Smoothie M2

[Tim]

So. . . It has been all plugged in and passed the "smoke test"! Although I have been taking it slowly, it has been pretty straightforward so far.

Here's what I like about the Smoothieboard:

• 1. No need to reflash the firmware to change a parameter. . . just edit the "config" file and reset.
  2. Since the microSD can mount as a drive off of my computer, I can edit "config" just by mounting the card and then editing it. So easy!
  3. A couple of extra power MOSFET-driven connections. I am using one for the LED lights, which can be turned on and off by command. I still have one spare connection for future use.
  4. Works with pronterface and Simplify3D, no issues seen so far.

Here's what I don't like about the Smoothieboard:

• 1. No fuses. Now, I've never had a problem that caused a fuse to blow, but running stuff with enough amperage to melt things on the circuit board or start a small fire, without some fuses around, makes me a bit nervous.
  2. The power connectors are split, neither are they on the back of the board, so I can't just conveniently unplug the power supply when I need to.
  3. Still no power switch on the board!
  4. Reset button is no longer conveniently placed on the front along with the connectors.

The list is short, and not convincing one way or another. Which is to be expected, in a way. The Smoothieboard is meant to be very much like a RAMBo and other similar boards. If it weren't, it would be a lot harder to set up. I don't yet have anything in the "pros" list that would make the average person rush out to buy one, but then I haven't started printing anything yet.

Later I will post an account of my board-swapping procedure, with pictures.

[Slipshine]

Tim.

Since the microSD is a mounted drive can you save the gcode file directly from S3D to the card..

Then while printing from microSD can you unplug the computer from the unit without issue?

Thanks.

[Tim]

Notes from a successful Smoothieboard M2 brain transplant

From box to first print in reasonably easy steps. No soldering required. This post is just a set of instructions. No judgement calls on whether or not this is something that you ought or ought not to do to your M2.

• 0. In preparation, connect the Smoothieboard by itself to your computer through the USB cable. Check that you can talk to the board through Pronterface or Simplify3D. Probably a good idea to back up the contents of the microSD card (which is a surprisingly large 400MB).
  
  1. The first thing to understand is that the Smoothieboard has a different supply distribution than the RAMBo. Not counting the 5V supply, there are two main inputs instead of the RAMBo's three, and these two are not are not side-by-side where they can make use of a 4-position connector; they are not even close to each other, or on the same side of the board, or pointed to the back. Once the power supply is connected in, you aren't going to want to remove it any time soon.
  
  2. But, the existing power supply block can certainly be used. Cut off or unscrew the existing 6-pin connector, and rewire the contacts to three of the 2-pin connectors included with the Smoothieboard. The 2-pin connectors are each just like 1/3 of the existing connector. Once the rewiring is done, you can still plug them into the RAMBo (I like this backwards-compatible aspect). The polarities are the same as the existing connector, so just make sure that you keep it the same way while rewiring.
  
  3. The existing cable is just three separate power cables held together and taped and cable-tied at the end. Remove the cable tie and tape, and add tape and another cable tie about 5 inches behind where the original was, so you have about 5 inches of free cable for all three cables. It should look like the photo below. Note that only two of the three connectors is used; the third is installed to keep backwards compatibility with the RAMBo, just in case.
  

  

  Rewired power cable from the MakerGear power supply. Still good for plugging into the RAMBo!

  rewired_power.jpg (97.97 KiB) Viewed 13281 times

  4. Time to rewire. Make sure you know which wires are which on the RAMBo. Label the wires if you're not sure (especially the extruder and bed thermistor connectors, which all look alike. They will end up in the same order left-to-right, T0-T1-T2, on the Smoothieboard, if that's any help). Then unplug everything, feed it out of the back of the enclosure, then remove the whole enclosure (it's not going to fit the Smoothieboard). Remember that the M2 frame is metal, and so you should definitely have some kind of insulator between the Smoothieboard and the frame. Eventually, I will design and post an enclosure that fits the M2, and you'll just print that before you start, and install the Smoothieboard in its proper enclosure.
  

  

  Connection diagram for the Smoothieboard on the M2

  smoothie_m2.png (216.65 KiB) Viewed 13281 times

  5. Label the connectors on the Smoothieboard. The Smoothieboard is supposed to be multi-purpose, so they didn't label it for a 3D printer like the RAMBo.
  
  With the board oriented with the USB and Ethernet connectors facing forward:
  
  • 5a. The thermistor connections are the row of header pins along the left side of the front of the board. In pairs, counting from the left, these are T0 (for extruder 0), T1 (for the bed), T2 (for extruder 1 if you have a dual extruder), and T3 (unconnected).
    
