0.9 Stepper question

[Holy1]

Hi, I am building another printer and wondered if there is an advantage to using a 0.9 stepper instead of the 1.8 steppers I already have. I didn't know if I would notice a difference by using the Rambo (that I already have) or would I need to go to a faster card to see the advantage?

Thanks in advance.

[Jimustanguitar]

You'll have twice the positional accuracy, but you're correct that it will toe the line of what an Arduino based board is capable of.

I say, if you're building the super printer, you might well put a super controller in it too.

[Eric]

While you might see a performance differences between two significantly different types of controllers, I doubt you're going to notice much difference because of the stepper upgrade.

[KAS]

By increasing the resolution, I absolutely have an increase in the visual quality of the printed part.

[bvandiepenbos]

By increasing the resolution, I absolutely have an increase in the visual quality of the printed part.

Makes sense to me.

[Holy1]

By increasing the resolution, I absolutely have an increase in the visual quality of the printed part.

Sounds good, what controller are you using?

[forrie]

Is it best to change to 16 teeth pulleys as well from the stock 20 teeth to take full advantage of the 0.9s?

[KAS]

I'll say yes for the 16t pulley although I didn't try it the 20t on the .9 stepper.

(steps * microstepping) / (teeth * pitch)
(400 * 16)/ (16 * 2) = 200 steps per mm

I printed with both the Rambo and Smoothieboard with no noticeable difference. Had concern/mention of possible loss of steps when printing high speeds towards the edge on the Rambo but I didn't observe anything out of the ordinary.

I know this is a broken record:

Before, stock setup: http://forum.seemecnc.com/viewtopic.php ... 150#p67435

After, .9 16t: http://forum.seemecnc.com/viewtopic.php ... 150#p69575


And with a geared extruder running JFettig's adapter plate for the ezstruder: http://forum.seemecnc.com/viewtopic.php ... 001#p76133

[0110-m-p]

I know this is a broken record:

Before, stock setup: http://forum.seemecnc.com/viewtopic.php ... 150#p67435

After, .9 16t: http://forum.seemecnc.com/viewtopic.php ... 150#p69575

And with a geared extruder running JFettig's adapter plate for the ezstruder: http://forum.seemecnc.com/viewtopic.php ... 001#p76133

After playing with my Flashforge Creator Pro for the past month or so and being in complete awe of how smooth the outside faces are compared to my Rostock Max (stock stepper/pulley/extruder setup), I had been planning an upgrade to 16T pulleys and a smoothieboard. Now seeing your results with 16T pulleys and 0.9-deg steppers only, I'm rethinking that.

Looks like I could change to 16T pulleys, 0.9-deg steppers, and finally setup my geared dual extruder setup for less than the Smoothieboard alone. I'll likely also ditch my Astrosyn dampers for cork or no dampers at all to remove as much potential compliance in the system as possible.

[CaptainMerica]

I'll thrown my hat in the ring, either that or my printer...

So I followed KAS's footsteps and installed 0.9 steppers with 16T pulleys, yadda yadda yadda, printed the bandaid model he used (before and after), using the same gcode off the sd card to eliminate any change in the print settings.

1.8 & 20T on left 0.9 & 16T on right.

Heres where it gets weird.

I went to recalibrate it using openDACT and was fighting getting it to do anything. Reset eeprom, reset eeprom, etc etc. tried to do a couple prints and every time it would rapid travel after homing and would get to about z 40.0 to z 1.00 and it would stop, and the lcd (staying lit) would go to the splash screen of (rostock max etc etc) before going back to the home screen.

I thought i was overdrawing maybe? checked and tried different current values, no change. i could traverse it up and down manually just fine. but when it tries to rapid travel, I think the drivers can't keep up with what it's trying to do. I messed with "non print speed" and "travel segments" and got it to start a print finally, and it would continue just fine. but that first initial plunge always causes problems. and it would do this when trying to run the opendact auto calibration.

I suppose I will try going to 1/8 microstepping and see if thats it, otherwise, you guys have any ideas?

EDIT: More info: I am using a rambo on my max v2 that shipped this spring, 24v power supply for bed through SSR, trick trucks, 325 CF arms, chimera hot end, planetary geared extruders, inductive prox switch z-probe, PEI sheet directly on TL heat spreader, I use matter control to slice. And to reiterate, when it gets to print, it prints great! but getting past that rapid travel is frustrating. when it resets, the pc has to reconnect (in matter control) the bed temp targets are erased if active, I can move full range at anything below rapid travel. and i can not find a setting in configuration.h that specifies rapid travel speed. But the g code showed f16000 i think. (Over 9000?!?!?)

[bot]

You should run your steppers at 24v as well, that could be the problem. David Crocker has a blog post about how 12v power on 0.9 degree steppers produces EMF above certain speeds. This EMF might be causing your board to reset? Seems weird, dunno.

[Jimustanguitar]

You should run your steppers at 24v as well, that could be the problem. David Crocker has a blog post about how 12v power on 0.9 degree steppers produces EMF above certain speeds. This EMF might be causing your board to reset? Seems weird, dunno.

https://miscsolutions.wordpress.com/201 ... d-printer/

[KAS]

That is interesting although my 400/r step setup on the Rambo was short lived. I'm not seeing any issue with the smoothieboard on 12v.

Granted I'm not printing 150+ mm/s either. I'll crank up the speeds on the same model and see what happens.

Matter of fact, give me a few min and I'll try to record it live on youtube.

[KAS]

Looks like the quality will be bad on live until it's uploaded/rendered later on.
ended up deleting the video, it was blurry and un-watchble at 240p.

