One of the folks I know here has a bit of an issue with packs of wild dogs around his property. To be honest it's an ongoing problem in some places locally and some people have resorted to indiscriminate poisoning which is a horrible thing to do but it's been going on for a while.
Anyway the option he is going for at the moment is a slingshot. I've made a few in the past for plinking and my favourite one is a little BB shooter that will accurately fire .177 BBs up to about 10m. I've been making and shooting slingshots for a few years now and it was good therapy when I broke my shoulder falling off my bike. 
For the dogs he needs something a bit bigger that will shoot small stones to discourage them but not cause any real harm.
The 3D print is from a wood PLA filament which is really quite neat to print with, I used it for spice racks and boxes in the past. The filament has real wood impregnated in it and its easy to sand and finish just like pine, in fact when it's printing it smells just like hot pine logs. I like using wood PLA for slingshots as they look quite natural but you can print them in any colour PLA really.
The pouch is 3D printed too from TPU filament which is a flexible plastic, it is a bit difficult to print with as it strings so you need to play around with the settings and the prints sometimes need a bit of a trim.
The bands are cut from Theraband, the stuff people use to make resistance exercise loops from. It comes in different resistance thicknesses which are designated by the colour. I tend to use Gold for most things but sometimes I use the very thin Blue bands for really zippy light pull slingshots, The blue is great when you are making slingshots to kids as it's a really light pull and over a couple of meters wont so any damage at all but still good fun to shoot. The only big issue is the bands a quite thin so don't last long with the sun here so you end up replacing then quite frequently.
To attach the bands I use a little jig that I 3D printed a while ago it lets you stretch the bands so you can tie the tightly with a thin strip of elastic. Just make sure that the bands are tied in the same place and the free end is on the back of the pouch or it may deflect the stone on release.
Once both the bands are attached to the pouch the other end is tied on to the slingshot using another length of elastic, make sure the the lengths are equal and you tie them on the face away from you as you hold the slingshot or they may pull out. If you want something more powerful you can double or triple the bands but there is no need for what this slingshot is going to be used for.
This type of slingshot is a Through The Fork or TTF style so the bands attach to the side of the Y leg. My little BB plinker is an Over The Top or OTT where the bands go over the top of the fork, obvious really, both types are accurate and it's usually just preference of the shooter. I do find that I sometimes whack the back of my hand with the OTT slingshot but the bands are so light on the one I have its not an issue. With heavy bands it would give you a bit of a bruise. 
I hope you Hivers enjoyed the little insight in to one of my hobby's and what's going on with my 3D printer at the moment.