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  1. #11
    Super Moderator curious aardvark's Avatar
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    He's already bought the tronxy :-)

    The sidewinder has a few design issues - too much like a creality machine for my liking.
    Also reviews are quite mixed. Usually more Indicative of manufacturing inconsistencies than any major issue witht he machines.

    Anyway - yes there are several ways to add multi material capability.

    You can go the prusa route and get a mumu: https://www.prusa3d.com/original-pru...-material-2-0/

    This has an added advantage in that Autowhiz alreadu has one and you could pester him with lots of questions :-)

    The other and slightly more expensive, but - in my opinion - much more elegant solution is the palette 2: https://www.mosaicmfg.com/

  2. #12
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    No. there is any confusion to suggest other printers than the 3 I have mentioned.
    Me also I am seeing some other, like Geeeteck A30.

    One issue of this printer you suggest, is manual bed leveling.
    Otherwise it seems to be a good choice.

  3. #13
    Super Moderator curious aardvark's Avatar
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    what's wrong with manual bed levelling ?
    Takes 2 minutes and if you change he levelling nuts for nylock locking nuts you do it maybe once or twice a year.
    Auto levelling can always be added if necessary.
    But bear in mind that auto-level DOESN'T level the build plate.
    All it does is record the inconsistencies. You still need to level it manually.

  4. #14
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    A quality built machine will not need the bed leveled after it has been leveled unless you physically abuse the build plate to knock it out of level. The btouch and auto level is an option that is nice to have but not required on a well designed and built printer.

  5. #15
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    After many hours of reading and watching videos, I have come to some conclusions:
    (that seems to me to be right, but any objection will help)


    1. Using Dual Head for dual filament printing, seems to be more "professional" than "many to one" head option.
    It needs much less filament, can have different temperature for various types of filament, but it has 3 disadvantages:
    A. Setting the same height for both heads can become a nightmare.
    B. Dripping of non active head can destroy a whole printing,
    specially if one of the filaments is water resolved.
    C. Useful printing area is reduced in the axis that heads are positioned side by side.


    So Dual Head option is rejected, and a 2 (or 3) to 1 head will be used.
    Of course the "separate" mixing systems that "assemble" many filaments to one,
    are an other option that can be used without any modification to a single filament printer.


    2. The most "straightforward" system of printing seems to be (to mine understanding) the Delta system.
    Plate is not moving at all, there are not any tooth belts, just 3 step motors to turn screw rods.
    The only moving part is head and its holding rods, meaning high speed movement creates minimum shake.


    The major drawback is their height, that it must be about double of the "useful" height.
    And then the circular bed that must be big enough to be "equal" to a square bed printer.
    Tevo Little Monster @ 720$ that can print on a 340mm diameter circle (about 240 X 240 square) and 500mm in height
    And the machine height is about 1.2 meters ...
    So this solution is out of my requirements, as I need a bad about 350X350 mm.


    3. The 2nd solution that bed moving is not big issue is the one bed moves vertically.
    Since this is done only on every layer change, construction shake is also minimal at high speeds.
    The problem on the solutions provided, seems to the use of CoreXY system.
    Very long tooth belts are used (equal to about the XY perimeter of the printer),
    and the tension as also the proper alignment of the bar in which head is moving, are critical.


    Bed vertical movement, is done by two screw bars at right and left of the bed,
    an two pairs of cylindrical bars for guidance. It seems to have no problems.


    4. Finally we have the -most used- moving bed solutions.
    In those printing speed can't be high, because bed has a bigger mass than other solutions in their moving parts (plus the part itself),
    in order to keep vibrations to a minimum.
    But forgetting speed, if we have a stiff horizontal frame and another one for XZ plane, vibrations may be not an issue.


    ---


    So these are my conclusions about plus and minus of the 3 most used systems.
    Selecting between CoreXY and Prusa ID3 types can't be a "clear" decision, without focusing on specific model details.
    So I tried a comparison between these types, between two of the same company, TronXY
    The X3SA of the Prusa ID3 moving bed type and the X5SA Pro of the CoreXY type.


