Instructables
Picture of precise Micro drill-dremel in 5 minutes
Need something to drill tiny holes in your pcb, or maibe you just made primitive cnc which needs some simple but precise router?

here is the answer: this method allows to make perfect holder with precision about 0.1mm or better. without using any tools.


(this is my first instructable, i will edit it later)
 
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Step 1: Stuff which you need

Stuff which you need:

1. Some small motor.
2. Epoxy resin or acrylic oxide(cures faster)
3. Syringe (size depends on motor axis and drill diameter)
4. drill bit which you want to attach to motor

Tools you will need:

something flat and sharp ( knife, screwdriver or anything else )

Step 2: Lets start

Picture of Lets start
EPSN2360.JPG
Now we need to make piece of hard plastic attached to motor axis.

there are few ways, you can either glue something or do in my way:

Mix some epoxy resin or acrylic oxide and put it in to syringe.
try to avoid bubbles.

now insert motor axis deep into syringe and wait until epoxy hardens( with acrylic oxide you only need to wait few minutes )

here all funs will start:
now we have piece of plastic attached to motor.
just power on your motor and use knife to cut away unnecessary part of syringe and shape that piece of plastic into nice and symmetric cone.
you may need to remove all syringe if it wobbles to much, then you can shape plastic freely.

finaly some hard job is coming. now we need to drill perfect hole in the end of cone.
so take your drill bit and use it.
Drill will find perfect center automatically. All you need it to keep drill bit straight somehow.

Drill bit holder is ready for use.


Step 3: FInish

Picture of FInish
Now we have perfect holder, you can insert your drill bit ,and see how it works.
best way to attach drill bit is to use super glue. it is not permanent fixation and since super glue does not bond to metal very well


Since all this is quote easy and cheap, it is easer to make separate holder for each drill bit.

precision is very high and surpasses cheap dremels or drills.
currently I have no better way to achieve same precision
tutdude982 years ago
You can use cotton swab plastic to attach to motor
tilmen3 years ago
Very useful instructabe.What else can we use other than Epoxy resin or acrylic oxide? How can I find acrylic.
drill unfortunately drill oversize too and that is dangerous, always drill undersized or use a taper fit please i don't want to meet ya one day without an eye.
zorif5 years ago
did some similar long time ago. :-)
still need some improvements.

http://www.instructables.com/id/DIY-Pcb-Hand-Drilling-Machine/
Hmm if you covered it in epozy to give it strength you could make it so Dremel bits fit in it to use as a sander etc
stone34085 years ago
If you set the shaft against a file while it is running it will sharpen the shaft to a point. If you turn the motor on and place the sharpened tip against plastic it will melt from friction and make a perfect hole. I have always used the method with great success and once it get rolling it cuts well too. This setup allows for a great deal of side loading. The melting plastic will attach itself to the shaft making for easy clean up. I have had the most success doing this with hairdryer motors as rpms are very important with this method.
Just a thought - It doesnt matter how concentric your cutting bit is to the motor shaft if your motor shaft is supported by two tiny brass busings with no lubrication that offer minimal support, arent designed for any side load, and will wear out quick. You would be better off sticking a shaft in your dremel and following the instructable from there. 0.1mm is about 4 thou inch which isn't very precise at all.
Dremels are cumbersome at the best of times. The stylus would be an option. I like this project, even with its flaws. I would say it will last a reasonable amount of time if just drilling holes in PCB's.