How is this 3d Printed? Slinkies

[3D_is_my_LIFE]

OK, I can't for the life of me figure out how this guy has 3D Printed Slinkies.



I don't udnerstand, because they stack perfectly. See below



And here is the Design file:


How do you keep the layers from sticking together?

[Compro01]

Have you tried asking the guy?

[3dkarma]

The STL file has a slight separation between the coils. He prints with support to keep them separate while they print.

[hercemer]

3dkarma is correct. There is a small gap between each coil.

Depending on the size of the gap, a very small amount of support is printed between each coil. I played around with the spacing to find a good compromise between “easy to separate” and “little support to clean off”.

Any support left behind on these consists of tiny intermittent hairs of support that I can scrape away with my thumbnail.

The gap varies a little between each slinky – I found the square to print well, separate easily, and little to no support is left behind. The octagon has the largest gap and separates very easily (I can pull the coils apart by hand), but also leaves a fair amount of tiny hairs of support. It’s not hard to remove, but it’s messy and time consuming.

For most of these I gently separate the coils with an x-acto knife by spinning the slinky into the knife and occasionally twisting the knife to “pop” the sticky parts loose.

edit - Each slinky prints with a sheath of support on the inside and outside of the slinky. The sheath can be easily cut away and removed so you can separate the coils.

[3dkarma]

These are very clever. Did you create them with a script?

[hercemer]

Thanks! These were created manually in Sketchup.

I posted an overview of how I created them in the thingiverse comments - http://www.thingiverse.com/thing:267773/#comments

I had planned on finding a quick script to generate the spring path but couldn’t (immediately) find one I was happy with. I also knew I would want more than just the circle slinky and didn’t expect to be able to find a spring generator that could take in custom shapes.

The Sketchup move/snap system worked really well for joining the coils so it was pretty easy to crank these out, but I had to undo a lot to make small changes.

[3D_is_my_LIFE]

Thanks for clarifying. Do you have any photos of it printing?

[DrLuigi]

I think he used some support that disolves in water, What was it again PVA or something?

I can't believe you could get support from between them without breaking it :P

[hercemer]

I didn’t get any pictures while they were printing or of them with their support

Here’s one of the heart and (some of) the support it printed –
fyykHxN.jpg

The heart had some of the easier to remove outer / inner support – it peeled away in satisfying sheets.

My first version of the star required me to scrape and claw at every piece (I fixed it by making the gap
smaller).

This was an attempt at printing the square scaled down -
qxohVCc.jpg

This is the only picture I have that shows what the support structure looks like. The coils on this were fused so I didn’t even bother to remove all the support.


Here’s a couple from the blooper reel.

My Glow in the Dark filament warps badly and this slinky turned out a mess. Most of what you see are un-separated coils, that’s just how bad they printed.
g85vSgM.jpg

I just noticed the Band aide in this picture, I’m tempted to replace it with a suture kit


And here’s what Pac-Man looks like when you hit “go” on an 8 hour print and then head to work. The first layer of support never stuck to the platform… you have to give it an E for effort.
L5efzId.jpg

It’s a real mood killer when you rush home all excited to see your brand new pac-man slinky and find this.


And here are some early test prints –
LGDznWP.jpg

You can really see the “hairs” on the star, this was before I tightened up the gap. The heart was just perfect on the first try

You can also see the 2 blue round slinkies. The front one has a 2mm x 6mm rectangle instead of my final 1.5mm x 6mm. The 2mm one is very stiff, you almost have to push it back and forth in your hands.

[hercemer]

These were all printed in various brands of ABS on my Up Plus 2 at default settings w/ a z-index of 20mm (I click open and print). You can quickly print a few test coils of the heart to see how the support prints and how the coils separate.

There really isn’t any support to remove when they’re done, at least not like you would think.

It varies by the size of the gap between coils but is either almost nothing or is single strands if tiny little hairs.

If the gap is optimal I get coils that I can separate easily and I am left with little support between them. Easily in this case means gingerly running an x-acto knife between the coils, occasionally popping a coil loose. The support between the coils consists of small, sporadic squares of support that you can scrape away with a thumbnail or even ignore.

If the gap is too tight I really have to work to separate the coils and am likely to break one. These have no support so if you can separate the coils you’re ready to rock.

If the gap is too loose I can easily separate the coils by pulling on them. The trade off here is that you make up that time by scraping tiny little hairs of support off of each…and every… single coil.


Here’s a close-up of the large round slinky. The arrow points to where I used acetone to join 2 slinkies.
AqZf2et.jpg

The top part was printed with tight coils that were very difficult to separate (I broke it twice).

The bottom part was printed with loose coils that were easy to separate, but are not as clean as the tight version. I printed this out more than a week ago and am still picking away at the support.


While I’m talking about joining slinkies…

I broke the pac-man slinky (the one in the thingiverse pictures) while I was separating it. I was able to fix it by covering both ends in acetone and pushing them together overnight. I used x-acto blades to keep the acetone off the other coils.

Since that worked, I’m trying to make a really big “large circle” slinky.

Here’s a coil I’m joining –
G1ck8Bi.jpg

That looks like a pretty big gap, I might have to cut this one and try again (it’s still drying).

Here’s the whole thing for scale –
mp48kLb.jpg

That’s 4 slinky chunks acetone’d together (since some broke). I got a little sloppy, but it’s possible to make a seamless join.

I’m hoping to have a slinky that can walk my entire stair case, or at least look cool on my desk