We all buy a 3D printer for varied reasons. I am sure that most owners are using theirs for scenery, figures, figurines, cosplay props and pieces etc… We connect with artists on sites like Patreon and MyMiniFactory to download and print models that we like the look of. Many owners are running farms; shelves filled with 3D printers that are running 24hrs a day printing models and other items for their clients. There comes a time, however, when a 3D printer owner will need to do a “Practical” print. They’ll come across something that’s broken, they’ll look at it and then find out that it’s going to cost money to replace. Then they’ll think “Hang on! I’ve got a 3D printer! I’ll just print a replacement!”
Welcome to the rabbit hole.
The question of practical printing is a genuine pit of possibilities. Has someone already modelled the part? Where can I find it? What filament/Resin do I need to use to print it? How strong does it need to be? Is it bigger than my printers’ bed? The list of questions is endless. So, let’s start at the beginning. We really need to know…
Has someone already modelled the part?
I am going to use my personal experience here. I’ve done a few practical parts, but I have two pieces that are in everyday use. Firstly the holder for my headphones, and secondly the docking station for our Roomba 555.
My first port of call for practical parts is Thingiverse. There are LOTS of parts here. Most artists are flocking around Patreon and MyMiniFactory for models, but if you need a thing that works then thingiverse is a good place to start. If you have a suggestion for other sites then do please comment! I’d like to see them! 🙂
So, I went to thingiverse and typed in “Headphone” There I found stands of all types, but I wanted to hang my Logitech’s on the wall out of the way. So, adding “Hanger” narrows things down quite a bit. Today, there are lots of headphone hangers. A few years ago though (And this might be down to thingiverse’s search) I didn’t find too many that were what I was after. So I did a search for a shelf bracket instead and found something I liked. Printed it and discovered that it was too small. Well, that’s easy to fix! Looked at the model in Cura and scaled it up by about 150% to make it large enough. Printed again, and voila! I used a 3M sticky wall “Command Strip” to stick it to the wall, job done!
Roomba’s new home
The second thing was the Roomba. Now, our little automated vacuum robot is generally quite grumpy. If it comes into a room where you are standing it will come for you. Or it will nonchalantly scuttle long the skirting board at the side of the room before abruptly turning and head directly at you in an effort to chew your toes. It doesn’t like humans very much. Nor did it like its docking station. Since we moved it would try and push the dock around even though it was up against the wall. It would also try and chew the power lead. So, I needed something that would stop the dock from moving around and also tidy up all the cables and power supply for it. Again, a quick search on Thingiverse turned up a Roomba Homebase AC adapter stand. This didn’t need scaling as it’s a straight print. Some more command strips to stick it to the wall and stop the charging station from moving around, and the Roomba has a new home that’s not going to migrate anywhere. Nice.
I found solutions that fixed my problems quickly, even if one of them needed a little scaling in Cura. However, what if no-one has already fixed your problem for you? You might need to…
Modify an existing part
This past year (2020) introduced many people to shopping online. It also introduced them to buying industrial items instead of the smaller versions you find in the shops. Back in 2019 I bought a 5ltr container of hand wash, the idea being that we could refill the various bottles around the house and use those bottles until they broke instead of just throwing them away/recycling when they were empty. Initially I was just pouring from the larger container to the smaller one. This was messy, and somewhat wasteful as I’d spill some over the sides. I needed a bottle coupler! A quick visit to thingiverse showed a few bottle couplers but not the one that I needed… 5ltr bottle to 250ml bottle. This time I needed to make something myself. There are quite a few ways to model a new item. My go-to modelling software is TinkerCAD. Sure, there is Autodesk’s Fusion360 or the open-source Blender, but applications of that level have a learning curve that can pose a barrier to entry for some people. TinkerCAD is super easy to start using quickly, it’s free and perfect for just quickly making something that you need.
I like TinkerCAD. It’s simple and straightforward. My bottle coupler consists of a nice thick tube with an internal diameter that matches the external diameter of the 5ltr bottle, a cone and an open ended cone that goes down to the external diameter of the 250ml bottle. I measured using some cheap digital calipers I got off the web, but a ruler will work just as well. Inside the tube is the other cone that forms a nice seal with the edge of the 5Ltr bottle. This lets the handwash pour out without it going absolutely everywhere! I printed it with extra-thick walls and a standard infill because I thought it would need the strength to stand up to repeated use. It’s a standard PLA print because temperature isn’t an issue for this use case.