Help please. Dip switches and mach 3 settings

[Clive S]

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.

What voltage do you have between an input pin and ground with out any switch connected?

[Radu_Andrei]

Hi.
Sorry for the late reply, the internet was out for a while.
Nice tester. It seems you guys are doing this electronics thing for quite some time. That.s why you.re all so smart. I suspected at first, that you.ve made a pact or something, like Faust, that you knew the answer to every problem I came up with. :P

Regarding the question, if I remeber right, as I measured a lot of connections today, I don.t think it was any voltage between the input pins and ground, but I might be wrong. I.ll check tomorrow, if it helps.
It seems ok so far how the project is going. I just finished a few hours ago to install the touch plate, added some script in mach 3, and it seems to work ok but a bit slow. I.ll change some numbers in there and should be fine.

Next week I.ll set the soft limits, reconnect the x and y motors to the ballscrews, and run some tests. I don.t know, what test I need to check if I get steps missed, but at least I have a plan. :)
Then add a flat wood surface and make it straight, mill it I guess, then add a sacrifice board on top of it, then learn some cam software, and also buy some ebay projects with sculptures and stuff, to have a go at cutting.

I don.t know if all this ideas are good either, but thanks to you guys, I kinda feel confident it will all work just fine.
There.s still quite some work to do, and I.m aware I.ll keep bothering you for some time, but still... A BIG THANK YOU to you all. :)
You mean a lot for people without technical backgrounds. A couple decades ago, people were struggling to find info like this, and most of the time they could not.
I have more gratitude to express, but I.m starting to sound creepy, so I.ll shut up.

[Clive S]

Regarding the question, if I remember right, as I measured a lot of connections today, I don.t think it was any voltage between the input pins and ground, but I might be wrong. I.ll check tomorrow, if it helps.

If you have connected 12-24 v to the centre two terminal on the bob you should have about 7-12v on the input pins.

if you have not got any volts on the inputs pins then you might have burnt the pcb track out on the board. I have seen this in the past.

So just get one thing at a time working. Those bobs although cheap I find to be quite good.

[Radu_Andrei]

Hi.
I just measured it, with and without the limits connected, and I get 0v between GND and all pins except P13, at this one I get 26v. P13 happens to be the probe, but I disconected the cable, and same reading.
I don.t know how I could have burned anything, as I just run the usb cable from the pc, and the 12v supply.

Yet the limits, estop and probe work fine. No more false signals. :)

[Clive S]

Yet the limits, estop and probe work fine. No more false signals. :)

Does this mean that all is working OK?

I am not sure why you have 26v on P13 !!

[john swift]

there must be a detail we don't have to explain why you measure 26V on input P13

which terminal did you connect the volt meters negative probe ?



the printer port ground is connected to the mains supply earth / ground

on the other side of the BOB's opto-isolated circuit

the 5 inputs can not be more than +10V more than
the 12-24V supply ground , input ground & analogue output ground
(which are all connected together on the BOB)

depending on the 12V power supply your using the 3 grounds may be at a different potential to the mains supply ground

small switch mode power supplies such as the ones used with laptops and other IT equipment don't have the negative output terminal connected to earth like PC AT or ATX supplies
they have a small capacitor bridging the mains input & DC output !!!!
( the capacitor is a backwards step just to comply with EMI requirements)

the leakage from a couple of devices is OK but several power supplies can add up to give you a shock

John

PS

[Radu_Andrei]

What I mean that all seems ok, is in comparison with the last state of the machine when the motors were going nuts and the limits were switching erratically.
The bob is not grounded by any individual cable. I assumed that via the usb cable, a ground is provided, which goes to the pc case, and then to the mains.
I did not measure the ground from the mains, but when I touch it, it gives a tingling sensation, like is has some voltage going through it. This is the mains earth as it comes into the property.

The bright side is that it.s all better than before, so I.m still happy, even if, righfully so, Clive disagrees with my so called ˇˇall okˇˇ opinion. I.ll rephrase that. All better than before.

[Radu_Andrei]

P.S. although the vfd is not connected just yet, on the bob I get 2 light on all the time, the 5v and 12-24v leds, and sometimes the relay led. It does not stay lit all the time. I don.t know if that.s bad or not, I just thought I should mention it.