Duet Wifi and CR-10



  • Hi,
    I am a newbie to 3D printing and having bought a CR-10 and just about got my feet wet and a setup that was working the mainboard went and died on me☹

    DjDemon spoke very highly of these boards when I bought the printer and I was considering it for a future upgrade once I knew more but as I have to replace the board anyway I have one arriving tomorrow☺

    I understand that this may well be a steep learning curve but I figure since I already know nothing I hopefully won't have any preconceived ideas working against me🤞

    needless to say I am digging around this and other forums to try to understand as much as i can in preparation and at least the wiring side seems like it shouldn't be to problematic but if there are any potential issues that may not be obvious then any pointers from the community would be gratefully received.

    while the configuration tool looks handy if anyone who has already done this could share their experiences and/or a working configuration to help me get started that would also be a great help.

    also does anyone know if I am correct in thinking that the motors on this machine would require a setting of 500mA? I think I found a reference from DC42? about this but it was late last night and I can't find it again now.

    thanks in advance for any help you can give.



  • Hi,

    Welcome to the Duet Owners Fan Club! 🙂

    While you can use the configuration tool you can also also do it step-by-step to develop a greater understanding of what the config file contains.

    For example you could configure as a starting point your end stop switches and verify that they are working.

    Then you could configure, say, your bed stepper and verify that it is working.

    Just something to think about.

    I've seen folks take a new config file generated by the tool and try to jump right in and print.

    Good luck.

    Frederick



  • @opentoideas Ref motor currents. A good starting point is to set them to about 85% of their rated current (no idea what a CR10 uses but you should be able to dig out a data sheet for the motors).

    Best advice I can give is to read through this https://duet3d.dozuki.com/Wiki/GCode.

    Not everyone's idea of bed time reading but an understanding of what all the gcode commands do (or as many as you can remember) will stand you in good stead for what is to follow. Bookmark that link and refer back to it often.



  • Thank you for the advice. It mirrors my own thoughts and that g code link is already in my favorites.

    Likewise with the step by step on the axis and end stops. Thats going to be the testing plan and certainly no printing until I am sure the basic setup is at least working.

    The configuration is I presume only a best guess and I expect a great deal of tweaking as already things are not standard as I have a Titan Aero extruder and Vilcano hotend as well as precision piezo Z sensor so lots to configure thats not standard CR-10 but hopefully it will give me some basic information to work from.

    Looking forward to getting started with this.



  • @opentoideas To test end stops, use DWC (that's Duet Web Control), go to "settings" (bottom item on the left hand side), then select tab "Machine Properties". Among other things, it'll show you the status of all the end stops. Assuming you are using some sort of switch, press each one in turn and the status should change. If not, check your config or wiring. It's safer than just trying to home an axis and hoping that the switch will trigger when the carriage reaches that point.



  • @deckingman

    simple and safe. Great plan and great to know the info is easily accesable as I would have started a home from far away and triggered them manually to check but this is much better.

    Thank you



  • @opentoideas Once you know the end stops are doing what they should, then it's reasonably safe to assume that you can home without crashing anything and doing any damage. Once the printer has been homed, the firmware won't allow you to go beyond the axes limits that you set using M208. Before it has been homed, the firmware has no idea where the print head is. So it used to be possible to initiate a move beyond the axes limits. Latest firmware prevents that happening by not allowing axes movements until they have been homed. During commissioning, you might find this annoying. If so, you can use M564 H0 to allow moves prior to homing. Use with caution though.



  • thanks again,

    other than to check direction of the steppers I hopefully won't need to run any moves prior to homing and like you say this is the danger area.

    looks Like for the moment I will have to use the bed heater mosfet from the CR-10

    did a quick test of the bed heater and while it can be kept under the 18A limit of the Duet that would mean keeping voltage to <12.4V and more like 11V to have a reasonable margin.

