Hi all,

How would I go about making a small round hole in plastic or maybe wood.

The hole would be about 2 or 3 or 4 mm in diameter.

It would be concaved inwards and circular shaped like a half ball.... maybe not quite so deep as a perfect circle.

A normal drill would leave a 30 degree angle where as I want a nice rounded indentation in my project.

Your thoughts gentlemen.

Regards Alan Davidson


http://www.alanzmuzik.com

Home of the Worlds only Portable Pianobar.

Greetings Alan, try using a machinist rounded bottom bit chucked in a drill press with your piece firmly clamped to the drill press table top. Then move the bit down slowly to the desired depth. These bits are used for milling metal but work great for plastic and wood as long as you do not run them at too high a speed. If you cannot find a source for the bits locally, let me know and I'll put you in touch with some suppliers over here that can help.
Marty

For plastic, how about using a hot piece of metal to stick into it and melt away what you don't want. Of course the hot piece of metal would need a safe handle for you to hold. An easy example is a sodering iron, though I don't know if that will fit your needs or how bad that will mess up your sodering iron. Sand away the resulting scrap you don't want. This is not the type of work I usually do, so I don't know for sure if this will get the results you want. That's what I personally would try first though, other than a visit to a local hardware or model store to ask them.

Good luck,
Allen

Alan,

Use a router bit in a drill press or variable speed drill. Router bits can be operated at a slow speed and come in full rounded shaped points in various sizes.

If you use a press, it will be easiest since without a point, a round router bit (try saying THAT three times fast) will wander. Use a small, shallow pilot hole if you decide to use a hand held drill.

Best Regards,
Ray

Alan,

Do you mean mm? If so, at 25.4 mm/inch, we're talking about rather tiny holes. Ray Haddad's method makes sense but are there any router bits that small?

Could you explain your purpose a bit more fully?

Sid

The right tool for the job is a "ball end mill"; these can be found down to very tiny. If a small number of holes are needed, a solid carbide (round end) dental burr may work, depending on what material you are hoping to machine.

PM me Alan, and I'll give you some sources of supply.

Regards,
Thomas Wayne

As Mr. Wayne suggested, a ball end mill is perfect for the job; but there are a variety of ball shaped burs (or burrs depending on where you live ) for Dremel tools. These come in a selection of small sizes which are readily available at many hardware stores. They work well in both plastic or wood. I suggest mounting in a drill press for better control. Do not run at too high a speed or the plastic will over heat and melt - the wood could burn. For plastic you could cool/lubricate with something like windex for this small job. This will also flush out the small shavings produced and keep the bur from clogging up with plastic.
Jim

Thanks everyone,

The replys have been very helpfull indeed.

Regards

Alan Davidson

http://www.alanzmuzik.com

Home of the worlds only mobile pianobar!!!.

Dremel tool with a tiny ball mill.....

If the hole is 3mm, how big is the countersink?

I built a prop last week that had a 2 mm hole in the base of a plastic punch bowl.

I had to put a flashing LED in this thing (er..., don't ask).

I heated an awl on the kitchen stove until it was very hot, and VOILA! a nice neat suitably sized hole in a cheap plastic item.

You could probably use a nail, a phillips screwdriver, or any suitably sized metal object to do the same thing.

Hi, if you are wishing to creat an indentation ( a blind hole ) that doesn't penetrate the material. If the metal is fairly think, a steel ball (2mm or 4 mm )can be punched into the metal. or heated for use on plastic.

Ian