Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: kolias on November 29, 2010, 11:53:57 PM

Title: Slave Axis
Post by: kolias on November 29, 2010, 11:53:57 PM
I plan to use two motors to drive the Y axis.

My current Y axis uses pins 4 and 5 for the Step and Dir in Mach3.

Since the second drive will be a slave drive I will assume it will be the A axis.

Do I use the same 4 and 5 pins for the A axis or I have to use different pins?
Title: Re: Slave Axis
Post by: Hood on November 30, 2010, 02:09:22 AM
You use different pins.
Hood
Title: Re: Slave Axis
Post by: kolias on December 21, 2010, 05:51:24 PM
One motor along with the 48” long acme has been installed on the Y axis and the backlash nut has been secured to the gantry and now I’m starting to install the second drive for the same axis on the other side.

I will assume that since Mach3 will drive both Y axes motors at the same time, the backlash nuts must be exactly in the same distance from lets say the front of the machine so the gantry will be square to the table surface. I plan to pick the flange edge on the backlash nut and measure the distance from one end of the machine and assure that this distance will be the same on the other side.

I never installed a two drives on the Y axis and wonder if there is anything that I should be aware
Title: Re: Slave Axis
Post by: ger21 on December 21, 2010, 09:00:21 PM
You really should install a home switch on each side. That way Mach3 will automatically square the gantry. You just need to make the switch mounting adjustable, as the switch position will dictate the squareness of the gantry
Title: Re: Slave Axis
Post by: kolias on December 21, 2010, 09:05:57 PM
I don’t understand Gerry, do you mean a limit switch?

Can you please explain?
Title: Re: Slave Axis
Post by: ger21 on December 21, 2010, 10:29:58 PM
When you "reference" the machine, Mach3 travels to the home switch, and sets the axis to machine coordinate zero when it hits the switch.

With slaved motors, each motor can move to it's own switch independently. So if the gantry is out of square, each side will move until it hits it's switch, squaring the gantry back up.

A home switch can be used as a limit switch, and vise versa.
Title: Re: Slave Axis
Post by: kolias on December 22, 2010, 12:26:55 AM
Thanks Gerry I think I understand; I will install a limit switch on each side but I will have to read the manual to see how this works.

I noticed in the manual 4.5.4 and 5.6.1 has a good description about the home / limit switches and I will have to study this carefully to understand
Title: Re: Slave Axis
Post by: kolias on December 23, 2010, 10:10:18 AM
Is there another way to square the gantry to the table top?
Title: Re: Slave Axis
Post by: ger21 on December 23, 2010, 11:51:01 AM
If the machine is square, move it all the way to one end against the stops.
Title: Re: Slave Axis
Post by: kolias on December 23, 2010, 12:56:54 PM
The machine is under construction Gerry and at this stage I was wondering if there is another way to assure that the gantry is square to the table top.

After my build is done, the motors are connected and the home switches are installed then I guess I can fine tune the alignment.

If I’m doing something wrong, pls let me know
Title: Re: Slave Axis
Post by: ger21 on December 23, 2010, 01:17:33 PM
Just make sure it's as square as possible when you mount the nuts, as they'll bind if out of alignment.
Title: Re: Slave Axis
Post by: kolias on December 23, 2010, 01:51:56 PM
Thanks Gerry, and Happy Holidays
Title: Re: Slave Axis
Post by: kolias on February 05, 2011, 06:19:30 PM
When you "reference" the machine, Mach3 travels to the home switch, and sets the axis to machine coordinate zero when it hits the switch.

With slaved motors, each motor can move to it's own switch independently. So if the gantry is out of square, each side will move until it hits it's switch, squaring the gantry back up.

A home switch can be used as a limit switch, and vise versa.


Tomorrow I will install two limit switches on the Y / A axes which will be used as Home switch. On the Y axis I will also install another limit switch which will define the travel at the opposite end of Home.

One thing I dont understand; lets assume that the gantry is out of square by 1/4". When the gantry hits the first limit switch lets say on Y axis would Mach3 stop the motor on the Y axis and keep running the motor on the A axis until the gantry is square?

And how Mach3 knows that the gantry is square?
Title: Re: Slave Axis
Post by: kolias on February 05, 2011, 06:23:09 PM
When you "reference" the machine, Mach3 travels to the home switch, and sets the axis to machine coordinate zero when it hits the switch.

With slaved motors, each motor can move to it's own switch independently. So if the gantry is out of square, each side will move until it hits it's switch, squaring the gantry back up.

A home switch can be used as a limit switch, and vise versa.


Sorry, dont know what I did wrong with my previous post

Tomorrow I will install two limit switches on the Y / A axes which will be used as Home switch. On the Y axis I will also install another limit switch which will define the travel at the opposite end of Home.

One thing I dont understand; lets assume that the gantry is out of square by 1/4". When the gantry hits the first limit switch lets say on Y axis would Mach3 stop the motor on the Y axis and keep running the motor on the A axis until the gantry is square?

And how Mach3 knows that the gantry is square?
Title: Re: Slave Axis
Post by: ger21 on February 05, 2011, 06:38:03 PM
Quote
One thing I dont understand; lets assume that the gantry is out of square by 1/4". When the gantry hits the first limit switch lets say on Y axis would Mach3 stop the motor on the Y axis and keep running the motor on the A axis until the gantry is square?

And how Mach3 knows that the gantry is square?

Each needs it's own switch. The Y and A will move together, the Y stops when it hits the Y switch, the A stops when it hits the A switch.

It's up to you to position the switches so it ends up square. :)
Title: Re: Slave Axis
Post by: kolias on February 05, 2011, 07:18:26 PM
Thanks Gerry, I got it

Yes I have separate home switch for the Y and A