    ---


    The moving bed solution is simple to assembly, as the moving bed is been assembled to main frame,
    and the XZ plate is also assembled in a single piece.
    So the final assembly is easy and there is not any need for trimming anything.
    https://www.tronxy.com/x-series/tron...d-printer.html
    Movement of the bed on Y axis is done on two thick guides that have adequate distance between them,
    in order to assure strict movement on Y axis with out any jolt on X axis.
    This is ensured by 3 rollers for each guide.
    They have a significant distance between them (in each guide), in order to minimize the possibility of any movement on X, .
    Movement is applied by a belt, and its tension can be regulated by a nut to the proper(?) elastic state.


    Z axis movement is done on two vertical guides that are fixed by small plates to the main frame
    and on top they have a connecting bar to keep them parallel between them.
    Movement is applied by two screw rods, which are controlled by two motors, one for each rod.
    The X axis bar is sliding to vertical bars by 3 rollers on each bar,
    that have eccentric bases in order to permit fine tuning to ensure strict vertical movement.


    Finally head is moving in X axis bar by tooth belt, and is held in bar by 3 rollers.
    So movement is controlled by belts in X Y axis and screw rods in Z.
    Rigidity of movement is depended on 5 sets of 3 rollers each.
    Y axis movement is rigid enough, since roller distance on each set is a lot bigger than this of other axis.
    This arrangement requires big space for the machine on Y axis, if someone has space restrictions.
    Z axis movement is also rigid due to the screw rods,
    and the rollers for the X axis are enough since head is a small part.


    ---


    The CoreXY solution is provided in totally DIY state.
    https://www.tronxy.com/x-series/x5sa-pro.html
    So there is a need for high skill on assembly procedures, as those of tuning.
    Movement on 3 axis isa also done by belts in XY and screw rods on Z.


    Bed is moving on Z axis, and its stability on X axis is been assured by two screw rods,
    at right and left of X axis sides of bed, at the center distance of Y axis.
    Y axis stability of bed is assured by 2 pairs of cylindrical rods and the bearings attached to bed frame.
    It seems to have no problem, but since the two screw rods are not "connected" between them,
    removing printed objects can move the bed frame and destroy leveling at X axis.
    So every time a new print will start, leveling procedure must be repeated.
    Fortunately this model provides an automatic leveling, so if the screw rods' positioning has been destroyed,
    the system will bring back the bed leveling.


    XY stability is depended on belts' tension, pulleys' stability, and rollers' proper positioning.
    Belts' tension has to be tuned by the user on assembly, and there are not any nuts regulating tension.
    So it is advised by some users to purchase fiber reinforced belts to keep their tension for longer period.
    Also the rollers that are keep X bar parallel to X axis may be need some tuning (on the eccentric bases), in order to provide XY stability.
    And the pulleys that keep belts in place, can have a little vertical movement that can create XY positioning problems.
    A user that tested an X5SA, had terrible complaints for the print result, and it seems that he did not try to fix the printer.
    https://www.youtube.com/watch?v=KiJg7f9ib4M
    But others who also had same problems, has fixed them getting very good results.
    https://www.youtube.com/watch?v=Pq3qjdaRnuY
    https://www.youtube.com/watch?v=UN-2KeuzAKs
    And one did some upgrades:
    https://www.youtube.com/watch?v=RIz5-1uCqLg


    ---


    So my final conclusion is that a careful assembly with some upgrades on a CoreXY models can give very good results.
    So the question is if am willing to proceed to improvements of to select a "ready to operate" solution.
    The 400X400mm model of X5SA is a challenge, as it offers much bigger area for a good price ($550 vs $380 for 330X330 model)
    To get a 400X400 ID3 model, Creality CR10-S4 400 is offered for $600, a very close price to Tronxy X5SA.

    So I will continue searching reviews to find more "secrets" ...

    ---

    Very interesting is the capability to build huge moving bed solutions using custom design like this one.
    https://www.youtube.com/watch?v=albFKmWW4nA
    I believe that CoreXY solutions can also be created.

  6. #16
    Super Moderator curious aardvark's Avatar
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    Interesting.

    Now as a person who owns all three systems: 2 deltas, 2 cartesian replicator clone dual extruders and a prusa style i3, there are some practical things you have wrong and a few you have not considered.

