Bridgeport Interact 1 Mk2 - axis drive failure

**AdeV** · 25-11-2024

Hi all,

I have a mid-1980s Interact 1 Mk2, and it's been my faithful friend for many years. It's a bit worn and the screen is on its last legs, but it's always been a good workhorse. Then, a few years ago, I moved to a new workshop, and for various reasons it stood unused for a while (it was inaccessible for quite a while!).

Recently, I've been getting it going again. This has involved replacing all of the RIFA paper capacitors, and a brand new speed controller/motor drive board, as one of the thyristors caught fire in the original. Anyway, I'd got it all moving again, except the Y axis was a bit rough/juddery. Weirdly, it ran lovely and smooth when using the rapid button, but machining-level speeds would cause the whole machine to shake & jump. However, I found that a few pumps on the manual oiler was starting to bring it around, I figured maybe if I drove it back & forth at rapid speed a few times, that might spread the oil around nicely.

And, indeed, it was, getting better and better.... until suddenly it wasn't. The axis drive simply stopped. I couldn't move any axis at all, either via the joystick or the handwheel. The main spindle motor was still spinning however.

So - power off, investigate (all 5 main fuses are fine, can't see any other fuses that would affect all three axes simultaneously). Power back on, and it gets to the "Pass Z reference mark" prompt, but the axes won't power up & therefore I can't get any further. I powered it off overnight in case it was a thermal trip, but still no joy after it had thoroughly cooled down.

So... does anyone have any idea what it might be? I *think* the axes drive contactor isn't pulling in, as I got "the usual" noise when prodding it with a screwdriver; but it's kinda hard/dangerous to do that whilst also trying to operate the controller. I could believe that the axis drive motor has quit, except I've had that happen before with the X-axis, and that only took out the X-axis. So my feeling is it has to be something somewhere has tripped/burnt out, but I've no idea where to look next. There were no magic smoke smells BTW, when it stopped.

Anyhow... if anyone's got any ideas, please do let me know.

Thanks!
Ade.