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francooz
20-12-2010, 12:37 AM
Dear all,

Long story short I got hold of a great little cnc. However it also came with a problem. It's a 3-axis engraver that sits on top of a box in which all the electronics are.

When I try to calibrate the axis from the machine's controls it makes alot of noise and does nothing. However if I move the axis individually I found that z moves fine, yet X and Y stalls when I press +/-. If want to move them at all I have to hit the +/- repetedly but it doesn't move much anyway.

So the first thing I did was to check the motors and connections and I found that motors work great if I just use the Z controls for X or Y. I also measured the voltage going to the motors and they are all 12v.

It does look like there is a problem with the main circuit board. Anyone out there have any ideas for tests I can do to narrow down the problem? I am starting to think that I will need buy another board.

Cheers,
Dan

M250cnc
20-12-2010, 08:39 AM
Hi Dan,

From what you say it sounds like the X & Y are stalling.

12v is very low and will limit your rapid speeds.

What type of control are you using ?

Phil

Sent from my HTC Desire using Tapatalk

francooz
20-12-2010, 12:25 PM
I'm using the onboard controls, on the front of the machine. I don't have the software at the moment so just testing it manually.

All motors are getting the same voltage so I assume the power supply is fine. If I switch the x or y feed to z then that motor travels Smoothly without any problems.

On the surface it looks like there is something wrong with the x/y sockets on the control board but it does seem odd. I would have thought if there was a problem with the board then all axis would be effected or just one.

M250cnc
20-12-2010, 01:23 PM
Dan give more details of the control.

Best sort out the writing first though

Phil


Sent from my HTC Desire using Tapatalk

FatFreddie
20-12-2010, 01:55 PM
Dear all,

Long story short I got hold of a great little cnc. However it also came with a problem. It's a 3-axis engraver that sits on top of a box in which all the electronics are.

When I try to calibrate the axis from the machine's controls it makes alot of noise and does nothing. However if I move the axis individually I found that z moves fine, yet X and Y stalls when I press +/-. If want to move them at all I have to hit the +/- repetedly but it doesn't move much anyway.

So the first thing I did was to check the motors and connections and I found that motors work great if I just use the Z controls for X or Y. I also measured the voltage going to the motors and they are all 12v.

It does look like there is a problem with the main circuit board. Anyone out there have any ideas for tests I can do to narrow down the problem? I am starting to think that I will need buy another board.

Cheers,
Dan

It's possible you have bad driver components on the X and Y axes, is it possible to post pictures or details of the board? A picture / more details (manufacturer / model no etc) of the whole machine may also help.

Mark

francooz
20-12-2010, 02:24 PM
Not sure what you are getting at.

This is an image of the dash board. Controls on the left are for the router and on the right for the axis.

http://184.72.239.143/mu/d9ab8145-5611-5c10.jpg

francooz
20-12-2010, 02:36 PM
http://184.72.239.143/mu/d9ab8145-596d-dfa9.jpg

Not sure how well you can see everything there. I'm not at home at the moment to take another picture.

The white box to the right is where the power coming from; straight to the motors. On the circuit xyz is from left to right.

I will find out the model number when I get back from work.

FatFreddie
20-12-2010, 03:36 PM
Not sure what you are getting at.
There are people who read this forum with a lot of experience (I'm not one of them) and they may recognise the bit of kit and be able to suggest some tests. Looking at the picture of the board it would seem to be a fairly easy job to replace the driver ICs which would be much cheaper than getting a new board but you'd need to do more tests before knowing whether that would be a solution.

M250cnc
20-12-2010, 05:04 PM
Well if its an electronics problem then i will be no help whatsoever

Phil

m_c
21-12-2010, 01:35 AM
Are you sure the stepper driver power is coming from the white box?
The white box looks more like a VFD to me, which should be connected to the spindle control panel and spindle...

The silver boxes look more like a PSU for the stepper drivers...

If the motors are moving when connected to the Z-axis, then it does sound like the driver board is at fault.



Best thing is to see if there are any model numbers on the different parts, as somebody may be able to identify them.

francooz
05-01-2011, 05:36 PM
All the components are Chinese and I am having trouble finding any model numbers. I'm starting to think that this is a bit beyond my area of expertise. So I have been thinking to replace the whole thing with something like System4C (http://www.diycnc.co.uk/html/cnc_systems.html). This would also give me a parallel port which I don't have at the moment in order to use EMC to it's full potential.

Anyone have any thoughts or recommendations?

I very much appreciate all your help, thank you.

Regards,
Dan

FatFreddie
05-01-2011, 06:27 PM
I have the previous version of the board (where the interface board is part of the main board) and it worked well on my old PC but the charge pump doesn't work on the new PC which is only 3.3 volts on the parallel port. The drivers work ok but are a bit noisy (the steppers make a hissing sound in some positions). Other than that it seems good value for money.