Ender3 + Duet Wifi,Dual Z, E3D Hemera, BLTouch. Need Advice



  • Hey guys,
    I've had a duet wifi on my Tevo Little Monster for about 6 months now, and although the print quality is not outstanding due to several mechanical problems, I've never really gone back to using my Ender 3 with it's MKS board and Octoprint ( The Duet board is just so much nicer to work with).

    Since Christmas is coming I wanted to treat myself to some Upgrades to my Ender and need some advice on a couple of parts. Currently I'm planning on upgrading to this:

    1)Duet Wifi - obviously
    - I want to keep by BLTouch - should work fine
    2)0.9 deg. Steppers
    - Possibly with some cheap Dual Z-Axis kit and two stepper motors for Z
    3)E3D Hemera
    4)Hiwin-Rails for Y und X (If i feel like spending another 200 bucks...)

    My main question is: Would the E3D High torque axis motors be a good choice? On paper they seem to be better than the 17HM19-2004S ones recommended by dc42, plus they are all black and have plugs instead of wires coming out of them...
    Stepper motors are confusing enough and reading the wiki and comparing the motors made it kind of worse πŸ˜„ I always assumed "they just work. 0.9 is better than 1.8 and longer motors are stronger! The DuetWifi can drive any Nema17, so you are fine with most of the stuff you find online"
    A little insight or someone more qualified than me saying "both are fine" would be a massive help for me πŸ˜‰

    Secondly the Dual Z idea seems a little challenging:
    When using mesh bed levelling, is there a benefit to not wiring the two steppers in series? (connecting one of them to the spare extruder driver and using software to level the gantry)
    It seems like this could reduce the z-movement during a layer with an unleveled bed, but is that even noticable?

    I hope you guys can give me some insight. I like tinkering but i might not be very good at it πŸ˜„ If you want to i can update you on my progress πŸ™‚



  • TL/DR: Both are fine! Or try the original motors first. Upgrade to a 24V PSU, if you're on 12V. Dual Z on different drivers is fine. Works fine with mesh levelling.

    Stepper motors are confusing enough and reading the wiki and comparing the motors made it kind of worse I always assumed "they just work. 0.9 is better than 1.8 and longer motors are stronger! The DuetWifi can drive any Nema17, so you are fine with most of the stuff you find online"

    Generally, this is my view too! Certainly, when all there was was 1.8ΒΊ motors, slow printers and stepper drivers capped at about 1.2A, I don't think there was much talk of inductance. However, if you want to go really fast (eg 200mm/s or faster), you're going to need low inductance motors, and 24V power supply. You can do the calculations if you want; see https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors#Section_Inductance
    If you don't intend to go that fast, then, as I do, just pick a NEMA 17 motor out of your parts bin!

    As the Ender 3 is a Cartesian printer, whether you choose 1.8ΒΊ or 0.9ΒΊ steppers is a bit trickier. There should be a small increase in quality, though the infamous Vertical Banding is seen more on CoreXY machines. With the Duet's (or rather the Trinamic driver's) interpolation, I can't say I've noticed it on my Cartesian machine with 1.8ΒΊ motors.

    I also use Dual Z motors. I like the gantry levelling (I use one of dc42's IR probes), which means that the X axis stays level and doesn't bind on the Z (as it would if it got a long way out of whack). It's quite simple to set up in config.g, and the homing macros don't need to change. I just wrote a separate macro to level the gantry when I feel like it needs it, see https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors. There's no issue with using this and mesh levelling at the same time; though I generally advise to get your machine as mechanically level as possible, then you may not even need to use mesh compensation, other than to check the bed is flat occasionally.

    Ian



  • Personally I wouldn't put too much effort into altering the Ender 3 in such dramatic ways. I just don't think there will be much improvement. The design as it is is actually quite good. The steppers aren't amazing, but they aren't bad. Switching to 0.9 degree on the X and Y won't likely show any improvement.

    The Z axis of the Ender 3 isn't that bad either provided the wheels have been properly tensioned. If there is any droop it would be compensated for by leveling the bed or using mesh compensation (which you should use because the Ender 3 bed is probably warped.)

    The one thing that I would change about the Ender 3 Z axis is the lead screw. I've switched to a 2mm pitch single start lead screw which improves the full step resolution from 0.04 to 0.01 without changing the motor. This improves the accuracy of homing and mesh compensation and allows for unlimited layer height selection. And it only costs a few dollars and takes a few minutes to swap.

