Have to start from scratch after hitting limit switch?

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Paul Rixon

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Sep 15, 2022, 12:34:15 AMSep 15
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Hello all.  I'm new to all this, but a technical user, and have been fighting the past couple weeks trying to get my machine going with no luck.

I've been trying to set up a Lite Placer with a TinyG (makr.zone fw), and use Issues & Solutions to do the calibration.  Something seems to always get messed up partway through the process, and I've restarted a few times now.  Tonight I was making excellent progress, and was about to calibrate backlash on the second axis when I accidentally hit one of the limit switches.  At this point, am I hosed, and have to start over from scratch?

I've noticed that if I run the machine to a limit switch, it halts.  When I hit reset, the system is wonky after that, like it doesn't know it's position.  The Home button moves Z up, then slowly moves X to the left a small amount, then stops.  It looks like I haven't made it far enough through the process for Home to be working yet.

I'm lost, and would appreciate any help.

Paul Rixon

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Sep 15, 2022, 12:40:45 AMSep 15
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Here's the machine.xml and the last logfile. 

This time I tried hitting home over and over, and it made it's way eventually to the front-left corner.  Is it supposed to take multiple tries if it's a ways out from that corner?

I never homed it before setting the soft-limits on the machine - shouldn't this be required?  Unless I missed it, this was never an instruction.  I tried to check to show completed and ignored settings, but the soft limit steps aren't showing up anywhere in I&S.
OpenPnP.log
machine.xml

mark maker

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Sep 15, 2022, 2:35:24 AMSep 15
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It looks as if your max. homing search distance is way too short. I'm not a TinyG expert, so I can't tell you the exact config you need to change, but you'll probably find it online.

_Mark

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tonyl...@gmail.com

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Sep 15, 2022, 11:48:19 AMSep 15
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I could probably help you if you post your TinyG configuration (dump if by sending $$ from the console).

Tony

Paul Rixon

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Sep 15, 2022, 11:58:59 AMSep 15
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Hi Mark,

Thank you for your suggestion.  It looks like my setting is 600mm, which is wider than the work area.  It only travels about 150mm, and at a very slow rate.  I'll try upping it to 2400mm tonight and try again.

It's interesting that the Home button goes black after the incomplete homing attempt (apparently after one axis hits the max travel.)  If I understand correctly, we're just sending a single but long command to the TinyG:

G28.2 X0 Y0 Z0 ; Home all axes

If it doesn't home each of those axes, shouldn't it fail instead of responding OK?  Is that a bug in the Tiny G?

Do I need to reset the soft limits after it's homed?  How do I do that since they're not showing up in Issues & Solutions?

BTW, I've watched some of your videos and read your page on OpenPNP with the LitePlacer.  Thank you for all of those, it is inspiring.  I even tried your machine.xml as a starting point, but was having problems, so reverted to starting from scratch and going through the I&S process.

-Paul

On Thursday, September 15, 2022 at 1:35:24 AM UTC-5 ma...@makr.zone wrote:

Paul Rixon

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Sep 15, 2022, 12:00:50 PMSep 15
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Thanks, Tony.  I'll get that tonight.  I have it running on a Windows machine, so I'm struggling getting data to and from the machine and don't have remote access to it.  Might end up switching to a Linux host instead.

-Paul

Paul Rixon

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Sep 15, 2022, 9:47:06 PMSep 15
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Attached is my stored TinyG config.  Going to play around with things a bit more tonight, like making the max distances longer.
tinyg_stored_settings.txt

tonyl...@gmail.com

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Sep 15, 2022, 10:42:34 PMSep 15
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Paul,

Here are the major differences I see with your TinyG settings:

[ex]  enable flow control         0 [0=off,1=XON/XOFF, 2=RTS/CTS]              <----- I have 2=RTS/CTS

[xtm] x travel maximum          150.000 mm                                                     <---- I have 600.000 mm

[ytm] y travel maximum          150.000 mm                                                     <---- I have 400.000 mm

[aam] a axis mode                 3 [radius]                                                             <---- This should be set to 1 [standard]

[asn] a switch min                1 [0=off,1=homing,2=limit,3=limit+homing]   <----This should be set to 0=off

I also noticed in OpenPnP you have your Rotation Axis letter set to "C", I think it should be set to "A".

Tony

Paul Rixon

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Sep 16, 2022, 2:05:07 AMSep 16
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Tony,

Those xtm/ytm values fixed homing.  I've gone ahead and set each of those values.  (My Y was a little deeper, so I upped it to 500, which seemed to work alright.)

Regarding all the other quirks, I've been muscling through them.  I'm starting to get the Machine Config tab, and how it correlates to the various I&S tasks.  So when some of them disappeared and weren't anywhere to be found (e.g. soft limits), I was able to find where they were set, clear them out, home, then reset them.  IMHO there's a bug in the flow, but at least it can be worked around.

-Paul

mark maker

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Sep 16, 2022, 3:59:40 AMSep 16
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> IMHO there's a bug in the flow, but at least it can be worked around.

Please elaborate, I'd like to fix it.

_Mark

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