Maestro hardware decisions



  • Hi everyone, I'm considering the purchase of a Duet Maestro to replace the proprietary mainboard in my current printer, however I'm having some difficulty pulling the trigger, as since this is a retrofit, I'm locked into the current parts. This includes a J-type thermocouple, 12V fans, and a 24V main supply. This printer has a single hot-end, three limit switches, and is a standard 4-stepper cartesian machine (3 axis steppers + 1 extruder).

    I really like the hardware and software design of the duet, however even the Maestro seems a bit overkill for a printer of this type (re: 2 extruder support), and from what I assume, the vast majority of existing printers are as well. Ender 3s, Tevo Tornados, etc. While I know that designing a board is a very time-consuming project, I was wondering why Duet does not sell a single extruder board for an even greater reduced cost? I think if the price-point was right, it would become a no-brainer for an electronics upgrade. From what I know about Duet, I believe there is only a single hardware/firmware engineer, @dc42, so his time would obviously become even further constrained by supporting and developing a new board, but I wonder if it may be worth considering as more people may be enticed by the lower price.

    I have no issue with paying for a well-built, genuine board, however some people have no interest in dual-extrusion, and what caused me to pause was when I found out that I also need to purchase an additional costly daughter board in order to use a thermocouple (which again, supports two thermocouples, which I believe most will only use a single one, and the MAX31856 is expensive even in quantity), and then a DC-DC converter in order to step down the voltage for my fans. If there ever was an even "lower-tier" (I use the term lightly) duet, perhaps the extra space that is saved by removing the circuitry for the second extruder could be used to implement the daughter board directly onto the main board, as well as a DC-DC converter built-in.

    Perhaps the market for the Duet is more targeted towards "higher-end" machines with 2+ hot-ends, dual Z-stepper, tool-changes and the like, but I am just curious as to other people's thoughts.



  • the 5 stepper layout is very much standard.
    The most common Controller setup, Ramps 1.4, comes with space for 5 steppers.

    Considering that the Duets arethe high end Controller and the maestro is the light version, i dont think it would be necessary to restrict the possibility event further. People who change to the duet mostly dont know about the possibilities of the board yet. For example dual independent z motor bed leveling.

    The duet maestro supports pt1000 temperature sensors, which do not require a daughter board. A Printer Setup with 24V but 12V fans is not very common. The Duet has a step down for fans, but that is to 5V, which is more common.



  • The extra driver chip adds, what, $2 to the BOM? so lets say $5 incl passives and PCB real-estate, maybe slightly more.

    They already axed the 6th and 7th drivers as expansion headers to cut costs, so I think a lot of consideration went into trying to balance their usual high end approach with lower cost, but ultimately its still a premium board.

    Why not skip the thermocouple board and buy a PT1000 sensor and some 24v fans instead (or 5v)?



  • @j3d Another way to look at is to evaluate what it is you don't like about your current setup, then decide if a Duet board is going to help. If you are happy with the prints that you are getting, then there is no point in changing the board unless you would like the printer to run quieter. If you have print artefacts that you don't like, then these may well be due to mechanical defects which a new board may not cure. On the other hand, RepRap firmware has a lot of features that help to compensate for mechanical deficiencies. For example, if your print surface isn't flat or level, and your current board doesn't allow you to compensate, then mesh bed compensation might be what you need. TBH, I'd say that rather than look at the hardware, look at the firmware and see if there are any features there that take your fancy. If not, stick with what you've got.



  • Pull the trigger!
    I have an Maestro and Panel Due 7i on an Ender 3 Pro
    I am not a professional printing person, more of a hobbyist and like tinkering.
    Considering the above parts and a new extruder, hotend and BL Touch my printing is going in leaps and bounds as the support from the people on this site makes it a worthy purchase, so the parts I have purchased are worth more than the printer when I bought it.

    I use step-downs or buck convertors to take 24v to 12v, no problem, just printed a nice looking case for the convertors.

    I was looking at the MKS1.4 + Stepper drivers + screen and it was nearly as much as the Maestro, but my main concern was the support.
    High quality steppers are all ready built into the Maestro
    Yes there are alot of options, IMHO you can not go wrong with the Maestro by Duet3D.



  • Thanks everyone for your input - it's very much appreciated.

    @paulhew said in Maestro hardware decisions:

    I was looking at the MKS1.4 + Stepper drivers + screen and it was nearly as much as the Maestro, but my main concern was the support.

    Yes, I've been looking into other options as well, and they all seem to come up to around the same price (without the LCD) as well. Re-arm + RAMPS, MKS, etc. However none seem to be as well regarded as the Duet. My main enjoyment of 3d printing comes from tinkering with the machine rather than printing, however the price of this upgrade seems to be snowballing.

    @veti said in Maestro hardware decisions:

    The duet maestro supports pt1000 temperature sensors, which do not require a daughter board. A Printer Setup with 24V but 12V fans is not very common. The Duet has a step down for fans, but that is to 5V, which is more common.

    Interesting. Around half of all the printers that I've ever used had this setup.

    @veti said in Maestro hardware decisions:

    People who change to the duet mostly dont know about the possibilities of the board yet. For example dual independent z motor bed leveling.

    Case in point, I didn't know about that - I'll look into it.

    @bearer said in Maestro hardware decisions:

    The extra driver chip adds, what, $2 to the BOM? so lets say $5 incl passives and PCB real-estate, maybe slightly more.

