[mflux_gamblej]

I found a disconnected diode (D4) which is in the Mains / Servo Drive cabinet. It is wire #61, which goes over to the spindle cabinet to one of the contactors there that pulls in when you press the green cycle start button. The complete pillocks at the factory never soldered it in place!! There wasn't a dab of solder on it!!! I would understand if someone had replaced a bad diode in the past and screwed up, but this one was a mistake at the machine tool builder. Thank you Bridgeport for the incredible frustration as well as time, money, and a well working spindle drive wasted... over a $0.10 diode that didn't get f*** soldered.

I guess the previous owners of this machine must have done the same thing - ran the spindle with the brake on, and ruined the spindle drive. I repaired the spindle SCR drive myself over a year ago, but until now had been using a loud buzzer to remind me to turn off the "automatic" brake.

wow..

I am pretty excited now though. I started looking at the circuit diagrams because I am installing a power drawbar (controlled by a microcontroller, not one of the simple mechanical air valve types) and I needed to control the brake and I also needed the tool in/out buttons to be disabled when the machine is running.

My goodness. If you own and interact 1 mk 2 and the 'auto' brake doesn't work, I hope it's unlikely, but check to see that diode # 4 is flipping soldered onto the machine.

[gridley51]

So what was wrong with the spindle drive?

[mflux_gamblej]

So what was wrong with the spindle drive?

A diode, and a wirewound resistor on the MTI-1 board had gone. The board was blackened a little near the resistor. I also replaced the caps on that board, but all of them measured OK before replacement.

Later after that repair, I programmed a M03 S4000, and didn't turn off the brake. The SCR that is on the MTI-1 board fried. I replaced that and the spindle runs - although the KTK drive isn't setup quite right. There is a serious overspeed, which I compensate for using a factor (see previous posts). CNC tapping works just fine like this and I wonder if the speed control using the factor (speeds measured with cheap laser tach) are more accurate than the factory setting. So, since that system works and has for more than a year, I haven't gone in to try and solve the overspeed issue.

[mflux_gamblej]

So,

After 2 years owning my interact 1 mk 2, I am considering selling the machine. It is a subject that creates bigtime mixed feelings for me as it was my first machine (of any type), and the machine that I learned to repair CNC systems, mechanical, and electrical on, and beyond those things, its the machine that I learned to be a machinist on.

At any rate, whether I sell her or not I suppose just depends on the $$ - I don't have to sell, but could use the space for additional CNC stuff, or other equipment of my choice - so I'm not going to take any reductions from the asking price.

Now, actually related to this thread, I thought the machine's speed readout ought to match reality (read below for all the details). It was just a matter of adjusting the MAX SPEED pot on the fac1r board, while someone else measured the spindle speed with a laser tach. I've got the machine dialed in so its within 1 to 5 RPM throughout the whole range from 40 to 4000. If you go playing in the cabinet to do this, just be careful of the crazy DC voltages that are on those boards, or near them.

[mflux_gamblej]

A diode, and a wirewound resistor on the MTI-1 board had gone. The board was blackened a little near the resistor. I also replaced the caps on that board, but all of them measured OK before replacement.

Later after that repair, I programmed a M03 S4000, and didn't turn off the brake. The SCR that is on the MTI-1 board fried. I replaced that and the spindle runs - although the KTK drive isn't setup quite right. There is a serious overspeed, which I compensate for using a factor (see previous posts). CNC tapping works just fine like this and I wonder if the speed control using the factor (speeds measured with cheap laser tach) are more accurate than the factory setting. So, since that system works and has for more than a year, I haven't gone in to try and solve the overspeed issue.

I know I posted something on another related thread, but the overall cause of the issue in the first place was that there was a diode in the CNC cabinet on the right side that didn't get soldered on at the factory. It was an open circuit, and just so happened to be a diode that controlled the machine's ability to operate the automatic brake. That is why the brake didn't shut off for me when I programmed M03 S4000, and trashed the MTI board, and so on as detailed below. silly, and serious all at once. 'thanks' bridgeport!