Sopport Material

#1
With several high end printers, the printed model has "support material" with it. Does anybody know why we do not need support material with the gMax?
 
#2
No printer can print into "thin air"; each layer must be built onto something else. If a model has no overhangs at all, it doesn't require support. If it has a 90-degree overhang (that's not "bridging" to somewhere else on the model), it's probably going to need support no matter what. Angles in between may or may not need support, depending on the angle of the overhang, printer parameters, filament parameters, how perfect you want the print to be, etc.

I think slic3r has support generation features where you can set support density, threshold angle, etc.

Support removal from PLA prints is generally more difficult than support removal from ABS prints. Some printers with proprietary firmware/software (like the Up/Afinia and Zortrax) generate support that's more easily removable than that usually generated by current open source tools.

julia
 
#3
True to everything Julia has said, although I've had some success with small 90 degree overhangs without support. The first 2 layers come out slanted, but miraculously the print self-aligns after that.

Support with PLA is a pain. My only solution is to make that density as low as you are comfortable with, or use a dissolvable support material once the dual extruder upgrade is released. PVA dissolves in water but is overpriced, I recommend looking into HIPS (high impact polystyrene) which can dissolve in 24 hours in a citrus solution called Limonene. About half the cost of PVA and theoretically less sensitive to moisture. (It's not water that dissolves it.) I would still store it in a dry place though.
 
#5
gMax will print whatever the slicer code tells it to print - it doesn't know if it's printing a part, or support for a part. Support is generated by your slicer (slic3r, Simplify3D, SkeinForge, KISS, etc) according to the settings you give it.

If you mean does the gMax have provisions for dissolvable support, that requires two extruders so that different materials can be extruded for the support structures and the part, respectively. Gordon has been working on a dual extruder design that can do this, and we'll hopefully be able to buy it soon.
 

GORDON.LAPLANTE

Administrator
Staff member
#6
As Julia mentioned, support material is controlled by the slicing program. Slic3r has relatively simple support options while I have seen other programs with much more sophisticated offerings. One feature I believe slic3r implements is a single 'blank' layer between the support and the solid layer above which makes removing support a little easier. You can also turn on 'support only where required' which will only generate support if the ceiling above requires it. In any case the support is still very much a pain if you are printing holes in objects as well as overhangs. I think other slicers offered branching support (to avoid the unnecessary web of scaffolding) but slic3r has yet to implement this. Of course you could always design support into your 3d model as you need it and avoid turning it on in the slicer.

All of the 3d models used to build the printer were designed as not to require support material. This speeds up the printing process on our end and makes it easier for people to work with.

The gMax can print up to around a 65-70 degree overhang without the need for support (this of course depends on the slic3r settings used) thanks to the improved fan shroud. As julia mentioned going beyond this threshold will require support (unless its a small distance of around 1-1.5mm). We've also noticed bridging to work quite well when using diagonal infill. I remember a few luck models where I was successfully able to bridge almost 2 inches as long as the point where the bridge began was solid enough. I noticed the PLA sagged when it first printed, then it contracted as it cooled forming a 'decent' bridge overhang.
 
#7
As Julia mentioned, support material is controlled by the slicing program. Slic3r has relatively simple support options while I have seen other programs with much more sophisticated offerings. One feature I believe slic3r implements is a single 'blank' layer between the support and the solid layer above which makes removing support a little easier. You can also turn on 'support only where required' which will only generate support if the ceiling above requires it. In any case the support is still very much a pain if you are printing holes in objects as well as overhangs. I think other slicers offered branching support (to avoid the unnecessary web of scaffolding) but slic3r has yet to implement this. Of course you could always design support into your 3d model as you need it and avoid turning it on in the slicer.

All of the 3d models used to build the printer were designed as not to require support material. This speeds up the printing process on our end and makes it easier for people to work with.

The gMax can print up to around a 65-70 degree overhang without the need for support (this of course depends on the slic3r settings used) thanks to the improved fan shroud. As julia mentioned going beyond this threshold will require support (unless its a small distance of around 1-1.5mm). We've also noticed bridging to work quite well when using diagonal infill. I remember a few luck models where I was successfully able to bridge almost 2 inches as long as the point where the bridge began was solid enough. I noticed the PLA sagged when it first printed, then it contracted as it cooled forming a 'decent' bridge overhang.
My friend was just looking for this information. Thanks