Considering a Duet: Could Use Some Insight (UMO)



  • Hey guys,

    I am considering a Duet board for my original Ultimaker (probably a Duet 2 Wifi).

    My goals:

    • Quieter operation
    • More integrated fan control options
    • More accurate / smooth stepper motion
    • Network connectivity
    • More processor overhead. 8-bit is pretty lean once you start adding features.
    • Touchscreen support would be nice
      .
      .

    My questions:

    • Does the Duet firmware provide some type of extruder advance to improve flow control in bowden based printers?

    • Do the Duet boards support the Reprapdiscount Full Graphic Smart Controller? Some older posts here show that they had no plans to develop firmware support, even though the connections are present. But, some more recent posts seem to show the controller working on a Maestro.

    • Is a Type-K Thermocouple supported directly, or would it require an expansion board?

    • I believe my current heater cartridge is 18V 40W, and wondering if that would be directly supported as well.

    If anyone has some insights on this, I would definitely appreciate it!



  • @CCS86

    Yes, it supports pressure advance for Bowden

    Only the maestro supports that type of display. For the full duet 2 or duet 3 you would need to buy a paneldue (although I have one and always use the web interface)

    K-type thermocouples need the daughterboard

    The 18v heater cartridge depends on input voltage of the PSU. If you're using 18v in you'll be fine. Anything above or below that I would recommend changing it.



  • @jay_s_uk said in Considering a Duet: Could Use Some Insight (UMO):

    @CCS86

    Yes, it supports pressure advance for Bowden

    Only the maestro supports that type of display. For the full duet 2 or duet 3 you would need to buy a paneldue (although I have one and always use the web interface)

    K-type thermocouples need the daughterboard

    The 18v heater cartridge depends on input voltage of the PSU. If you're using 18v in you'll be fine. Anything above or below that I would recommend changing it.

    Thanks for the reply Jay.

    That is pretty disappointing that the less expensive board supports the LCD display/controller, but the more expensive ones do not. If they already wrote support into the firmware and the connections are present on the Duet 2 wifi, what is missing?

    Web control is nice to have, I just don't want to be forced into it. If I am wanting to make some small tweaks to a print: Z babysteps, flow, temp, etc; and I am in front of the printer, it seems super awkward to go across the room to the computer for every change. I don't want to bounce around the room like a ping pong!

    Do you use pressure advance? If so, what's your extruder setup and how would you rate the effectivenmess?



  • Pressure advance is VERY effective on my large bowden based printer.
    Re the web interface - do yourself a favour and buy a used old laptop (or maybe a tablet) and dedicate it as the display for the web control. It can be an ancient unit as no computing power is needed.


  • administrators

    @CCS86 said in Considering a Duet: Could Use Some Insight (UMO):

    That is pretty disappointing that the less expensive board supports the LCD display/controller, but the more expensive ones do not. If they already wrote support into the firmware and the connections are present on the Duet 2 wifi, what is missing?

    What's missing is hardware to gate the clock signal and level-shift it to 5V, which is the level that these displays require (the manufacturer specifies 3.5V minimum). I've heard of folks using these display with other 3.3V electronics without level shifting, and they had to slow the SPI clock speed down to make it work at all.

    On the Duet Maestro we included that gating and level shifting hardware.

    I would happily add firmware support for the 12864 display in the firmware build for the Duet WiFi/Ethernet, but users of it would need to add the missing hardware (basically a 74HCT08 chip) themselves.


  • Moderator

    @CCS86 You don't have to ping-pong across the room, just pull out your phone/tablet, connect to the Duet on your network, do it from there. Way more available functionality, too. No bending over/crouching down to look at the awkward screen that is at the bottom of the machine and not tilted back! Yes, I've used Ultimakers...

    Ian


  • Moderator

    @CCS86 said in Considering a Duet: Could Use Some Insight (UMO):

    If I am wanting to make some small tweaks to a print: Z babysteps, flow, temp, etc; and I am in front of the printer,

    That's why I love my PanelDue



  • @dc42 said in Considering a Duet: Could Use Some Insight (UMO):

    @CCS86 said in Considering a Duet: Could Use Some Insight (UMO):

    That is pretty disappointing that the less expensive board supports the LCD display/controller, but the more expensive ones do not. If they already wrote support into the firmware and the connections are present on the Duet 2 wifi, what is missing?