    11.5V gives roughly 180W for the bed heater at 16A
    15.5V gives roughly 350W for the bed heater at 23A

    I suspect this is why the mainboard failed as the PSU has some adjustment and the prior owner had it turned up to 15.5V which certainly helped make the bed heating less painful to wait for but the regulator on the board has a 15V limit so I suspect when it let go it passed an over voltage and pop lol

    I think another future upgrade will be mains heating on the bed but for now I can live with waiting a few minutes for it to heat up



  • This post is deleted!


  • @opentoideas

    Above post deleted because I was stupid and got my maths wrong☺

    If you were going to change the bed heater, it might be worth changing the printer to 24V. I use a mains heater but for a bed your size, a 24V heater would likely give you the heating power you need. It's a bit safer than mains power and saves the cost and complexity of a SSR. 24V @16 Amp is 384 Watts. You'd need to change the hot end heater and possible fans but there are ways to run 12V fans on a 24v system - it's just a jumper if all the fans are 12v.



  • @deckingman I understand the safety side of mains heaters and the benefit and simplicity of keeping it all 24V. some of the conversions I have seen online are just scary and while wiring is simple and will work safe is not a word that should be used for them! watched one yesterday with a chap using the low voltage CR-10 connector and not even considering that if unplugged the pins are live and easily touched! but it worked!!! 😨 😨 😨

    (just finished a 3 phase 24KW silicone pad heated plating tank running at 230C, man was that fun to ensure fail safe and safe operation! but agreed 24V would be the simplest and safest option for most)

    To be fair have not yet decided how I will go about this however I have just dug out a 200W Meanwell PSU I had spare and will most likely use this though I do need a new hotend heater first ( I did read its possible to have 12V hotend with 24V system but its not ideal so I will wait for the cartridge before doing this.(its only a few pounds and the benefits seem well worth it)

    given I already have this PSU and SSR's from other projects I am not sure that 24V bed heater is the best option for me but there is a lot to be said about keeping everything 24V and it should always be the first option.



  • @opentoideas Another consideration is noise. You'll likely find as most people do that the machine runs very much quieter with the Duet. Then things like fans start to become intrusive and many of us have then started to use quiet fans but this is sometimes difficult to do with the PSU. So running a mains heater enables one to use a fanless PSU of around 200W or less. It sounds like you know what you are doing with a mains heater, in which case that might be a better choice. But there are other advantages to running 24V. I believe that steppers can be driven faster before the start to lose torque for example. I'm just trying to point things out but you'll have to weigh up the pros and cons and decide what is best for you.

    HTH and best of luck.



  • thank you deckingman, your input is appreciated and it is reassuring to have others thinking along the same lines as I am.

    the consensus seems to be that going to 24V is well worth it for many reasons and as I have the PSU I would be daft not to but as there are a few other bits that need to be changed to work on 24V this may have to wait for now but it is certainly on the list.

    please let me know anything you can think of, its all good, and I want to work things through and while I am not the type of person to take a suggestion blindly and run with it at the same time I am fully aware that "you don't know what you don't know" so I would rather work through 1000 things I may have already considered as you never know when that one thing you didn't know will come along and bite you on the ass



  • waiting sucks - Duet on the Fedex van for delivery but not here yet lol

    currently thinking over temperature monitoring....

    so thermistors and PT1000 connect direct

    thermocouples and PT100 require a daughter board to work

    most of my printing is PETG so for the moment high temps should not be a problem and with only one machine consistency is more important than accuracy I presume. (again please remember I am newbie so feel free to correct me if i am talking out of my rear!)

    assuming that despite accuracy being poor the thermistors are at least consistent then is there any reason I should swap as the cost is not insignificant. I am also assuming that I can add a correction factor to the temp reading in software if needed?

    if so then any suggestions for ones that will work with the volcano's pocket?



