UNSOLVED Please help with a couple of Delta queries.



  • Hi all,

    I'm looking to build a large format delta machine, 600mm diameter print bed. I am reading through all the various documentation but can't find an answer to a couple of questions.

    Can I have my z height controlled independently of the carriages and so also the effector? So if the bed is movable in the z and controlled by a drive motor, can it be configured as such to do the z moves?

    I understand I can have up to 6 towers which would be useful as I can keep a second parallel effector to hold extruder above the print effector, it would follow the exact same movements, is this something that the firmware would automatically do? Or would it somehow need to be programmed via the slicer software? The reason i'd like to do this is to keep minimal weight on the print effector as it will be a dual extrusion set up and gives me some options in the design.

    Many thanks for any advice.



  • @scerbera said in Please help with a couple of Delta queries.:

    Can I have my z height controlled independently of the carriages and so also the effector? So if the bed is movable in the z and controlled by a drive motor, can it be configured as such to do the z moves?

    Interesting question.

    What would be the advantages of that?

    You have to have vertical movement on the towers to obtain XY movement and you get the needed Z motion as well.

    Thanks.



  • @fcwilt said in Please help with a couple of Delta queries.:

    @scerbera said in Please help with a couple of Delta queries.:

    Can I have my z height controlled independently of the carriages and so also the effector? So if the bed is movable in the z and controlled by a drive motor, can it be configured as such to do the z moves?

    Interesting question.

    What would be the advantages of that?

    You have to have vertical movement on the towers to obtain XY movement and you get the needed Z motion as well.

    Thanks.

    Because lets say I need 300mm vertical travel to give me the full range of motion on the xy planes, but I want for example 600mm print height then I need 900mm total travel. If I can separate out these requirements then I can create a much more rigid structure with only the 300mm. I intend for the chamber to be heated with a max temp of 200c so it also allows me to do this with less heat affected areas.



  • @scerbera

    I hope you will post pictures of your work as it progresses.

    As to your other question I know other folks have implemented "flying extruders" but I don't know the details.

    Have you considered using remote direct drive units like Zesty Nimbles or Flex3Drive?

    I used Nimbles with success on deltas and non-deltas. I also have a Flex3Drive but have yet to use it.

    Frederick



  • @fcwilt Thanks for your replies. Much appreciated. Do you know if what I have asked is possible and configurable? Thanks, Ryan.



  • @scerbera said in Please help with a couple of Delta queries.:

    @fcwilt Thanks for your replies. Much appreciated. Do you know if what I have asked is possible and configurable? Thanks, Ryan.

    No I don't.

    dc42 is the master of all that the Duets can do. If the current firmware cannot support that design he would be the one to implement it.

    Frederick



  • @dc42 Any thoughts? Many thanks, Ryan.



  • @dc42 I note this has an unsolved tag, is this something you are able to implement? If so can you advise an approximate timescale? many thanks, Ryan.


  • Moderator

    Hopefully DC42 will be able to take a look shortly.


  • administrators

    @scerbera said in Please help with a couple of Delta queries.:

    Can I have my z height controlled independently of the carriages and so also the effector? So if the bed is movable in the z and controlled by a drive motor, can it be configured as such to do the z moves?

    That combination is not supported directly at present. However, you can define additional linear axes when using delta kinematics. So you could create a U axis and post-process the GCode file generated by the slicer to replace all instances of Z by U.

    One of the big advantages of a delta printer is the fixed bed. What do you see as the advantages of moving the bed in the Z direction? You are already planning to use a flying extruder, so it wouldn't shorten the Bowden tube.

    I understand I can have up to 6 towers which would be useful as I can keep a second parallel effector to hold extruder above the print effector, it would follow the exact same movements, is this something that the firmware would automatically do?

    Yes.



  • @dc42 said in Please help with a couple of Delta queries.:

    @scerbera said in Please help with a couple of Delta queries.:

    Can I have my z height controlled independently of the carriages and so also the effector? So if the bed is movable in the z and controlled by a drive motor, can it be configured as such to do the z moves?

    That combination is not supported directly at present. However, you can define additional linear axes when using delta kinematics. So you could create a U axis and post-process the GCode file generated by the slicer to replace all instances of Z by U.

    One of the big advantages of a delta printer is the fixed bed. What do you see as the advantages of moving the bed in the Z direction? You are already planning to use a flying extruder, so it wouldn't shorten the Bowden tube.

    Thanks, my design is continuing to evolve so 6 towers probably not required, however z height via bed is integral to design. The biggest plus is structural rigidity and the requirements for a heated chamber. I have isolated the towers from any chamber heat and that would not be possible with existing conventional designs, I have settled on an 800mm bed diameter and will want 1000mm in z axis. I'll post design features in my build thread in the next week or so.

    Thanks for the information regarding potential U axis, would bed levelling still be an option with 3 drives on the U?

    Thanks again.


  • Moderator

    @scerbera said in Please help with a couple of Delta queries.:

    would bed levelling still be an option with 3 drives on the U?

    Well you could potentially still map it as Z axis and use independent bed leveling, but it would also depend on your probing arrangement.

    Admittedly I'm having a hard time picturing your kinematic, so maybe more will become clear when you reveal more.


  • administrators

    I don't think you will gain from increased rgidity, because you need more rigidity to raise a heavy bed than you need to raise the carriages and effector.

    I presume you are keeping the towers out of the chamber to protect the belts. You will still somehow need to have the connection between the carriages and towers crossing the chamber boundary over quite a long range of movement. Is it really that much harder to increase the movement range to the full range needed for a conventional delta?


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