Originally Posted by
drhanger
Dang, I haven't been getting any notifications from this thread since my last post a month ago, only logged on again because I had another question about the inverter circuit. I have a little catching up to do....
Don--I may be able to help with the presser bar circuit, I made some mods with a single button in place of the original two buttons on the head for the tool change. If I get some time soon I'll post some pix and diagrams. Mine's a bit simpler than Timothy's but it also involved making a new cam plate for the presser and two limit switches. When I first set up the machine I had removed the presser motor system completely and replaced it with an air cylinder for manual tool changing. After some time I realized that the Belleville washers for the drawbar were worn out and needed replacing (many of them were broken). After replacing them the force required to operate it was beyond the air cylinder's ability, so I went back to the original motor and made the mods to it. It wouldn't work if you plan to get the ATC working though.
Marty--you asked about the problem I had that I corrected--after a month I've almost forgotten, but it was just simply not connecting the -12V correctly. But I do have another issue I hope you may be able to help with (the reason I logged on today). I just now finally got the circuit board completed and temporarily in place when I ran into a funny issue with it that hadn't shown up before because I hadn't run the speed up fast enough for it to show. Last night I started testing by slowly increasing the spindle speed, when I got up to 3,000 RPM the spindle actually started slowing down with each bump upwards in speed. The more I increased the speed at the control the slower it went. I started checking the output voltage at the VFD on the MX3660, and it was increasing normally as expected, so I was getting a proper PWM signal out of LinuxCNC and from the MX unit. The only thing left in the train is the inverter circuit you gave me. I must have something wired wrong, but I've been over it several times, comparing mine with yours and can't find anything wrong. I've attached an image of the board I made, maybe you can spot something I've done wrong. There are two relays added to the board, one for enabling the spindle amp and another for passing the +5V signal to the inverter section. Any clues?
Thanks,
Dan