Jump to content

tachyio

Dormant
 View Profile  See their activity

  • Posts

    54

  • Joined

  • Last visited

    Never

 Content Type 

Posts posted by tachyio

    Dual Head Future upgrade ?...

    in Third party products & modifications

    Posted

    But I do notice the Bowden Tube "lag" as well. When the extruder gear reverses, the hot plastic continues to drip out.
    This is fixable. This is an Dual head Ultimaker print:

    http://www.thingiverse.com/derivative:27402

    But you do not want to know how long the slicing took, as it was manually edited GCode to get it to work. (Not my print)

    In Cura there's the retraction distance, under advanced options, though I haven't yet messed with it.

    Should I try it out by setting a retract distance? I imagine that if the gear reversed enough...it could lift the filament back into the nozzle, maybe the retraction distance at this point in time is too short.

    I visited a reprap farm yesterday and the guy said that if you retract the filament early enough, it shouldn't drip out over empty space...but that the GCode would have to do this before it reaching the empty space, since there is a retraction lag.

    Dual Head Future upgrade ?...

    in Third party products & modifications

    Posted

    I too would like dual extrusion, printing with soluble PLA as support would open up so many possibilities for my designs :)

    But I do notice the Bowden Tube "lag" as well. When the extruder gear reverses, the hot plastic continues to drip out.

    How do they combat this on the commercial printers? The hp 3d printer, design jet, uses FDM but prints with support too. So there's some dual extrusion magic going on there...

    Or...just some imaginative thinking, could the extruder system be made to switch between filaments? Like those multi-cd loaders we used to have in our cars...that way one head can print multiple materials.

    A friend of mine is thinking about using drums to print entire layers at once, like a laser printer only in 3d. Personally, I'm still stuck on the concept of DLP printing, but yeah resin cost is expensive, and having worked with it in a lab before, resins with UV cured photo initiators are not child-safe.

    Grilled Cheese Sandwich (Base Warping Issue)

    in UltiMaker 3D printers

    Posted

    Okay I uploaded the part to Thingiverse.com!

    http://www.thingiverse.com/thing:22791

     

    that's the way - circles look even more cool than squares. how did you do the funky stress simulation thing btw?

    It's design is a culmination of some of the suggestions posted here such as adding circles, reducing bulk volume, etc :)

    Solidworks 2010 and later has a built in stress simulation module. It's under tools, Simulation Xpress.

    Just set fixtures (parts that don't move, like the floor, or a bolted portion) and then specify where the loads will be. Next, choose a material. I used high-impact acrylic for the simulation, since I couldn't find PLA in the list. But my goal was to see where the stress was, rather than see if the part would fail - since failure can be determined after I print it, but to design the trusses, I needed to know where to add them to minimize flex and improve strength.

    Grilled Cheese Sandwich (Base Warping Issue)

    in UltiMaker 3D printers

    Posted

    Daid > Nope cannot reconnect, have to disconnect usb then reconnect usb, then reconnect in software. Most likely software related, gone now that I've restarted the PC.

    Alaris > I've added these 1-layer circles, hope it works! https://plus.google.com/photos/104220463645938697004/albums/5739490261864478145/5740154749355539954

    Here's a stress simulation of the part: https://plus.google.com/photos/104220463645938697004/albums/5739490261864478145/5740156859240514514

    Also I've edited my part to give it a more cool 3d-printed feel, yeaahh :p

    Grilled Cheese Sandwich (Base Warping Issue)

    in UltiMaker 3D printers

    Posted

    Hmm okay I shall redesign my part to incorporate holes in the bottom to use less material :)

    One other thing though, my Ultimaker just started randomly shutting down during prints. The error is a serial write-timeout-error. It's never happened before. Anyone know what's up with it? Everything else is fine though, extrusion, x-y accuracy,temp control...but it just STOPS mid-way through a print.

    :/ I am jinxed...

