• Z-axis falling-prevention AKA Stepper-shorter

    Christian Lerche • 06/17/2018 at 06:30 • 0 comments

    One of the guys in the Danish 3D DIY facegroup asked for a solution, for his original Ultimaker bed. 

    It moves quite easy when not enabled, or when power is disconnected. 
    Same problem I have seen online, with the Cetus 3D printer, where a printed part was used. 

    My solution is: 

    Short out the stepper, when power is disconnected, or the driver is disabled. 
    This is done using a regular DPDT relay, and (if you're using drivers with !ENABLE) a MOSFET/Transistor. 
    I'm working on a schematic for most uses, and also a PCB. 

    But the fun thing is in the relay: 

    When the coil is energized, the stepper lines go through the relay, to the output. 
    When power is disconnected, the relay goes back to NC, and shortens the stepper. 

    I just need to work on the driver-circuit for this, so the enable stuff will work. 

    Have a nice one!

  • Dual drive gear, using Prusa i3 mk2 extruder

    Christian Lerche • 03/18/2018 at 12:35 • 0 comments

    Fetch the files in the files-section in this project. 

    I've changed some minor things: 

    • Made a little more space with the stepper, for E3D Hobb-goblin drive-gears.
    • Printed tiny gears to glue onto motor-shaft, and idler-shaft. 
    • Changed idler, so two MR105 bearings to fit. 
    • Printed a 5mm shaft to the idler (You can just cut some steel or what-not), I like the flex the shaft gives me
    • Modified hole-size, for M4 to mount it in the printer. Mine is a RepRap-XY, with sdavi's mods. 
    • Changed to 12mm inductive probe

    The gears can be printed with 0.4mm nozzle, however, I printed a bunch with 0.25mm, with a much nicer result. Slic3r takes some persuasion to print in 0.4, but it's possible. But had to go to Cura to slice 0.25mm, otherwise it wouldn't print. 

    The idler bearings are glued in place. Make sure to turn the shaft a couple of round before glueing, so the bearings can wobble into alignment. 

    All the parts is printed in PETG, works nicely. 

    I have printed a couple of kilos of filament now, no problem what so ever. Before I would strip PLA in the V6, but the only thing stopping it, is maximum motor current. 

    Original files are here.

  • 3D printed caravan part

    Christian Lerche • 01/21/2018 at 20:53 • 0 comments

    This is again one of the older projects/repairs. 

    My wife's aunt came to me, as the caravan center told her, that she couldn't get a replacement for the locking mecanism, for the blinds. These things break. At least when the caravan is 20 years old. 

    So after taking some pictures with a caliper on the part, a new was sketched up (I used sketchup back then, pun intended). 

    It was printed in PLA, which will probably not hold up to the temperature in the caravan, but in not-so-sunny Denmark, it is not much of a problem. 

    Two of these goes in the mount, with a spring in between. She said it fitted like a glove. 

  • 3D printed patio door hinge/lock

    Christian Lerche • 01/17/2018 at 08:09 • 0 comments

    Again, an old part printed for a friend in need.

    The parts was originally PA, but printed and worked nicely in PET-G. Written in OpenSCAD. 

    So even if the PET-G is a lot weaker than PA, prices for replacing these once in a while are next to nothing. So printed a bunch for him. Job done! 

  • 3D printing for a hospital (and also for the home)!

    Christian Lerche • 01/16/2018 at 18:17 • 0 comments

    I am a medical technician (I repair electronics, that repair humans), and in this field, not many plastic objects can be printed (everything needs to be auto-claved). 

    But once in a while the carpenters, electricians or someone else comes to me and asks: "Can you print one of these?" 

    YES! 

    So far not many objects has been printed, but some of the simpelts, is the most cost-saving. 

    The first image from OpenSCAD, is a tiny spacer, used in a washing-machine door. The spacer goes on the two rods holding the door. These wear down over time, going more and more loose. And the door starts clapping, clacking, clicking and what-not when it's washing. A spacer cannot be bought, unless you buy the whole door. That's $800. So these spacers cost next to nothing to produce a lot of. Cheap, works like a charm. Saving the hospital at least $4000 now. 

    Next is my own calipers (Nevermind the broken plexiglass, happened after printing.) It was printed on the original PrintrBot (My first printer), actually was my second print on the PrintrBot. The file are long gone, this was done in 2012 I think. 

    Last is the BRIO Train my son has fallen in love with. Broke a wheel the poor little train. OpenSCAD/RepRap-XY to the rescue! Happy son again!