Toy Dump Truck Convoy

Dump Truck fleet

Dump Truck fleet

The Tiny Toy Dump Truck by madscifi makes a fine tchotchke for a presentation, serving to illustrate the risks and rewards of printing flat overhangs without support. A fleet of six printed well, after repairing some failures as those tall, tall rings and posts near the dump bed pivot fell over. I pasted them down in mid-print using ABS slurry, which is not a technique to emulate.

A closer look shows the overhang problem in the dump bed and the broken pillars behind the wheels.

Truck overhang failure - grayscale

Truck overhang failure - grayscale

It’s in monochrome because the camera choked on that much Safety Orange filament in the image, to the extent that no amount of color correction produced a usable result.

  1. #1 by madscifi on 2011-09-18 - 16:41

    I’ve had the same problem with the back end getting knocked out of place. Making certain that the first layer is stuck to the platform really well seems to mostly eliminate the problem. Another potential aid is to increase the height of the skirt until it is up to the level at which the back panel has been connected to the rest of the object.

    • #2 by Ed on 2011-09-18 - 18:35

      At this point, I’m using a not-quite Scary Sharp wood chisel to pry objects off the Kapton, so that first layer sticks about as firmly as can be!

      Some reversal zits snagged the nozzle on the way by and, given the aspect ratio of those columns, there just isn’t enough base adhesion in the world to hold them in place. Next time I do a presentation, I’ll run a few variations and see whether anything gets better…

      Everybody loved ’em, even with the bent back ends: thanks for great tchotchke!