin portion of a pin chuck.

The pin only wedges between the flat in the rod and the bore when the lathe is running, so once the lathe is turned off, the blank will simply slide off the rod. Be careful when removing the blank - if the flat ends up anywhere other than 'top dead center' when the lathe stops running, removing the blank will allow the pin to drop down into the shavings under the lathe, and it will never been seen again. DAMHIKT. I try to keep one hand under the end of the blank to catch the pin when it falls out as the blank is removed.

The point that Rick made is that if the diameter of the rod is smaller than the inside diameter of the bore in the blank, the rod won't be centered in the bore and as a result the turning will be slightly asymmetrical. John mentioned using transfer punches from Harbor Freight as rods - transfer punches are metal rods that come in a set containing various diameters. John's approach is to select the transfer punch that most closely matches the inside diameter of the bore and therefore minimize any asymmetry that might result from a mismatch between the diameter of the rod and the inside diameter of the bore.

Ok, first of all thank you for your time explaining this, i get it now. It seems to me that is a compromising (to some extent) solution but a solution whatsoever. Has anyone measured how accurate this method is, i mean how round do the pens come out?

 

[monophoto]

Ok, first of all thank you for your time explaining this, i get it now. It seems to me that is a compromising (to some extent) solution but a solution whatsoever. Has anyone measured how accurate this method is, i mean how round do the pens come out?

It all depends on how closely you can match the OD of the rod portion of the pin chuck with the ID of the bore (tube). If you can match them exactly (so that the rod slides into the bore with no 'wiggle'), the pen body will be round.

 

[jttheclockman]

I am sorry but I have to take a second here and just remark about something I noticed over time here on the site. That is Louie (monophoto) gives the most in depth explanations that are also well thought out of just about anyone I have seen on here. It is not just this thread but many others. Well done sir. You should have been a writer and published some novels or something.

 

[mark james]

Ok, first of all thank you for your time explaining this, i get it now. It seems to me that is a compromising (to some extent) solution but a solution whatsoever. Has anyone measured how accurate this method is, i mean how round do the pens come out?

Just a few with my Harbor Freight 7 mm pin chuck. In person, these are still in my wife's handbag , she loves my cheap slims... , so I just did a fingernail test for any out of round. I'll put it to anyone's. I have NO problem spending money to improve my results, and I also have no problem being frugal when possible.

 

[MedWoodWorx]

I have seen someplace an expanding mandrel, i don't remember the design in detail but i remember it had a nut that when tightened it would expand the ends of the mandrel to grab the tube/blank. Has anyone used such a tool?

 

[monophoto]

I have seen someplace an expanding mandrel, i don't remember the design in detail but i remember it had a nut that when tightened it would expand the ends of the mandrel to grab the tube/blank. Has anyone used such a tool?

Its another way to skin the cat. Haven't used it, but PSI sells such a tool. It's basically a threaded shaft with a rubber outer sleeve. Tightening a nut on the end compresses the rubber sleeve axially causing it to expand in diameter to grip the inside of the bore in a pen blank.

Here's a picture of it.