    Cura Console Error Message:

    https://plus.google.com/photos/10422046 ... 1129241778

     

    Grilled Cheese Sandwich (Base Warping Issue)

    in UltiMaker 3D printers

    Posted

    Hmm okay I'll give that a go. Ultimaker is having issues again so I'm fixing them, printed well for 2 days and then it had a very bad jam...

    So if its one layer and I'm printing the first layer at 0.3mm, I just add 0.3mm thick discs to the 3d model using my CAD program?

    I don't see an option for discs in Cura, thanks Daid! =)

    Grilled Cheese Sandwich (Base Warping Issue)

    in UltiMaker 3D printers

    Posted

    Hi Guys,

    I'm trying to solve the dreaded grilled cheese sandwich problem, I notice it happens on long rectangular parts that are either symmetrical or assymetrical, and less so on rounded, cube-shaped and generally symmetrical parts.

    Here's a photo of the warpage:

    I have several ideas on how to counteract this apart from a heated build platform, but I'm not sure if they will work - so I will be testing them out after this current print finishes.

    I am printing with Cura RC2, at 220C, 0.2mm layer height, 50mm/sec

    Theorized Countermeasures:

    1. Increase the thickness of the bottom layer from 0.6mm to 2.0mm - my hope is that this would provide less shrinkage-space for the material, and reduce the intensity of warping

    2. Print a thick raft that would hopefully provide more adhesion and spread-out the forces from cooling

    3. Slow down layer 0 even more, currently at 12mm/sec

    I have done other prints with Cura RC2 and they all have minimal warpage, hard to discern anyway so its as good as not being there. But this particular rectangular piece that I'm printing out for a camera part is particularly irritating.

    Cura Prints so Far: https://plus.google.com/photos/104220463645938697004/albums/5738998358660985857

    3D Model of the Part I'm trying to print: https://plus.google.com/photos/104220463645938697004/albums/5739490261864478145

    Any ideas would be much appreciated, thanks! =)

    this fault makes your print look like this..

    in UltiMaker 3D printers

    Posted

    I didn't see Daid's post about the 0.3mm first layer height, but I'm using Cura RC2 and everything's working like a breeze now! Thanks Daid =)

    Anyway I think Ultimaker should just recommend beginners use Cura...I personally spent weeks messing with ReplicatorG and Netfabb with no results, but with Cura, *bam* my prints now look like the photographs you see online!

    (Also I tightened my stepper belts, I think that was affecting x-y accuracy, but generally I attribute my results to Daid's software lol)

    I'll post some up later =)

    Photo link:

    https://plus.google.com/photos/10422046 ... 8660985857

    I'm working to reduce hairs and improve bridging, also the dimensional accuracy of the x-axis is slightly off - trying to work these 3 most important issues out.

    Funky Prints

    in UltiMaker 3D printers

    Posted

    Hmm right the tightness of the thumbscrew could be fluctuating.

    Strange though, I haven't changed anything currently, but its printing fine now...so really not sure what the matter was.

    :/ Diagnosing machines really not my thing haha!

    And Cura is awesome :p Thanks Daid! Ultimaker should just recommend Cura for beginners rather than Netfabb or RepG which both are so buggy.

    Funky Prints

    in UltiMaker 3D printers

    Posted

    Okay to be scientific, I printed a second cube and watched it very carefully.

    What happened was that the filament began to jam again. In total the filament jammed 4 times, as seen by the 3 distinct lines along the sides of the cube, as well as the gaps at the top of the cube. As I was watching it print, I counteracted jamming successfully by using my hand to apply force to the filament being fed into the extruder motor. My new theory could be that the toothed gear of the extruder motor is getting dirty and loosing grip.

    As jamming occurred randomly, it cannot be attributed to some sort of systematic error, which makes diagnosis tougher.

