Sunday, September 5, 2010


I have started the wiki page for my new extruder at the RepRap Wiki.

I thought I would be smart and put all four spring on the extruder for it's 1st test run, it literally squeezed the ABS so tight that it came out the other end flattened out (but by god it didn't slip!).  I think I need to test it with only 2 half springs tonight :).


  1. Looks great. Is there a reason for not putting the motor mounting screws directly above and below the motor shaft? Are the idler screws M3 or M4? I still think that rather than hex head bolts with their heads in the block and wingnuts on the other side, it would be better to have cap screws going the other direction, with captive nuts in the extruder block. Though, I suppose this version can be assembled that way without modifying the RP parts. It will take an allen wrench to tighten/loosen it, but you should have one of those near your reprap/makerbot at all times anyway, and it looks like the wingnuts are running into the mounting plate.

    I'll have to order some parts from makerbot so that I can make one. I just got my Wade's printing REALLY nicely today, but I had to re-hob the bolt AGAIN to do it. I think they're wearing down with use and I want to try one that uses the MK5 drive gear. I am concerned about oozing, because I tried it without filament retraction to diagnose a problem with filament stripping and I got a lot of oozing, though oozing probably isn't as much of a problem without inter-layer homing. I wonder if there's a reasonably priced stepper either with a gearbox or just very high torque could be mounted to this. That would probably be more reliable than the printed gears on Wade's or Adrians's.

  2. The orientation of the motor mount is shear laziness, I didn't bother turning it, and with heekscad, it would not be entirely easy to turn it. I know there are obsessives out there who don't take there medication, and post on the comment sections of blogs. I will straighten them out before release. :)

    Idler screws are m4 because they would be a little tougher against the shearing forces. I bent a set of m3 on one of the early protos. 45mm long m3 are very bendy.

    Good advice on the bolts, that will be changed before release.

    As for the last paragraph, all I can say is ":)"

  3. (obsessive-chanting-voice)THEIR.. THEIR medication, not "there"!!!(/obsessive-chanting-voice)

    Now where are those meds..

  4. Yeah, I'll admit to being obsessive. The "their"/"there" thing grates on my nerves too, and did you notice I edited your wiki page just to change "Do" to "Due" and fix some punctuation? Obsessive. That must also be why I love OpenSCAD instead of using something like Heekscad or Sketchup.

    I printed one of these yesterday while I was supposed to be modeling my idea for a new x-carriage for Huxley. I say supposed to be, because now that mine is printing well enough to use it to make parts, it's really distracting. I couldn't stop staring as is laid down the overhangs and whatnot.

    It is meant to be printed on its side like Wade's, the way it is oriented in the STL you posted on the wiki, isn't it? I ask because he orientation of the idler block in its stl didn't make any sense. I printed them together with the idler block in the spot where it mounts, but laid flat, as I've read that this type of arrangement helps prevent warping (the opposite corner of the block did warp, slightly). I'll have to wait to assemble it until I can justify the price of all the stuff in my makerbot cart to myself.

    One other thing about the design, the idler block seems a bit flimsy. I know Nophead designed a beefier one for Wade's because he and others have had problems with Wade's idler block cracking under the stress of the springs, and Wade's original idler block is a lot thicker than yours (the thinnest part of it, I mean, behind the bearing bolt). You may want to move the bolt further from the center of the block.