Printing Prusa Parts

What settings does everyone use for printing their Prusa parts? Currently I'm using 2 perimenters, 35% Fill density, and 3 solid layers. Too much? Too little?

Also, any one know the height of the x idler and motor mounts? I want to make sure I have enough clearance on my huxley. I recently added a Wade to the x carriage to replace the bowden cable. It significantly cut down on my Z height but I get great quality prints. I may have to seperate the top cross bars to make room for the extruder between them. But I'll do that when I absolutely have to. Thanks!

35% infill is a bit overkill with a 0.5 mm nozzle, but is fine with a 0.35 mm nozzle. You can get away with 2 solid layers on a really well-tuned machine, too, but it's best to work up to that point. The X motor and idler mounts are 62 mm tall.

For the z-couplers, extruder idler and all pulleys/gears I use 0.9-1 fill to make them strong enough.

It the extruder body and x carriage is in PLA, it benefits from 0.5 or higher infill, mostly to stand up to the heat in the area better, but for the x carriage also to avoid flexing.

The rest I do with 0.25-0.35 infill, three perimeters and three solid layers.

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-Nudel
Blog with RepRap Comic

Everything is in ABS with a .5 nozzle. I have machined pulleys so thats not a big deal and already have the wades printed. But the height of the X axis is going to cause problems. Maybe I'll try the Vert-X parts instead.

Nudel Wrote:
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> For the z-couplers, extruder idler and all
> pulleys/gears I use 0.9-1 fill to make them strong
> enough.
>
> It the extruder body and x carriage is in PLA, it
> benefits from 0.5 or higher infill, mostly to
> stand up to the heat in the area better, but for
> the x carriage also to avoid flexing.
>
> The rest I do with 0.25-0.35 infill, three
> perimeters and three solid layers.


My machines have extruder bodies and gears printed with 25% infill and they've been printing for a little under 2000 hours now, at ≈18 hours/day. I've needed to re-tension the belts, clean the hobbed bolt teeth, replace the hot ends, and re-level the bed, but not one of the printed parts has broken from this kind of use, or even shown any sign of breaking anytime soon. Not saying that 90 or 100% infill will hurt anything, but IMHO there's no reason to go much beyond 35%.

Edited 1 time(s). Last edit at 03/25/2012 08:38PM by Pointedstick.

I print in PLA and make the extruder and idler 50%, gears I make 80% and everything else is just 25% and so far after 6 months of use there have been no breakages at all

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Experimenting in 3D in New Zealand

Pointedstick Wrote:
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> My machines have extruder bodies and gears printed
> with 25% infill and they've been printing for a
> little under 2000 hours now, at ≈18 hours/day.
> I've needed to re-tension the belts, clean the
> hobbed bolt teeth, replace the hot ends, and
> re-level the bed, but not one of the printed parts
> has broken from this kind of use, or even shown
> any sign of breaking anytime soon. Not saying that
> 90 or 100% infill will hurt anything, but IMHO
> there's no reason to go much beyond 35%.

I've melted/deformed at least four extruder bodies and a couple of x carriages, broken at least three idlers clean off and have had to replace more than 6 small extruder gears. I have yet to break a big gear though, and I do use metal pulleys.

Most of this is due to the lack of cooling, bad prints/calibration/slicing and excessive idler tension. I chose to up the infill to 100% on parts that kept breaking, just to be on the safe side, but you can or course get away with far less than that if you're more careful/sensible than me. The one part I'd strongly recommend 90-100% fill on is the gregstruder idler, due to the nature of its design and printing it laying flat, the hinge is a weak spot.

I also find the infill calculation to be pretty different from skeinforge to slic3r, where in sfact I used 0.1-0.15 all the time, I rarely go below 0.2-0.3 in slic3r to get good parts. Anyone else notice this, or am I just imagining things?

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-Nudel
Blog with RepRap Comic

So I've printed everything except the x axis ends with no problem. I am having a ton of difficulty printng the bar clamps. They end up beng really brittle and breaking. Any idea why this is? I've printing them with 100% infill and still breakage.

What plastic are you using ?

By the way I wouldn't recommend 100% for X ends. They have been designed to reinforce the parts where it need by using very tiny holes which turns into plastic pillars, and lowering the infill will help the part flex in the other places.

I print them with 20 or 25% myself.

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Entropy Wrote:
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> So I've printed everything except the x axis ends
> with no problem. I am having a ton of difficulty
> printng the bar clamps. They end up beng really
> brittle and breaking. Any idea why this is? I've
> printing them with 100% infill and still breakage.


The bar clamps are designed to bend pretty substantially. Higher infill means more rigidity, especially with PLA. I'd recommend trying 20%, or even 15%. The resulting prints will still be plenty strong since they're stressed along their strong axes.

I'm using ABS, which happens to be glow in the dark. I will try and print with a lower infill. Could it be a layer adhesion problem? It seems like they are extrememly brittle.

Entropy Wrote:
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> I'm using ABS, which happens to be glow in the
> dark. I will try and print with a lower infill.
> Could it be a layer adhesion problem? It seems
> like they are extrememly brittle.


That's quite possible, too. Do you happen to have a picture of any of your printed parts?

I reprinted them at a lower infill and with red ABS and they turned out fine. It seems like the glow in the dark ABS had moisture in it or something. The finish had tiny bubbles in it and it was very brittle. Does this sound like a moisture problem?

Or it might need a lower printing temp than your other plastic. I notice my extrusion gets bubbles and turns brittle if I turn the temp up too high.