    What's missing is hardware to gate the clock signal and level-shift it to 5V, which is the level that these displays require (the manufacturer specifies 3.5V minimum). I've heard of folks using these display with other 3.3V electronics without level shifting, and they had to slow the SPI clock speed down to make it work at all.

    On the Duet Maestro we included that gating and level shifting hardware.

    I would happily add firmware support for the 12864 display in the firmware build for the Duet WiFi/Ethernet, but users of it would need to add the missing hardware (basically a 74HCT08 chip) themselves.

    Thanks for the quick reply!

    This would also be the case for the Duet 3?

    What are the biggest differences between the Maestro and Duet 2 Wifi?


  • Moderator



  • @Phaedrux said in Considering a Duet: Could Use Some Insight (UMO):

    https://duet3d.dozuki.com/Wiki/Comparison_of_Duets_vs._other_32-bit_controller_boards

    https://duet3d.dozuki.com/Wiki/The_Duet_family_of_motion_control_electronics

    Thanks for these links.

    It doesn't really seem like the Maestro would involve much sacrifice for me, compared to the Wifi (besides the wired connection).

    Can you think of anything for my application that would leave me wanting more from the Maestro?



  • @CCS86 said in Considering a Duet: Could Use Some Insight (UMO):

    Web control is nice to have, I just don't want to be forced into it.

    You don't have to get a paneldue, you can find an old phone/tablet that you bolt on to your printer (or not) and that connects through the web. You can either use the full web interface (DWC) or you can use the reduced web interface (dueui: https://forum.duet3d.com/category/33/dueui ) that's better suited for the small screen. That will be cheaper than paneldue and give even more versatility.



  • It looks like if I went with the Maestro, I could just order this heater and sensor for direct compatibility, right?

    https://www.filastruder.com/collections/all-e3d/products/e3d-pt1000-sensor

    https://www.filastruder.com/collections/all-e3d/products/e3d-heater-cartridge?variant=17411368550471 (Premium, 24v, 40w)

    The Duet 2 Wifi doesn't offer direct support for the PT1000 sensor?



  • @arhi said in Considering a Duet: Could Use Some Insight (UMO):

    @CCS86 said in Considering a Duet: Could Use Some Insight (UMO):

    Web control is nice to have, I just don't want to be forced into it.

    You don't have to get a paneldue, you can find an old phone/tablet that you bolt on to your printer (or not) and that connects through the web. You can either use the full web interface (DWC) or you can use the reduced web interface (dueui: https://forum.duet3d.com/category/33/dueui ) that's better suited for the small screen. That will be cheaper than paneldue and give even more versatility.

    Good call.

    I think I already have a mini windows tablet I could use.



  • Most of my printers are without screen. I am using octoprint and I connect from old useless under $10 android phones using printoid (android app that connect to octoprint) and while fairly cheap printoid pro can monitor multiple printers I use on these old phones printoid lite and have phone directly on each printer attach to a charger, as batteries are long dead. Works great for me. I'm now setting up new printers with DUET hardware (for now duet2ethernet but will soon get some duet3 boards too) and on few I have paneldue that I almost never use, so I decided not to spend more money on panel's and use only web interface, or if someone comes up with android/ios app I might use that. If push comes to shove I might even get some of my employees to make me something like printoid for android/ios that will work with DUET hardware. That might not be a bad business decision 🙂



  • @arhi : DueUI might work for you. I did not see an APK at the latest release assets, but Ik am site you will get one when you ask for it.



  • @DaBit already using dueui, I would not recommend it to ccs86 otherwise 🙂



  • @CCS86 The Duet 2 Wifi doesn't offer direct support for the PT1000 sensor?
    Er yes the Duet Wifi does offer full native support for a PT1000 without any other hardware!



  • @Dougal1957 said in Considering a Duet: Could Use Some Insight (UMO):

    @CCS86 The Duet 2 Wifi doesn't offer direct support for the PT1000 sensor?
    Er yes the Duet Wifi does offer full native support for a PT1000 without any other hardware!

    Thanks!

    They should update this page:

    https://duet3d.dozuki.com/Wiki/Comparison_of_Duets_vs._other_32-bit_controller_boards

    It is mentioned specifically for the Maestro and Duet 3, but not mentioned for the Duet 2 Wifi/Wired

    Also, on this page: https://duet3d.dozuki.com/Wiki/The_Duet_family_of_motion_control_electronics

    It says that it will work with the PT1000, but with "reduced accuracy". That's not as exciting.