Anyways, I didn't seen any issues all the way up to 300mm/s. Again it's a small part on a different controller, so chances are I cant repeat the error.

[CaptainMerica]

I dont know how to youtube live so heres my ip cam. i just started a bandaid print too haha

tinyurl.com/printerviewer3

I think im getting somewhere. i made my "start g code" go to z 100. so that way it rapids down but not as rapid rapid as it was.

Edit/Update:
Just kidding. I need to recalibrate it again. something is way off H-radius wise.

[KAS]

left is 40mm/s, Right started at 150mm/s. at the first noticeable band in the middle I increased 150%. Just above that is the next band that was increased 200%.


You can definity see the rounding of the corners at higher speeds.

Right side top looks horrible with 3 layers, probably need to increase the temp.

[CaptainMerica]

Right side top looks horrible with 3 layers, probably need to increase the temp

That's exactly what the top of mine looked like with 3. I can get mine to print just fine now by "manually" moving to z100. At the start of gcode before rapid-ing to z0, and that seems to bypass the back-emf problem I was having at the start of a print, but I am having issues getting my calibration nailed down, partially due to it resetting once in a while from rapid-traveling down to the z-probe height.

Is there a clear cut "Rapid travel speed" parameter somewhere? Such as to put a printer/firmware based cap on how fast it can ever go.

[KAS]

You might have to verify this info, as I'm not using repetier to test.

The firmware should have hard limits that can be adjusted. I'm not sure if these are Cartesian settings or if they work for Delta printers as-well.

#define MAX_FEEDRATE_X 200
#define MAX_FEEDRATE_Y 200
#define MAX_FEEDRATE_Z 40


In Simplify3D the slicer setting is called X/Y & Z Axis Movement Speed. Mattercontrol, under speed settings it should be "Speed for non Print Moves"

You should be able to test the various speeds to determine what you like.

Just change F value to a speed your comfortable with. I come down slow just so I can remove the ooze before printing.

G28
G0 Z20 F3000

[CaptainMerica]

G28
G0 Z20 F3000

Yeah i added similar to that in my start g code

G28
G90 G0 Z100 F5000

This way it moves down to Z100.0 at a defined speed and then it super rapids from there where it wants to. It's a short enough move that it doesnt have time to build up enough disturbance to reset the board.

Mattercontrol, under speed settings it should be "Speed for non Print Moves"

I tried moving this from the original 300 to 200 or even less, as well at the "max Feed rate" parameters, this seemed to have no effect. I think that the max feed rate and non print moves speed is for moves generated inside of a sliced program. And that the G0 command at the start of the print (where i always pucker up a little bit that i hope my Z height is good) when it plunges all the way to the bed, is set somewhere in the firmware that i have yet to find.
I may be completely wrong at any given time, about any given thing, these are just my thoughts/opinions.

[KAS]

For the heck of it, try a different slicer and see if it's a software vs firmware issue.

[CaptainMerica]

I have some questions regarding the stepper current. These are the stepper motors I installed, and they are working just fine currently. (haha get it?) I have gotten past the hurdle of the rapid travel causing the board to reset, by adding a rapid travel to z20.0 at a given speed before starting the print, and I haven't had the problem since.

http://www.amazon.com/gp/product/B00W9A2L3S

In the assembly manuals it says what value to use for kysan or wantan steppers which is fine, but the steppers I got are... ? brand. I have the tech specs for them, so I'm trying to figure out what my current values "should" be, and/or what I need to change.

The known:
The motors are working and printing just fine.
Rostock Max V2
Rambo
stock power supply (heated bed runs off seperate 24v)
16T pullies
current eeprom value is 175 for towers, 165 for geared extruder motors.
holding power seems to be sufficient, I have had a couple prints failed due to missed steps from snagging, but I suspect they were because of a mechanical issue, but this is part of why I am checking everything.
steppers appear to be running at appropriate temperature, maybe even cooler. warm to touch, but not uncomfortable.
(from manufacturer)
* Manufacturer Part Number: 17HM19-2004S
* Motor Type: Bipolar Stepper
* Step Angle: 0.9°
* Holding Torque: 46Ncm(65.1oz.in)
* Rated Current/phase: 2.0A
* Phase Resistance: 1.4ohms
* Recommended Voltage: 12-24V
* Inductance : 3.0mH±20%(1KHz)

I have been trying to look around and understand the calculations behind it, ohms law and the like, but I'm afraid I am just confusing myself without understanding the full system. I understand the resistance of the stepper makes the current draw higher, and that higher voltage at lower amps is generally better, but what I cant figure out, is the stepper drivers output what voltage to the steppers? or is that what the drivers change to generate current and therefor motion? and if these motors suggest 12-24v, are the drivers giving anywhere near enough juice to them? or is the "ideal" settings for these given the hardware just too far out of realm of possibility without converting them to 24v as suggested?

Thank you all for helping,
Pete

[KAS]

I would start by increasing the current to around 80% of the max and work my way up until you're able to print at the speeds you expect towards the edges of the bed. Just watch the stepper temps, and you might have to remove the plexi sides to allow more air flow.

The Rambo has a maximum current of 2A with the A4982 driver (a 255 value)
http://reprap.org/wiki/Rambo_developmen ... or_current

This link has the formula if you want to dig into it a little.
http://reprap.org/wiki/Rambo_firmware#Motor_Current


The driver datasheet ( http://www.allegromicro.com/Products/Mo ... sheet.ashx ) is only showing 5v input but outputs anywhere from -2 to 37v. Not sure how it determines the values.