Upgrading to ARM and 0.9 Steppers - Vertical Banding Issue

[xnaron]

An added benefit of the 0.9 steppers is that they are quieter than the 1.8 steppers. I didn't install the noise dampers with these. I think there is a slight quality penalty with them on so I opted to leave them off. I was concerned about going back to the noise as they really made it quiet. It was a happy surprise to find these 0.9 steppers to be quieter than the 1.8 stock steppers. They aren't silent like the dampers but they are a happy compromise.

[626Pilot]

Did you try upgrading the extruder to a 0.9 degree motor?

[xnaron]

[youtube]http://www.youtube.com/watch?v=3sMw_UAM994[/youtube]

[xnaron]

Did you try upgrading the extruder to a 0.9 degree motor?

No. I am running a geared stepper. I do want to try a 0.9 on a wades variant. I need to pick up a hobbed gear though before I can do that.

[enggmaug]

for .9 degrees steppers, should you buy unipolar stepper or bipollar ? what voltage ?

[xnaron]

for .9 degrees steppers, should you buy unipolar stepper or bipollar ? what voltage ?

I believe these are the ones I have http://www.kysanelectronics.com/Product ... ordID=6875

However I wouldn't recommend upgrading to 0.9 steppers without moving to the ARM and some compatible shield such as RAMPS-FD or RADDS. The atmel arduino mega will not have enough horsepower to drive the 0.9 steppers at whatever top speed you use now. As the steppers require 2x the steps your max speed will be divided by 2.

Right now I am tweaking the Repetier ARM board in concert with others including the repetier developers. Lucky for us the dev also has a DELTA. Once I come back with a good working config I will post the details.

I wouldn't advise anyone buy the Rev 1A version of the RAMPS-FD on ebay made by getech. This is because it is an earlier version that has bugs. Some of them are safety bugs. There is a problem with the way the fet circuit is designed for heaters. Right now if the ARM board fails it is possible for the heaters to turn on and of course this would be unregulated by the thermistors and could start a fire.

[xnaron]

[youtube]http://www.youtube.com/watch?v=L_stokiQRZ8[/youtube]

[youtube]http://www.youtube.com/watch?v=wdiY4GKug-I[/youtube]

[626Pilot]

Psst... it's not doo, it's doo-ay. It's an eye-talian word!

[xnaron]

Psst... it's not doo, it's doo-ay. It's an eye-talian word!

lol...thanks and will call that out on the next vids.

[mhackney]

Xnaron, I don't know if you know this, I just found out today, but there is a special #define EXACT_DELTA_MOVES that improves the delta calculations. It was originally created for ARM boards but .91.7 Repetier has experimental support for AVR. I've enabled it (just add #define EXACT_DELTA_MOVES to your Configuration.h file) and testing now. Unfortunately, I'm printing a part in black PLA now which hides everything! I'll move to a translucent PLA for the next print that might show more.

[xnaron]

Xnaron, I don't know if you know this, I just found out today, but there is a special #define EXACT_DELTA_MOVES that improves the delta calculations. It was originally created for ARM boards but .91.7 Repetier has experimental support for AVR. I've enabled it (just add #define EXACT_DELTA_MOVES to your Configuration.h file) and testing now. Unfortunately, I'm printing a part in black PLA now which hides everything! I'll move to a translucent PLA for the next print that might show more.

I'm pretty sure this applies to the AVR version of Repetier and not the ARM version I am using. I sent Roland a PM asking him just to be sure.

I am currently running 4x the resolution I was with the stock rmax. I doubled the resolution when I wen from 1.9 to 0.9/deg per step steppers. I doubled it again when I we from 1/16 to 1/32 stepping on my allegro drv8825 stepper drivers. I went from 80 steps per mm to 320. The latest bleeding edge version of repetier is amazing for ARM. I have DELTA_SEGMENTS_PER_SECOND_PRINT set to 600 and DELTA_SEGMENTS_PER_SECOND_MOVE set to 200. I am able to print at the same speeds I was before the upgrade. The performance is simply amazing. I have reduced the vertical banding so it is barely noticeable. I think any artifacts now are due to mechanical issues. Yesterday I bought Simplify3d slicing software. I am getting some of the nicest prints I have ever made.

[mhackney]

According to Roland on the repeater github issues list the EXACT_DELTA_MOVES subsegment computation was originally written for the ARM version. Have you heard back from him?

[xnaron]

According to Roland on the repeater github issues list the EXACT_DELTA_MOVES subsegment computation was originally written for the ARM version. Have you heard back from him?

Yes I heard back from him. He said Due always has it enabled. He made a switch for avr because he wasn't sure the cpu could handle it.

