Help please. Dip switches and mach 3 settings

[john swift]

this BOB
https://www.ebay.co.uk/itm/5-CNC-Axi...4AAOSwaxlZiq98

is the type of BOB I would use





it looks like its a version of this BOB found in some control boxes supplied with some 6040 CNC machines



the TX14175 has the advantage of having a 5V to 5V DC converter to provide the isolated 5V supply for the 75HC245's
instead of taking a 5V supply from a USB port


the HDBB2 looks good
I am not sure why they have used a expensive 36 way centronics connector instead of a 25 way D-type connector


John

[Radu_Andrei]

Ok. Thank you. Will order today. :)

[Radu_Andrei]

Hi again.
I.ve build the metal box and reorganized everything, and wired the new Bob. It seems the motor problem has gone, but will post a video soon and let you be the judge of that.
Now, I.ve wired the Bob like in the photo attached, and I.m not getting any response from the input pins, from none. P10 to 15 are not seen in automated setup in mach 3.
I should know the answer from the first picture from post 49, but the truth is that I don.t. :(

What am I missing?

[cropwell]

If you are using the BoB in the picture, you will need the 12-24v input to work the LEDs in the output opto-isolators. It looks like you have a fault there. Also check that the GND connections are all together, except for the PC ground.

[john swift]

the USB cable powers the two 74HC245 octal buffer IC's that connects the printer port outputs to your stepper drivers

the 12 to 24v supply is required to power the five input opto-isolators
& the PWM to 10V analogue converter that's controlled by pin 1



when a switch grounds an input current flows through the opto-isolators LED so the NPN photo transistor is turned ON
so the corresponding printer port input is grounded

when the switch is tripped and opens
the printer port pin goes high
(set pin as active high in mach3)



John

[Radu_Andrei]

It has the 12 v input, a light is on on the bob at the end of the input pins. It makes a subtle high pitch noise when I connect any of the input pins to the ground pin, but it does not register it in mach 3.
All grounds are together, but now I.m testing it with a single wire.
Pc gnd is not connected to anything.
The only difference with this bob is that it has a P14, to which all I ran all ENBL- from the drivers.

[john swift]

does it still make a noise if you remover the jumper to disable the relay ?
(I can't think of anything other than the relay that could make a noise)

having a quick look at the data sheet for the LM317 regulator
the 12 to 24V DC supply needs to be a minimum of 13.5V

the supply goes via a diode that drops about 0.6V and the LM317 regulator should have an input that's at least 3V more than the 10V output

is the 12V supply regulated ? or is it unregulated and is more than 12V if lightly loaded

for your initial tests you can disconnect the connection to the stepper driver enable

John


PS

a simple input tester I used to test a similar BOB without using a PC (or motion controller)

[Radu_Andrei]

the supply is a 12v transformer, which used to power up some car led.s strips. the multimeter reads 12.1 v. it is the one i use for the enclosure fans.
as i fiddled with the wires, somehow it works now. probably a bad connection from the 12v supply. so Thank you!

I looked a bit online, and the eccomerce webs in my country have plenty of 12v, but no 24 supply. Surely there might be some specialized shops somewhere.

It works like this now. Do I ask for trouble if I don.t use a higher supply, 13.5v and above?

Now on the other side of the bob, for spindle control via mach 3, from what I understand, the gnd pin goes to ACM, the 0-10v to V1, 1st relay pin (5th in order) to DCM, and 2nd relay pin to FOR.

Is this correct?

[cropwell]

PS

a simple input tester I used to test a similar BOB without using a PC (or motion controller)

I made a pass-thru tester years ago when I was trying to work out what was happening with a printer/plotter I had. Exactly the same as that but with lower value resistors but each LED was powered by the printer or PC.

[cropwell]

Pc gnd is not connected to anything.

So you are using a USB cable from the PC?