Smoothie M2

[Tim]

TinyG or G2? G2 is a completely different beast as far as I can tell.

Oh, I didn't look too closely at the history of it. I assumed that G2 was just a port of TinyG to the ARM processor. Tiny beast or large beast regardless, I meant the G2, as I would not care to duplicate the effort of an ARM port.

[Tim]

To finish up this project, I designed an electronics enclosure for the Smoothieboard. I call it the "M2 Smoothiebox" and posted it up on Thingiverse at http://www.thingiverse.com/thing:841736. The eSUN black PETg arrived while I was still designing the box, so I went ahead and printed it with the new filament. It looks great; the top of the lid, which was against the glass when printing, is a mirror-smooth gloss finish that looks like acrylic. I had a couple of jams that turned out to be due to bad settings for infill; when that was corrected, it printed without trouble, and remarkably defect-free.

Full disclosure: The one in the photo actually just barely doesn't clear the Z stage, by less than a mm. The one posted on Thingiverse is corrected. Anyway, nothing is ever Made that can't be Improved. . .

[jimc]

nice. im really glad you took on this project. its interesting to get some first hand feedback on the smoothie board and firmware.

[Tim]

The algorithm is linear pop. If you've got the programming stones, try compiling "G2" (a fork of TinyG) to run on Smoothie.

I got curious about why this is called "linear pop". For that matter, "constant jerk" is a somewhat weird turn of phrase. I looked it up and found out that "jerk" has been used for a long time to denote the 1st derivative of acceleration, although "jolt" has also been used, especially in the UK. Formally, the 1st derivative of jerk is called "jounce" and the next two derivatives are unnamed, but the fact that "jerk" and "jounce" both begin with "j" is confusing. Somebody, whose name I have not been able to discover, decided that "jounce" just wouldn't do, and that it and the next few derivatives needed catchy names, and came up with, respectively, "snap", "crackle", and "pop". Wikipedia decries these designations as "facetious", but it appears that the stepper motion planning software developers have taken them seriously. Personally, I like it; if you can have strange, charm, and beauty quarks then surely you can put some snap, crackle, and pop into your. . . motion planning.

Read:

http://math.ucr.edu/home/baez/physics/General/jerk.html

and you will learn about yank, tug, snatch, and shake as well.

With all the jerking, yanking, snatching, shaking, popping, tugging, snapping, and crackling going on, it's no wonder that you've got ripples in your prints.

[Volcom7114]

With all the jerking, yanking, snatching, shaking, popping, tugging, snapping, and crackling going on, it's no wonder that you've got ripples in your prints.


That's very true!


Very good job with this heart transplant! You did a great job explaining everything and on the box to hold it all together. I ordered yet another Smoothieboard 5XC to play with on the M2 so ill use your config and box if you don't mind.

Did you by chance use jumper's JP11 & JP27? I see you used the jumper for the small MOSFET's (JP28)..

Awesome job!

[Rara]

Watching this with curiosity, but I have a tiny bit of an unscientific contribution via observation:

I designed a part at my old job which was printed on a Stratasys machine of some sort. The tooling manager heard about my toy and wondered what it could do in comparison to the big machines, so I took the same file, sliced it up in Simplify3D and ran it on my M2. I don't have pictures, but the ripples/waves/ghosting were nearly identical between the two. For what it's worth...

[Tim]

I don't have pictures, but the ripples/waves/ghosting were nearly identical between the two. For what it's worth...

That's interesting. I have been exchanging emails with Arthur Wolf, a principle designer of the Smoothie; he doesn't think that the acceleration discontinuity makes much of a difference. He might be right; it's obviously true that the ripples are vibrations, and the vibrations are produced in any component that isn't permanently bolted to an iron I-beam. But whether or not that vibration is caused by discontinuities in acceleration or just by the acceleration itself, I have no idea. I'm trying to find out. One very nice aspect of the Smoothieboard is that it's ridiculously easy to re-flash the firmware. You just compile the source, then copy the executable file over to the microSD card, reset the Smoothie, and five seconds later it's done. Makes it very easy to play with. Debugging is supposed to be easy, too, although at the moment all I'm getting through the debugging serial port is non-ASCII gibberish.

Did you by chance use jumper's JP11 & JP27? I see you used the jumper for the small MOSFET's (JP28)..

