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Topic: question about changing stepper drivers

I have an older version of the SD2 with the wood Z platform and resistor heated bed.  I believe that my SD2 motherboard has the separate stepper drivers.  Could someone explain the benefit of switching out the drivers?  I'm planning on doing alot of mods to my printer in the coming weeks.  I'm going to change the Z rod to a 5mm.  I'm installing an aluminum platform to replace the wood.   Also I'm installing a heat pad to replace the resistor on the bed.  I have an E3D hot end ordered and I will be replacing the solidoodle one.  I also have a 300W power supply I will be replacing the original with. 

So I'm wondering if I should also replace the stepper drivers.  I've heard I think that you can get a moire pattern when you go to the 5mm or 3mm Z rod and changing the driver can help.  Will I need to change the stepper motors also?  In any case here is the motherboard I have.

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2 (edited by Stevos758 2013-12-06 15:09:55)

Re: question about changing stepper drivers

E3D causes some moire, The Z rod shouldn't effect moire, only banding I believe. I just changed the extruder stepper. Everything else should be Ok.

From what I gather changing anything other than the extruder stepper is almost unnoticeable. Yes, you might gain some accuracy but the other drive components are lacking to make up for it(belts and pulley slop.).

It definitely wont hurt.

3 (edited by 2n2r5 2013-12-06 15:14:29)

Re: question about changing stepper drivers

Your A4988 stepper drivers are capable of 1/16 microsteps. This should be fine for X Y Z movements. The DRV8825 or SD8825 drivers are capable of 1/32 microsteps which is particularly helpful with the Extruder. If you are planning on swapping any out then start with the extruder (E).

Moire is caused by the extruder but you will notice moire more when you get rid of the Z wobble.

There is no need to swap out motors. If you are really really bored and just want to change things just because then you can swap you extruder motor out for a .9 degree stepper motor instead of the 1.8 you have now. That and the driver will each double your steps/mm for the extruder.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: question about changing stepper drivers

Great, I think I will look at that then.  In followup will this work for my board? http://www.pololu.com/product/2133

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Re: question about changing stepper drivers

yep. keep an eye out for sales on Geeetech.com

Every weekend they have sales on certain items. The DRV8825 is a common item for the sale and sells for about $5-6.

http://www.geeetech.com/stepstick-drv88 … p-652.html

As with most mods, make sure you have spares and keep your old drivers.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: question about changing stepper drivers

Any recommended sources for the .9 stepper motor?

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Re: question about changing stepper drivers

I got mine here https://www.sparkfun.com/products/10846

The motor is too big to put a fan on but it seemed to do okay without one.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: question about changing stepper drivers

Great thanks! And is it just a simple eeprom steps/mm change? or is it more involved than that?

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Re: question about changing stepper drivers

just an eeprom adjustment

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: question about changing stepper drivers

Do I need to make the eeprom change if I just change the driver or if I change the motor and the driver?

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Re: question about changing stepper drivers

yes, you will need to change the steps per mm after changing either piece. The 1/16 -> 1/32 microstepping driver and 200 steps/rotation -> 400 steps/rotation motor will both require this if changed individually.

(current Extruder steps/mm) x 2 = new value

If changed at the same time it will be:

(current Extruder steps/mm) x 4 = new value

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.