    5b. Along the left side, the connectors are well marked. M1 is for the X stepper, M2 for the Y stepper, M3 for the Z stepper, M4 for the extruder 0 stepper, and M5 for the extruder 1 stepper in a dual system, unconnected if not.
    
    5c. At the back, one of the three power supply connectors (doesn't matter which) goes into the right side (labeled "VBB"). The left side is for a dedicated 5V power supply, which isn't available on the MakerGear power supply unit, so it will be left unconnected. The one green connector on the back side facing the back remains unconnected.
    
    5d. Along the right side, from back to front, the connectors are (and should be marked appropriately in permanent marker so you can see them easily): Extruder 1 heater (for dual extruders), fans for extruder & electronics ("always-on") (12V fans connected in series, so they go to only one connector), bed (switched) fan, unconnected (or use for LED lights, but be aware that LED lights usually take 12V, and this is a 24V connector), bed heater, 24V power supply in, and the extruder 0 heater.
    
    5e. Along the right side, and wrapping around to the front, are the six endstop connectors, three pins each. Counting from the back, these are: Z max (unused), Z min, Y max (unused), Y min, X max (unused), and on the front side, X min.
  6. On the RAMBo, heaters and fans all use the same type of connector. On the Smoothieboard, heaters use the same kind of connector, but lower-power components like fans use a smaller connector. Heaters have no polarity, so the existing connectors are okay as-is. The fans will need to be disconnected from the existing screw terminals and rewired into the smaller ones provided in the components bag with the Smoothieboard. For fans, polarity does matter, so watch where the "+" and "-" are marked on the board for each connector, and make sure the red wire goes to "+" and the black to "-". All other connectors are okay as-is.
  
  7. Remove all the cable ties from the cable harness, and re-sort the wires according to where they go on the Smoothieboard. With the Smoothieboard unplugged from the USB, and with the power supply unplugged, plug all the connectors in (I'll deal with orientation in the next step). Put cable ties back on in some arrangement that makes sense and keeps everything in sensible groups and in reasonable order.
  

  

  Smoothieboard, all wired up.

  smoothie_connected.jpg (203.38 KiB) Viewed 13281 times

  8. Now check and adjust orientations. This can be done interactively with pronterface or S3D, but I've already done that, so I'll tell you the orientations, then hopefully you'll have no debugging to do later. If the colors make no sense, then the cables may have changed since my vintage M2; if so, then rely on the debugging method.
  
  • 8a. Steppers. X: Blue/red wires at bottom. Y: Green/black wires at bottom. Z: Blue/red at bottom. Ext0: Blue/red at bottom. Ext1: Blue/yellow at bottom (this it the dual extruder extra harness).
    
    8b. Thermistors: Orientation does not matter.
    
    8c. Endstops. These are easy because there are only two wires connected into a 3-pin connector. But having it the wrong way will cause a short between power and ground, which you defintely don't want. X min (on the bottom side of the board): The unconnected pin is the one on the right. Y min and Z min: The unconnected pin in the one on the top.
  9. Add a jumper to J28 on the board, which is unlabeled but which is the pair of header pins directly below the capacitor can that is closest to the top right corner of the board. This jumper shorts all three small connectors on the board's right side to the VBB (24V) power input. Without this jumper, the fans won't operate.
  
  10. Okay, it's all wired up! Make sure the electronics fan is hooked up, or else the extruder fan won't be working, either. Double-check connections and orientations.
  
  11. Mount the SDcard on the computer, then replace the "config" file with the one attached here (unzipped, of course). This file has been edited for a dual-extruder setup, and all the values for the stepper motors, thermistors, endstops, etc., are correct for the M2. For a single-extruder setup, all the references to "hotend2" will have to be commented out. Connectors are assigned as described above. On boot-up, the firmware finds the "setup" file and reads it, so you don't have to flash firmware to make these changes. Just stick the revised "config" file on the microSD card, and then reset (or power cycle) the Smoothieboard (the RESET button is just above the unconnected Z max endstop connector).
  

  config.zip

  Configuration file (corrected 5/29/2015)

  (5.64 KiB) Downloaded 595 times

  12. Critical "smoke test": Turn on the power supply. The red LED (the one on the left of the row of LEDs in the middle of the board) should turn on, brightly. The orange LED next to the "always-on" fan connector should also be on, and the electronics box fan and extruder fan should be running. Nothing should be smoking, sparking, catching fire, or smelling funny. Note that since I have not talked about soldering a 5V power regulator on the board, the board's electronics are all running off of the USB's 5V supply. Pulling the USB cable out will cause the board to shut down.
  

  smoothie_running.jpg

  Passed the "smoke test".

