IDEX Support



  • Is it possible to use/configure dual independent extruders with the current firmware? After building a CoreXY i'm tempted to convert it to a classic Cartesian and add a stepper to each side of the Z axis.


  • administrators

    I am working on the hardware for this right now so I have a printer to test with. Converting a BigBox with the development design : https://forum.e3d-online.com/index.php?threads/bigbox-dual-x-carriages.2184/



  • Well if I do my conversion now as I can still use a single extruder,maybe I can help with testing?



  • This is how they do it on the sigma:


  • administrators

    Having multiple machines to test on would be good. I know they are a few people working on BigBox rebuilds for this but most are not using Duets (yet 😉 )


  • administrators

    I have stared work on firmware support for IDEX. See https://duet3d.com/wiki/Configuring_multiple_independent_X-carriages_on_a_Cartesian_printer for how it will work. I have already committed a 1.16 alpha release to github with support for the additional axis.


  • administrators

    @iDevelo:

    Is it possible to use/configure dual independent extruders with the current firmware? After building a CoreXY i'm tempted to convert it to a classic Cartesian and add a stepper to each side of the Z axis.

    Is there any way to generalise CoreXY so as to have 3 stationary motors controlling the XY positions of 2 print heads, where the Y positions are constrained to be the same? I'll ask this on the reprap.org CoreXY forum too.



  • @dc42:

    @iDevelo:

    Is it possible to use/configure dual independent extruders with the current firmware? After building a CoreXY i'm tempted to convert it to a classic Cartesian and add a stepper to each side of the Z axis.

    Is there any way to generalise CoreXY so as to have 3 stationary motors controlling the XY positions of 2 print heads, where the Y positions are constrained to be the same? I'll ask this on the reprap.org CoreXY forum too.

    I really don't know. I struggled to get my head around basic corexy!

    Good work on 1.16 🙂

    I'll probably just copy the way the Sigma does it. It will also make it quicker to level my bed as I'll have a Z switch on each carriage in series instead of the IR probe.


  • administrators

    I posted a question on IDEX for CoreXY at reprap.org and got this response http://forums.reprap.org/read.php?397,714601,715065#msg-715065. So perhaps you don't need to convert to Cartesian.



  • @dc42:

    I posted a question on IDEX for CoreXY at reprap.org and got this response http://forums.reprap.org/read.php?397,714601,715065#msg-715065. So perhaps you don't need to convert to Cartesian.

    Interesting you may be the first to invent CoreXYU 🙂

    I'll do the conversion anyway to try it out as I've nearly got all the parts ready.


  • administrators

    I have released Duet firmware 1.16 beta 2. This completes the work to support the extra axis needed by IDEX. So anyone who has an IDEX machine should be able to configure, home and move the second carriage. You can also configure X axis mapping in M563 as described in the wiki. However moves are not yet mapped, so printing with the second carriage doesn't work yet.

    I have also released PanelDue firmware 1.15 with support for additional axes in the homing buttons and movement grid.



  • Well done. I'm on track to get my X/U done tomorrow. Is the E0 high endstop working in the beta?


  • administrators

    @iDevelo:

    Well done. I'm on track to get my X/U done tomorrow. Is the E0 high endstop working in the beta?

    Yes according to M119, when you configure it that way in the M574 command. E1 is also working as a V endstop if I enable the V axis.



  • Can E1 be the U endstop? I use E0 for my Z microswitches.


  • administrators

    No, E0 has to be the U endstop. If your Z microswitches are normally closed and you are using them to implement Z probe type 4, you can connect them to the Z probe connector and select type 5 instead. I may also add an option to connect a switch-type Z probe to the E1 endstop input when there is no V axis.



  • Ok thanks. I'll give that a try.

    With IDEX I have a micro switch on each carriage that can measure the height of the bed and make it easy to level.

    So am I thinking right if I switch from T0 to T1 and viceversa in gcode the Z offset will be applied for that nozzle and move the bed up or down?


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    @iDevelo:

    So am I thinking right if I switch from T0 to T1 and viceversa in gcode the Z offset will be applied for that nozzle and move the bed up or down?

    Yes.


  • administrators

    I have two IR probes, one on each carriage. I plan on levelling the bed with one and then using the other (on the U axis) to set the second extruder Z offset.

    In the long term I can envisage a Idex system that can automatically determine all the offsets by scanning the bed which has a variably reflective pattern at one point. Or anyone head printing a pattern and the other head scanning it with the probe.

    Anyway, the probe on the X axis carriage is connected to the probe header, currently the on in the U axis carriage is connected to the Z end stop, is this correct?



  • My glass is raised 10MM off the alloy bed. The alloy is 550x550 and the glass is 450x450 so i have enough room around the glass to use switches. The switches are on each carriage about 5mm above the nozzle. The carriages move the the edge of the glass and lower down until they hit the switch. I then get the Z reading.

    To level i use a 3 screw system so i only ever have to adjust the front 2 screws. The routine probes the back left corner of the glass and sets Z0. Then the front 2 corners are probed and i get the 2 readings i need to level the bed.

    Now i'm going IDEX i will have a switch on each carriage. It will allow me to level the bed and also set the Z offsets for X/U easily.


  • administrators

    That sounds like a good design. There is not space in the BigBox for that configuration but the probes should allow me to do a similar thing.

    That said if I want to print two objects at once, one per axis, then I need to have the Z height identical for each nozzle



  • @T3P3Tony:

    That said if I want to print two objects at once, one per axis, then I need to have the Z height identical for each nozzle

    But I see issues there on the BB because per design the extruders are fixed, you can't adjust them. Well maybe be pushing and pulling but there is no mechanism. So if the offset is too big, lets say more than a layer height, then you will have hard times doing so.


  • administrators

    Can the BB design be changed to provide a height adjustment on one carriage? It would be a shame not to be able to print two identical objects at once. Could one of you raise this on the BigBox forum?



  • Well you could make long holes on one X carriage but that you be a pain to level I think. Best would be to decouple the extruder mounting from the bearing mounts with a part between which can then be height adjusted…


  • administrators

    The design could be modified. one simple way that might work is to make the extruder motor mounting hole elongated. Then start with them slightly loose and rest both hot end tips on the bed in the centre (one the bed is levelled for the X axis). then tighten up ensuring the tips remain incontact with the bed. The one issue with this is one of the titan mounting screws is obscured by the hotend so tighten 3, then remove hotend and tighten last one, replace hotend, and test.

    A complete carriage redesign, that allowed for quick swapping of tools would be good anyway so maybe it could be incorporated into that.


  • administrators

    In fact you would only need to do this for one carriage, which I will do and report how it works


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