DRV8825 Can't set 1/16 stepping

Hello

My Core XY was working fine on A4988 drivers until a slight mis-hap.

I had to replace the drivers and replaced them with DRV8825 chips.

I doubled my steps per unit from 80 to 160 to allow for the 1/32 step.

X & Y while correct would occasionally miss steps. I increased current from ref volts up to about 0.6V and still it missed steps. (1.2A motors)

I've read some doubts about using 1/32 stepping on RAMPS. Whether true or not I don't know.

I removed jumper MS3 (furthest from capacitor below the driver) thinking it would give me 1/16 stepping.
It seems that that has set it to 1/8 stepping.

(I halved my steps per unit back to 80.The travel was double expected. I halved the steps again and it was correct. Implying that it is 1/8 stepping)

Any suggestions how to get 1/16 stepping?

Also - even at 1/8 stepping it seems to be missing steps. It's hard to tell whether X or Y with the coreXY set up. It's making some horrible grinding stuttering. Reducing acceleration didn't help.

Any suggestions?

Thanks

a

You have to remove two jumpers to get 1/16 microstepping on the DRV8825.

[www.geeetech.com]

Thanks for the answer. I'll try that.
I see the answer is in your link.
Oddly 1/8 isn't there, maybe just a typo as 1/4 is listed twice.

I'm a bit disappointed with these drivers - maybe I have a faulty one. The A4988 seemed no bother.
The Z is nice and quiet on 1/32 steps.

A

Yes it's a typo. 1/8 is the line between 1/4 and 1/16.

BTW my DRV8825 "made in China" drivers have been working perfectly at 1/32 microstepping - but I have no complaints about the A4988 ones at 1/16. Both types work well for me.

Edited 1 time(s). Last edit at 03/12/2015 08:19AM by AndrewBCN.

Nope.
Funny enough its still not having it - having removed ms1 and 2, Left 3 in, still gives me what seems to be 1/8 step.
I wonder about the driver having 3 jumper settings for 1/32.
Maybe I'll experiment with other jumper settings but I just can't seem to tune these to run the motors smoothly without skipping if I drive them from pronterface even 1/8 step.

My previous A49988 were fine. I'm tempted to get some more. I thought these would be an upgrade.

a

Edit: Even with a much reduced feedrate, when I issue a move command, it stops at the end with a clunk and skips on about a quarter to half a turn on the motors. Both X and Y

Does that make any sense to anyone?

Ta

a

Edited 2 time(s). Last edit at 03/16/2015 12:03PM by alan richard.

My edit button has gone!

Donkey that I am, I changed the stepper jumpers and steps/min in Marlin but didn't update the eeprom with the new config settings.

That just added to the confusion.

a

Indeed after a couple of days you can't edit a post anymore.

Parameters in EEPROM are a real nuisance, imo. I decided I wouldn't use the EEPROM in any of my printers and every time I have a chance to do so, I recommend not using this "feature".

So, 1/16th microstepping is working for your DRV8825's now? I assume yes, because there is no way it wouldn't work.

If you are using EEPROM just load the config with M502 and save it with M500. That's it.

---

Triffid Hunter's Calibration Guide

--> X <-- Drill for new Monitor

Most important Gcode.

Yes Andrew.1/16 works but I miss the nice quietness of 1/32. I don't miss its freakish behaviour though.

Yes Wurstnase. Easy when you remember. Can be very confusing when you forget.

"Hier Bohren für neuen Monitor" Haha

I'll go and get my drill. Does it arrive by post or something? I'll let you know when it arrives.

Thanks

a

You just saved me a wasted weekend trying to figure out why after installing these drivers and updating Marlin that I couldn't get them to step right. Thank you!

-Kevin

Quote
alan richard
My edit button has gone!

Donkey that I am, I changed the stepper jumpers and steps/min in Marlin but didn't update the eeprom with the new config settings.

That just added to the confusion.

a

I'm having the exact same problem with skipping using 1/32 settings. I read that they were compatible with Ramps 1.4 so that's why I bought them but it looks like I'll have to set my jumpers to 1/16 to have a working printer.

I am running 0.9 steppers at 1/16 and it is as quiet as running 1.8steppers at 1/32 i think, or is it because i run the DRV8825?. But doesn't 1/32 steps "require" 0.9 steppers? Anyway..

A 0.9 stepper actually have double the steps pers turn of a 1.8 stepper even at 1/16step..

My fans on the ramps and hotend is all i hear when printing (almost).. it is MUCH quieter than my Velleman K8200..

Edited 3 time(s). Last edit at 04/16/2015 06:29PM by AndersE.