Small spindle crashed (SOLVED)

spumco wrote:

You can test this by creating a small program to move the Z-axis up and down at rapid speed.

You don't need to move far... just an inch or two, but far enough for the axis to reach top speed (depends on your axis acceleration).

Start with the head/tool at a known distance above the table, perhaps using a 1-2-3 block or a steel rule. Repeat the up-down move a number of times with the program ending at the start point.  Make sure your reference height device is not in the way - nothing close ot the head in case you lose steps and the head is lower than you expect.

Once complete, check if the tool is in the same position.  If it's not, then you've lost some steps.  There are a number of fixes, but reducing top speed, acceleration, head weight, or friction all will help.

Or get bigger motors.  That's my go-to solution

Yes

I placed order for a closed loop stepper, 

Actualy I have a 34 stepper motor (long body) but I have no driver. So I will swap the z-x because the x has the larger motor.

I under estimated the Z requirments.

This stuff is adictive and enjoiable. I am enjoying every nano second.

Philip
 

You might find that a lower Z joint acceleration will circumvent the issue.

I think it is clear now

thanks everyone

It looks like the G-code is OK

It is obvious to me now that the Z-stepper missing steps, slower acceleration and speed should help. Also a larger motor maybe necessary.

Why the Z-step motor is missing steps?

because when the cut of the circle reached the depth of the cut (11mm) it is time to move the bit up to safe altitude.

It does that with G0 which is maximum speed. Which when I was jogging after first start of the machine I knew that G0 will not work.

While exited because this the very first time I run the machine after 8 months of work, I did not adjust the maximum speed in the ini file.

Maybe I thought also the bit will move up according to the cutting speed which I know the stepper motor is capable to handle, while in fact it will go up with G0 speed as I found the hardway.

So the first thing to do is to reduce the speed and acceleration until I change the motor, and run the program recommended by spumco in order to find the limit of the new motor.

I will install a spare small spindle, and be more carful this time.

Also I have to spend more time studying the G-code

during this thread, I made some wrong and confusing conclusion. And since no one quoted those posts, I edited, and deleted the wrong nonsense I wrote earlier. This is to make the lesson more clear for beginners like me who may have the same issue.


My best regards

Philip

Do you need to set a safe height and a rapid height in the CAM?

I did not try to leave those entries blank in the cam.

But I am assuming that a safe height is necessary for the machine to move to the cutting location.

What I could do is replace G0 entries with G01 (in the G-code file) that is related to Z axis prior to executing the G-code

On uptravel, you are fighting gravity. Excluding gravity and cutting forces, the motor works hardest when accelerating. Once at speed, torque requirement is < 20% of that.
Try reducing your acceleration and increasing your motor voltage if its < 48 volts