  • administrators

    The Maestro has the following limitations compared to the WiFi/Ethernet:

    • Stepper drivers limited to 1.6A vs. 2.4A
    • No stall detection
    • Limited expansion, basically 2 more stepper drivers + a few GPIO pins
    • Available only in Ethernet version
    • Slightly less powerful processor, in particular no hardware floating point

    It has the following advantages:

    • Drivers support stealthChop, so quieter if you print slowly (stealthChop is not recommended for high speeds)
    • Supports low-cost RepRapDiscount LCD as an alternative to PanelDue
    • Easier wiring of BLTouch probes
    • Thermistor inputs optimised for PT1000 sensors (but a little less good for high-temperature thermistors)

    So if you don't need more expansion, and 1.6A current is enough for your motors (it's enough for almost all Nema 17 motors), and you are not running a Polar or SCARA printer that especially benefits from hardware floating point, then the Maestro is adequate and costs less.

    HTH David



  • @dc42 said in Considering a Duet: Could Use Some Insight (UMO):

    The Maestro has the following limitations compared to the WiFi/Ethernet:

    • Stepper drivers limited to 1.6A vs. 2.4A
    • No stall detection
    • Limited expansion, basically 2 more stepper drivers + a few GPIO pins
    • Available only in Ethernet version
    • Slightly less powerful processor, in particular no hardware floating point

    It has the following advantages:

    • Drivers support stealthChop, so quieter if you print slowly (stealthChop is not recommended for high speeds)
    • Supports low-cost RepRapDiscount LCD as an alternative to PanelDue
    • Easier wiring of BLTouch probes

    So if you don't need more expansion, and 1.6A current is enough for your motors (it's enough for almost all Nema 17 motors), and you are not running a Polar or SCARA printer that especially benefits from hardware floating point, then the Maestro is adequate and costs less.

    HTH David

    Thanks again David!

    The technical differences and real world interpretation are just what I was looking for.

    What would you say the speed limitation of stealth chop 2 is? And what happens when you exceed this? (Skipped steps, resonance?)


  • administrators

    @CCS86 said in Considering a Duet: Could Use Some Insight (UMO):

    What would you say the speed limitation of stealth chop 2 is? And what happens when you exceed this? (Skipped steps, resonance?)

    In my experience, the issue is skipped steps. That's what I experienced occasionally when I switched my Maestro-powered Ormerod printer from spreadCycle to permanent stealthChop.

    The maximum safe speed for stealthChop will depend on your steps/mm and you motors, but I think it would typically be between 50mm/sec and 100mm/sec.

    To counter this limitation, the drivers are normally programmed to switch from stealthChop at low speeds to spreadCycle at high speeds. The snag is that when it switches over, you get a slight motor jerk. The higher the speed, the worse this jerk is. You don't want a large jerk to happen during printing. This leads to two possible settings:

    1. Set the drivers to switch over to spreadCycle at a low speed. So they will be in stealthChop mode when idle and at very low speeds, but mostly in spreadCycle during printing. This is the default in RepRapFirmware.

    2. Set them to switch over at a speed higher than your highest printing speed, so that they only use spreadCycle during fast travel moves. Or, if you limit the travel speed, they will always be in stealthChop mode. This may be what the Prusa i3 it does in "slow and quiet" printing mode.

    HTH David



  • Thanks David,

    I tend to print mostly under 50 mm/s. If I ever went higher, it would be for infil moves, where a slight jerk for a mode change shouldn't be a big deal.

    In regards to the 1.6 amp max current, I am running these steppers to drive X and Y: https://www.omc-stepperonline.com/nema-17-bipolar-0-9deg-46ncm-65-1oz-in-2a-2-9v-42x42x48mm-4-wires.html

    They are rated at 2.0 amps. I highly doubt that my Ultimaker Original board is driving them anywhere near 2.0 amps. For a very light print, bowden print head there wouldn't be any issues at that 1.6 amp limit on the Maestro, right?


  • administrators

    2.0A motors is higher than I would recommend for a Maestro, however 60% of rated current is often enough, and some printers use as low as 50%. So a current setting between 1.2A and 1.4A should work. As you said, I suspect that the existing board drives them at much less than 2A.



  • Well, I pulled the trigger on the Maestro!

    Thanks again for the help everybody!


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