Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: mrpeja on April 12, 2009, 04:17:36 PM

Title: Z axis drops down
Post by: mrpeja on April 12, 2009, 04:17:36 PM

Hi,
My plasma table finally runs (not yet cuts).
I have Z axis with toothed belt and pulley.
There is new problem: when Mach3 ends (File>Exit), or if I press Reset button Z step motor is disabled and Z axis with plasma torch immediately drops down.
Any idea how to prevent this drop?
mrpeja

Title: Re: Z axis drops down
Post by: Hood on April 12, 2009, 07:00:08 PM

Sounds like you may need to fit a brake or some form of balance system..
Hood

Title: Re: Z axis drops down
Post by: mrpeja on April 13, 2009, 01:59:23 AM

Hi Hood,
I'd prefer a electromagnetic brake, because counterweight balance involves inertial load and spring balance requests more torque from the motor. But at this moment I'm not sure how to controll the brake.
When the machine is off, the brake must hold the axis, then when I turn it on, first the brake must be on, (releasing the axis) and then I do Homing. But at this moment axis will drop down!
I'm not sure what to do!
Maybe is better lowering the x axis slowly until it touches the material and then doing OFF the mach3 and the machine.
In this case (I suppose) I'll need to program this sequence. How to do this?
Please urgent help
mrpeja

Title: Re: Z axis drops down
Post by: Hood on April 13, 2009, 02:09:56 AM

The motor I have on the lathes spindle has a brake, it is electromagnetic with springs so that when unpowered it is On and powered it is Off. I control this via the servo drive itself as it is an industrial drive which allows all sorts of internal controls. You could however control the brake via a relay from an enable signal, when the drive is enabled the brake would be released.
Hood

Title: Re: Z axis drops down
Post by: mrpeja on April 13, 2009, 02:45:39 AM

Thanks Hood!
All ingenious thins are so simple!
mrpeja