Help please. Dip switches and mach 3 settings

[Radu_Andrei]

Hi again,

Here are the photos I.ve promised 4 weeks ago.
It is a 5/5 machine (1.5m/1.5m) made of 2.3 inches (6cm) steel tubing, and aluminium plates.
Rails and ballsscrews of 20 mm. Nema 34 motors (overkill for z axis, but i.ve bought a kit of 4 a few years ago, I.ll get a nema 23 kit sometime in the future). The part of the gantry moving left and right weighs apx 65 pounds (30 kg), while the whole gantry apx 240 pounds (110kg). I did not have any problem so far with the supported rails and bearings, or screws and motors, just a limitation in speed, as a hard stop at a high speed will shake the whole thing. Adjusting each motor to a certain speed seems to work fine.
The project was designed at first with 2 motors on the y axis, and it weight apx 200 pounds, but the fact that I could not mecanically sync the two ballscrews involved, had me worried and I.ve decided to go with one screw in the middle, as any kind of failure does not have the potential to break or bend something.
It is this large, as I need this mainly for carving soft and hardwoods, for cabinet making, and this size let me fit 6 door panels at once on the table.


This is where i.ve got so far with the project, and once again I ran into an issue which I.m not able to fix. Everything was going fine, until I.ve wired mains for the vfd, then I had a surprise when I almost crushed the z axis as it did not stop when I released the keybord. After I.ve wired the spindle, evrything went nuts, as the steppers make a strong noise, and move back and forward quite fast. It.s a chinese 1.5 kw air cooled kit.
As it can be seen in the photos, my idea was to put eveything in one box, including the pc.
I.ve decided to make another enclosure for the vfd and move it a bit further away, and it did not fix the problem. When I turn on the power for steppers (with a contactor) and the vfd (cam swith), even if the pc and mach 3 are off, or even if the vfd is off, the steppers go mad until i hit reset in mach 3, then they stop and work fine, until i turn on the vfd and/or the spindle.

The wires are shielded, 4 wire cable for all steppers and spindle (18 and 14 awg). I did open the cap of the spindle and connected to the case a ground wire (the 4th one) and connect it to a steel rod in the ground. I did this because it says in the manual to avoid having a common ground with a welder. And I do use one quite often. I did not connect the shielding to anything. I.ve only tried yesterday to connect one end of the shielding at the vfd end to see if it makes any difference, and it did not, and also disconecting the spindle ground from the vfd did not do anything (as by default there is not a 4th wire available). No shielding it connected at any end for the steppers or the limit switches. The only non shielded wires are the mains for everything, pc, sources, drivers, breakout board and vfd.
All the wires go togheter in a cable drag chain.

So this beeing one issue, the second is how to wire and configure the limit switches. From what I know so far, I can wire all of them in series, normaly closed, and connect then to the breakout board (DB25-1205 in my case), to one pin from P10 to P15, and to GND. Well, I did something like that, only that I.ve separated each axis 2 limit switches to separate pins. So P10,11,12 to X,Y,Z and P13 to Probe, P15 to Estop, and all grounds together. And it does not work, as the RESET button from mach 3 stays on emmergency limit swicth all the time, when I enable the pins in cause.

So 3 issues,
1. How to fix the stepers issue? I though I.ll ask first here, and then call an exorcist. (it looks a lot like in the movies) :P
2. How to wire and setup the limit switches?
3. Opinions, reviews, criticism, potential problems and solutions for this particular design, if you may. :)

It.s a long post, so before anything else, thank you for taking the time to read it.
Regards,
Andrei