In this episode I'm investigating whether, and indeed how well,
sugru sticks to PLA filament. And I've got the gloves on again so it's about to get real.
meh or it could just be that sugru is sticky and stains your fingers.
contrary to what you might think, I'm actually not struggling to open the box. I'm looking for
the expiry date, which oddly doesn't seem to be on the packet. Which is weird considering this
stuff lasts around 13 months after manufacture, so it's something you would really need to know.
Of course, it's on the individual packs once you open it up, but
there's quite a range in this box..august...and... march next year. Okay then, we'll be using the
august ones in this experiment since that's a month away. Which as it happens is most of them.
For those of you who don't know what sugru is, it's a silicone formulation that air cures.
Kind of like bathroom sealant but also nothing like bathroom sealant. For one it doesn't stink,
but also its texture is more like plasticine. When
cured, it's basically a hard rubber texture which is "toy safe" whatever that means, and waterproof.
But what I want to know is can you use it on your 3d printed stuff. And how strongly will it bond?
To test this very superficially I printed out eight cubes, four with smooth sides,
four with a cross shape cut into them. I want to know whether the sugru will adhere at all,
and whether a notch in the surface will help it grip. I also want to test whether it will sit in
a notch so that I can decide whether it's suitable for non load bearing applications like say
rubberised edgings, feet, that kind of thing. This would be a much easier way to rubberise a print by
using PLA and a sugru bumper instead of trying to design a multi piece part with TPU.
I simply spread out the sugru and stuck the cubes together.
It's very easy to work with using gloves because it doesn't stick to
them at all. Rolling it to a sausage shape helped with the indented cubes.
You have about half an hour to work sugru before it sets, but
to fully cure it is recommended to wait at least 24 hours.
*24 hours later*
Well close enough. I don't have any fancy measuring
equipment for this but at the same time I don't think we need any, there's not much point knowing
the load bearing capabilities of the stuff, it's very much more in my interest to know whether it
stands up to everyday abuse which luckily I can simulate by...well...a bit of smacking around.
It's actually a lot better than I expected - it's a tall order to stick to PLA.
I think this works about as well as superglue in my experience
You can see here I'm pushing it against a scale with a shear force and it gets
up to the limit of the scale, this tops out at 3kg. That's quite a
lot of pressure - and this is even the case for the smooth cube test.
I did manage to separate it as you can see,
so it's not completely welded. But it took some effort which arguably is well outside
of the normal forces you'd encounter for most applications you'd be using it for.
But I felt this wasn't really enough testing. We know now that
sugru will stick well to PLA, but I wanted a bit more.
I designed -using the term very loosely - some blocks with loops on. In the end I redesigned
these to have thicker loops because I didn't want the failure point to be the puny loops,
and here they are.
I've put diagonal grooves in these, the reason was because
it meant I could print them on their sides without supports, that's all.
Once again I put sugru on one side, pushed them
together very firmly...... and restarted the timer.
...24 more hours later...
well....near enough.
This time I wanted to do some kind of larger measurable force test so I took
this dumbell and hung it on. *dont try this at home*
The sugru held perfectly. I left it hanging for several hours and it did not
fail. Unfortunately I don't have any heavier weights and was worried about
damaging something or myself by trying to add any extra forces.
But I think we've made our point in this video. Conclusion time.
Firstly - sugru does stick to PLA, AND more surprisingly it sticks PLA to PLA really well.
Secondly - a single pack has a holding weight of at least 10kg if you use it like I did.
Thirdly - and perhaps the main use - it is absolutely suitable for use on feet,
bumpers, and so on. Here's an example of a pen holder that I wanted a non scratch rim on,
I designed a v groove into the base, then you can roll a sausage out of sugru and insert it.
I think this kind of thing is the main use case for sugru with 3d prints,
but I can see it used on drone parts too - if you print drone parts, what do you think? Good idea?
Finally - It also sticks to glass, ceramic and metal so can be used to stick a printed
part to any of these. I can testify to the metal part, I made an ugly headphone hanger
around eight years ago on the metal leg of my desk and it still works to this day.
Of course these are all pros, on to the con: it's relatively expensive. It's really not
suitable for anything large at these prices. Since I'm not sponsored in any way by sugru
I can freely say what I think, and I think this stuff is overpriced. I'm sure it used
to be cheaper too. It feels like if they did larger packs it could be more useful.
For what it's worth in case you're wondering generally,
the best "glue" I've found so far for PLA is actually to melt it - I
tested out welding it with a 3d pen in the episode hopefully linked now.
Also a footnote, according to the website, it doesn't stick to Polyethylene,
so it looks like PETG might be out for sugru. I didn't test this. Perhaps in the future.
Well that does it for this episode, if you liked it consider subscribing
and as usual please comment below. Thank you for watching!