[netart]

Hi,

I am using Mach3 Breakout Board 5 Axes on my second Parallel port for Spindle switching ON/OFF, Spindle speed controlling (PWM 1-10V output) and Auto Tool Zeroing...

When I try to change spindle speed from MACH3 I get only 0 to 1.865V on output pins... Also there is about same value of 1.865V on LM317 output pins...

LM317 input voltage is 14V
LM317 output voltage is 1.865V
Voltage between ADJ and Vout is 1.25V
Resistance ADJ to GND 20KOhm
Resistance Vout to ADJ 24KOhm

Any idea, and/or schematics of BOB?

[netart]

PWM looks OK on oscilloscope....

[netart]

Finally... Everything works now...

There is production error on this board... Resistor R19 and Capacitor C4 are replaced during manufacturing of the PCB.

Also, in my case, Resistor R5, R18 and R19 are wrongly calculated (in relation with LM317), so I add multi-turn potentiometer in parallel with R19 (between Output and Adjustment pin on LM317) and fine fix maximum voltage (10V) for 100% spindle turning (BOB output to VFD).


Before>

[asuratman]

How did you check them wrong ?

[netart]

How did you check them wrong ?

Did you mean that "Resistor R5, R18 and R19 is not calculated according LM371 datasheet"??... And because of that output voltage from LM317 was 1.865V and from bob output to VFD from 0 to 1.865V!

According LM317 datasheet>

VOUT = 1.25 * ( 1 + R2/R1 )

[sanderdeassis]

I'm new to the forum
a question, what is the output voltage on the pull / dir pin, with 24v power on the 5 axes breakout board

[john-100]

the pulse & direction pins switch between 0V & +5V depending on the output signals from your parallel printer port ( or motion controller)

they are connected to the output pins of a 74HC245 octal buffer that is powered by the USB connector input

the +12 to 24V power is only for the analogue PWM spindle control circuit and the input side of the 5 input opto-isolators for the E-Stop & limit switches

a while ago I reverse engineered the TX14175

Attachment 377410

I would expect your Mach 3 interface board to be like this

Attachment 377412

basically the TX14175 with the LM2576 5V regulator and B050LS (DC to DC converter) replaced by the USB 5V supply

John