    The other sore point of the ender 3 design is the extruder. Either swapping out the stock extruder for a geared extruder or converting to a geared direct drive would be beneficial. The extruder is also the only Axis that would really benefit from a 0.9 degree motor.

    As an aside I'm actually nearly finished Part 5 of the Ender 3 guide series that goes through some upgrades. Stay tuned for that.

    https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+1:+Wiring/37



  • @droftarts
    I Will definitly look into that! I was kind of scared that the two Z-Motors might bend the gantry, but the documentation states that i could adjust the maximum correction value for each leadscrew, so that should not be a problem! Thanks a lot! I'll be aiming for about 60mm/s print speed and 150mm/s travel, so the motors wont really matter i guess... (i have a 24v power supply already. the cheap one that came with the printer... If you know a "safer" option with about 350 Watts and a silent fan, I'd be happy to upgrade that fire hazard as well)

    @Phaedrux
    I know what you mean... I've thought about "just getting a Prusa" a lot, but 3D-printing is more of a project/hobby for me, not a tool, so spending dumb amounts to not see a huge improvement is kinda fine...
    anyways: I've been looking to upgrade to a direct drive for a long time and the hemera seems just perfect! It does not require huge modifications and should work just as good as a bondtech/V6 combo (which would cost a lot more) and should come with a 0.9Β° stepper (although it's not stated in the datasheet)
    I live in germany, so the prices for a Duet-Wifi and a Hemera add up to about 300€. The metal piece i need for the dual z conversion costs about 4€ (a leadscrew, brass nut and coupling add up to about another 20€), so even if it does not help much, the cost does not really matter after spending 300€ on important stuff...
    btw: new steppers for the machine would cost about 60€. I don't need a panel due (which would cost about 100 €).

    I've read your guide and really like it:) It's part of why i thought upgrading the Ender 3 until it's no longer a creality machine but rather my very own machine seemed plausible πŸ˜‰

    I might just go ahead with the Duet and Hemera stuff and look at the prints before upgrading any of the mechanics (other than the lead screw with 2mm pitch which i ordered for 10€ jesterday after reading you comment).

    Thanks a lot guys!

    EDIT:

    well... nominal steps/mm is 409 and if The titan documentaion is correct (which i assume), that means it's a 1.8° stepper with a similar gear reduction. That should still be fine though @Phaedrux , right? It's half the resolution of their titan extruder. I don't get why they would do that 😞



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  • @Laurensvdg said in Ender3 + Duet Wifi,Dual Z, E3D Hemera, BLTouch. Need Advice:

    well... nominal steps/mm is 409 and if The titan documentation is correct (which i assume), that means it's a 1.8° stepper with a similar gear reduction. That should still be fine though @Phaedrux , right? It's half the resolution of their titan extruder. I don't get why they would do that 😞

    It depends on if you get the titan as a kit that includes a motor. With a 1.8 degree motor, yes it's about 409, and with a 0.9 degree motor it's obviously double that. Both are viable options. The 3:1 gearing is the main thing. It increases torque and resolution to the point that either 1.8 or 0.9 motors are just fine. Perhaps if you have a long bowden setup and you want more torque the 1.8 motor makes the most sense since the added resolution of the 0.9 is likely lost to compliance in the bowden tube anyway. Whereas if you have a direct drive system and are printing high detail low layer height small nozzle diameter miniatures the extra resolution of the 0.9 motor makes more sense.

    @Laurensvdg said in Ender3 + Duet Wifi,Dual Z, E3D Hemera, BLTouch. Need Advice:

    the cheap one that came with the printer... If you know a "safer" option

    If you wanted an easy and cheap upgrade for the ender 3 PSU, the Ender 3 Pro PSU is a MeanWell. It's silent for the most part, but with the bed heater on it will kick in the fan occasionally during a print and it's a bit loud. If you're using the stock fans for the hotend and electronics enclosure you won't likely notice it, but if you've swapped those out and are using the quiet drivers of the duet the PSU becomes the loudest component by far.

    I'm tempted to open it up and add a resistor to the fan and wire it up as always on. I've seen it reported that the fan is actually a 12v fan getting 24v so it spins fast and loud. The only redeeming factor is that it's temperature controlled.

