DELTA e movimenti XY ad arco HELP !
Posted by Gigio2k
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DELTA e movimenti XY ad arco HELP ! December 22, 2014 03:55PM |
Ciao ragazzi,
sto terminado a tempo perso i vari settaggi della delta.
Ora tocca al movimento XY
Qui ed in altri link si trova sempre la stessa formuletta,
[www.repetier.com]
i miei settaggi ora sono :
Giocando con i settaggi anche mettendone di strani l'arco dal centro verso i bordi si forma sempre :/
In un forum dicevano di aumentare la diagonale ma cosi' la dimensione del pezzo non rispecchia quelle reali.
poi col firmware 0.9.2 del repetier han introdotto sto coso ma non so da dove iniziare a configurarlo e che valori mettere.
Qualcuno con una delta che ci e' gia' passato e voglia aiutare un disperato ?
Grazie
Gigio2k - [Pescara] - RepTrash
-=Delta G2K=-
| My Thingverse stuff | Vi aspettiamo su Stampanti 3D Italia su Facebook |
sto terminado a tempo perso i vari settaggi della delta.
Ora tocca al movimento XY
Qui ed in altri link si trova sempre la stessa formuletta,
[www.repetier.com]
i miei settaggi ora sono :
Giocando con i settaggi anche mettendone di strani l'arco dal centro verso i bordi si forma sempre :/
In un forum dicevano di aumentare la diagonale ma cosi' la dimensione del pezzo non rispecchia quelle reali.
poi col firmware 0.9.2 del repetier han introdotto sto coso ma non so da dove iniziare a configurarlo e che valori mettere.
Qualcuno con una delta che ci e' gia' passato e voglia aiutare un disperato ?
Grazie
Gigio2k - [Pescara] - RepTrash
-=Delta G2K=-| My Thingverse stuff | Vi aspettiamo su Stampanti 3D Italia su Facebook |
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Re: DELTA e movimenti XY ad arco HELP ! December 22, 2014 04:20PM |
Step #3 -- Flat Print Surface
Even after all this, we still aren't done. There is another variable to calibrate on the Kossel, the flatness of the plate.
We have already calibrated the Kossel's print volume height. This means if we send the command G X0 Y0 Z0 then the hotend-should come to rest at the center of the print bed, about .1mm above the surface. But, delta printers have an additional variable of flatness. Consider the two following images:
In this image the blue line is the print surface according to the Marlin firmware.
Do you see how this could create a problem? The center Z offset may be correct, but as the hot-end moves towards the edges, it gradually rises until the hot-end is resting 2-10mm away from the print surface.
Let's look at the other, possibly more damaging, scenario.
If the print bed, according to firmware, is convex, then the hot-end might be correct when at center, but as you get to the edges, the machine tries burying your hot-end into the glass plate.
This is why Johann's auto-probe was such a nifty addition to the Kossel build. But let's not get ahead of ourselves, physical calibration first.
Well, that's sort of a lie. To correct for flatness we are going to adjust the firmware. The flatness of a Kossel is reliant on the variable DELTA_RADIUS and it is the sum of several variables. So, to adjust DELTA_RADIUS we focus in on either increasing or decreasing one of the variables. I picked DELTA_SMOOTH_ROD_OFFSET at random.
Ok, the adjustment is pretty straight forward, but requres tinkering to get it right. But before we make an adjustment we need to know what direction to go. We can determine this by visually comparing difference between the distance between the hotend and the print surface when the hotend is at the center, and the distance between the hotend and the print surface when near one of the towers. Let's go back to pictures.
This image is to give you an idea what points we want to compare for flatness. For instance, if Kossel passes the paper-test at point A, then it should at points B, C, and D.
But if the Kossel passes the paper-test at point A, and is too high at B, C, and D then you have a concave print surface.
Likewise, if the Kossel passes the paper-test at point A, and is too low at B, C, and D then you have a convex print surface.
B Height > A Height = Concave
B Height < A Height = Convex
One more bit, you maybe asking how to find the spots B, C, and D. Well, I used the following calculations
Xb = (Build Radius) * COS * (Angle of B tower)
Yb = (Build Radius) * SIN * (Angle of B Tower)
Also, know your towers should be at angles: 90, 210, 330
If you have the same build radius as me, 170, then your points should be.
Y70, X0
Y-35, X-60
Y-35, X60.62
But remember, we are really looking that all four points pass the paper-test.
Let's move on to how to make the adjustment. I will not go into the math explaining how adjusting DELTA_RADIUS affects flatness, mainly because I don't understand it. But secondly, because we don't need to understand it to adjust it. Just know the following,
Increasing DELTA_SMOOTH_ROD_OFFSET lowers the hotend.
Decreasing DELTA_SMOOTH_ROD_OFFSET raises the hotend.
Really, it is changing the firmware's idea of flatness.
Now, make the adjust from the visual information you collected by comparing point A to point B, C, and D. Then, comparing them again, adjust again. Compare, adjust. Ad infinitium.
