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

[Desertboy]

the whole thing was whizzing around without a hitch like a ferret on amphetamines.

Have you been looking at my new cnc designs ;)

[Palletlad]

here's a small test video of me checking the rails and ballscrew. Note - found almost no grease on anything

[m_c]

Something about the ballscrew/bearings does sound a bit dry, but nothing I'd worry too much about. They don't actually need that much grease, as too much grease can be as bad as too little grease.


Did the parallel port (latency?) test pass OK?
Those clunks could be cause by a glitch in the pulse stream, which is often something causing an interrupt on the computer. I'm going to assume you've done the basics, like ensure all non-essential software has been removed/disabled (that includes any anti-virus).
I'd re-run the parallel port test, and see what results you get. Some hardware configurations are just not suited to running the parallel port for motion control.

[Desertboy]

Something about the ballscrew/bearings does sound a bit dry, but nothing I'd worry too much about. They don't actually need that much grease, as too much grease can be as bad as too little grease.


Did the parallel port (latency?) test pass OK?
Those clunks could be cause by a glitch in the pulse stream, which is often something causing an interrupt on the computer. I'm going to assume you've done the basics, like ensure all non-essential software has been removed/disabled (that includes any anti-virus).
I'd re-run the parallel port test, and see what results you get. Some hardware configurations are just not suited to running the parallel port for motion control.

I have a core i7 running my machine with PP BOB

I had to use on the board graphics as my Nivdia GPU really didn't play well with linuxcnc & turn off hyperthreading then I started to get decent performance, you can also restrict the cores to improve latency.

Multicore and real time are not inclusive terms lol and 20+ years of trying to parallelise to cpu's don't lend themselves to out operation. I've seen more than once people cry out for the good old days of DOS lol.

[Doddy]

Just a quick experiment : Have you tried inhibiting micro-stepping (set micro stepping to 1) on the X/Y, retuning the motors and trying again? Be interesting to see if you're losing steps during the micro-stepping and the clunk is the rapid acceleration of the stepper to catch up on a higher-torque A/B coil step phase.

[Palletlad]

urgh this machine is doing my head in... really tempted to just scrap it all, been trying to find out what the Chinese charts actually mean on the board so I don't damage the board by doing something wrong.
I initially was looking around at breakout boards and their reviews and discovered my breakout board has on board axis drivers as well so if I ever decide to replace it I have to buy stepper drivers as well.
So was looking at the MX3660 which seems perfect (all in one, little hassle) just trying to find a seller and then thought I'm getting distracted again.
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?
Also I'm going to do a test by taking the motors off of the frame and see if they still make the jarring noise when not attached to the rails, if they still do whilst disconnected then that should eliminate any frame/rail/ball-screw issues I presume and my guess would be either power or a faulty connections somewhere right?
if the motors run smoothly and no jarring when loose then I pretty much scrap the frame? (take hammer to it)
Also (sorry for all the questions) but how can I tell what PSU I have as the only sticker on it was all in Chinese?
PS. the things I have done so far are the following:
brought a standalone dedicated pc with XP and parallel cable for the cnc so no background extras or settings to interfere.
tested multiple settings in Motor Tuning with all having same affect (all three axis jar at least twice and not always in the same area)
tested the rails and alignment also checked the frame was square
have not yet used the machine in any form or had the spindle on whilst testing the motors.
I have not been able to switch the parallel cable with another yet as do not have a spare.
would a UC100 connection solve issues between pc and control box IF it is a communication issue?
(tired now but was trying to think all possibilities)

[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.

[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.