G540 + EMC2 = missing steps

Hi

ArcEye wrote:

Give it a try and see if it cuts properly.
If so you can add things back until it errors and you will get a good idea what is causing problems.

Did you ever do this?
Your PSU was under powered, but if that was not the root cause, then something else affected the problem

The thing against this being simple binding, is that the modified code worked properly.

Was it setting G61?
If so that tends to go against binding too, exact path mode cannot affect that.

Andy Pugh wrote:

How does the hole size compare to what is being requested? I could imagine what you see being due to machine flex. (especially if the Z rocks during a plunge)
Tangential arc lead-in moves would be nicer.

Did you try this?
Change the code to begin at a point outside of the shape to be cut and plunge at a tangent down to just above the workpiece.

What your original code was doing was the opposite, it started at X0 Y0 and then plunged towards the outside extent of the shape, meaning any overrun through flex would be outside that extent not within it.

My changes in breaking up the moves, brought the cutter above the plunge point and then lowered the Z axis, removing this outward tangent.

Might also be time to share exactly what machine this is, we can guess it is pretty small and probably router-ish, but not much beyond that

regards

Hi,

This is my machine:
K2cnc capable of cutting 13" x 25" with 296 oz of stepper motors and a porter cable router .See attached photos.
software by Cut2d.

Thanks

Hi,

What do you mean by spiral ?

Thanks

Fredasiong wrote: Hi,
This is my machine:
K2cnc capable of cutting 13" x 25" with 296 oz of stepper motors and a porter cable router .See attached photos.
software by Cut2d.

OK so it is a small router type machine.

How about the other questions re the code, what did you try and what were the results?

regards

Hi,

I cut 3 circles with 20mm dia and came out 19.54 to 19.62 using 1.5875 dia mm end mill(1/16). I have played with the accel and velocity so many times no luck and also I have checked all the spindles and they look tight.

Thanks

Hi

You don't seem to be answering the questions I am asking, so I should probably be more specific.

Run my altered code, it should run without overcutting, as it did before.

Then remove the G61, still run OK?

Then combine the X Y and Z moves for the first circle into one move as per the original code, does it overcut now?

If it does, try changing the direction of the tangental plunge, by starting the program with
G0 X20 Y20 instead of G0 X0 Y0

Does that stop the overcut?

... and so on through the program to isolate the moves that are the problem.

Regards the circle diameters, they will be as good as the maths used to calculate the the G3 moves (without cutter compensation), plus the amount of spindle run out.
So long as they are round and not oval, I should not worry about that right now

regards