Bed Front, Bed Left setting change themselves

Hi,
I finally figured out (maybe) why the repetier printbox has always been presented to me backwards (like I am looking from the back of the machine).
I have a Mendel90 and as you know it has the 0,0 at the center, xmin = -100 and xmax = 100, ymin = -100, ymax = 100.
the endstops are at zMAX (at the top of the threaded rod), xmin (at the left) and ymin (in front).
so, the correct values should be 100 for bed front and -100 for bed left. If I enter these values they are ignored and automatically recovered to -100 -100 at the next startup.
what is wrong here?
is there an explanation? am I doing something wrong?

There is a function called "sanityCheck" that overwrites the value. I'm investigating and I'll soon post more.

Edited 1 time(s). Last edit at 08/21/2013 07:37AM by flurin.

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3D Printing :: bit-by-bit - Thingiverse

@Repetier

There is a possible bug in "sanityCheck":
Please see GitHub.

Edited 2 time(s). Last edit at 08/21/2013 09:03AM by flurin.

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3D Printing :: bit-by-bit - Thingiverse

-100,-100 is correct in your case. If I enter these values I see exactly what I expect. Origin in center and top view centered around the origin.

Bed left/front are coordinates and the left front edge has the coordinates -100,-100.

@flurin: sanity check is correct. It tests that front = -100 + depth(200) is < yMax. So if the bed fits within reachable coordinates it will be enforced.

But maybe you misunderstood the front definition. Front is the smallest coordinate in y direction in an right handed coordinate system.

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repetier Wrote:
-------------------------------------------------------
> @flurin: sanity check is correct. It tests that
> front = -100 + depth(200) is < yMax. So if the bed
> fits within reachable coordinates it will be
> enforced.
>
> But maybe you misunderstood the front definition.
> Front is the smallest coordinate in y direction in
> an right handed coordinate system.

I didn't reflect much about it, my Hadron has coordinates like the attached image, but sometime the y-direction is inverted.

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3D Printing :: bit-by-bit - Thingiverse

... it seems to me to be confusing. The value is overwritten and stored in the file "repetier.Repetier-Host-Mac.plist" but the user is not informed about this change and he will see the changed value only by starting Repetier-Host again.

Suggestion:

Instead of overwrite the value I would show a message to inform the user, so he can correct the value in "Printer settings".

Edited 1 time(s). Last edit at 08/21/2013 01:21PM by flurin.

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3D Printing :: bit-by-bit - Thingiverse

The next version reloads settings after applying them, so you see all changes from sanity checks.

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Quote
repetier
The next version reloads settings after applying
them, so you see all changes from sanity checks.

Okay, I put some imprudent settings just to see what happens, something is curios with sanitycheck, see attachment

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3D Printing :: bit-by-bit - Thingiverse

These values are valid.

xmin = -95 -> 0 = Bed left -> +190 bed width -> 195 xmax

That fits.

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... I've set xmin = -95 and xmax=95, this is also valid isn't it?
However sanityCheck changes the value from 95 to 190!

Edit:

I think there are - at least on my Mac (Repetier-Host Mac 0.56) - cases, the input data are not stored. This may be the issue.

Edited 5 time(s). Last edit at 08/22/2013 11:29AM by flurin.

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3D Printing :: bit-by-bit - Thingiverse

There is a mistake in my first post:

the coordinates of my front left vertex are x=100 y=100.

if, after homing, I send G1 X-100 Y-100 the extruder ends up on the vertex on the back right of the bed (see attached pictures)
to end up in the front left corner I need to send G1 X100 Y100.

why is it a problem to have a 100 100 value? what is that the sanity check does not like about this?

Edited 1 time(s). Last edit at 08/25/2013 04:18AM by andrea.rimo.

repetier Wrote:
-------------------------------------------------------
> @flurin: sanity check is correct. It tests that
> front = -100 + depth(200) is < yMax. So if the bed
> fits within reachable coordinates it will be
> enforced.

Shouldn't il check for "<=" instead of strictly "<"?

Edited 1 time(s). Last edit at 08/25/2013 04:21AM by andrea.rimo.

Ok I see your problem is a very unusual firmware configuration. For some reason you liked your print bed rotated 180° to the bed of all others.
Your fron is indeed at -100,-100 but due to your rotation this is the back right of your printer. Front/left means with respect to the x-y-coordinate system and that is rotated in your case.

You could rotate it in your firmware so left/front is really your left front. Simply invert x and y direction in firmware and perhaps adjust endstop configuration. Then your printer das the same coordinate system like all the other printer and you get less confusion.

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repetier Wrote:
-------------------------------------------------------
> Ok I see your problem is a very unusual firmware
> configuration. For some reason you liked your
> print bed rotated 180° to the bed of all others.
>
> Your fron is indeed at -100,-100 but due to your
> rotation this is the back right of your printer.
> Front/left means with respect to the
> x-y-coordinate system and that is rotated in your
> case.
>
> You could rotate it in your firmware so left/front
> is really your left front. Simply invert x and y
> direction in firmware and perhaps adjust endstop
> configuration. Then your printer das the same
> coordinate system like all the other printer and
> you get less confusion.


But my printer is a Mendel90 with its standard firmware configuration. you mean that all Mendel90 users have the same problem?

Sure it is the same? If you flip your motor connectors 180 degree your coordinate system is ok. It is easy to change motor direction so firmware settings must match to your wiring. If you open any 3d software the x axis goes from left to right and on right handed systems the y axis from front to back. Z axis up. It is only natural to copy the same view to your printer and in this logic your coordinate system is wrong. It is no problem to work with it but you always have to think that all programs show it 180° rotated - so to make life easier I would just turn the orientation on the printer.

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andrea.rimo Wrote:
-------------------------------------------------------
> repetier Wrote:
> --------------------------------------------------
> -----
> > @flurin: sanity check is correct. It tests
> that
> > front = -100 + depth(200) is < yMax. So if the
> bed
> > fits within reachable coordinates it will be
> > enforced.
>
> Shouldn't il check for "<=" instead of strictly "<"?

Actually it is "bedFront > yMax-depth" (it corresponds to "bedFront + depth<=yMax ")




Note:having an issue inserting the code I had to upload a screenshot

The Printer settings still doesn't correctly work on my Mac.

Edited 6 time(s). Last edit at 08/26/2013 04:26AM by flurin.

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3D Printing :: bit-by-bit - Thingiverse