Material & Tools
+ Metal pen
+ Piece of conductive foam - high density 2"x1/4" 1/8" to 1/4" thick
this is the foam material that computer chips are frequently shipped with
+ A Q-Tip or other cotton swab
The most signifiant challenge was finding an existing pen, made with metal and having an opening large enough to support a good sized tip end. Amazingly I found an ideal solution with the Zebra Telescopic Bright pens. They have everything we need as well as a cool telescoping feature.
Here are my Amazon links:
Zebra Tele-Scopic Ball Point Pen
Zebra Telescopic Brights 2 pack
I found one for about $3, but last I looked prices were $4 to $5 per pen.
The second challenge is finding some conductive foam. I had a bunch lying around, if you don't, find someone who works with electronics, they probably have a bunch. This is the foam that computer chips are often shipped with. Although you can buy sheets of High Density Conductive PU Foam, the typical 12"x12" will cost you about $8 and will give you way more than you need, enough to make more than a couple hundred stylus tips.
With your Zebra pen, conductive foam, your scissors and a cotton swab, you are ready to make your stylus.
(WARNING: Be careful that you have some soft conductive foam, test to make sure you have something that will not scratch the surface of you screen. You can also test how well it conducts by just holding the foam and tapping the screen. I've heard suggestions of aluminum foil and steel wool, I would not get them anywhere near my screens. And, if you are curious how the touch screen works, here is a good explanation: http://electronics.howstuffworks.com/iphone2.htm )
Step 1: Prepare the Pen
The good news, you are done. If you don't have the Zebra pen you might need to find some way of enlarging the tip. Other ink pens usually have an opening just large enough to accommodate the ink tip. The Zebra Telescoping is nice because it has the additional sliding tip insert (a very cool design btw). We remove this tip, but it is the reason we have a pre-made tip the right size.
Step 2: Cut the Conductive Foam
I have found 2" x 1/4" with foam about 1/4 to 1/8" thick foam about the right size. You may need something different depending on the density and thickness of your foam. Be prepared to try a couple pieces. If you start a little large, you may be able to trim it later if there is too much.
Step 3: Fold and Insert Foam
By squishing together the ends of the foam and twisting it into the pen, you should be able to get the foam into the pen tip. I use a continuous twist to squeeze it in. When you get near the folded end, be carful not to squish the end too much. Also you want to have the tip bulging out, not folded in on itself.
Getting the tip to be a nicely rounded might take a couple tries. You don't have to have a nicely rounded tip, but I find it feels best to get the tip just right.
Step 4: Add Some Support With a Cotton Swab...
+ Insert it into the pen
+ Screw the pen together
+ If it does not fit, cut a little more
Once you have the foam inserted, you need something top keep the foam from being pushed back into the pen. A cotton swab does the job. Use scissors to cut the swab, so it is about 2 inches long. You will insert the stick end where the pen ink tube used to go. The fluffy cotton should be next to your foam.
Your goal is to continue cutting the swab until it is just the right length so that you can screw the pen tip back onto the pen body. I should just stick a little out of the pen body.
You can cut the swab or the foam to make it fit, but you want a fairly tight fit. The swab is what keeps the foam from pushing back into the pen when you use your stylus.
Step 5: Have Fun Drawing With Your Stylus...
You are done.
You should now have a stylus for your iPad or other capacitive screen or touch pad. The stylus is not going to be as sensitive as your finger, but I find the Zebra works well. If you use the Zebra in the shortened, un-telescoped state, part of you hand or fingers touch the unpainted metal part of the pen. The painted area does not conduct well.
BTW: Adobe Ideas is a vector drawing app for the iPad and iPhone that use with my stylus all the time, and a great way to try out your new stylus. Adobe Ideas in the iTunes store http://bit.ly/bGN4fE