Geeetech Rostock 301, current limit setting for all motors

[wushu2266]

So far, 0.6V is working fine for me.

[tuskman]

Hi all, A4988 Vref = 0.6v does not work for me. The motors continue to lose footsteps with impressions of short distances and direction changes.

[Lami René]

Hello wushu2266,
Bonjour wushu2266,

You can find the original text into English following this original French text.

Vous trouverez le texte original traduit en anglais à la suite du présent texte originale en français.

Est-ce que vous réussissez de belles impressions avec votre imprimante delta Geeetech Rostock 301 (301) ?

Cordialement,

L'ami René
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hello wushu2266,

Excuse me, I am unilingual francophone and I use Google translator to translate the texts of the forum in French and to write to you in English. Thank you for your understanding and your indulgence for these texts translated mechanically!

Do you make beautiful prints with your Geeetech Rostock 301 (301) delta printer?

Cordially,

Friend René

[Revs]

Hi guys, I'm new to 3D printing and to the forum, so bare with me if I'm talking rubbish...

I picked up a Rostock 301 tri-colour this week and I'm having issues with the motors slipping/skipping when moving fast. Definitely not the belts. I haven't checked the stepper voltage, so that's the next job. Though I'd like someone to confirm something for me before I do....

Are these setup for micro-stepping? It a GTM32 Pro with adjustable A4988 steppers (see below). If so I believe the voltage should be 0.6v max (1.5a motors / 2.5). If not I read they only get 70% of the currect, so I could up the voltage to 0.86v (0.6v / 0.7).

I just need to know what the max setting is. I don't want to over-load anything before I've even attempted a print. Thanks for reading.

Paul

http://litbimg.rightinthebox.com/desc_i ... 006442.jpg

[Revs]

OK I've upped the stepper voltage from 0.55v to 0.65v and it now moves about without slipping to over 200% speed. Before it was slipping at anything over 85%. Motors don't seem to be warming up much if at all.

[Lami René]

Hello Revs,
Bonjour Revs,

You will find the original text translated into English following this original French text.

Vous trouverez le texte original traduit en anglais à la suite du présent texte original en français.

À ce jour, j'ai relevé des configurations de 0.55 Volt à 0.9 Volt. Personnellement j'ai configuré les 6 pilotes des moteurs à 0.6 Volt et je ne note pas le moindre saut de pas lorsque j'ai fait mes quelques impressions ratées (4 ou 5), j'attends des pièces. Avec le critère de la température de fonctionnement des pilotes et de leur moteur, voilà les seuls critères à retenir pour augmenter le voltage.

Mais il est recommandé pour des raisons de sauvegarde des composantes mécanique et électronique de l'imprimante, de maintenir le plus bas voltage possible pour les cas ou les limites de mouvement des moteurs dépassaient les limites de l'imprimante.

Par exemple une fausse manœuvre qui enverrait la tête d'impression plus bas que le plateau chauffant d'impression. Le fait que le voltage n'est pas au maximum préservera en cascade; les courroies, puis les pignons, puis les moteurs pas-à-pas, puis les pilotes des moteurs, puis la carte contrôleur et finalement l'unité d'alimentation principale.

De la même manière, en cascade, l'état du plateau chauffant d'impression sera sauvegardé, ainsi que la pointe de la buse, ainsi que les rotules et le roulement à billes des chariots, etc.

Donc, ont règle au plus bas pour qu'en fonctionnement normal, il n'y est jamais de saut de pas des moteurs des courroies et des moteurs des extrudeurs, mais qu'en cas de dysfonctionnement, que rien ne soit détérioré.

La puissance des moteurs des courroies et des moteurs des extrudeurs peut être réglée à des valeurs différentes. Par exemple les moteurs des courroies à 0.6 Volt et les moteurs des extrudeurs à 0.7 Volt.

Pour d'autres points de calibrations ou des problèmes de fonctionnement, voir le sujet suivant :

http://www.geeetech.com/forum/viewtopic ... 27&t=18578

Cordialement,

L'ami René
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hello Revs,

Excuse me, I am unilingual francophone and I use Google translator to translate the texts of the forum in French and to write to you in English. Thank you for your understanding and your indulgence for these texts translated mechanically!

To date, I have seen configurations from 0.55 Volt to 0.9 Volt. Personally I configured the 6 drivers of the motors to 0.6 Volt and I do not notice the slightest step step when I made my few missed impressions (4 or 5), I expect parts. With the criterion of the operating temperature of the pilots and their engine, these are the only criteria to retain to increase the voltage.

But it is recommended for reasons of backup of the mechanical and electronic components of the printer, to keep the lowest possible voltage for the cases where the limits of movement of the motors exceeded the limits of the printer.

For example, a false maneuver that would send the print head lower than the hot platen. The fact that the voltage is not at maximum will preserve in cascade; The belts, then the sprockets, then the stepper motors, then the drivers of the motors, then the controller board and finally the main power unit.

In the same way, in cascade, the state of the print heating plate will be saved, as well as the tip of the nozzle, as well as the ball joints and the ball bearing of the carriages, etc.

Therefore, they have been set at the lowest level so that in normal operation, there is never any jumping of the motors of the belts and motors of the extruders, but that in case of malfunction, nothing is deteriorated.

The power of the motors of the belts and motors of the extruders can be adjusted to different values. For example, belt motors at 0.6 Volt and motors at 0.7 Volt extruders.

For other calibration points or operating problems, see the following topic:

http://www.geeetech.com/forum/viewtopic ... 27&t=18578

Cordially,

Friend René

[MikaëlV]

Been studying and browsing for many hours now:

https://www.pololu.com/product/1182
The formula for Imax @ Pololu per today states: Imax = Vref/(8*Rcs)
Rcs in the Geeetech knock off boards is 0.068Ohms. So Imax = Vref / (8*0.068) = 1.838 * VRef
This means a Vref of 0.7 gives Imax = 0.7*1.838 = 1.287A

And then we still have the fact that Geeetech has nog published and datasheet on the actual Extruder motor. All I found was a statement that it is to be considered equal to another type of motor, that has the same spec. Whatever that means... https://www.geeetech.com/hybrid-stepper ... p-947.html
A fact: whatever value I drive the extruder motors with (even Vref at max, 1.1V, so Imax=2A) these extruders motors don't get warm and are still functional after many hours of printing

Those many hours of printing are preferrably without retract, cause that I don't seem to get fixed - even after shortening the bowdentubes like 10cm and hanging the extruder motors "at the ceiling" - it makes the filament loading more difficult, but the retract slightly better.
Those many hours are preferrably printing with mix 33-34-33% - like this all motors and all filaments are in use, spreading pressure and retract evenly. The trick for me to mix red and yellow to get orange while still mixing 3 colors is to add as third color a transparent PLA - aha...


https://reprap.org/forum/read.php?178,722021
https://www.youtube.com/watch?v=89BHS9hfSUk
http://blog.inventables.com/p/stepper-motors.html