COMPRA ITALIANO - sostieni le nostre aziende - sostieni la nostra gente - sostieni il tuo popolo - sosterrai te stesso.
Alberto C. felice possessore di una Kossel K2
My Blog - My Thingiverse
Even after all this, we still aren't done. There is another variable to calibrate on the Kossel, the flatness of the plate.
We have already calibrated the Kossel's print volume height. This means if we send the command G X0 Y0 Z0 then the hotend-should come to rest at the center of the print bed, about .1mm above the surface. But, delta printers have an additional variable of flatness. Consider the two following images:
In this image the blue line is the print surface according to the Marlin firmware.
Do you see how this could create a problem? The center Z offset may be correct, but as the hot-end moves towards the edges, it gradually rises until the hot-end is resting 2-10mm away from the print surface.
Let's look at the other, possibly more damaging, scenario.
If the print bed, according to firmware, is convex, then the hot-end might be correct when at center, but as you get to the edges, the machine tries burying your hot-end into the glass plate.
This is why Johann's auto-probe was such a nifty addition to the Kossel build. But let's not get ahead of ourselves, physical calibration first.
Well, that's sort of a lie. To correct for flatness we are going to adjust the firmware. The flatness of a Kossel is reliant on the variable DELTA_RADIUS and it is the sum of several variables. So, to adjust DELTA_RADIUS we focus in on either increasing or decreasing one of the variables. I picked DELTA_SMOOTH_ROD_OFFSET at random.
Ok, the adjustment is pretty straight forward, but requres tinkering to get it right. But before we make an adjustment we need to know what direction to go. We can determine this by visually comparing difference between the distance between the hotend and the print surface when the hotend is at the center, and the distance between the hotend and the print surface when near one of the towers. Let's go back to pictures.
This image is to give you an idea what points we want to compare for flatness. For instance, if Kossel passes the paper-test at point A, then it should at points B, C, and D.
But if the Kossel passes the paper-test at point A, and is too high at B, C, and D then you have a concave print surface.
Likewise, if the Kossel passes the paper-test at point A, and is too low at B, C, and D then you have a convex print surface.
B Height > A Height = Concave
B Height < A Height = Convex
One more bit, you maybe asking how to find the spots B, C, and D. Well, I used the following calculations
Xb = (Build Radius) * COS * (Angle of B tower)
Yb = (Build Radius) * SIN * (Angle of B Tower)
Also, know your towers should be at angles: 90, 210, 330
If you have the same build radius as me, 170, then your points should be.
Y70, X0
Y-35, X-60
Y-35, X60.62
But remember, we are really looking that all four points pass the paper-test.
Let's move on to how to make the adjustment. I will not go into the math explaining how adjusting DELTA_RADIUS affects flatness, mainly because I don't understand it. But secondly, because we don't need to understand it to adjust it. Just know the following,
Increasing DELTA_SMOOTH_ROD_OFFSET lowers the hotend.
Decreasing DELTA_SMOOTH_ROD_OFFSET raises the hotend.
Really, it is changing the firmware's idea of flatness.
Now, make the adjust from the visual information you collected by comparing point A to point B, C, and D. Then, comparing them again, adjust again. Compare, adjust. Ad infinitium.
COMPRA ITALIANO - sostieni le nostre aziende - sostieni la nostra gente - sostieni il tuo popolo - sosterrai te stesso.
Alberto C. felice possessore di una Kossel K2
My Blog - My Thingiverse
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Re: DELTA e movimenti XY ad arco HELP ! December 22, 2014 04:34PM |
ok in repetier dovrebbe essere la voce "PRINTER_RADIUS" faccio un po' di prove e vi aggiorno.
Gigio2k - [Pescara] - RepTrash
-=Delta G2K=-| My Thingverse stuff | Vi aspettiamo su Stampanti 3D Italia su Facebook |
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Re: DELTA e movimenti XY ad arco HELP ! December 22, 2014 07:11PM |
ho trovato questo video mooooolto piu' comodo dell'usare a mano pronterface (y) [www.youtube.com]
In pratica ho scoperto che l'eprom conteneva dei valori errati, quindi anche se facevo un refresh del firmware i valori in eprom sovrascrivevano le mie giuste modifiche (y)
Grazie a tutti per stasera mi son avvicinato tantissimo ai giusti movimenti XY e Z !
Gigio2k - [Pescara] - RepTrash -=Delta G2K=-
| My Thingverse stuff | Vi aspettiamo su Stampanti 3D Italia su Facebook |
In pratica ho scoperto che l'eprom conteneva dei valori errati, quindi anche se facevo un refresh del firmware i valori in eprom sovrascrivevano le mie giuste modifiche (y)
Grazie a tutti per stasera mi son avvicinato tantissimo ai giusti movimenti XY e Z !
Gigio2k - [Pescara] - RepTrash
-=Delta G2K=-| My Thingverse stuff | Vi aspettiamo su Stampanti 3D Italia su Facebook |
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