Some updates, Marlin update, new boards?

New Home Forum Updates Some updates, Marlin update, new boards?

This topic contains 49 replies, has 12 voices, and was last updated by  Ryan 1 month, 1 week ago.

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  • #30835

    Ryan
    Keymaster

    I have been watching the marlin github, checking it every few days. It looks like an update is coming, https://github.com/MarlinFirmware/Marlin/issues/6188

    The rc8 update had screen issues for us and some other random things. These issues were quickly rectified in the RC8 bugfix branch but the devs were making crazy fast progress so I didn’t want to waste the time trying to constantly update.

    When the update is released I will try it out, release it in the forums if there isn’t any issues I will try and make all the crazy updated different versions that are sorely needed, 8mm lead screws, no therm, different lcd’s, try and make it so most people even if they did not get the kit, should not need to mess with the firmware.

    This falls right in line with tomorrow’s shipment, Legit official Mini-Rambo 1.3 boards at a crazy good price! While at MRRF Barry and I got to chat with Johnny R from Ultimachine for a bit and, boom, better boards. A few guys from SeeMeCNC proved the rambo’s were better and made the introduction. The import Ramps are causing me to waste too much time and money so I am trying to get all my sourcing inline for a possible switch to the rambo mini, followed by the archim… The rambo boards are more expensive but should take significantly less time for me to deal with on the kits and troubleshooting side. So I will offer both but hopefully the price difference will be as little as possible for you guys and the board improvements and component quality is seriously impressive. US made boards!?!?!?!!

    I also think I am going to switch back to the other LCD’s that don’t require the ug8lib as I think they take less resources to run and honestly they always seem to run better.

    1 user thanked author for this post.
    #30852

    Wesley Gardner
    Participant

    hmm well i hope its a crazy good price would be interested in that board myself lol

    #30880

    Barry
    Participant

    Hahahaha, “Don’t try this at home kids!!!”

    #30884

    Mmmfishtacos
    Participant

    How expensive are we talking? Because i want one or two.

    #30893

    Bill
    Participant

    1.3 or 1.3a? They handle the LCD differently on the two versions IIRC. I think the Mini RAMBo also is limited to 1/16 stepping instead of 1/32 on the RAMPS, but that’s not too big of a factor if the price is right. Looks like the heat bed output is a little weak for this (200W aluminum bed), so no ABS without an external MOSFET.

    #30894

    Neil
    Participant

    Very cool, I myself love ‘cheap’ and the price of the ramps board is awesome! That said the form factor is a pain. I have yet to get mine mounted in anything that doesn’t tick me off lol (I should have just printed your ramps enclosure to begin with). I have had my ramps stack literally sitting on the spoil board for about a year now (on my most used mpcnc).

    I would love to have an all in one solution that I can mount inside of say a micro pc case or rack mounted blade (you know cut an lcd window out of the face of it install the lcd and boom instant sexy).

    I have been holding off on using my laser machine until all of the issues are resolved with the firmware (then again I have yet to see any issues while using the rc8 load I have on there now – not moving the z-axis so I am guessing that is why it works).

    Glad to see new fw is on the horizon!
    Neil

    #30895

    Bill
    Participant

    With the Mega2560 board we’re using now it’s possible to reprogram the USB chip to meet the spec for the Windows 3D printer driver (set compatibleID to “MSPRINT”), which allows printing directly from 3D Builder in Windows 10 (The USB connection shows up as 3D Printer instead of Mega 2560 and 3D Builder then generates the gcode). Do you know if there’s a similar option with the Mini RAMBo?

    #30896

    Ryan
    Keymaster

    I am hoping to sell them for $85 if I buy a bunch on the next round I might be able to do $80, no wires just the 4 plugs.

    Barry, exactly, that sold me! That and I just got another batch of 50 boards and 10 had bad mosfets, 2 where physically crushed in shipping. I’m over it.

    Bill, 1.3a it has a 15A bed rail instead of an 11a (or less on the import) on the ramps, but going to 24V should fix your issue, no externals. I am not sure about the windows thing but I can not imagine the windows slicer is worth the time? I need to look into what code they are using….yikes.

    #30900

    Mmmfishtacos
    Participant

    Put me down for one at that price.

