Monday, 9 May 2011

Bowden extruder configuration and final mechanical assembly

I have now reached the point of axis testing and calibration, all the mechanics are now working and hopefully apart from a bit of oil and adjustments I should have ScrewBallStrap running in the next few days.

This is the machine with the Full size build-bed, about 330mm x 480mm
I'm going to only use half of it for initial testing, this is easy as I just slide out one end and change the 20mm x 20mm supports to be smaller.

This will be the smaller build bed for testing the machine (slightly over A4 sized)

I have mounted the Bowden extruder on the underside of the electronics at an angle so I can keep the PTFE delivery tube as short as possible to the hot-end.

Side view makes it a little easier to understand - 
E = Electronics Box.
A = The Rubber isolation points, these provide vibration isolation and also allow the platform (B) to be angled.
B = 12mm Polycarb base.
C = Is the point where the filament enters the Extruder from the back of the machine.
D = The filament exits the extruder inside the PTFE deliver tube.

A back view of the same assembly.

More testing later and some updates to follow, it's getting close to printing now.



  1. Why are you using a bowden extruder with three leadscrew axes. You can easily handle the mass of the extruder on your axes, and you'll get better response from your filament drive if it is closer to your nozzle.

  2. I have NEMA23's on the X and Y so yes I could push around quite few KG. I do expect to also have some directly mounted extruder's and paste dispensers, I have made it very easy to swap them over.

    The main reason is that I want to add 2 or 3 hot-ends for outline, fill and support. With a Bowden configuration I can get them all very close, if the extruder motors were also on the X axis it would take up space and reduce build area.

    I also wanted to have easy access to the extruder's loading filament and servicing and have a few different hot ends that could be swapped out without too much trouble, that's why the push-fit connectors are being used.

    Also I wanted to try a Bowden configuration as it looked like fun.

    And finally I hope to be able to speed up everything by using ballscrews so the lighter my axis hopefully the faster it may go.

    I still have lots to learn so I'm sure things will evolve as I go.


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