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Revolutionary Pen Idea Answered

This morning I had an idea. Last night I was dissassembling a huge bagful of insulin pumps (my cousin is a diabetic and he uses them, cleans them, and gives them to me to take the guts out of them) and in them I keep the springs, casing, and insulin resevoirs... (I ALWAYS throw those horrid needles away; I don't want to get stuck with one) I had an idea looking at the resevoirs... I wanted an ink pen that could write/draw in ANY color ink with the turn of a dial, adjustment of a slide, etc.. anyway, I have about fifty of these resevoir things (they have little pistons in them) and I was curious if there was a way to reach my goal. Should I use red, blue, yellow ink, or should I use magenta, cyan, and yallow? Do I have to make the inks myself, or could I drain them from printer cartriges? Should I use only primary colors, or secondary colors as well?


Medtronic or Roche? These aren't the actual pumps, they're just the insulin refills? So you'd need some kind of drive for 'em? L

Here's the pumps I get the syringes from: I seperated the usable parts into four piles: Batteries (still full power), springs, syringes, and cases. Those parts were taken from about 7 individual pumps-and I've still got a whole bag left!


Hey, you could string all the batteries together for a high voltage DC supply! Rather than take these apart, I'd try to use the whole units (refilled with ink), you just need the control mechanism to activate the drive. L

The pistons in the pumps are threaded...I was planning on using a spring, but would all the ink leak out if I did?

If the springs work properly, I doubt I'd need any motors in it.... As the ink is used, the spring will push the piston downward (upward, whatever) until it hits the bottom and there is no more ink. Then I simply remove the piston, add more ink, put the piston back in and continue writing/drawing/etc. So, I don't think I really need motors in it....unless I used the threaded shaft and motor rotation to move the piston instead using a simple spring. (I wouldn't know how to easily do that anyway....... so I think I'll try to use springs to move my ink)

They're basically a cylinder open on one end with a plastic/rubber piston and threaded shaft come out , and on the other end, you have a capillary tube. Fluids only move on the "Push" stroke of the piston... I was thinking that adding ink and attaching it to a ball point pen and giving it a spring to create pressure and help it write (or leak)...

Here's a pic of a large ink pen (empty) with three sryinges attatched to it (also empty) to see if they fit...


Okay everyone, here's a few pics of the syringes: They're not too big, and they've got a capillery tube coming from the bottom of them.


9 years ago

As I remember from my dad using them, you turn a dial to set the amount of fluid dispensed from the vial and then "click" the button on the end? I'm thinking of the injecty pen type, not sure that was what you meant by "pumps". In that case I guess you'd have the three (or four) ink reservoirs injecting into a central mixing reservoir, which then feeds the pen. To get a bit of orange ink you'd dial maybe 4 clicks of yellow and 2 clicks of magenta, or for lots of blue-black for writing you'd dial 10 clicks of black and 4 of blue. Then you'd click all the ink buttons you were using (after somehow "flushing" the pen reservoir, maybe just by scribbling or blotting) and write away. You can buy ink cartridge refills which come with four bottles of ink, or you can use food colouring if you don't mind water solubility. I don't know what sort of nib would be best though- probably a regular washable-ink fountain pen nib? gmjhowe is probably your man to ask about inks, but magenta, yellow, cyan and black are the usual printing "primaries" (you can make black from magenta, yellow and cyan but it doesn't come out great, black ink is better). Personally I think this is a great concept, I'm tempted to just get four of those small syringes and a fountain pen and play around.

Thx. I was wondering how I'll be able to see the color I have before writing/drawing though. I might have a little "window" in the body of the pen and pulse the mixing motor to see my color.................I might need a way to clean that out between color mixes so that the previous mix doesn't mix too. This might be what you called "flushing" (good term by the way). I'll see if I can add some sort of water intake tube that puts water in AFTER you're done with the color and you're ready for a new one. Clean water in, pulse the motor, and push the dirty water out. I still have a lot of work to do...

This model (made in Google SketchUp)(join my group) may make the design a little easier to understand. On the left, I made a little whiteboard showing a diagram of how everything connects. The boxes with horizontal lines running through them (the pistons) are the ink resevoirs. the little line at the bottom is the ball point tip (see how everything connects very close to it). I did not show a motorized mixing chamber anywhere, but I'm seriously thinking that it is the way to go(!). On the right, I have another little whiteboard showing how this pen mixes 3 primary colors to get secondary ones, and how adding black/white ink can change the hue of the ink. And finally, in the middle I made a model of the five resevoirs (on little stands) and a mixing chamber connected to a small DC motor (try to imagine little wires coming from it to a battery, and try to imagine little tubes coming to it from all the resevoirs).

RYB pen diagrams.png

I encountered a few obsticles in my design. The initial mixing of the three colors makes a new color ink. The ink in front of is slowly used. The colors are going to have to be mixed together (thouroughly by the way) right next to the ball point tip. If I don't do this, what'll happen is that I'll change colors, and nothing will happen until I least expect it (I'll be working on an art project) and (of course) WHAM! it'll change to the color I chose three months before! So, this is a problem, but all I have to do is (as my dad calls it-"getting the ox out of the pit") be creative, and find a way to (maybe use a SMALL motor-I have one that is very tiny) to mix the colors effectively and connect all three resevoirs either directly to the tip, or connect them to a "mixing" resevoir first.

For an ink pen you can get drawing ink from art supply stores in lots of colors. If you want the cyan, magenta, yellow printer ink spectrum just go to somewhere like inkrepublic.com and buy refill ink. While you're at it, I highly recommend modifying your printer to run continuous ink, it's a lot cheaper than cartridges!

awesome idea, hard to make. good luck.

:D I'm sorry, but that already exists! It's an awesome idea of course - it'd be neat to see how to make it yourself.

REALLY? Where could I buy one of these? I NEED one!!! What does it look like? Do you have pics???

Oh......yeah, I've seen these...Not quite the same idea that I'm going for.... My idea is to mix the colors magenta, cyan, and yellow together in different amounts by turning a knob or something like that to achieve ANY color... (I might need a white and black ink resevior as well... The pens you showed only have certain colors you can select, while my concept uses an "adjustible" color...

Ah, I see what you mean. Intriguing idea, I hope it comes to fruition.