    #30902

    Ryan
    Keymaster

    Really trying to ship out the day’s orders before I plug this puppy in. So small, the quality difference is immediately clear.

    #30904

    Mmmfishtacos
    Participant

    Very nice. Will you carrie the wire connectors?

    #30905

    Ryan
    Keymaster

    Just these plugs and I think I will offer them in singles they are actually expensive.

    The wiring harness fits (pretty tight but it works well), I will remove the resistor from the firmware, and all the standard stuff should fit.

    #30922

    Ryan
    Keymaster

    Hmmm, compared to the ramps boards there is very little info out there on the mini’s.

    I am not sure how far I can push the drivers. I ran them for a little less than 5 minutes with my test script at the stock settings and this corner of the board gets piping hot. I believe the stock settings are equal to the drv8825 at .7v so 1.4A out of the steppers max 2a, which usually leaves the steppers warm but not hot.

    Not sure If I should slap on some heatsinks or not. Maybe I need to sacrifice a board in the name of science. Torture test, I am pretty sure the thermal shutdown will kick in before anything really fails.

    #30923

    Ryan
    Keymaster

    The documents say don’t worry about it. So far so good. The board is hot as hell but I don’t have a fan on it. I will slap it on the mpcnc turn it up a bit higher and run a print for a few hours and report back.

    #30926

    Barry
    Participant

    My Rostock has a fan on the rambo, probably a good idea.

    I wish I had taken a video of Andy making the printer light up by throwing the carriage around.

    #30927

    Ryan
    Keymaster

    I definitely reccomend a fan but I am going to torture test without one…just to see.

    #30968

    Mmmfishtacos
    Participant

    Did you break one yet?

    #30969

    Ryan
    Keymaster

    Nope!

    I ran it for a long time on a parallel wired mpcnc, today I will run it on the series. I am very confident with a tiny fan these boards are are gunna be awesome since they work fine without a fan.

    The flashing is a bit more involved the first time (I have updated the firmware page), but the LCD’s plug right in and work with the RC8 bugfix without all the edits shown for the older firmware. Pretty pumped about them.

    #30999

    Ryan
    Keymaster

    Well I mixed up the hot end and the bed turned on the heat and popped a fuse. That was a new experience. Run out to the truck grab a space replace it and good to go.

    I have no idea what is going on with the “digi”pots, they are PWM

    
    // Motor current PWM conversion, PWM value = MotorCurrentSetting * 255 / range
    #define MOTOR_CURRENT_PWM_RANGE 2000
    #define DEFAULT_PWM_MOTOR_CURRENT  {1400, 1400, 1400}

    I assumed this meant 1400*255/2000=178.5pwm
    178.5/255=.7 Meaning 70% of max current, max current is 2A, so 2*.7=1.4A this is what we run the 8825’s on and they just barely get warm.

    Well nope, that is not what that equation means.

    At the 1400 setting I just started to get thermal shutdown of the driver of one axis and after 20 minutes or so the steppers were so hot I could not keep my hand on them at all.

    So what I learned. The built in drivers with no fan can supply more than our steppers can handle, with the slightest breeze it can go much higher.

    Trying again at 1100, I think I am on to guess and check at this point because my google-fu is getting me nowhere to an actual equation, for pwm-digipot-current conversion. So far 1100 has the steppers running much warmer than usual, but no missed steps. SeeMeCNC uses the same boards and steppers and they have theirs set at 1000. So I guess I should go a little lower. Good news I guess.

    I accidentally shorted the board (piece of metal hit the bottom) it rebooted and runs fine….

    #31016

    Bill
    Participant

    Here’s a link to details about the built in Windows slicer, looks like they’ve got most of the bells and whistles, though who knows how well it’s been implemented.

    And here is a link which describes how to install the generic gcode version, it requires Windows 10 Pro or Enterprise to manually install.

    #31031

    Jeffeb3
    Participant

    I’m looking here: http://reprap.org/wiki/Rambo_firmware#Motor_Current

    If that’s what you’re doing, then I agree with your math. If 255 sets Vref to 1.66V, then that would be equal to 2A. I’m suspicious of 255 = 1.66A. is there somewhere you can measure it? That will get rid of this guessing game. It seems like 255 should be 100% duty cycle, so I would guess that’s 3.3V…

    #31044

    Ryan
    Keymaster

    Yeah There are test points but there is just something off about they way these are set. I am guessing it is this way in case you are using a 24 or 36V power supply and it would change everything?

