Home/Limit advice, please

Hi!

I've gotten to the point in setup where I have XYZA motors moving expected amounts in expected directions, and now on to the next challenge...homing (or not...).

This is a simple hobby setup - a Taig mill, with steppers, G540, 7i92, and NO limit/home switches. While I've certainly had to give pncconf some nominal 'home' positions, I'm still left with the matter of actually getting and keeping the various axes PHYSICALLY in the home position - but wondering whether it even matters and whether just orienting to the workpiece is sufficient and I should just move on to a little G-code practice...

What say you?

Thx!

- Bob

That sounds like a vote for limit switches for safety, but not home switches. Correct?

why dident yoiu read bevor buying NO
With NC you only woudt lose one PIN on all 10Switches if you want
XYZ you can have HARD limits on the Taig and a REF so its 9Switches BX inductive
and a Index at the Rotary

all wired as a Chain (CHERRY Switch) or as inductive the Black together
This gives you also the advantage if one switch fails the whole machine will not start ((inductive fail will bring a red light to one switch))

bbsr_5a,

I'm having a little trouble parsing your post, but I think I see two key points:

1) Scolding me for not having read (presumably the manual), before buying. Well, I did. And it was about what I expected to find. Long on description of individual features, and very light on guidance for new users who just want to get their installation working. I knew what I was getting into, based on experiences in other settings. The software would work, but setup would be painful.

My guess is that linuxcnc users who are already familiar with motor control and machine tools are fairly ok with the doc, as they bring a lot of understanding in with them. And as shareware/freeware goes, the breadth of doc coverage is impressive.

But for the new user who's just arriving on the scene and doesn't come in prepared with that background? Sorry about the dumb questions, but it's a rough go...

2) I think you're advising me to use switches that are wired serially so that the whole machine halts if one trips. This is an interesting tip, and will send me back into the doc. Absolutely - if one axis bangs into something, you certainly would want the whole machine to halt while you sort out what went wrong. Thank you!

- Bob

Are these switches you have NO ie (normally open contacts) and are they the sensor type.

For a small mill just 3 would be ok one at the top of Z (Z should be -ve going down) and one each for X and Y they can be setup as a home switch including soft limits.

Now you have your mill working it is better to edit the HAL and INI files by hand. Or make a new config with the switches in, then copy and paste the relevant bit sto each of the two files.

Clive,

Well, I don't have switches at the moment - I'd have to source those.

But...I would think that Normally Open would be what you'd want for individual switches, but if wired serially, as bbsr_5a was suggesting, then surely I'd want Normally Closed?

- Bob

Normally closed is usually suggested since a broken wire
will result in a fault and stop