Introduction: Magnetic Levitation Pen
Not unlike the trains in Japan this pen uses opposing magnetic forces to hover in mid air. For trains, this practically eliminates friction allowing the trains to move very quickly. For pens, it makes for a little added entertainment value on your desk.
Precision is key with this project, so like many of my woodworking projects I spent the majority of my time making jigs. Please excuse my continued reminders to be careful and make accurate measurements, it really is important. You may be able to do it without the primary drilling jig but be very careful and don't be surprised if you need to do some tweaking and adjustments before it works perfectly.
Step 1: Materials and Tools
Here's what you'll need in the way of small things:
1 Chanel Cutting Jig for 2 Inch Dowel (https://www.instructables.com/id/Safely-Cut-a-Chane...)
1 Bar Clamp
16 Small Wood Screws
4 Toggle Clamps
1 Pen Turning Mandrel (http://www.woodcraft.com/Product/2003759/2325/2-MT...)
1 3/8 Inch Walnut Dowel (or Plug Cutting Bit)
Sand Paper (Fine Grit and Rough)
8 3/8 by 3/8 Inch Neodymium Cylinder Magnets (Axially charged)
2 Neodymium Ring Magnits 9/32 Inch ID, 1/2 Inch OD, by 1/8 Inch (http://www.magnet4less.com/product_info.php?cPath=...)
1 Block of Walnut (about 4 by 4 by 1 inches)
2 Blocks of Maple (About 2, by 3.5, by 10 inches and about 3 by 3 by 12 inches)
1 Small Sheet of 3/4 Inch Plywood (2 by 4 feet should be more than sufficient)
1 Very Small Sheet of 1/2 Inch Plywood (Scraps will probably do just fine)
1 Slimline Pen Kit (http://www.woodcraft.com/Product/2001973/17436/Sli...)
2 Inch Round Nose Router Bit (http://www.wholesalepowertools.com/freud-2-round-n...)
7mm Drill Bit
3/8 Inch End Mill
Also, your shop should be equipped with:
Router Table (With 1/2 Inch Collet)
Step 2: The Drilling Jig MONSTER
Yes, this is a monster of a jig for what seems like a somewhat simple task but... so it goes. In order to get the pen to levitate the best method I found was to direct the force of all 8 axially charged bar magnets towards the same line in space where the pen will hover. The method I chose to achieve this may not be the easiest but through the use of jigs it is extremely repeatable. About half of this Instructable will be about the design and fabrication of the primary drilling jig for this project. This jig was designed to hold the pen levitation station in place for the drilling of all 8 magnet holes. I did not originally think I was going to need toggle clamps for this jig so it ended up becoming much more complex than I had anticipated but, such is the case often in wood working.
Step 3: Turning a Giant Dowel
As I said in the last step, the intention is to point all the magnets towards the center of the same imaginary cylinder. First, lets make that imaginary cylinder not so imaginary for a while.
It is possible to buy a 2 inch diameter dowel, and you can do that, but I wanted to practice my lathe turning so I made my own. If you chose to do it this way be extra careful to make it extremely precise. I messed up the first time and had to back up a few steps and start over. Here is a pretty good guide to turning if you are new to it (https://www.instructables.com/id/Rolling-Pin/).
Step 4: Making It Groovy
Now that you have the cylinder cut you are going to want to make stay in place and hold your work where you need it. This is done by cutting grooves into the dowel and placing plywood rails inside them. The first groove will hold the dowel in place on the jig base and the other two will make positive stops for your pen stand to sit while drilling.
For this I built a meta jig (jig for a jig) (https://www.instructables.com/id/Safely-Cut-a-Chane...). It is fairly simple and uses no tools that you won't need later in the process. I suppose you could do these operations on a milling machine but you probably don't want to get a mill all covered in wood shavings so I don't recommend it.
Make sure your channels are perfectly straight and pointed exactly towards the center of the dowel. This isn't easy to do. As you can see in the photos, one of my smaller channels is not quite centered. In order to do this first, clamp your dowel in the jig and place it on your router table. Next, adjust the router table fence until the bit is centered on the dowel and cut about a quarter inch in. The plywood bits don't need to go really far in, it isn't holding a bus, just a little bit of clamping force.
The large channel should be 3/4 inch wide and it should be cut first. The smaller ones should be 1/2 inch wide. One small channel should be at about 10 degrees off of the horizontal and the other should be 40 degrees off. (drawing above for clarification)
Step 5: The Jig Base and Rails
Again, another warning to be careful and measure twice before cutting.
Cut your dowel with the grooves cut to 6 and 7/8 inches on the chop saw. Before you cut I would suggest inspecting the grooves since they might be straighter on one end than the other. Routers tend to not quite straight sometimes.
