Fill print?

[VonKlutch]

So i'm making this lawn orniment type print, and I'm saving myself a ton of time by printing it with 0 % infill.

I printed this last night, and i was really happy with the results, but when i was inspecting the build quality, my print split wide open. (which makes me question my layer fusion and need to learn how to calibrate that) Its a Diglett from Pokemon if anyone's familiar, basically a cylinder with a rounded closed end on it. right where the cylinder started to close, It split right off, the two remaining peices were quite strong.

Anyways, I've decided to re-print and coat with XTC (being shipped in to me) along with a few other prints, but I was wondering what could I FILL this print with to give it structural integrity and give it enough weight that it will stay wherever I put it?
I was thinking like a plaster of paris or something with a peice of plastic on the bottom to cap it off.

I'm looking for a cheap solution, thats why plaster came to mind. But I figure expansion and retraction is going to damage the print, or i'd use like quickcrete cement or something.

Any ideas?

[sindrele]

Stick something real heavy inside and spray some "Great Stuff" gap filler in there to seal it up and hold the object in place. Expansion of the foam shouldn't damage the print.

[Davo]

Why not try 15% hexagonal infill and a few solid layers in all dimensions?

If you get it to work hollow, put a hole in the bottom and fill it with dry sand, then seal it up.

[curious aardvark]

polyurethane foam gap filler.
Cheap, expands to fill gaps without massive pressure and it's fun stuff to play with :-)

Plus will make the print almost indestructible.

If using sand, mix it with a little pva glue first. it'll set like concrete and bind to the plastic at the same time. Plus no expansion or contraction to worry about.

[VonKlutch]

Davo: Thanks for the reply man, and yes a few solid layers, and an infill would absolutely solve all of this. It would also turn a 7+ hour print into god knows how much longer. This has been kinda an exercise to see how I can accomplish this without spending extra time and plastic.

Either way the peice is already printed, http://www.thingiverse.com/thing:1705856
So what w'ere looking for is a product we can pour into the hollow inside to make it structurally solid. Like a resin, plastic, plaster, expanding foam, there are tons of options. I just wanted to see if someone had any particular suggestions.


Curious aardvark: i'll have to look into this. Would it be something I could fill the whole structure with and still properly cure? If i leave the bottom open will it just expand out the bottom (top when i fill it) instead of epanding in circumfrence?
I'm worried about filling it with somehting and having it expand as it cures and blows open my print lol.
Also looking for something dirt cheap..

I've kinda also switched gears on this, i've had many people expressing interest in one of these prints, so now i'm actually looking at making a glove mold of it and making a few copies, and will also be looking into whats best to use to pour the copies out of. So looking for a cheap resin or something else that would be good. I figure it needs to be weather proof as this would be best to go in the garden or something like that. though I guess for an office worker they could have it at their desk. Thought of putting like a usb hub in lol.

[curious aardvark]

the polyurethane will expand to fill the whole thing and then gradually cure to rock hard in a few hours.

You don't get much cheaper than sand and pva :-)

people want these ? http://www.thingiverse.com/thing:633274

people are weird :-)

ps: don't tell brian it looks like a butplug or he'll write an article on it ;-)

[VonKlutch]

To be specific, this one
http://www.thingiverse.com/thing:1712556

I modelled it (not alot of modelling skill here) but I have several friends and the like that want one. so i figured if i made a mold of this maybe I could find a cheap solution for casting copies.


but back to the original point, I just did a rather large animal skull, The cubone skull to be exact.
http://www.thingiverse.com/thing:819181

only I maxed out its size so its about 170mm at the widest point.
Anyways, I printed it again, with no infill cause i'm lazy that way and it was all together like an 18+ hour print.

I think my extruder started to under extrude during the night, cause there are sections that are super weak and i barely have to push to flex and hear some delamination. So because the print is a hollow object, theres the inner and outer walls to this, not just a shell, and i figured, if I could maybe pour something with a light viscocity into the gap I could effectively make the skull solid.

I have a reservation with this method because well i know the inside of it, is super stringy, so I see whatever I pour in there, getting gummed up and never reaching the bottom.

So my thought is, should I just run down to Crappy Tire, or whatever local hardware and pick up some fiberglass resin and just brush the print with a few layers of the resin? will this make the print strong enough to withstand dropping and handling? these are all display peices, but I'd hate to have something fragile in someone's hands.

[curious aardvark]

fibreglass resin will look like crap on the outside. So paint on the inside.
also - check it doesn't dissolve the plastic first before painting large areas.
That stuff has some serious solvent.

How many layers and outlines do you use on your hollow prints ?

I'd go for at least 4 if I was making something hollow.