On 05/04/2011 06:18 PM, Mouse wrote:
On 5/4/2011 9:13 PM, Tim Wescott wrote:
On 05/04/2011 06:03 PM, Mouse wrote:
On 5/4/2011 8:13 PM, wrote:
On May 4, 6:09 pm, Tim wrote:
I have two sizes of disk to cut, from two or three different
materials:

Disk 1: 3/4" diameter, from 6mm thick "Depron" foam. This is a
close-cell polystyrene foam (I think it's extruded).

Disk 2: 0.125" to 0.150" diameter, from 1/64" plywood or 0.015"
styrene
(I have the plywood, the styrene matches the color and chemistry of
the
foam).

Both need to have a .025" diameter hole drilled, but that's not the
big
problem.



How many do you need to make? If it is not too many, I would try
making a single sided die and use it spinning in a drill press. It
could have a .025 drill so it drills the hole first and then cuts the
disk in one operation. Think of a toothless hole saw. I have used
something like this for cutting rubber disks. I did not need the
hole in the center.

Dan
That's what I was thinking. When I worked in a printing company they had
a hole drill that would melt through a 1/2" stack of paper with ease--a
sharpened thin tube spinning in a small hand press--had a cutout on the
side to eject the paper disks. Should be easy to make one for a drill
press. I believe it was sharpened on the inside of the tube since they
were after clean holes, for clean disks sharpen from the outside.

Hmm. I'd be making batches of 10 or 20. That would certainly do if I
weren't going to try to farm the work out to my 12 year old, but I
wouldn't want let him close to the power machinery.

Well, you know your kid's capabilities/responsibility level best. I
won't go into what I was into at his age, lol. Parents are more careful
these days.

#1 son may have been OK, but #2 son gets anxious when there's a need for
honest caution. Then he locks up and stops thinking.

If you're not afraid of power tools at all then you won't think about
the hazards, and you shouldn't use them. If you're so afraid of power
tools that the hazards make you stop thinking -- you shouldn't use them.

Hopefully he'll grow out of this.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html