Brendin

[mhackney]

Great. I've got something like 8 hrs with it enabled now and 6 prints with no performance issues. But, I have been printing in black so haven't been able to validate effect on part quality/appearance. Hope to do some of that today.

cheers,
Michael

[xnaron]

[img]http://i57.tinypic.com/2hwen9l.jpg[/img]

[mhackney]

Show off! Seriously, rub it in to those of us ARM-challenged!

That looks super fantastic!

(and oddly erotic)

[Maco]

Xnaron super nice print, have a question how is the simplify3d software? it really helps? it wortht to have it?

[xnaron]

Show off! Seriously, rub it in to those of us ARM-challenged!

That looks super fantastic!

(and oddly erotic)

Very funny as usual lol

[xnaron]

Xnaron super nice print, have a question how is the simplify3d software? it really helps? it wortht to have it?

Thanks. Yes I really like Simplifiy3d. I wanted a go-forward slicing path as KISS seems to be abandoned by its developer. KISS was my go to slicer and Simplify3d has quickly replaced it. It can do everything KISS can and so much more. For me it was well worth the money. I went in to it very skeptically. I was not impressed that they didn't have a demo. I even emailed them asking for one and was politely told no. I figured that if I bought it and it was complete crap I would fight for a refund. Happily I don't have to worry about that hassle.

[xnaron]

Here are some important things to know about the ramps-fd in case anyone is considering it.

I have that this one http://www.ebay.com/itm/281246436199. It works well but it is the first beta of the board. Unfortunately it is the only version out in the wild. It has some safety issues with the way the mosfet circuit is designed. If the arduino were to fail it is possible that the mosfet could switch a heater on. Other than that risk the board is working very well for me. Others have complained that the QA isn't very good with the boards and some have had issues with them.

Here are some important things to know. The arduino due does not have an eeprom. So in order to store the settings you need to add a $3 eeprom chip that connects to the i2c connector on the board. Wiring the eeprom to the board is really simple. The other thing to keep in mind is that the arduino due is 3.3v and not 5v. This means that the lcd and encoder won't work out of the box. You will need to add a board with level converters on it. I don't have it hooked up on min. The designer of ramps-fd made a design for an adapter board. I don't see anyone making it though. The design is all open source and you could send it to a pcb fab place to get the board made. You'll need to populate the components on it and some of them are SMD. They could be hand soldered but it might be a bit tricky.

Anyhow other than the above stuff it is working fine for me. There is another board out there called the RADDS. I have one coming to me. It may be better and have all the eeprom and lcd level converters built in. I need to take a closer look at it when it arrives.

The other thing you'll want to get is the drv8825 from polulu http://www.pololu.com/product/2133 They will allow you to step at 1/32.

[lordbinky]

I really didn't need to read over this thread. I already had .9 steppers in transit right now, and a smoothieboard waiting for me to put in the connectors. I have new extrusions to install on the max, my stock ones are now less than straight which is completely my fault, but the new ones are black to match the rest of the rostock . Now I just have to complete the 3 other projects I have currently to bring these upgrades to the top of the queue. *sigh* One of these day though! One of these days....

[thenewguy]

Does anyone have the max working with the smoothieboard yet? I don't know much like if our current software will run with a few setting changes.

I still have the old Rambo with 1/8th stepping so I need this upgrade soon.

[xnaron]

Here is a video on the second driver shield I am testing called the RADDS (Reprap Arduino Due Driver Shield)

http://youtu.be/VKYRT1vvErc

[lordbinky]

Smoothieboard firmware is actually really easy to convert over too. I don't like the non-locking connections that they send with it though. Blew a driver because of that. You don't have the EEprom menu change settings on, but they give you G-code commands to change all the variables you want, then commands to dump your current settings, and there's a drag and drop config file I edit with Notepad++ after I'm done playing with settings in real-time. You can also set up a terminal session to interface with the board that way if that's your cup-O-tea to change settings with that.

As for being a drop in replacement, if you go with the stock connectors, unless you used some flexible wires for your power on the order of high strand silicone test lead wire, it's a very tight fit with a bend radii that would make an NEC acolyte faint. From what I understand, the Azteeg X5 has a smaller footprint that would fit better within the Rostock. Don't know if the standoff holes would align though.

[critical_limit]

Hi all,

having this banding issue as well, I decided to go the 0.9° road with a smoothieboard /azteeg X5. Magnetic ballarms are nearly finished and ready to install. Everything is upgraded to 24V as well. Removed the astrosyn dampers as well.
I installed 0.9° Stepper motors to my RM2 last night. Now waiting for my Azteeg X5. The Rambo is far too slow for that. Had stuttering movements above 30mm/sec.

Anybody here who installed a 0.9° stepper to the extruder as well? Or doesnt it make any sense? Should the extruder also with 1/32 microstepping? Or better to install 0.9° and use ½ step? What are you using?

thanx
Dirk