Is 3D printing feasible for this design?

  • Is 3D printing feasible for this design? Shivanand

    In a design that I need to prototype, I have a coaxial, rotational joint between 2 cylinders connected to another coaxial rotational joint between 2 cylinders by a hinge. I have attached the individual part files as well as their assembly where you can use your mouse cursor to check how they move. Click here for the SolidWorks parts and assembly files

    Initially when I 3d printed them by splitting them in half, the outer tube did not close, even after filing the inner tube sufficiently. enter image description here

    Could you tell me an alternative method to get this complicated joint working? I need to 3D print them. I plan to use ABS for the 3D printing.

    Thanks for your patience :)

    EDIT: Lubrication: I plan to use grease to lubricate the sliding surfaces.

    Clearances: I printed them without clearances initially (this is my first ever 3D print and I wanted to know how accurate it would be). I then used Dremel and filing tools to file away about 0.5 mm of both the surfaces. It should have been enough for mating the parts. The gap between the edges of the outer shell while trying to close it around is 3-4 mm which doesn't suggest 3D printing inaccuracy. I suspect that the outer tube isn't circular enough in cross section. It meets the inner tube at the the two ends of the semicircle and not inside its belly (you can see it in the picture). I have already tried the obvious, which is removing material from the surfaces wherever the parts touch. The model seems to be too warped for any success. The parts were printed upwards from the bottom, so it is not the warping due to gravity.

  • Have you considered to use a service to have the part printed? You can print almost anything in one "pass" using selective laser sintering, typically done in nylon. I am currently un-boxing an SLS printer, so I cannot currently offer to print it, but the capabilities of SLS are substantial for parts of this nature. I've read of entire planetary gearboxes being printed, fully assembled, with appropriate clearances for operation, once removed and "dusted," or cleaned of residual powder.

    The printer I hope to be assembling soon has 80 micron powder, so the resolution is quite high, although I forget at the moment the x/y/z figures.

    Do you think such a method would suit your purposes?

    Edit (add):

    because FDM printing by nature causes "oozing" especially in the x/y directions, I would not be surprised to learn that your outer piece has a smaller inside diameter than your design has specified. You may have to make adjustments to the design to compensate. Those adjustments would be specific to a particular printer/filament combination as well. Calibration prints would make the task slightly easier.

  • Depending on your tolerances and how many you need - and how valuable your time is - you can 3D print in ABS with a regular FDM printer, then clear out support material and do an Acetone vapor treatment or vapor wash. It will be smooth enough for most prototypes.

  • Consider ball bearings

    Depending on the requirements for your joint, I would consider making a design that utilizes ball bearings. With ball bearings, your join will not wear down as quickly, and also move smoothly.

    Handling dimensional inaccuracy

    The topic of how to achieve dimensional accuracy of FDM printers has already been discussed in this question. You might want have a look at Ryan Carlyle's answer for a specific routine on how to calibrate a Cartesian printer.

    From the question linked, a summarized approach for handling dimensional inaccuracy could be:

    1. Add any desired tolerances into the joint in your CAD model, without regarding the inaccuracy of the actual printer you will use.
    2. Tune your printer and slicer to reproduce those dimensions set by your CAD program.

    Generally speaking, the printer settings should handle filament independent dimensional accuracy, while the slicer should be used to account for different characteristics in each filament type. Correcting size through your CAD model is ill-advised, since you should be able to use the same model for multiple printers.

fdm abs 3d-models 3d-design support-structures
Related questions and answers
  • of the layers so I think it must have something to do with slicing settings, but I'm at a loss for what I need to change to fix it. See below for images of the issue. On the orange piece near the right hand side you can see light shining through the gap. The black cube has it at the top, though it's not deep enough to let light through like with the orange one. There is also an image of the layer preview which shows the same gap. I have a Rostock Max v2 (stock hot end). I am using Matter control using mostly stock settings, I've tweaked around layer height, speed, and temp but I don't think those

  • One of the local libraries has a new small Makerbot 3D printer. I have been submitting Sketchup files converted to STL files for printing. The tech guy who runs the printer for patrons is having... is printed with a base of 2 inches, and the item itself comes out smaller. Does anyone have suggestions about this? I can get more info if someone can give me the right questions to ask. The tech is open... to create it's own base and supports. Additional info: When I printed it by letting Makerbot create the base and supports, it came out to be 1 3/4" as shown here: Printer

  • I have been studying the differences between version 2.x and version 4 of the P3Steel frames - in particular the AC08 bracket at the top of the frame which secures the top of the smooth bars... an indentation for the bearing which holds the top of the threaded rod (from Twitter): Here is a close up of the diagram from the google docs repository, listed in the v4 section on the RepRap Wiki page for the P3Steel, which shows the bearing assembly just apparently "resting" against the indentation: Here is the bracket shown with the bar and threaded rod (again, from google docs): Does

  • can appreciate that maybe this is a detail to the slicing which is model dependant). Layers are 0.2 mm, top and bottom set to 4 layers. I had walls set to 1.6 mm, (4 layers) and the wall features here are 1 mm (i.e. 2.5x the nozzle). The features are solid so far as I know, not drawn as a hollow. I found a relevant bug for Cura: (and I also...I've just tried to make some small labels with embossed lettering. Base is 1.5 mm, with letters and a perimeter protruding by another 1 mm. After printing, I realised that Cura is not giving me a top

  • The Sainsmart Endstops I picked up are different from the ones described in the RepRap Prusa i3 Rework electronics assembly wiki; they have 4 female plugs that go into the RAMPS 1.4 board instead of 3: Since these endstops are different, how do I hook them up, and what do the markings on them mean?

  • task. Another option is to use a cutter to remove the outer surface layer (basically I remove the rigged surface, making it smooth again) but it's not safe and even more time consuming. How can I quickly generate said controlled gaps on the contact surfaces between two objects, but not on the rest of the object? to make it everywhere I could use shells, I guess, but I don't need...When I design parts that must fit in each other, I usually keep in mind that prints are 0.2-0.5 mm wider than expected (depending on material) and I size the parts accordingly. However, sometimes I

  • . It had been printing fine with ABS, but the ABS would peel up from the heated bed, so somebody suggested that I use PLA and hairspray. Hairspray is AWESOME !! It sticks really well and removes...I'm using brand new PLA filament and am getting frequent clogs in my extruder. I've had this problem with 2 different filaments from 2 different vendors. It will be print just fine, then clog up. It doesn't ever seem to go more than 5 minutes before clogging. When it clogs, and I pull out the filament, it is always twisted in a spiral (helix) shape like a corkscrew. I have put a picture of 2

  • 220°C) Print speed is 2700 mm/min (45 mm/s) Has anyone seen this issue before? UPDATE: Increasing outline overlap from 60% to 90% almost fixes the problem (at least visually if not structurally... of those last holes but I have to think that maxing out S3D's outline overlap setting to just barely make the print work means I haven't found or addressed the true root cause... ... pretty close to dialed in and tried a bigger print last night. It turned out pretty good in most respects except for where vertical structures rise up from the horizontal surface (and a retraction

  • with marlin firmware. I use Slic3r and Pronterface SW. I didn't find answer in following troubleshooting guides: Simplify3D - Print Quality Troubleshooting Guide A visual Ultimaker troubleshooting guide RepRap - Print Troubleshooting Pictorial Guide - 16 Common 3D Printing Problems (And Solutions) Do you have an idea what can cause this issue? Update I did a new print, where I just...I recently upgraded to a E3D full hotend and I started to have problems with slowly printed parts. After I print first object and start next one, then the first layer has serious issue. The first

Data information