No, I was a bit concerned about the limitations of those jumpers, because it's mentioned in the instructions that the jumpers themselves have a much lower current rating (about 2 Amps) than either the power MOSFETs or the terminal connectors. JP28 connects two of the three small MOSFETs, and used the way I am using it, makes the Power-in2 connector an output which is an additional load drawn from the main VBB power connector. I've got these three connectors going to two fans and a strip of LED lights; each of those is about 2 Watts, so at 24V that's a total current draw of about a quarter of an Amp, and that's well within the specification of the jumper. But because the MakerGear power supply is already divided up into three separate cables, it was easiest to make use of the Power-in1 connector and feed that to the two large power MOSFETs for the heated bed and primary extruder, and not worry about whether or not that overloads the jumpers.

[Volcom7114]

No, I was a bit concerned about the limitations of those jumpers, because it's mentioned in the instructions that the jumpers themselves have a much lower current rating (about 2 Amps) than either the power MOSFETs or the terminal connectors. JP28 connects two of the three small MOSFETs, and used the way I am using it, makes the Power-in2 connector an output which is an additional load drawn from the main VBB power connector. I've got these three connectors going to two fans and a strip of LED lights; each of those is about 2 Watts, so at 24V that's a total current draw of about a quarter of an Amp, and that's well within the specification of the jumper. But because the MakerGear power supply is already divided up into three separate cables, it was easiest to make use of the Power-in1 connector and feed that to the two large power MOSFETs for the heated bed and primary extruder, and not worry about whether or not that overloads the jumpers.

I agree and chose not to use those jumpers myself due to the same reason you stated above.. I am having an issue with MOSFET Q5 not working and I'm not for sure why yet, it's being used as one of two extruder heaters the other works fine and when i swap the two around it works. I'm not getting anything on the multimeter either? weird

[Tim]

I agree and chose not to use those jumpers myself due to the same reason you stated above.. I am having an issue with MOSFET Q5 not working and I'm not for sure why yet, it's being used as one of two extruder heaters the other works fine and when i swap the two around it works. I'm not getting anything on the multimeter either? weird

Hmm. Q5 is powered directly off of VBB; is your supply connection at VBB good? I assume the other extruder is also running off of VBB? Otherwise, how is the extruder hookup to Q5 declared in the config file?

[Volcom7114]

Hmm. Q5 is powered directly off of VBB; is your supply connection at VBB good? I assume the other extruder is also running off of VBB? Otherwise, how is the extruder hookup to Q5 declared in the config file?

Yea I checked to be sure that my power supply is plugged in nice and tight and tested around the board to see what kind of voltage I was getting which is pretty even across the board at 23.41v.. I understand that the fets are ran off the VBB.. I used your config file and its on pin 1.23(Q5). Hmm I'm using S3D wonder if this has anything to do with it? Right extruder heats up fine and so does the bed but when I switch over to the left it won't heat up at all and I did test with a multimeter and I get nothing. Are you using Pronterface? Im not sure whats going on since im able to get a thermistor reading on T1 also even by holding my fingers on it a sec it will show a change. bad something or other?

Thanks for your help with this one Tim! I wonder if anyone else is having the same kinda problem with S3D or just in general.

Here is the config part in question.----->

# Hotend temperature control configuration
temperature_control.hotend.enable true # Whether to activate this ( "hotend" ) module at all.
# All configuration is ignored if false.
temperature_control.hotend.thermistor_pin 0.23 # Pin for the thermistor to read
temperature_control.hotend.heater_pin 2.7 # Pin that controls the heater, set to nc if a readonly thermistor
# is being defined
temperature_control.hotend.thermistor EPCOS100K # see http://smoothieware.org/temperaturecontrol#toc5
#temperature_control.hotend.beta 4066 # or set the beta value
temperature_control.hotend.set_m_code 104 #
temperature_control.hotend.set_and_wait_m_code 109 #
temperature_control.hotend.designator T #

temperature_control.hotend.p_factor 24.4 # permanently set the PID values after an auto pid
temperature_control.hotend.i_factor 1.126 #
temperature_control.hotend.d_factor 133 #

#temperature_control.hotend.max_pwm 64 # max pwm, 64 is a good value if driving a 12v resistor with 24v.

# Hotend2 temperature control configuration
temperature_control.hotend2.enable true # Whether to activate this ( "hotend" ) module at all.
# All configuration is ignored if false.

temperature_control.hotend2.thermistor_pin 0.25 # Pin for the thermistor to read
temperature_control.hotend2.heater_pin 1.23 # Pin that controls the heater
temperature_control.hotend2.thermistor EPCOS100K # see http://smoothieware.org/temperaturecontrol#toc5
#temperature_control.hotend2.beta 4066 # or set the beta value
temperature_control.hotend2.set_m_code 884 #
temperature_control.hotend2.set_and_wait_m_code 889 #
temperature_control.hotend2.designator T1 #