    I have to set the value in pins-minirambo.h, but there is a section in config adv.h for the pwm but it is commented out. I have them set now to 900 which gives .78v on the xy ref pin, .76v on the z and E ref pin (why are they different?).

    At this setting the drivers are hot but I can touch them, the steppers feel warmer than the 8825’s at .7v (1.4A).

    The board is working great, I just don’t like this guessing thing and none of the formula’s seem to fit what is happening, even if the stepper rating is off I am trying to compare it to the 8825 settings and it seems off.

    #31045

    Ryan
    Keymaster

    Nevermind, sorry, solid brain fart on my end.

    The steppers I am using are rated at 1.5A per coil….I kept thinking 2A.

    The equations in case someone needs them in the future (most likely me).

    ITripMAX=(As stated Setting the drivers to 70%-90% of max rated amps is a good idea, 70% seems pretty good to me.)

    VRef = ITripMAX * 0.8 (this gives you the ideal test point voltage)
    Wv = (VRef / 1.66) * 255 (Wv=the pwm value needed (if you are using a rambo stop here I believe))

    // Motor current PWM conversion, PWM value = MotorCurrentSetting * 255 / range
    #define MOTOR_CURRENT_PWM_RANGE 2000
    #define DEFAULT_PWM_MOTOR_CURRENT  {900, 900, 900}

    So Wv/255*2000=DEFAULT_PWM_MOTOR_CURRENT (Values are XY, Z, E)

    #31178

    Mmmfishtacos
    Participant

    When do you think theyll be up for sale?

    #31191

    Ryan
    Keymaster

    This evening I hope. I have been beating up this one little board and it seems to be a great alternative to the ramps.

    #31203

    Mmmfishtacos
    Participant

    Its pretty much the same thing right. Same drivers and all, but just a much better design?

    #31204

    Ryan
    Keymaster

    Well once it is up and running there is no difference.

    This is the from the same designer of the Ramps stack, but with all the improvements he learned over the years and ramps iterations, and US components.

    They are different drivers, and set in the firmware instead of the little pots. The connections are better and all plugs. There are more safety features built in so it should last longer, and be much harder to mess up. I have seen them take some serious back voltage from the steppers (please don’t try it on purpose), and embarrassingly I set the board down on my metal bracket while powered up and it rebooted and has had no issues.

    I will still offer the ramps but I am going to offer these as well I feel they are a better option and worth the money especially for the newcomer who is more likely to make a ramps killing mistake and this board should not die.

    The down side to the Mini is only one extruder port, whereas the full rambo has dual. But I have only seen a few dual extruding MPCNC’s but maybe I will get a few full rambo’s as well.

    #31332

    Bob Swika
    Participant

    Thinking of ordering a board and a LCD display. Is there any reason I shouldn’t go with minirambo board? Does this board work well with ESTLCAM. Also will the wiring harness include the needed plugs or can I order them seperatly? I’m very experienced 3D printing but no CNC time yet. I do not care that there is no second extruder port. Thanks a lot.

    Bob

    #31377

    Ryan
    Keymaster

    Hi Bob. You have a few questions in there so in list format.

    1)Is there any reason I shouldn’t go with minirambo board?Nope Mini Rambo looks like an all around improvement to me. I am a cheapo with the board cost so much more I really needed a reason to carry it, I put my stamp of approval on there.

    2)Does this board work well with ESTLCAM. It works perfect with ESTLCAM, but it does not work with ESTLCAM Firmware. I don’t use estlcam firmware but if you wanted to there are other boards that are more supported. The basic workflow is shown on the getting started pages.

    3)Also will the wiring harness in the kit include the needed plugs or can I order them seperatly? Not to sure what you are asking here so here is all of it. My wiring kit from the shop plugs into the mini-Rambo. The mini rambo does not come with the wires they are separate. The hardware bundle does come with the wiring kit.

    #31410

    Bob Swika
    Participant

    You clarified everything very well. I ordered the minirambo board. Can’t wait to get it. Thanks,

    Bob

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