    With a standard dual extruder system - replicator clones are the most common.
    Yes they are slow, yes getting nozzles level can be a pita. But I have never had any issues with filament dripping.
    Given that they are usually direct drive extruders, retractions work really well and quickly.
    The biggest argument against a side by side dual extruder setup is the length of time and the extra material used by the purge walls.

    As far as I3's and speed goes. They are actually the FASTEST of all three basic models.
    On a proper i3 (NOT the creality abominations) the bed is supported on two side rails with smooth linear guides. So there is no vibrations, and because the extruder is also moving and the overall speed is a combination of the two - even at 300mm/s there is no obvious issues.
    And that's as fast as simplify3d would let me print.

    Deltas, deltas are great. They are also the most compact in terms of frame size for their print volume.
    Height does NOT take up any desk space. and in fact my mini delta actually sits on top of my larger delta :-)
    Maximising desk space in a way it's difficult to do with any other style of machine.
    There are also less things to go wrong on a delta.
    And if you use an extended flexible drive shaft, you can also fit one with a proper, very light weight, direct drive extruder.

    My delta is currently my main workhorse. I have hopes for my cheaper than chips ctc (full prusa mechanics: side rails, direct drive, dual z-motors) if, I ever get a working combination of screen, board and firmware.
    Tests proved it's significantly faster than the delta.
    Why people insist on running I3's at such low speeds, is beyond me.
    Like there's some weird kind of badge in spending three days printing something that should have taken a few hours.

    Now one thing you have neglected is the best of all combinations - the IDEX printer.
    Independant Dual Extruders.
    These can be fitted to a corexy/cartesian style OR to an I3 setup.
    Alas while I can envisage a possible way to fit a delta with two heads (not dual/multiple nozzles - seen that) I have no idea how you would create the relevant firmware and slicer.

    Of the two machines you've decided on The tronxy is probably the best.
    I just don't like what creality did to i3's and have no clue as to why they did it. Their design took a great and stable system and deliberately crippled and slowed it down. While saving about $10 a machine.
    Illogical.

    The latest x5sa pro seems to be a well made machine, couple of people round here who bought them have been impressed.
    Last edited by curious aardvark; 03-31-2020 at 09:40 AM.

  7. #17
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    Thanks for the reply.

    All my conclusions about what could be the plus and minus of various systems, were based on two things:
    A. The reviews and complains I have found in youtube and other sources.
    B. My view as an engineer, from the materials used and the Scientific laws that apply on the solutions I saw.
    So for a moment I will "forget" what reviewers are saying
    (I accept that many people do not have deep knowledge and their opinion can be wrong),
    and I will stick on science.

    -----

    Bigger mass needs bigger force to accelerate at a required level.
    And it is obvious that a printing bed with the required frame to support it,
    is heavier than a hot end and the required bar to support X movement.
    And we must not forget that during printing the bed is becoming heavier, as the printed object is being build up.

    And since my requirements ask for a bed that is in "big" side of 3D printers that cost less than $1K
    (and in this price I include any modifications needed),
    the bed weight is increasing by square, and that of printed object by cube.
    while hot end weight remains the same and only the X bar weight increases linearly.

    For example moving to a 400X400X400 printer from a 200X200X200, means that bed weight is multiplied by 4.
    And (maximum) printed object weight by 8.
    (While X bar will have just double weight, and hot end is the same.)
    That requires about 6 to 7 times bigger force to move the bed and the object.
    So how this solution can be faster than those bed is not moving at all, or is moving a little vertically on layer change?
    How those bigger forces will not create bigger vibrations?

    I suppose that most of users print at low speeds (40~60mm/s) because printer manufacturers advice so.
    And that's because cheaper printers have less rigidity.

    -----

    Purge walls are needed also for the many in to one out solutions.
    Actually they need more waste than side by side dual heads.
    Because multi filament heads on every change they mix a little the two filaments,
    so a bigger quantity must be wasted.
    Specially if one filament is a water soluble one ...

    I will consider again dual head, because I found that there are dual heads in one body.
    So probably the can be aligned with less effort.

    INDEX is not an option for me, since I do not need most of what they can do,
    and I do not see any such options within my budget.

    Also I do not see any Delta option in the size I need.
    Delta solutions are small if your prints have cylindrical shape.
    If not, they are huge compared to XY printers.

