Re: [CAD_CAM_EDM_DRO] Reed switch for limits - anyone done it?

On Thursday 15 August 2002 09:40 pm, you wrote:

> Hi Matt,
>
> How much info can you supply? a pix of brackets and switches you used,
> and a text description of where each goes (i.e., "left end of X bed...")
> would help! Or even a drawing (DXF, JPG, etc) of the brackets.

There's a link to my "working" (i.e. sloppy) drawing at the bottom of this
page:

http://users.erols.com/mshaver/index.htm

Download sherline.dwg, it's an ICAD/ACAD drawing file made in Intellicad
(under Linux using WINE I might add... just in case anyone cares...). This
design requires no modifications to the Sherline mill, but a lot of details
(like screw lengths, assembly instructions, etc.) isn't in this drawing.

> If you
> are using std. micro switches, we can probably figure out which switch
> is used. Give us some hints!

No need to guess, it's this:

http://rocky.digikey.com/WebLib/Omron Web Data/D2SW.pdf

> Alan KM6VV
> P.S. Want to sell a set of brackets?

Yes, and no. I did this design with the intention of making a bunch and
selling them, but:

1. There are a lot of parts including nylon tipped set screws, an Allen nut,
etc. and the cost really starts to add up.

2. Producing a complete professional set of detailed installation
instructions with photographs, line drawings, and exploded views would be
very time consuming.

3. With all the parts, in small quantities, the cost per set could be $200.
Who would spend that kind of money on limit switch brackets for a $600 mill?

4. If I cranked out a big batch they'd be lots cheaper, but I'd have to sit
on all that inventory until I broke even, and I haven't a clue what the
demand would be (this is the classic engineer's dilema).

This is why I've settled on building high quality, turn-key systems. Once I
finish the cnc control design I'm working on, I can start building up
complete cnc systems based on Sherlines and other larger machines.
Ironically, it would then be easier to justify selling parts because I'd have
them made periodically anyway to support the production of the complete
systems, the profit from which which would make the whole scheme economically
viable.

One more point (from MAKING MONEY THE OLD FASHIONED WAY By Joe Martin,
President of Sherline, Inc):

"DON'T MAKE SPECIAL ACCESSORIES FOR OTHER PEOPLE'S SPECIALIZED PRODUCTS"

"A risky venture is to design and build products that can only be used with
another specialized product. You would be at their mercy. A design change and
your product will only fit their old models. The type of product I'm thinking
of is not an accessory that would go with many motorcycle models but an
accessory that would be used with another accessory; that is, a specialized
accessory for a specialized accessory."

Like limit switch mounts for a Sherline mill...

I'll try to take some pictures of the next one I put together!

Matt