Re: [CAD_CAM_EDM_DRO] DRO stuff

>From: "james owens" <wotisname@...>
>
>Hi,
>
>This question of resolution can be increased by using a rotary encoder and
>cable return sping from a vacuum cleaner or windup clock main spring. A
>drum is connected to the encoder and fine stainless cable/wire hooked up
>to the slide of the machine. The wire is kept under tension by the spring.
>It is posible to obtain 2000 line per rev on the encoder x 4 which is 8000
>lines per rev. The hard part is paying out the wire in a uniform way so
>that too much error doesn't creep in. This has all been done. If I can
>find the web page where I saw it I'll post it.
>
>Terry.

The other day I saw a Bridgeport with a digital read out system where there
was some kind of friction wheel which rotated on the edge of the machine
table, like a bicycle speedometer. My reaction was, "you gotta be
kidding". What if it hits a chip? I would think that a wire on a drum might
have the same drawback, although it could be mounted farther from the chip
cascade.

David M. Munro