Re: [CAD_CAM_EDM_DRO] CNC questions

> 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?
>
> 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.
>
> 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.
>
> Thanks for any info
>
> Paul
>

Well, I have spent a good part of the last year or so rebuilding a BTC-1
from the ground up , more or less. This included throwing away all of
the original electronics, cabinets, wiring, etc. The computer cards were
gone as were the servo amps so I did away with the rest also. I replaced
the original computer with an Alleny Bradley 8400MP which I had in hand
previous to getting the BTC. The 8400 runs the mill very nicely but you
need to do something about all the machine functions such as changing
tools, orienting the spindle, shifting gears, handling the tool changer, etc..
This machine is all pneumatic with electric valves. To solve this problem,
I built a little microcontroller which is programmed in BASIC (8052 core) and
this controller handles all the machine functions and interfaces to the 8400
for command input. I have spent a good deal of time writing the code and
getting the bugs out. There are timing problems which need to be addressed.
I have not had it drop any tools as of yet. Probably if the timing were off, it
might do so.
The BTC uses a BT35 taper toolholder. These, I believe, were specially
made for this machine by Erickson Tool. If you don't get them with the
machine, you may have trouble finding them. I am always looking for
more. Anyway, there is a short overview of my little project....
Larry....