Y-Axis can't find zero right

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Toby
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Re: Y-Axis can't find zero right

Post by Toby » Sat Apr 19, 2014 7:50 pm

MichaelH wrote:
Toby wrote:

what is the endstop reading when the bed stops early?
RECEIVED: X:0.00Y:0.00Z:0.00E:0.00 Count X:0.00Y:0.00Z:0.00
I meant the reading for the endstop states- M119. Probably it will show the endstop triggered but I'd like to see it if you're interested in pursuing this angle of investigation.

Those negative values make me want to know more about the firmware. I would have thought it would disallow any motion past the limits.

ketil
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Joined: Wed Apr 09, 2014 9:58 pm

Re: Y-Axis can't find zero right

Post by ketil » Sat Apr 19, 2014 8:03 pm

After homing once, my experience is that the firmware ignores the endstop if you tell it to move to a negative coordinate, like -20, so it certainly doesn't stop moves off the platform. I've no idea why this is so, and when I get around to compiling my own firmware that's on my list of things to change.

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MichaelH
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Location: Fredericton - New Brunswick - Canada

Re: Y-Axis can't find zero right

Post by MichaelH » Sun Apr 20, 2014 1:53 pm

@Toby
M119 At home: RECEIVED: x_min:L x_max:L y_min:H y_max:L z_min:L z_max:L
M119 At +250: RECEIVED: x_min:L x_max:L y_min:L y_max:L z_min:L z_max:L
M119 after stop: RECEIVED: x_min:L x_max:L y_min:L y_max:L z_min:L z_max:L
Stop position was +107mm I jogged back -107mm to hit the switch.

@Dale please see attachment.

Thanks for helping!
Firmware_files.zip
Firmware files for review
(13.66 KiB) Downloaded 166 times

Toby
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Re: Y-Axis can't find zero right

Post by Toby » Sun Apr 20, 2014 4:10 pm

MichaelH wrote:@Toby
M119 At home: RECEIVED: x_min:L x_max:L y_min:H y_max:L z_min:L z_max:L
M119 At +250: RECEIVED: x_min:L x_max:L y_min:L y_max:L z_min:L z_max:L
M119 after stop: RECEIVED: x_min:L x_max:L y_min:L y_max:L z_min:L z_max:L
Stop position was +107mm I jogged back -107mm to hit the switch.
That is bizarre. Just to recap: The end stop shows High when Y is at 0, and Low when Y is at 250. When homing from there in Y, the bed stops early. At that point the firmware shows a Y-value of 0, and yet it still shows the end stop at Low.

This has got me so puzzled I'm inclined to go hack the firmware and print out some diagnostics. I have the C experience but it may take me a little while to get setup in order to compile, etc. I'll report back if/when I make any progress.

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MichaelH
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Location: Fredericton - New Brunswick - Canada

Re: Y-Axis can't find zero right

Post by MichaelH » Sun Apr 20, 2014 4:16 pm

Yes that is exactly what's going on. :?: :?: :?:

Thank you Toby I really appreciate taking the time to help.

Michael

jsc
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Re: Y-Axis can't find zero right

Post by jsc » Sun Apr 20, 2014 5:32 pm

What happens when you simulate homing through gcode? Try this:

Home Y.
G1 Y250
G1 Y0

Also, try your homing test from Y200, to make sure you're not hitting the hard limits.

Toby
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Re: Y-Axis can't find zero right

Post by Toby » Sun Apr 20, 2014 5:40 pm

jsc wrote:What happens when you simulate homing through gcode? Try this:

Home Y.
G1 Y250
G1 Y0

Also, try your homing test from Y200, to make sure you're not hitting the hard limits.
At one point we tried jogging back to home in 10 mm increments (or something) and the report was that it went freely and never stopped. This would be a good test as well.

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MichaelH
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Location: Fredericton - New Brunswick - Canada

Re: Y-Axis can't find zero right

Post by MichaelH » Sun Apr 20, 2014 10:04 pm

@jsc

I tried that when I made the video. The result is that it stop's and thinks it is on zero and goes to 250 again and that shoots over. I stop then with Emergency Stop to save the stepper.
If I put you code in it goes back to zero. I tried roughly 30 times.

Michael

jsc
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Re: Y-Axis can't find zero right

Post by jsc » Sun Apr 20, 2014 10:47 pm

What I am interested in is if it ever stops short when you are not using the Home Y button, just when it is commanded to do a long y axis travel move.

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MichaelH
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Location: Fredericton - New Brunswick - Canada

Re: Y-Axis can't find zero right

Post by MichaelH » Sun Apr 20, 2014 11:40 pm

jsc wrote:What I am interested in is if it ever stops short when you are not using the Home Y button, just when it is commanded to do a long y axis travel move.
Hi jsc I tried the attached GCode.
The interesting thing is that I was able to run the code once with no problem but the second attempt wasn't successful at all nor was the third it stops with in the first 10 rows.

I need to get Rick involved to me it looks like the board has trouble.
As I said a few days ago my heated bed shuts off mid print sometimes like today again, I then have to unplug the printer for 15 min and start again.

Michael

Y-Axis move test.rar
Y-Axis move test
(161 Bytes) Downloaded 150 times
Last edited by MichaelH on Mon Apr 21, 2014 1:07 am, edited 1 time in total.

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