    Photographs:

    http://radiusdev.com/tachyio/um/ok-cube.html

     

    Funky Prints

    in UltiMaker 3D printers

    Posted

    Hi All,

    I recently moved to Cura, and I had to do some recalibration of the Ultimaker as it was jamming frequently.

    I finally got it to print tonight, after I did the following:

    1. Core out the end of the bowen tube in contact with the nozzle assembly with a drill to make the exit aperture wider

    2. Readjusted the extruder screw tightness very carefully

    3. Moved printing temperature from 185C (on Netfabb) to 220C (on Cura, since I was printing at high speed)

    So it was printing all fine, though at a higher temperature so now I could smell the plastic, and its appearance was more fluid and wet-like. And I was pretty glad that I improved the accuracy of the steppers by tightening all the belts and rods properly. So surface finish was awesome.

    But then what happened was that mid-way the filament began to jam again, I could tell by listening to the extruder motor grind away. So not wanting to lose my print, I heroically fed the printer with my hands, hoping brute strength could bypass the bad section of filament. And it worked! After a while the extruder began to pick up and filament came out smoothly from the nozzle again.

    I'm not sure why this happened, that's why I'm posting this. All my adjustments seem to work alright at least for the first 50% of the print and the last 40%. So I'm wondering if what happened was the following:

    1. The diameter of PLA filament is inconsistent

    2. PLA plastic contains impurities

    I believe that: Either of the two issues will cause the melting rate of the filament to change, which would cause the extruder to slow down its rate of extrusion (or speed up, but most likely slow down in my case). When the rate of extrusion slows, the soft melty filament expands under pressure from the extruder motor to fill up the Bowen Tube. When this happens, the soft melty filament comes into contact with the cool wall of the Bowen Tube and hardens as it looses heat to the wall. This hardening action thus causes the jam.

    I was also studying the designs of the Reprap and I notice they place the extruder motor directly on top of the nozzle assembly. Perhaps if we shortened the melt zone of the Ultimaker and do away with the Bowen Tube, we could get more reliable prints? I really dislike the design of the PEEK-Bowen Tube interface, practically all my jams happen there. There must be a better way of feeding filament into the nozzle, whilst reducing the length of the melt zone at the same time - since I believe I have a long melt zone extending from the PEEK to about 1cm upwards into the Bowen Tube.

    Here's a photo to see the result! It did complete printing by the way! =D So I am not totally upset lol!

    http://radiusdev.com/tachyio/um/damaged-cube.html

     

    this fault makes your print look like this..

    in UltiMaker 3D printers

    Posted

    Alright thanks :) I'll try that once I get it rebalanced and unjammed.

    I've been thinking a lot about SLA though, has anyone seen this?

    http://www.instructables.com/id/Build-a ... phy-at-Ho/

    It seems like the logical next-step, less moving parts and no filament to jam in a tiny nozzle.

    Also with lasers we can actually get much higher resolution - nanometer wavelength.

    And I'm thinking to myself how to eliminate the need to calibrate the gap between the nozzle and the stage. It's really tough to get it just right for high-detailed prints. My friend and I designed a little mechanical piece that would allow us to adjust the z-axis end-stop, but even then its hard as our stage isn't perfectly level.

    Could a laser be used to measure the gap-distance, then we can tune it accurately?

    this fault makes your print look like this..

    in UltiMaker 3D printers

    Posted

    Oh boy I just tried replicating 0034, and somehow the new marlin firmware really messed up the extruder motor - the thing was moving at lightning speed. And basically the print jammed when a load of plastic got deposited onto the stage - haha!

    Anyone else have the same weird problem? I'm going back to 0026 for now, at least that works. :O

    What's Wrong With Print?

    in UltiMaker 3D printers

    Posted

    I was thinking that we should compile a "Ultimaker print diagnostic kit" for everyone.

    So we all post our bad prints up, and the experts can critique them and provide solutions and then we compile a online manual of sorts.

    Is there such a project underway? :)

×
×
  • Create New...