Proper Homing w/ Ra2 Rotary

LightBurn Software Questions
1

Can someone elaborate on the proper way to home a rotary? The ra2 does not have limit switches so I get the following error.

ALARM:9
Homing fail. Could not find limit switch within search distance. Defined as 1.5 * max_travel on search and 5 * pulloff on locate phases.

And then I cannot do more since when trying to frame I then get this error.

error:8
Grbl ‘$’ command cannot be used unless Grbl is IDLE. Ensures smooth operation during a job.

So what is the proper procedure to startup the laser with ra2 rotary in use?

2

There is none. A rotary can rotate forever in either direction because it has no limit switches. You must disable Homing by setting $20=0 in the Console window.

Here is some info you might find useful…

Do a site search for ra2, chuck, and rotary. You will find a boatload if information here.

3

Mike,

Thank you for the reply.

I was reading the below thread where Jack mentions it harder to use the machine that doesn’t home properly.

Post 8/21

"Absolutely… It’s clear you don’t have your machine setup properly and/or you don’t understand the coordinate system and it’s associated controls…

Most people have a tough time with a machine that doesn’t home… it’s so much more work along with inconsistent results."

I have homing disabled but I was told in that thread that’s not a good idea and my machine isn’t setup properly.

4

That thread wasn’t for a rotary… Just a regular table laser.

The more comfortable you are with the coordinate system the better… A rotary in it’s simple form is a table that is round. It works the same way, just rotating instead of moving the Y axes, or whichever axes you use with the rotary.

On my Ruida, I make use of user origin for a start from and center left for a job origin… Never used a rotary on one of the grbl machines… so this is just the way I set my jobs up.

Rotaries have no way to set a home position, so when you go to them you have to think how the machine works and use what you know…

Before changing anything Edit → Machine Settings. This will bring up a menu of the current settings. Then save it somewhere you won’t lose them. This is a back up copy of the machines settings.

Save this again, as your hack-able copy, under a different name/location.

Modify it as needed for your rotary. When you are done, you can re-write the regular version…

You can load whichever you need to use… And you still have a pristine copy of the factory settings…

Make sense?

If you have questions, sing out…

:smile_cat:

1 Like
5

I’m slightly confused now…

The title of that post is

“[Xtool RA2 Pro rotary chuck]”

And the first line is the following

"I’m struggling with consistent use of the chuck rotary. "

6

I’d be totally confused… went to the post… I really mis-worded the reply, which I have fixed… thanks for pointing it out…

In his previous post he manually homed the laser by power it up where it needed to be for the rotary…

Home enables the machine to know where it’s workspace is. If it cannot home automatically, such as a machine that does not have home switches, it must use it’s current position as home or 0, 0.

Make sense?

:smile_cat:

1 Like
7

I have not finished my vented enclosure yet, but I suspect a GRBL machine would be the same. I too have a new Sculpfun and RA2 rotary.

Every laser machine and project is a journey. Don’t take everything you read as carved in granite. Use what you read as a guidline, not as absolute rules. And ask lots of questions here. Why we all read these postings is to get and give help…:nerd_face:

8

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