    Alternatively, there are passive MeanWell PSUs with no fans but they cost as much as the Ender 3 or more for a 350w.

    By the way, here is a first draft of the Ender 3 Upgrade guide: https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+5:+Upgrades/54



  • @Laurensvdg said in Ender3 + Duet Wifi,Dual Z, E3D Hemera, BLTouch. Need Advice:

    I was kind of scared that the two Z-Motors might bend the gantry, but the documentation states that i could adjust the maximum correction value for each leadscrew, so that should not be a problem!

    In my opinion dual Z motors on the Ender 3 cause more issues than it fixes. Aside from the additional cost and complexity, there needs to be some compliance built into the gantry to allow for independent adjustment. But really, it's just a non-issue. The short length of the X axis means there is very little if any sag. Just look at the PrintrBots or the new Prusa mini that use a cantilevered X axis. At such a small size it's just irrelevant. The added rigidity from having the other end of the X axis supported by the 3 wheel tensioner makes it totally fine. For a much larger printer like the 500x500 CR-10 Max having a lead screw and motor at each end makes sense.

    I'll be aiming for about 60mm/s print speed and 150mm/s travel, so the motors wont really matter i guess...

    Totally doable. I've got the Ender 3 Pro up to 80mm/s print and 200mm/s travel with still good quality using the stock motors. The only thing that starts to lag is the extruder, but as long as you're within the volumetric extrusion limit and you can cool the layers fast enough it's fine.



  • @Phaedrux
    Thank you for all the good advice!
    I will definitly wait with the dual z upgrade and see how the print quality changes with the better extruder and control board (Duet and Hemera have just been ordered). The added weight of the direct extruder might make it worthwhile, but i will not jump to conclusions before actually trying it.

    That Guide is, as always, very helpful, but since i used the ender 3 for about a year before getting the tevo little monster, I tweaked quite a lot πŸ˜‰
    I added a BL-Touch first and got a MKS board with 2208 drivers. I used capricorn tubing and new couplers for the stock hotend and extruder (the couplers helped a lot more than the tubing i guess... ) and swapped the hotend fan to a noctua with a buck converter.
    As a part cooling fan i used a 6000 rpm 5015 12v sunon fan which is actually pretty nice, but does not like to be run with less than 12v and i can't figure out how to control the speed on it...
    I also have a 92mm noctua fan for the PSU (with a PLA-Cover instead of the metal one... feels sketchy) and one 80mm fan for the electronics.
    Basically I only hear rattling when small infill patterns are printed and the part cooling fan.

    I just really want to get rid of all the converters and might swap all the fans to 5V ones once the Duet is here. Controlling the part cooling fan a little bit more granually than "on and off"would be nice...

    Tanks for the Tipp with the ender 3 pro PSU. I could get that for about 35€. The passive Meanwell ones i could get from reputible sources in Germany are about 150€; The ones with temperature controlled fans are about 90€. I will look into that a bit more; I dont really know if i can trust Brand-Stickers from chinese vendors πŸ˜›



  • I have an Ender 3 with Maestro, Bondtech, E3Dv6.

    My advice:

    Flip the Z so the motor is on top (I cobbled together a mount, which was cake) , no dual Z

    I messed with 0.9 motors before and they were more trouble than they were worth. Especially on a direct drive extruder. You would be better served by a geared stepper on Z.

    The Hemera should be awesome

    If you don't have a Pro you need to widen the Y rail. I would not just stick a single linear rail there. I would stay with rollers and a wider rail. 3 point is also preferred to 4.

    Mine has the updated hard clear rollers. They are well worth it.

    Put in a good part cooling duct with opposing cooling ducts. Might be a challenge to find for Hemera. I dislike the single sided ducts.



  • @Laurensvdg said in Ender3 + Duet Wifi,Dual Z, E3D Hemera, BLTouch. Need Advice:

    As a part cooling fan i used a 6000 rpm 5015 12v sunon fan which is actually pretty nice, but does not like to be run with less than 12v and i can't figure out how to control the speed on it...

    Try adjusting the PWM frequency using the M106 F parameter. Values from 10 to 30000 hz are valid. The Sunon blower I'm using is not super powerful so it basically needs to be at 100% at all times anyway, but changing the frequency can often help adjust for sound level as well.


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