Re: [CAD_CAM_EDM_DRO] CNC questions

paul@... wrote:

> Hi Jon,
>
> Fitch thought you might know something about this.
>
> I've tripped onto a deal for a Bridgeport BTC-1 machine with
> toolchanger with a Boss 7.1 control. Do you know anything
> about that machine or control?

I'm assuming this is for Jon Elson, but I'll try to answer anyway.

> There may be a glitch in the controller. The story I'm getting
> is it worked fine in service, the current fellow got it and
> fiddled with the tool changer and it hasn't really worked since.

Hmmm, well the BTC is not highly thought of by industry experts.
Advice I've heard is something like "get steel-toe shoes to protect
yourself from the dropped tools, which it will do daily". Yikes!
I can't afford to replace all those end mills and holders!

The Boss-7 is a servo system, I don't know whose servo amps they
use, but I think this has the same SEM motors that are still used in
the EZ-Trak machines.

> I was looking for an EMC candidate (actually, that's not quite true, I
> was _going_ to look for an EMC candidate - when I had the room for it.
> Figuring out what to do with this thing now is a problem). I will
> probably go take a look at it in a couple of weeks (it's about 400
> miles away). The fellow wants $1500 for it, including some tooling,
> which seems like a good deal if it's in decent condition.

Gasp! If the mechanics are in good shape (ballscrews, spindle and
ways, etc.) then it sounds like a **DEAL** for sure! If the servo amps
can be salvaged, and are compatible with the standard +/- 10 V signals,
then it should be a very inexpensive conversion. Since it is a BOSS-7,
it can't be too old, maybe 1990 or so. Unless it was used to machine
something hideous (dusty and abrasive) or horribly maintained, it should
be in excellent condition.

Yes, this machine should be an excellent candidate for a control upgrade.
The BTC is not currently supported by EMC, but there is work going on
to add that feature. With the ability to tweak timings and sequencing of the
toolchanger, it may be possible to make the BTC run more reliably.

Jon