I've got a bit of a conundrum. I've got a 10 pound chihuahua whose entire world is a very specific 1.75 inch diameter rubber ball. (And when I say "entire world", I'm understating.) She's gone through a handful of this specific brand and model of rubber ball as old ones have gotten to the point of being too damaged to be safe.
But now the manufacturer has discontinued that line of ball and we're on our last one.
The few other models of rubber balls the same size that I've been able to find have been summarily rejected by the dog. I'm not sure quite what her criteria are for rejecting a ball, even. But I know she'd be a very sad dog indeed if we didn't manage to procure a suitable substitute.
So, at this point, I (and the dog too) am desperate enough to start thinking in terms of maybe crafting a ball as much like the one this dog currently loves to play with.
Of course my primary concern is safety. I wouldn't want pieces of rubber coming off of the final product to be ingested and cause blockages or anything. Nor any danger of blocking an airway.
The ball I'd be apeing is composed of natural rubber. I know you can get liquid latex like this stuff that air dries. Anyone have any idea if that would be suitable for this application? (Or would it be insufficiently durable after drying?)
I've got at my disposal a 3d printer and the skill to design 3d-printable molds. Hopefully the process of molding a ball could avoid heating the mold enough to deform it. I don't have any experience with printing anything but PLA and TPU. But I might be convinced to branch out into ABS or some such if necessary.
I'm just hoping to get some pointers and suggestions. I and my chihuahua thank you all in advance!
It might be the rubber itself. Maybe try and contact the company and find out what it is made out of if they even know. As far as I know, most rubbers are vulcanized.
I'm not an absolute expert on every filament, but like, I'm the mod of [email protected], and I've printed most common filament types. I haven't done a ton of TPU but I think I've got 4 partial spools in the lab. None of them seem right for a dog toy IMO. I haven't gone looking for dog toys, but in passing I haven't seen many people that have been printing them. Most filaments have additives to improve flow with printing and there is no telling what is in them. I wouldn't put them in my mouth. The general disclaimer for all prints mixed with food is to avoid this. There are always micro inclusions in every print and there is no way to effectively access and clean these little cavities in the print, so anything can grow inside them unchecked. I wouldn't give my dog anything I would not initially put in my own mouth.
I also owned an auto body shop for many years and dabbled in composites. It has been nearly 20 years since I was really into this stuff, but I haven't seen anything that is like a really durable rubber. Most catalyzed stuff tends to be more hard and brittle and the silicones I have tried are all that same fake rubbery feel that wants to tear and chunk off. As far as I am aware, stuff like running shoe soles and bicycle tires are all vulcanized rubber. The term means they are held under high pressure at high temperature for a specific duration using a special vulcanization pressing machine. Again, I'm no expert here.
Thanks for the response!
Yeah, I wouldn't want to 3d print a ball for my dog to chew and slobber on. I was only thinking about 3d printing a mold and using that mold to make a ball out of... something. Are you thinking a 3d-printed mold might leave bits of plastic or additives in the molded item and so even that wouldn't be safe? Might making one ball from the mold just to throw away before making the second ball to give to the dog mitigate some of those issues? (Or even throw away the first two or three.)
I've also heard of people using food-safe coatings on 3d printed things. I could maybe use something like that on the mold before using it to make a ball.
But also, it's disappointing to hear there might not really be any material out there durable enough that could be done without really specialized machinery. Still helpful to know, though. Might save me from investing too much in that approach. Ha!
I guess another approach I might take might be to fashion a ball out of something that's already vulcanized rubber. Maybe tying rubber tubing (like they use to make scary-powerful slingshots) into a monkey's fist knot?
Hmm hmm hmm. Whatever the case, this gives me a lot more to think about, at least. Thanks again for weighing in!
(And I love the 3DPrinting Lemmy community! I print a lot with my two Ender printers and design a lot of my own models.)
I might be wrong about this, but I seem to remember an episode of How It's Made that showed the process of injection molded rubber. It might have been for tires. But the process required intense heat and pressure. It's not like making lost wax castings or epoxy in silicone molds. Even plastic injection molds can be done on a small scale, but rubber seems like it needs industrial scale machinery.