Once you have done this, create a base for your jig. The size is not crucial on this but make it significantly larger than the length of the dowel. 10 inches square should work fine. I used two sheets of 3/4 inch plywood but this was probably overkill. Again, using the router table cut a 3/4 inch groove in the center of the base about half an inch down. A dado blade on the table saw would work for this too but it is more work to change out blades. Cut a piece of 3/4 inch ply the same length as your base but only about 2 inches wide and glue it in. This will be where the dowel lives.
Next, cut two piece of 1/2 inch ply, also 6 and 7/8 inches long and about 1.5 inches wide. Glue them into the smaller grooves in your dowel. Once those are dry you can glue the dowel onto rail that you just attached to the base.
The jig is almost done!
Step 6: End Blocks and Toggle Clamps
Cut two 3X3 inch pieces of plywood, and make a 3/4 inch notch in the middle of one side about 1/2 inch deep (pictured above). 3/4 or 1/2 inch ply will work. I used the router table but in hindsight it was not safe so I would suggest using a band saw or some other method to cut them. Once the grooves are cut, glue them onto the ends of the dowel and apply pressure with a clamp.
The toggle clamps should be mounted on blocks angled appropriately for the work piece they are clamping. On the side with the lower rail a 45 degree angle block will work for this. On the other side a tall block parallel to the table surface is close enough. Screw each toggle clamp on with 4 short wood screws. See the photos for reference this part is a bit hard to explain well.
Now your jig is done and ready to use.
Step 7: Levitation Station Preperation
So, now that the jig is finally finished it is time to make the actual levitation station and magnetic pen.
The levitation station is the part that houses the majority of the magnets.
Start by cutting a piece of hard wood on the table saw to 1.75 inch by 2.75 inches. Keep it long if you can to make a few of the later steps a bit easier.
Next, using your giant 2 inch round nose bit, cut a groove along the long axis of the wood. The groove should be 5/8 inch deep. Be sure to do this in multiple small passes rather than one big one. Taking cutting the entire groove al at once will leave a messy cut and is much more likely to result in injury.
Now take that piece over to the chop saw and cut it to exactly 3 7/8 inches. Again, a very important dimension.
Step 8: Getting Jiggy With It
Time to use that super complex jig you made.
Positioning the jig correctly is probably the most difficult and also most important step of the process. You want your 3/8 inch end mill to be centered on a point that is 3 and 1/8 inches from one end of the dowel pointed down exactly at the center of the cylinder. Clamp it down SUPER HARD on the drill press table. You don't want this budging at all thought the drilling process. Also set the stops on your drill press to stop 1/8 inch away from the top of the dowel. This will ensure that the magnets are close enough to the surface of the wood to have a strong effect on the pen while remaining hidden.
Place your work piece (the levitation station in progress) upside down on top of the dowel. Press it against one of the end stops and one of the side stops and clamp it in place with the appropriate toggle clamp. once it is firmly in place turn on your drill press and make the first hole. Repeat this process for all 4 positions on the jig and the flip your work piece around. and repeat again for the remaining 4 holes.
Step 9: Magnet Time
Time to insert the magnets. The holes you just drilled in the levitation station will align the magnets where they need to be.
The magnetic field of all 8 magnets must all be pointing in the same direction. I suggest double checking between each magnet to make sure you are still on track. Also, I found due to the small amount of friction on the one wall of the levitation station, the pen doesn't quite fly straight. In order to balance it better I pushed a 1/8 inch slice of the dowel into the holes on that side before inserting the magnets. Because the magnets repel each other it is easiest to put one in at a time and glue in a 3/4 inch piece of dowel in after it before moving onto the next magnet. It is also a good idea to hammer in the dowels with a rubber mallet to make sure the magnet is where it is supposed to be.
After all the magnets are in there and the dowels are firmly in place cut off the excess dowel and sand them flush with a belt sander.
Step 10: Levitation Station Completion
I have a bit of a confession, this Instructable will show you how to make a pen levitate in a stand, but it isn't completely in thin air. It needs to be touching one solid wall in order to stay up, otherwise it will fly in one direction or the other along the axis of the pen (just like the trains in Japan).
Cut a square block out of your walnut piece about 3/4 inch thick. The other two dimensions should match the base of the levitation station. Now just go ahead and glue it on the end and clamp it as shown in the photo above.
Aside from sanding and finishing and whatever sort of extra shaping you want to do, the levitation station is complete. Now onto the pen.
Step 11: Getting to the Point
At this point you have created a wooden block that will magically become quite fuzzy if you throw it in a bucket of iron dust. It might also be pretty good at holding paper clips, pins or X-acto blades, (does anyone else hear a new Instructable coming?) but it won't make your pen magically levitate yet. For that, you must also create a new pen.
Pen turning is a great craft in it's own right and I suggest giving it a shot independent of this project if you have never tried. Handmade pens make great gifts for people you wish to receive hand written letters from.
This pen in particular is different from your standard wooden pen for one primary reason, it has two embedded ring magnets. These magnets must be placed in very specific locations in order to work properly, so the cutting of the wood pieces is pretty important. I have a fear of cutting pieces too small and having to remake them later, so for this stage I left the wooden bits a little bit large and sanded them down after turning. I'll get to that in the next step though.
