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Author Topic: How to make a Pocket RIGHT!!  (Read 6891 times)

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How to make a Pocket RIGHT!!
« on: February 07, 2014, 08:18:21 AM »
Hi,

I have made a pocket size 60x40 mm and 2mm deep and it is cutting 0.5mm at a time.

But when it's done the right side off the pocket is not like it should be...

I'm using Cut2D
Look at the images....

Thanks!
« Last Edit: February 07, 2014, 08:20:23 AM by SirFinland »

Offline Fastest1

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Re: How to make a Pocket RIGHT!!
« Reply #1 on: February 07, 2014, 10:04:37 AM »
   To me it looks like you are losing steps in the X axis (as the pic is posed). Is the deepest part of the pocket the correct width? It looks much worse in the upper picture. Did you change the feedrate? What changed in those 2 pockets?
« Last Edit: February 07, 2014, 10:06:14 AM by Fastest1 »
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)
Re: How to make a Pocket RIGHT!!
« Reply #2 on: February 07, 2014, 09:46:36 PM »
Looks to me like some kind of formula is active in X direction. Because it comes back to the same location on the left side.

Not much in common with the pockets if they are all supposed to be the same program. Something is real odd looking, that's for sure.

Offline ger21

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Re: How to make a Pocket RIGHT!!
« Reply #3 on: February 07, 2014, 09:54:47 PM »
Looks to me like some kind of formula is active in X direction. Because it comes back to the same location on the left side.


No, it doesn't. It keeps moving farther to the left with each pass, ans since they're deeper, each successive pass makes a full depth cut.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: How to make a Pocket RIGHT!!
« Reply #4 on: February 07, 2014, 10:18:38 PM »
guess it looked like it did to me, my bad.
Re: How to make a Pocket RIGHT!!
« Reply #5 on: February 08, 2014, 01:01:25 AM »
Hi,

I changed a bit on the feedrate an thats why it's different on the other picture, but how can i get it so that it cuts right the hole pocket?

Thanks!!
Re: How to make a Pocket RIGHT!!
« Reply #6 on: February 08, 2014, 06:07:25 AM »
Can someone help me...
Thanks

Offline ger21

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Re: How to make a Pocket RIGHT!!
« Reply #7 on: February 08, 2014, 07:47:55 AM »
It looks like your machine is losing steps. This can be caused by many things.

What kind of machine is this?
First thing you should do is go through the entire machine, and make sure everything is perfectly aligned, with no binding. If you still have issues at that point, then reduce your acceleration and velocity setting in motor tuning by 25%-50%.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: How to make a Pocket RIGHT!!
« Reply #8 on: February 08, 2014, 07:59:19 AM »
It is CNC3040

Thanks for the help I will see if i can do something I'm new with this ;)

Offline Fastest1

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Re: How to make a Pocket RIGHT!!
« Reply #9 on: February 08, 2014, 09:37:20 PM »
SF, Sure there are some things you can do.

 Lube all ways, slides ball or lead screws too.

Then as Gerry said, lessen your velocity and or acceleration.

Find out the micro stepping that your controller is on and see if changing its value doesnt lessen the resonance. This will require some retuning so if you are very new, hold off a bit. Not that it is difficult.

Btw is this all of a sudden? Was there a change in its operation? Or are you new to the machine and experienced these problems right away?Just out of curiousity, what kind of speeds/accels were you running?

Either accel or velocity can cause lost steps depending on their values, so it could be the velocity was fine but the instant accel for its mass caused loss of steps or vice versa.



« Last Edit: February 08, 2014, 09:41:11 PM by Fastest1 »
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)