RepRap Wally Can Print Larger Versions of Itself

Reprap Wally

SCARA based 3D printers seem to be all the rage these days, and with good reason. This RepRap Wally doesn’t use any linear rods or timing belts — in fact, it can even print larger versions of itself with each iteration! Well, minus the electronics of course.

It was first spotted out in the wild at the NYC Makerfaire, and looks to be a pretty slick design. Using fully 3D printed limbs, the steppers move the arms using a fishing line. To reduce the load on the joints, a bowden extruder is also used. The really cool part of this is the z-axis, it uses a 4-bar linkage to stay level, but because of this, it also moves along an arc in the y-axis as it raises or lowers. This is accounted for in the firmware — otherwise you’d have some rather interesting curved prints!

Stick around after the break to see it in action, it’s a nice change to watch from the standard gantry style printers.

Looking for more SCARA based printers? We recently shared a giant industrial SCARA robot that has been converted to a 3D printer!

[via Reddit]


  1. Galane says:

    Instead of compensating for the curved motion of the 4 bar linkage for the z axis, they could’ve used a Peaucellier-Lipkin linkage.

    • Zac says:

      Yes, except they’d have to use 2 pauecellier-lipkin linkages in a 4 bar-linkage configuration in order to keep it level.

    • adcurtin says:

      While that may seem like a good idea, the 4 bar linkage has way fewer joints and linkages than the Peaucellier-Lipkin linkage. Since most of the slop comes from the joints, fewer joints means less slop, which means tighter tolerances. Accounting for the lateral motion is done in software, which doesn’t suffer from slop. Adding the software translation is also a lot cheaper than printing more linkages for every printer. The 4 bar linkages is cheaper and more accurate. The only downside is the development of the software translation.

  2. Liam says:

    Sarrius linkages seem to be one of those things sounds like an awesome idea for reprap, but I’ve not seen a working one in a printer yet.

    I’ve thought many a time about how cool dual arm scaras are for reprap, though I want to put the motors on a rising platform, not the bed, to do away with the need of a back board.

    Bowden extruders are the reason I don’t have a delta, so it would be good to have arms strong enough to support a direct drive extruder.

    I’ve also wondered if those brushless gimbal motors would be good to drive the arms. Though they’re the same price as steppers the electronics to drive them could work out a lot cheaper.

  3. bom says:

    More detailed video here:

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