Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Field Worker on January 17, 2009, 03:52:11 PM

Title: My machines shakes really bad when cutting a circle
Post by: Field Worker on January 17, 2009, 03:52:11 PM

I can feel the pulses in the concrete floor when I cut a circle out ( wood working CNC ).
The spindle shakes, the gantry shakes really hard.
I do not know what is causing this but what I hear is a loud pulse bang bang bang as it moves around.

Can anyone help pinpoint this to a problem?

It will do this even without a tool inserted.

Roger

Title: Re: My machines shakes really bad when cutting a circle
Post by: Hood on January 17, 2009, 04:00:18 PM

Your code is likely to be made of many small segments rather than an arc. You may also be running in exact stop mode which will make it worse, constant velocity should improve things.
Hood

Title: Re: My machines shakes really bad when cutting a circle
Post by: Field Worker on January 17, 2009, 04:29:31 PM

Thanks Hood for the quick reply.
Where do I go to change this?
Do I need to slow the stepper motor down on both drives?


Roger

Title: Re: My machines shakes really bad when cutting a circle
Post by: Hood on January 17, 2009, 04:51:42 PM

CV is set on the Genral Config page , you get that from the Config menu.
 Even if you have CV enabled code can still change it, so have a look in  your code and see if there is a G61 at the beginning, if there is change it to a G64.
Hood

Title: Re: My machines shakes really bad when cutting a circle
Post by: Field Worker on January 17, 2009, 05:34:25 PM

I'll try this out and let you know how it went.

Thanks again!

Roger

Title: Re: My machines shakes really bad when cutting a circle
Post by: BluePinnacle on January 21, 2009, 04:05:44 AM

Odd, mine's ok, cuts nice small circles. What comands are you using for the circle? If as hood says it's a string of G01s then it would rattle between them with G61 on. G64 is the right medicine for curves.

Title: Re: My machines shakes really bad when cutting a circle
Post by: Field Worker on January 21, 2009, 09:04:09 AM

Thanks for your reply Blue.

I tried what Hood said and it is smooth now. Before is was nasty. I Have another problem now, the ball screw for "Z" axis, the bearings inside are powder now or should I say in a paste form.

Soon I will have this totally rebuilt.