    Last I checked, the MAX31856 is $4.19 USD in 2500 quantity. Adding two of them brings the cost up to $8.38 without passives. That's very expensive considering the main processor can be found for as little as $2.46.

    @bearer said in Maestro hardware decisions:

    Why not skip the thermocouple board and buy a PT1000 sensor and some 24v fans instead (or 5v)?

    The prices that I've seen are quite high $40+ USD. Is there a specific model that is recommended? I'm only printing PLA, so perhaps a thermistor would be a better choice? Specifically, I'm using Noctua fans, which unfortunately utilize 12V. Since one reason to move to the Duet is quieter operation, wouldn't it make sense to have an option for quieter fans?

    @deckingman said in Maestro hardware decisions:

    @j3d Another way to look at is to evaluate what it is you don't like about your current setup, then decide if a Duet board is going to help.

    Oh, there are many things I don't like about this particular printer, and the biggest is that I'm locked out of anything advanced. Unfortunately if I need to replace the hot-end so that I can fit a standard temperature probe, I might as well build a new printer from scratch, as I would have changed everything but the mechanics.



  • @j3d said in Maestro hardware decisions:

    The prices that I've seen are quite high $40+ USD.

    https://www.precisionpiezo.co.uk/product-page/pt1000-sensor

    or from trianglelab


  • administrators

    @j3d, thanks for your comments.

    I have no issue with paying for a well-built, genuine board, however some people have no interest in dual-extrusion, and what caused me to pause was when I found out that I also need to purchase an additional costly daughter board in order to use a thermocouple (which again, supports two thermocouples, which I believe most will only use a single one, and the MAX31856 is expensive even in quantity), and then a DC-DC converter in order to step down the voltage for my fans. If there ever was an even "lower-tier" (I use the term lightly) duet, perhaps the extra space that is saved by removing the circuitry for the second extruder could be used to implement the daughter board directly onto the main board, as well as a DC-DC converter built-in.

    Very few 3D printers use thermocouples, far more use thermistors, or sometimes PT100, or more recently PT1000. As you have pointed out, the MAX31856 is not inexpensive; so we can't justify including one on the main board given that almost nobody would use it. In contrast, quite a lot of users want a 5th stepper driver, either to do dual extrusion, or to drive dual Z motors (or sometimes dual X or Y motors), or just as a spare; and the extra TMC2224 chip is inexpensive. Most users expect a 5th stepper driver these days, or at least a socket for a 5th plug-in module.

    So for us it's a no-brainer to include a 5th stepper driver chip, and to support thermistors and PT1000 sensors on the main board, but to use daughter boards to support other types of temperature sensor requiring specialist chips.

    We could make single-channel versions of the PT100 and thermocouple daughter boards, but the cost saving would be small given the other associated costs i.e. component purchasing, assembly, stocking, and distributor margins. If you have some knowledge of electronics, you can purchase a single-channel 3.3V-compatible MAX31856 board from Adafruit or on eBay and connect that to the daughter board connector instead. There is documentation on connecting such boards to older Duets at https://duet3d.dozuki.com/Wiki/Connecting_thermocouples#Section_Duet_0_6_and_Duet_0_8_Num_5 so you would just need to adapt those instructions to use the correct pins on the daughter board connector.



  • @j3d said in Maestro hardware decisions😆 @bearer said in Maestro hardware decisions:

    The extra driver chip adds, what, $2 to the BOM? so lets say $5 incl passives and PCB real-estate, maybe slightly more.

    Last I checked, the MAX31856 is $4.19 USD in 2500 quantity. Adding two of them brings the cost up to $8.38 without passives. That's very expensive considering the main processor can be found for as little as $2.46.

    stepper driver (TMC2224). Not having the thermocouple chip when they support regular thermistors and pt1000* sensors which can cover most use cases makes sense. On the other hand saving $5 and loosing the ability to do either dual extruder or dual z-motors which are becoming increasingly common does not make as much sense.

    *) there is also a thread that claims to use pt100 without the extra board, but I haven't gotten around to verifying myself.

    So while I understand your use case, its a result of trying to shoehorn a problem into a solution, not something likely to affect the largest target for the product. OEMs, and the majority of enthusiasts will just replace the thermocouple and use a DC/DC buck converter for the fans. Print a case to make it neat afterwards.



  • Thank you all again for your comments. I thought thermocouples were much more prevalent as I've found that some people use the term interchangeably with thermistor.

    Now that I know that my situation is rather unique with this printer, I completely understand the design decisions. To be clear - I was never second guessing the design, as obviously they had thought long and hard about it, I just wanted to understand the reasoning.

    I still think adding an adjustable DC-DC regulator on board would be a nice addition. I don't really trust the no-name ones that are so prevalent online.



  • @j3d said in Maestro hardware decisions:

    Specifically, I'm using Noctua fans, which unfortunately utilize 12V. Since one reason to move to the Duet is quieter operation, wouldn't it make sense to have an option for quieter fans?

    Well they do make it very easy to supply your own separate voltage into the fan block to supply only the fan headers.



  • @phaedrux Neat, but that still requires an additional external buck converter. It's not hard to do, but is a bit inconvenient.



  • Fair enough, but now you're advocating for adding hardware after saying you wanted a more stripped down board. ☺



  • @phaedrux Touché 😏



  • and there are 5v noctua fans which can be connected directly to the duet. even better there are 5v pwm noctua fans.


 

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