Setting up x axis / zero datum

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gasmeter
Posts: 11
Joined: Mon May 04, 2015 9:00 am

Setting up x axis / zero datum

Post by gasmeter »

Hi

I am at the point where i can do a home on all axis.
However after a home the x position is a crazy - value

thus when i try to do a text X because its thinking its starting at a minus value it goes slamming into the far right gantry.

Is there a G code or some way in the sw to set the zero point after a x,y home

Peter
mrandt
Posts: 407
Joined: Mon Apr 27, 2015 10:56 am
Location: Stuttgart, Germany

Re: Setting up x axis / zero datum

Post by mrandt »

Hi Peter,

sounds strange - my machine does not behave like that. The software resets the virtual coordinates to 0,0,0 right after homing mechanically (limit switch).

Optical homing then moves the machine to a slightly larger X and Y coordinate, depending on the position of the mark on table. Are you using optical homing yet?

Have you tried to home each axis individually? That can be done on "Basic Setup" tab.

Please note that there is an issue with "Home X" - if the machine is already at the far left, it will not detect hitting the switch. So you should always move the gantry a bit to the right before you home the X-axis. I think this is a bug as Y-axis does not have that problem - but it is easy to work around.

Of course, you have to set a correct machine size (Max X, Y). My machine has a larger work area, so I had to increase the default values to use full width / length.

Last not least, you should double check your limit switches. Make sure that NC and NO are not accidentally flipped and that each switch is wired to the correct input on TinyG.

If all this does not help, please copy & paste the ouptut of the status window (click it, hit Ctrl + A to select all, Ctrl + C to copy to clipboard) here to help diagnose the problem.

Good luck!
gasmeter
Posts: 11
Joined: Mon May 04, 2015 9:00 am

Re: Setting up x axis / zero datum

Post by gasmeter »

Hi

Yes this is in basic setup

And yes i always do the home with the head off the limit switches.
Not quite got as far as optical homing yet .

Stuck now though as the machine is out of safe limits and it should be setting itself to 0,0 after the home operation.
I'm thinking if its a tiny G code side issue there must be a g code I can use after the homing operation.

I have tried a G2 code to go to some x,y and that works but with the caveat its stil starting massively negative.

So for instance telling to it go to x = 10 is almost 3/4 of the x travel but correct as it thinks its starting from a negative position.

Peter
mrandt
Posts: 407
Joined: Mon Apr 27, 2015 10:56 am
Location: Stuttgart, Germany

Re: Setting up x axis / zero datum

Post by mrandt »

OK. Can you do two things?

1. Run home X as usual
2. send $ command to TinyG to dump configuration

Copy & paste the output from the status window. That should give more details about what is going on.

And another (potentially stupid) question: You have enabled "homing switch used" and loaded settings onto TinyG?
gasmeter
Posts: 11
Joined: Mon May 04, 2015 9:00 am

Re: Setting up x axis / zero datum

Post by gasmeter »

Juha got back to me

He thinks its a tiny G issue as it homes ok but then doesn't zero

waiting to see what tiny G mfg's say.

Peter
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