Control box rebuild

[john swift]

how many axis are you using?
I can only see 3 stepper drivers in your photo
If I am correct move the Y axis to the unused A axis on pins 8 & 9

this diagram is the result of reverse engineering a board to help another member


do you have an old PC with a parallel port you could use to test the BOB ?

John

[JohnHaine]

When I had this problem (except with the Z axis) it turned out that the "direction" wire had come out of the drive. The drive thought that the direction was always the same polarity (whichever it pulls to) so the step pulses always made it go the same way. It happened just after I had done some mods to the unit that involved disturbing the wiring. Poked the wire in the term block, did the screw up properly, problem solved. The same thing would happen if the connection had come off at the BoB end of the link, or on the BoB itself. Trace it through before you buy a new BoB.

[Palletlad]

I tested the wiring but not the actual pins on the board, I will do that as well as try using the A axis pins.
question what would I be looking for when using a multimeter on the pins or should I say what are they meant to read if worked correctly? actually I could compare the other working axis to show what it should be so answered my own question there.
Also was thinking over the A axis swap method as JohnSwift mentioned, When I activate the A axis with 8 and 9 pins how do I make the system treat A as Y or do I put the Y pins 4 and 5 into the A axis?
Before I did have a parallel port with a previous BoB which did have all 3 axis working however I burnt that one out accidently so got the cheap one you see in the picture also I went for this BoB because it had the relays for controlling the VFD on/off and Speed control.

[john swift]

assuming you are using mach 3

I expect in ports and pins you have

X axis step = pin 2 , direction= pin 3

Y axis step = pin 4, direction = pin 5

Z axis step= pin 6 , direction= pin 7

if that is correct

change the Y axis to

Y axis step= pin 8 , direction = pin 9
then connect the " A axis " output terminals 8 & 9 to the Y axis stepper driver

John

[Palletlad]

Sorted, all axis are working now. Just need to finish figuring out the vfd part now. Funnily enough I know how to wire the spindle speed but the simple on off relay on the bob connects to ? on the vfd...probably staring right at the answer but can't see it.

[john swift]

great result you have control of the stepper motors sorted

the relay will connect between the common and the forward switch terminal on the VFD

in the VFD manual there is usually a diagram to wire switches for the manual control of the VFD and a remote potentiometer to control the speed

on a CNC machine the variable DC voltage from the potentiometer is replaced by the 0 to 10V output from the breakout board
and the relay replaces the forward switch

do you have a link to download the VFD ?
or post the make and model number to search for the manual

John

[john swift]

if your VFD manual has a manual remote control some thing like this -



you could connect the BOB like this



John

[Palletlad]

Hi all, I'm having another go at the control box to get rid of the gremlins.

My first attempt failed ended up killing my drivers and breakout board with a static discharge (so I've been told) so have brought a new container with a metal backing and have started from scratch a new design.

I have made a video in order for you to review and see with your experienced eyes anything that stands out as good/bad, criticism is all welcome.


https://www.youtube.com/watch?v=FL1fY_2_VPo