  • @opentoideas Based on my own experience, I bought both PT100 and thermocouple daughter boards. Never used thermocouples. Tried PT100s (not the E3D ones I hasten to add, as they wouldn't fit in my Diamond hot end). The ones I used had very thin wires which kept breaking and replacing them started to get too expensive. Changed to a simple thermistor and never looked back. OK so even if it's 5 degree out, it doesn't matter. When you try a new filament, you do some tests to determine the best temperature to print it at on your machine. So if you find 225 deg C to be best, that's what you use. It doesn't matter if the actual true temperature is 220 or 230.

    I still have the second PT 100 connected to my bed but it picks up interference from the Z motor wiring somewhere that I've never been able to trace. It's no big deal - I just get short spikes to 2,000 deg C when moving te bed a long way such as starting a new print with the bed a long way down. I keep meaning to change it for a thermistor but simply haven't got around to it.

    E3D thermistors would be the best compatibility wise. They'll fit and the data is readily available. But any known 100K NTC should do the job.



  • @deckingman - thanks again, this mirrors my own thoughts. I had a read the post where you also asked this and noticed in DC42's description of the types that though the PT100 is most accurate but that it could suffer interference.

    shielded cables should deal with this but it's an added hassle.

    I guess if you have more than one printer or farm out jobs then accuracy is most important as you want repeatability between machines but I was thinking along similar lines as you that as long as the temperature reading is consistent then the actual value is not so important for me as it would be for some.

    I have some thermistors and PT1000 on the slow boat heading my way so it will be interesting to see if there is a difference.

    I am more familiar with thermocouples for industrial use but they are a pain as you really need to have the same wire from the junction to the sensor so demounting the hotend is less simple.(though I have got away with connectors in less critical applications this defeats the point)

    why is it that when I didn't need the parts the Fedex delivery was mid morning and now I need the part it's looking like I will get it at the last possible moment of the delivery day!

    Murphy strikes again!!



  • next thing to think about.....

    I currently have dual Z axis drive motors and the current wiring has these in parallel.

    Looking at the Duet board it seems this has been considered and there are 2 Z axis headers and the advice I have found is that these are wired in series and this is better for our use.

    so if I am understanding how stepper motors work then am I correct in thinking that if I use these 2 connectors one for each motor then the "A" coils on the two motors are linked in series and the "B" coils are linked in series?

    if so then I just have to make sure that the wiring looms board to motor are the same for each motor to avoid them going in opposite directions?

    is there anything I have not considered or am I just plain wrong?



  • @opentoideas I'm not the best person to answer that as I only use a single Z stepper. What you say sounds right but to be sure, I think you'll find all the answers you need here https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors



  • @deckingman lol not quite. been there and read that but it only got me as far as I am. hopefully there are others out there that will read this but either way I can test without the leadscrews connected just to be safe.

    starting to look like Fedex re not bothering to deliver to me today - only 15 min left of the delivery window so not very happy with them. think I will be complaining to E3D in the morning - not that it's their fault but the couriers dont give a damn about the recipient only their client


  • administrators

    @opentoideas said in Duet Wifi and CR-10:

    next thing to think about.....

    I currently have dual Z axis drive motors and the current wiring has these in parallel.

    Looking at the Duet board it seems this has been considered and there are 2 Z axis headers and the advice I have found is that these are wired in series and this is better for our use.

    so if I am understanding how stepper motors work then am I correct in thinking that if I use these 2 connectors one for each motor then the "A" coils on the two motors are linked in series and the "B" coils are linked in series?

    Correct.

    if so then I just have to make sure that the wiring looms board to motor are the same for each motor to avoid them going in opposite directions?

    Yes.

    However, if they are wired in parallel in the wiring loom, I suggest you leave them that way. If they are low current motors, then parallel wiring is better than series anyway.

    Alternatively, if you have no other plans for the E1 motor output then you can connect one to Za and one to E1, then if you have a Z probe on your machine, you can get them to sync up automatically. See https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors. Use the M584 command in config.g to tell the firmware that you have them connected this way:

    M584 Z3:5 E4


 

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