Where is the fountain of knowledge for learning about CNC setups / understanding them

[cropwell]

I don't know if this has been covered and frankly at 2:30 in the morning I can be arsed to go back over the posts and look. BUT have you checked that the wiring to the stepper motors is solidly connected and that there are no internal breaks in the wiring. Is your machine new or 'pre loved'?

[Doddy]

I have on the board ("ON DP" K1, K2, K3, K4) accompanied with SW1, SW2 AND SW3 per X Y and Z drivers
K3 and SW1 are the switches set for all three drivers
I found a chart that may assist but still I know too little on this side as all I wanted was to make stuff with the machine.
http://img.yunqudao.com/UploadFolder...ault/3_649.jpg
is changing K3 to K1 what you mean Doddy to set the micro stepping?

A quick bit of clarification, the "ON DP" marking on the DIP switches (the 4-inline blue switches) - the ON represents the position of the "On" state of the switch. So it's not a case that you have K3 on, but rather that you have K1, K2, K4 on. Looking at the markings on the board that represents 8 micro steps. Change one axis (and one only) to Off, Off, Off, Off (all toggles towards the numbers, away from the "ON DP" and retest.

(I'm assuming in the chart on the board that '1' represents a switch in the ON position... not a safe assumption, but the existing settings support that)

Note, that axis will run at 8x the original speed, so you'll have to tune the motor for that axis.

Do this with the motors still hooked up to the machine.

I think removing the steppers from the machine to test... interesting if this does present the problem, but I doubt that it will - the sound is mechanical, and likely related to the stepper performance in situ with the machine. Doesn't mean the machine is toast - just that you have to track down the system, rather than component behaviour... altogether more fun.

[magicniner]

This is probably shutting the stable door......... but, only bugger about with one thing at a time.
I know it's a temptation to change multiple settings on multiple axes in hardware and software at the same time but all that does is confuse you and make it impossible for anyone else to draw any conclusive conclusions.

[A_Camera]

is changing K3 to K1 what you mean Doddy to set the micro stepping?

K1 and K2 is the microstepping. K3 and K4 is the holding current. SW1 - SW3 are the motor current settings. As it is configured in the picture, it is set to 1/8 micro stepping, 50% holding current and 2.5A motor current. Micro stepping means that the total number of steps per rotation (most steppers 200) must be multiplied by the number set by K1 and K2, in your case 8. It means that the driver must receive 8 times as many step pulses as without micro stepping, so 1600 pulses needed for a full 360 degree rotation. It will simply take smaller steps.

all three axis jar at least twice and not always in the same area

I guess you mean "jam"...

Can it be that what you call jam is actually stalling caused by too high speed or acceleration for your machine? Or maybe something mechanical, misalignment for example. Disconnect the motors and try to turn all axes by hand. Is it easy all the way? If not then start with fixing all the mechanical issues first. All screws must rotate pretty easily and most of all, smoothly all the way from one end to the other. If the linear guides are misaligned or twisted then you will have problems, even if you may be able to force your way through using more current.

[m_c]

Going by the picture, K1 and K2 set the microsteps.
K3 and K4 set standby current.
And the SW set motor current.

If the new computer has made no difference, then that should rule that out.

You've got nothing to lose by trying with the motors disconnected from the machine.
What's making me think it's not mechanical, is the seemingly random position the thud occurs, and that it affects more than one axis. If it was something like a bit swarf in a ballnut, I'd expect it to stall completely until the direction is reversed. I'd also expect to be able to feel something moving it by hand. You could perhaps try running the screws with a cordless drill and see if you can feel anything, as something like swarf may only show itself at speed.

However, to me it sounds more like a glitch in the electronics side. My next step would be to try a different power supply, or hook up an oscilloscope to see what was going on.

To answer your previous post, don't get an all in one system. Get a separate BOB, and if funds are really tight, get some of the basic TB6560 stepper drives. They're far from high performance, but they'll match what you've got, and individual drives can be swapped later if needed.

[Palletlad]

I do plan on doing the checks in stages but I thought about seeing if I can prepare a check list and go through it step by step.

I have ordered another db25 cable so going to check the cable.
I am going to grab lithium WD40 spray and give the ball screws and rails a coat.
I am going to test the motors on their own.
If still no luck I will check the board settings as Doddy suggests.
If still no luck then I will purchase PSU I found this one https://www.ebay.co.uk/i/15261107092...9916224&crdt=0, are these safe to purchase or do i need to go to some specific website to avoid dodgy components?
then go from there by purchacing a bob and stepper drivers as recommended by M_C.
Thanks guys btw for the help thus far and don't panic I am not going to do all and everything in one go.

[Doddy]

However, to me it sounds more like a glitch in the electronics side. My next step would be to try a different power supply, or hook up an oscilloscope to see what was going on.

I tend to agree - but am not convinced yet that this isn't an interaction between the electrical side and the mechanical side. I fear a scope is literally beyond the scope of the investigation so far, and a PSU should show problems simultaneously on jogs on two concurrent axis (and likely exacerbated by such).

OP: Are you familiar with microcontrollers?, I'm thinking in particular I could knock you up an arduino sketch to generate a pulse train to step an axis over a predetermined distance, reverse, etc. Even check out the effects of pulse-width and so on. This would give a health-check on the machine from controller through steppers (including PSU). But for this you'd have to be happy with how to program an arduino and how to connect it to the parallel port interface on the controller (3 wires - ground, step, dir).

[Doddy]

If still no luck then I will purchase PSU I found this one https://www.ebay.co.uk/i/15261107092...9916224&crdt=0, are these safe to purchase or do i need to go to some specific website to avoid dodgy components?

VM (Max) for a TB6560 is 40V. I'd suggest a 36V PSU.

[Doddy]

I do plan on doing the checks in stages but I thought about seeing if I can prepare a check list and go through it step by step.

Don't forget the cordless drill test on the ballscrew that m_c suggested - it's a good idea.

[m_c]

Just checked, and I should of said get TB6600 drivers if you do replace them.
TB6560 is the older chip, whereas the TB6600 is newer, far more resilient, and has better performance.

Which has also reminded me that the TB6560 has quite a large pulse width requirement. It needs a 10uS minimum pulse width, which limits it to 15KHz step rate. Some where in the Mach settings (think it's the motor tuning screen), there is a box for setting the pulse width. Make sure you have it set long enough.

The attached chart shows the key differences between the chips.