SpiderBot Delta 3D Printer

Dual head closed beta release...

Written by Ph. Boichut on Tuesday, 26 August 2014. Published in News

After months and months of tests, design iterations, 7 prototypes, some unfortunate delays,  the SpiderBot 3D printer dual head is close to being publicly released. Will be testing untill next week, if everything is fine, the beta test for the first 10 dual heads will follow.

Important  improvements have been made compared to a standard dualhead and the earlier shown design.

We discovered that the second head often touched the object when printing and even if you retract the material of the inactive nozzle, there is often a small amount of material on the nozzle tip that can leave traces.
As an example, see the left part in the picture below. This part was printed with a standard Dual Extruder design, the right part is printed with our rotating Dual Extruder.
The green material is ABS, the white material is HIPS (soluble in Limonene) meant as support material.

To prevent this, a radical design change was required, we came up with a completely new dual head with rotating support and inclinated nozzles, which will avoid the unused nozzle hitting the object during printing.

The mechanism explained. When head #1 is printing material (red in the picture below), the second head is rotated away from the print area and can't damage or mark the object and vice versa, when head #2 is printing support material (green) head#1 will be rotated away. This furthermore allowed to reduce the distance between the nozzles, improving the overall object print size area compared to a standard dual head.


 

Interactive 3D view 
Click the arrow button to initiate a interactive 3D view of the DualHead, use the mouse with click and drag to change orientation and the mouse wheel to zoom. Interaction is already possible during the loading process. Works also on mobile/tablet! Use one finger to drag and change orientation and pinch to zoom.
Patent pending

Video of the dual extruder

The software used is KISSlicer Pro, one of the clever things in KISSliser is that the support material is only on the "interface" area. This saves a lot of dissolving time and thus uses less (more expensive) support material and the material limonel that is required to dissolve it.

  • Very cool, but I'd be concerned about the servo versus the limit screws. Servos aren't designed to have their positions externally limited: they expect to go right to where they are told to go. You'll get the servo constantly straining against the limit screw, which may produce heat, noise and premature failure.

    You need repeatability on the tilt angle, but I'm guessing you don't need the actual angles to be precisely adjustable. If that's true, then perhaps you could redesign the servo linkage so that it gives you the repeatability you need. How about a 180 degree servo with a custom arm so that the linkage is parallel to the arm at each end of the travel? Then the linkage travel won't depend precisely on the servo position, just the distance from the servo axis to the arm-to-linkage connect point.

    My $0.02,
    Dan

    about 3 years ago
  • Guest - P. Boichut

    In reply to: Daniel Griscom

    We use a Micro-Servo with metallic gears, we made test of resistance, our servo made 42000 cycle at ambiant temperature and 42000 cycles at 72°C without any visible damage (no play in the servo, no play in the ball end)
    In fact the lever on the servo is a bit flexible, when we stop to power the servo after rotation, the servo motor is not over charged.

    about 3 years ago