# Closed End mandrel idea



## davinci27

*Closed End mandrel idea - Photos Added*

I may not be the first to post this, but I haven't seen it so I thought I would put it up here.  

So I wanted to make a closed end pen, but I didn't want to buy a bunch of closed end mandrels, so I had an idea to make some shims.  I purchased a 7mm mandrel from Arizona Silhouette, then I glued up a scrap piece of wood to a standard 7mm tube.  I then turned the blank down to the same diameter as the pen kit I wanted to use.  My first one was a Jr Gent.  After I had the blank turned down to fit inside the tube, I split it in half with the band saw.  I then had a set of shims I could use with the 7mm mandrel.  

--Edit For More Details--

So I added some more pictures.  Basically you start buy gluing up and turning a blank into a sleeve so that it just fits inside the tube you are using for the closed end.  I turned until I was close, then finished the sleeve to size with sand paper.  You also want to trim the sleeve so it is shorter than the actual tube you will be using for the closed end pen.

Next you split the sleeve in half.  I used a bandsaw to do this, but be careful you've got to get those fingers pretty close to the blade.  It would be much safer to use a scrap of wood and make a jig to hold the sleeve.

Now you should have 2 shims.  You are ready to put everything together.  first take your standard bushing, flip it around and slide it on the mandrel.  Next put the shims on the mandrel. Make sure the shims are put together so they match the split in the mandrel.  When the mandrel expands, you want the shims to be able to spread apart.  Then you just slide it all together.

If this still isn't clear, let me know.  These shims were just my initial test.  I'm going to make  new set sometime in the next few days, and I can take pictures along the way to put together a more complete tutorial.


--End Edit For More Details--

The nice thing about using the shims and the 7mm mandrel is I can flip my bushings around and continue to use them as well.  So now I have one mandrel that i can use with any kit.  You can see my first closed end using this idea in the show off your pens section.

http://www.penturners.org/forum/showthread.php?t=40198


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## mwildes

Can you post a few pics of your mandrel idea?  Thanx!


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## hewunch

2nd on the pictures. You had me until the "shims" and "splitting it in half".


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## davinci27

Sure thing, I'll take some photos tonight and post them.


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## alphageek

That is a COOL idea!  I have that mandrel and now have something new to try!!!!

COOL.. Looking forward to the pictures too, though.


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## davinci27

I added some pictures and some more details to the original post.


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## Paul in OKC

Nice, and a great idea! Nice pen, too.


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## WoodenDragon

Thats pretty slick! Nice job and thanks for sharing!


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## mwildes

Totally awesome, thanks for the pics!


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## VisExp

That's a great idea Ben. I have a closed end mandrel for Baron/Sedona. I might see if I can adapt it for the cap end, and also for both ends of a Jr. Gent.

I was thinking, instead of cutting the shim in half, of building a jig to allow me to cut only one side of it on my table saw. The advantage would be not having two halves of a shim to mess with and possibly lose.


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## thewishman

Great idea!


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## davinci27

Originally  I was going to leave about 1/2 an inch not split so I wouldn't have 2 pieces.  Unfortunately with this one the brass tube was a little jagged and I didn't have a file I could get down into the tube.  I had to split it so I could file off the burrs.  I've come up with a pretty good idea for a safe way to split the sleeve, I'll probably try that this weekend to see if it works.


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## davinci27

I actually changed the bushing position.  instead of putting it on backwards, I cut the shims a little shorter, and put the bushing in the tube like you would normally.  This gave be a tighter fit at the hardware end of the pen, and made the blank more stable.  You can see another closed end i did with this idea in this thread:

http://www.penturners.org/forum/showthread.php?t=40552


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## davinci27

Just a quick update.  I changed my shims just a bit.  Instead of completely splitting the tube, I split it from each end and leave a little space uncut in the middle.  This seems to work even better.  Here are a couple of pictures of the new shims and the shims on the mandrel with the bushing.


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## cnirenberg

Ben,
I like the new shim design.  It looks like you will get a better grip on the inside of the tube.  I did try your idea with a larger CE Mandrel and it worked great, I'm in for the 7mm size it is more versatile.  Great idea thanks for sharing.


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## Ligget

Thanks Ben for taking the time to share your idea with us, it is an excellent one and I am sure it will be used by many members of this group including myself!


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## workinforwood

hey, thanks.  I need to steal that idea.  I have one of those, but it's a 10mm instead of a 7mm, not that it matters.  Keith...I turned a sedona on the cigar mandrel, it fit perfect.


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## davinci27

the biggest benefit for me was the fact that I can use the bushings from the standard mandrel on the 7mm closed end mandrel. This new sleeve is much easier to use then the completely separate shims.  I wish somebody with a metal lathe would make some of these.
Ben


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## Skye

I wonder if you couldn't whip this into a tutorial and squeeze it into the birthday bash somehow. "Best New Tutorial"? Is that a contest? If not, it should be.


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## davinci27

Yeah, I've got another tutorial I've been meaning to write and just haven't gotten it done.  Didn't I hear we were going to a 25 hour day sometime in the future :biggrin:


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## Skye

I hope so!

Hey, speaking of contests:

http://www.penturners.org/forum/showthread.php?t=42295


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## workinforwood

I found a small flaw in this whole set-up.  I built it and it worked fine.  But..there was a small fisure in the burl I was spinning.  I put a couple dabs of CA over the fisure to seal it up.  Can anyone guess the result?   If you guessed that the wood insert became glued to the inside of the tube and could not be removed without destroying the blank..then you are a winner!   So...if you use the method proposed in this thread, and even if you just use the proper mandrel...wax it really good so no CA can stick to it or else remove the blank and fix any problems!!!


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## davinci27

That sucks sorry man.  Did the blank have a tube glued in it?  I haven't tried this on a blank that didn't have a brass tube in it.  I also make the shim short enough so they don't extend beyond the brass tube. I might try making some shims out of Derlin to see how that works.


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## workinforwood

yes, the blank had a tube in it.  But it's a closed end and the wood is all fizured.  thin CA can really travel..I'm sure it found a path between the blank and the tube then came through the closed end portion and back to the shim. It's like water..the leak in your roof can be on the opposite side of the house as the damage.  I wasn't thinking..I could have prevented it in the first place.


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## Darley

Sorry by  that Jeff, you should wrap the shime with glad wrap before inserting it ( I thin you guys call this sarran, any way is food plastic wrap ) 




workinforwood said:


> I found a small flaw in this whole set-up.  I built it and it worked fine.  But..there was a small fisure in the burl I was spinning.  I put a couple dabs of CA over the fisure to seal it up.  Can anyone guess the result?   If you guessed that the wood insert became glued to the inside of the tube and could not be removed without destroying the blank..then you are a winner!   So...if you use the method proposed in this thread, and even if you just use the proper mandrel...wax it really good so no CA can stick to it or else remove the blank and fix any problems!!!


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