Design flaw...?

#1
I'm sorry to say this, but many of the 3D-printed pieces used to connect to the aluminum extrusions are cracking under pressure. As instructed I hand tightened the pieces, and then during final assembly tightened with the allen wrench just slightly, and many of them cracked. In particular every one of the corner braces have split, as well as the LCD holder "legs" and curved pieces that hold the vertical / angles extrusions. I have been very careful not to over tighten, but at the same time you want the machine to be solid so the pieces are printed with precision. Some of the 3D printed pieces have not been printed thick enough, or simply should not have been used IMHO.

While I appreciate the utility of having many of the pieces 3D printed, for some it simply doesn't make sense. For example, the corner brackets for the extrusion are readily available and should be used instead of printed pieces.

My suggestion - please provide proper hardware where possible:
Example: http://www.grainger.com/category/80-20/ ... /N-1z0zhnp

OR, provide a metal backing for the 3D printed pieces so they do not split when tightened.

Will you provide a source so I can purchase replacement parts? (While I realize I can print replacement parts, I can't do that if my printed isn't working...)

I've attached an image for reference. Essentially the piece is too thin, or there is no backing to handle the stress of the piece being tightened. It's interesting to note that every piece splits across the natural "grain" of the printed piece.

Thanks.
 

GORDON.LAPLANTE

Administrator
Staff member
#3
Sorry robotman. We offer a 1-year warranty on printed parts. Email us for information and let us know what you need.

We have since been printing parts with more exterior walls and thicker infill to avoid future problems.
 

Kurt

New Member
#4
GORDON.LAPLANTE said:
Sorry robotman. We offer a 1-year warranty on printed parts. Email us for information and let us know what you need.

We have since been printing parts with more exterior walls and thicker infill to avoid future problems.
If anyone else has trouble with cracking:
Mesh tape (http://www.fantasyfiberglass.com/pic/bi ... 224022.jpg)
and Araldite (http://www.toolstop.co.uk/components/co ... RAPSYR.JPG)

I'm only now looking at upgrading all of my 1.0 parts with PETG, a few years on.

Don't get me wrong, all my parts broke as well. Very quickly, and to be honest I was a too lazy to print spares first thing.

However, PLA glues very well, and so it is very easy to repair most parts without reprinting.

Too small to glue? Not a problem! If you use a bit of fibreglass mesh in as well, then your parts are nigh unbreakable. I might post a photo later, my printer is pretty funny I think with bits of fibreglass holding it together.

I had a heck of a problem keeping the little bit that holds the z-axis stopper attached to the vertical pole repaired though. Solution, chose a spot for it to stay, and Araldite the heck out of that too... I actually can't get it off now...