First lets cut a pen blank and drill a hole down the center. Pen blanks are approximately 3/4 inch by 3/4 inch by 5 inches. You can order pen blanks on the internet and they will be really nice and already cut to the appropriate dimension, but..... it's really just a little tiny block of nice wood, so I think it's better to just make your own. Scraps of wood around this size are abundant in most shops. You will probably need to cut the blank in half before drilling unless your 7mm bit is super crazy long. I used a hand miter saw rather than the powered saw for this because the pieces are super small and I didn't want to cut my fingers off. In the interest of safety I recommend you do the same if you can.
Once you have your two pen blank halves mark the center with a ruler or straight edge and drill straight down with the 7mm drill bit. If you have a drilling jig like the one in the photos I would suggest using it but if you don't it is pretty easy to make a nice right angle jig to hold your blank straight on end.
Step 12: More Cutting, More Gluing
And now, for some more dimensions. Cut two pieces of the pen blank that are 1/2 an inch long and two that are 1 and 9/16 inches. I messed up on the size of the larger sections which will become apparent in a later step but in order to save you from the same fait I'd say keep it a bit longer than that and sand down later if necessary.
If you placed the magnets all in the same direction in the levitation station earlier they will repel the ring magnets in one direction, but if you flip the ring around they will be attracted. Make sure you know which direction is repulsion and which is attraction before you go onto gluing them in. I did this by taping them onto a pencil and making sure that pencil floats in the levitation station. It was lighter than the pen will be so I had to add a bunch of tape to keep it from flying away.
In your pen kit you will find two brass tubes. Take a bit of time to rough those up with sand paper before gluing them in to ensure a bit more longevity for your pen. Once you have done this mix up some epoxy and lightly coat the outside of the brass tubes. Now, press one of them into each of the longer pen blank pieces you cut in the last step. Next, place one of the magnet rings onto the tube (in the direction determined to be the repulsion direction), followed by the smaller wood block. Clamp it lightly while you wait for the epoxy to cure.
Step 13: Turn, Turn, Turn
Turning on the lathe is one of my favorite activities. There is a ton of skill involved and I am far from an expert but pens are a great way to get started. If you only have a small lathe and a few lathe tools pens are a perfect small project. You will need a pen turning mandrel, but other than that everything you need is standard turning equipment.
Put the pen mandrel into the live end of the lathe and slide on one of the bushings (provided with the mandrel). Next put on the two pen halves you just glued up in order as pictured above. Slide on the other bushing and tighten the large brass nut to secure it all in place.
Tighten the tail stock onto the free end of the mandrel and adjust your tool rest before turning on the lathe. The shape of the pen is not crucial as long as you turn down to the bushings on either end. I prefer fat pens and simple curves but some people like a more wavy contour so feel free to go wild.
Some turners frown upon sand paper, but I'd say go for it. Sanding is a really easy way to make your final product look really great.
Step 14: Assemble the Pen
Before you press in the other pieces of your pen kit, I would suggest taping the two sides together and trying to get it to hover without the inner workings. This is a good way to make sure you know which end is the back and which is the front. The back end is the one you want to face towards the supporting wall of the levitation station. If the measurements are all right it should float really nicely when you space it off from the wall with something the same size as the metal end piece. If it doesn't work out quite right, try sanding off a tiny bit of material at a time until it does.
I ran into trouble here because the magnets were too close together. I ended up having to glue in a 1/8 inch piece of walnut and spent a significant amount of time carving and sanding it to match the profile (see picture above). If I had done a better job of checking before I pressed the metal pieces in I could have easily cut and sanded it to shape on the lathe.
Once you have confirmed that your measurements are right press in the metal end piece and pen tip. These press fit parts are easiest to insert using a big bench vice or similar clamp. I would not suggest using a hammer for this at all. Pen turning enthusiasts sometimes have specific tools for pressing in the fittings, but really a vise works just as well. Next press in the ink holding twisty bit into the front half of the pen, thread in the ink cartridge and press the two halves together. Now that the pen has all it's inner parts it will hover a bit lower than it did empty.
Step 15: Finishing
Take some time before applying finish to do some sanding. Bad sanding marks show up really clearly on small pieces like this. Always sand with the grain of the wood if possible and use progressively finer grits as you go. Also, make sure you get all the dust off of your piece with an air hose or tack cloth before applying finish.
I used a Watco Danish Oil for this project but any wood finish will really work. What ever you prefer is probably fine. Most wood finishes are applied using a rag instead of a brush and require multiple coats to achieve a desirable finish.
The best part about applying finish to a levitating pen is that you don't need to worry about it touching the table and making a mess of your nice finishing work because it is FLOATING!
Step 16: Enjoy
Congratulations to you if you have made it to the end. It's a pretty difficult project but the final product is quite fun. A really precisely made levitation pen will spin or bounce for a surprisingly long time before friction gets the better of it.