Codewheel Generator for Homebrew Optical Encoders

[James Arthur]

John Fields wrote:

On Thu, 19 Jun 2008 18:55:56 GMT, James Arthur
bogusabdsqy@verizon.net> wrote:

Martin Griffith wrote:

can it do this?

http://www.telegraph.co.uk/news/newstopics/howaboutthat/2144652/Most-complex-crop-circle-ever-discovered-in-British-fields.html?=rss


martin
I get the rest, but where's the "3" ?

---
The innermost arc goes 3/10 of the way around the circle.

JF

Thanks -- I'd missed that.

--James Arthur

 

[JSprocket]

Tom2000 wrote:


I just released a freeware Win XP/Vista program that generates
codewheel images and prints them to any home inkjet or laser printer.

With a good codewheel in hand, you can build your own optical encoder.

Nice one, I've created them using FastCAD but this saves a lot of
hassle, especially for Gray encoders.

Just a little request: an option to fill the page by step-and-repeat
when printing?

JS

 

[Rich Grise]

On Thu, 19 Jun 2008 19:22:31 +0000, James Arthur wrote:

John Fields wrote:
On Thu, 19 Jun 2008 18:55:56 GMT, James Arthur <bogusabdsqy@verizon.net
Martin Griffith wrote:

can it do this?

http://www.telegraph.co.uk/news/newstopics/howaboutthat/2144652/Most-complex-crop-circle-ever-discovered-in-British-fields.html?=rss

martin
I get the rest, but where's the "3" ?

The innermost arc goes 3/10 of the way around the circle.

Thanks -- I'd missed that.

I once saw a thing on teevee where the two guys who had been making all of
the "crop circles" show exactly how they did it. It's trivially easy to
walk through a grain field like that without leaving a trace - just walk
between the rows. And you can make a perfect circle by standing a guy in
the center with a rope, and you can figure out the rest.

But even after seeing that, the True Believers refused to believe that
the "real" crop circles were a hoax. ;-)

I'm thinking of making sort of a mask of that Jesus pic,
http://www.eyetricks.com/jesus.htm ,
and scorching it into a tortilla, and sell it on ebay: "Jesus on a
tortilla Hoax!" - it'd probably sell for tens of thousands. ;-)

Cheers!
Rich

 

[Tom2000]

On Fri, 20 Jun 2008 08:45:23 +0100, JSprocket <JS@internept.org>
wrote:

Just a little request: an option to fill the page by step-and-repeat
when printing?

That feature occurred to me the first time I looked at that lonely
little wheel in the center of the page. Then I thought that it would
be hassle enough to make one encoder. Who would ever want more than
one copy?

After trying to punch an accurately-located center hole, though, I
quickly realized why someone might want more than one. (It took me
three tries.)

So, I'll consider the feature for a possible future upgrade.

Thanks for your suggestion.

BTW... a bit of irony...

I ordered some tiny SMD phototransistors from Electronic Goldmine to
use in my homebrew encoder. With the transistors, I also ordered some
junkbox filler parts to fill out the order enough to make the shipping
costs worthwhile.

One of the add ons was an assortment of pots, since I thought I'd be
tearing more than one apart before I figured out a good mechanical
codewheel mounting arrangement.

Included in the pot assortment were two quadrature encoders! One a
Clarostat 128 CPR encoder, the other a beautiful Bourns ball bearing
256 CPR encoder.

I hope to find time to test them this evening. If either of them work
(particularly the Bourns), I won't have to fiddle around with a
homebrew encoder.

So there's irony for you. I bought the pot assortment as a throw-in
of project parts, and acccidentally received encoders that might
eliminate having to build the project at all!

There must be a lesson there.


Tom