  (221.05 KiB) Downloaded 408 times

  13. Good so far? Then connect to the board with Pronterface or Simplify3D. Both should connect and start communicating. Temperatures from all the thermistors should report close to room temperature.
  
  14. Check the endstops. Send command "M119" to the Smoothieboard, and you should get back readings of zero from the X, Y, and Z endstops. Now close each endstop switch by hand, and with the switch closed, send "M119" again. Check that the endstop you have pushed down is reporting "1".
  
  15. Check stepper motor direction. Move each axis a short distance forwards and backwards, and do a short extrude and extract on the extruder(s). If any directions are wrong, then you will need to power everything down, fix the connector orientation, then restart everything. If all the X, Y, and Z axis orientations are correct, then you should be able to "home" each axis with a nice, gentle stop.
  
  16. Check heaters. Turn each heater on to a LOW temperature, like 50C, and make sure the temperature readings show the correct heater heating. 50C is warm enough to feel but not hot enough to burn you, so you can do a touch-test to check that the correct element is being heated. If the thermistor reading does NOT match the element being heated, then you get a runaway reaction, so be prepared to turn the heat back off immediately if that happens.
  
  17. Once the communication channels, steppers, endstops, heaters, thermistors all check out, you should be ready for a test print (maxed out allowable attachments, so see the next post)!

[Tim]

Since the microSD is a mounted drive can you save the gcode file directly from S3D to the card.

Yes! It looks just like a disk on your computer, so "Save toolpaths to disk" can go straight to the microSD.

Then while printing from microSD can you unplug the computer from the unit without issue?

In the form the Smoothieboard comes from Hackaday, there is no 5V regulator installed, and if you power it from the MakerGear power supply block, then there's nothing other than 24V available. So the only 5V is from USB, meaning that unplugging the USB shuts everything down immediately. But, buy and solder in the 5V regulator (discussed in another thread, Digi-Key part number 945-1648-5-ND, $2.84, order from http://www.digikey.com) and you can unplug the USB and keep going.

[PcS]

Have you printed anything yet ?

[Jules]

Meant to tell you the other day, then just got slammed.....that's a great write-up Tim! Very clear and easy to understand with all the pics. Thanks for doing this!

[Tim]

Have you printed anything yet ?

I have not printed anything significant. I printed a Z-knob stop because having the bed drop on an electronics board that is sitting out in the open with all the wires exposed suddenly seemed like a bad idea. One of the first things I'd like to do is to design an enclosure for it; there are some enclosure designs on the microSD that comes with the Smoothieboard, but none are particularly well suited for the M2. The spacing for the Smoothieboard on the M2 is a bit tight, width-wise, because the connectors on the right side stick out rather farther than I would like. I think it will fit fine, but there's no extra room, and the enclosure will have to be designed accordingly.

Meanwhile, if anybody can suggest a simple print that really shows up the problem with ripples, please let me know. The Z-knob stop was not a particularly good example for that, although there are definitely visible ripples on it, just very small ones that are hard to see. But that's basically a meaningless metric. I have noticed on past prints that ripples tend to show up most visibly on flat surfaces with large round cutouts, in certain orientations. For making comparisons, I have the additional complication that I used to have a RAMBo with the 8-microstep stepper drivers, and now have 16-microstep drivers. There must be some difference in quality due to the drivers, although I've never seen a direct comparison between 8-microstep and 16-microstep drivers. There's certainly an audible difference in the stepper motors, which is probably a combination of the driver chips and the rate at which they're being pulsed.

Also, if anybody wants me to do a specific test, like seeing how fast I can make it go, or particular suggestions about setting acceleration parameters and the like, just let me know, too. I'm sorry to leave everyone hanging. I'm working on a big software project, which is almost done; maybe I can finish that up tonight and have tomorrow to play with the Smoothie M2 some more.

[insta]

There shouldn't be a huge difference in X/Y/Z on 1/8th vs. 1/16th stepping, but extruders will notice it a bit more on fine layer heights.

As for testing ripples (a thing I really want to see tested...) try this: http://www.thingiverse.com/thing:678295

[PcS]

Thanks for the update and taking the initial plunge on this board. I know I am not the only one with an interest in your projects outcome ! Thanks !!!

[jsc]

I suggest a box at 100 mm/s or higher, and maybe my dimpled cylinder ringing test: http://www.thingiverse.com/thing:247162

Although as you've pointed out, the acceleration handling is not much more advanced than in Marlin (although I think grbl was there first). There have been developments in the grbl motion control after Marlin incorporated it, though, so maybe it's better?