    -----

    I still do not understand why you ... throw in garbage bin Creality printers.
    Do you have any specific objections on why they should be selected?
    Looking in many details the construction of Creality and Tronxy models,
    I found that Creality has better quality both on the parts they use,
    as also that of construction solutions.
    Do I miss something?

  8. #18
    Super Moderator curious aardvark's Avatar
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    I found that Creality has better quality both on the parts they use,
    as also that of construction solutions.
    Yes you missed something.
    You ignored the reasons I gave for why creality suck.

    Weird as you claim to be an engineer :-)

    Also creality have one of the worst reputations for build quality and customer support in the industry. They make I3's that have been crippled compared to the original design.
    There is no logical reason - josef prusa's design is opensource, you don't get sued for copying it.

    As far as moving a large mass around - you just need better belts, linear rails and more powerful stepper motors.
    I admit I have bolted my printer to a fairly substantial aluminium sheet with rubber feet (frame was in 2 parts, so i made it one :-). So that probably helps somewhat with my particular machine
    Also the acceleration settings will also help.

    But basically a good i3 can and should be a very fast machine.


    And until you've attempted to align dual side by side heads - you have no idea how tricky it can be :-)

    Look into the mosaic palette 2.

    Most reviews on youtube are done by people who are paid to review the machine.
    Mostly they are 'paid' with the machine itself.
    And that's one reason there are so many positive creality reviews - people don't want to kill the golden egg laying goose.

    Even a 'bad' review will say things like: 'well it's got a few niggles, but on the whole its a decent machine.'
    After all, who wants to upset someone who gives you free stuff ?

    My other reasons are simpler still. Creallity leads the pack in the number of issues and problems people come here with.
    We have significantly more posts about problems from creality owners than ALL other 3d printer manufacturers put together.

    I mean, by all means ignore everything I say. My opinions are purely based on extensive experience with 5 assorted 3d printers and 6 years of dealing with issues on this forum as well as extensive study and research into 3d printing in general.
    I just cannot be arsed to set up a youtube channel. I'd be up to my arse in free printers if I had, as it's the only question manufacturers ask when they contact you.
    And I have been contacted a fair few times.
    Last edited by curious aardvark; 04-05-2020 at 10:49 AM.

  9. #19
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    This past year I was a mentor for a FIRST robotics team at a private high school for underprivileged kids. They are in a new building that is less than a year old (one school year) and the 12 new Creality printers that were donated as part of the engineering lab have all failed, every single one. I know nothing about them other than what I read here and now the rack of non functional printers at the school. You get what you pay for when you buy a machine that must be mechanically and electrically accurate and reliable.

  10. #20
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    Thanks for the reply,
    I think that there is a misunderstanding about quality.

    There are 3 different areas about the quality of a product:

    1. Quality of parts used for the product.
    2. Quality of design, meaning solutions selected to implement the product
    and required calculations to fulfill specifications.
    3. Fabrication quality and "repeatability" of produced items
    (how much identical to what was designed are produced items,
    and how much identical are between them).

    Looking at videos, pictures etc, can give an indication about 1 and 2A, but not to 2B and 3.
    So this is a reason I have this conversation with you.
    To hear your opinion about these matters.
    Which in previous posts was not clear.

    ---

    So seeing all offered printers within some budget (that I can buy without problem in Greece),
    I think that best solution is to by a smaller (and cheaper) one,
    to see in action all these 3D printing issues I am reading or viewing in youtube, fora etc.
    And then design one it will fit to my requirement, using the small one to print the plastic parts needed.

    I know that this solution will become more expensive than buying at once a big printer,
    but it is less "dangerous" to throw a lot of money.

    So I see two "candidates" (both from Tronxy) the XY-2 Pro and the X5SA Pro.
    It seems that XY-2 Pro is a more "safe" product (and with less money).
    But X5SA Pro is of CoreXY type, that I think it's better for a bigger machine I am planning to construct.
    Also it is using sliders for X and Y axes, that I think they are more precise than V slot rollers.
    I think it is better to buy this type to see in action problems and possible solutions.

    I am open to any suggestion or other proposal, based on the above consideration ...

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