So I’ve been printing with the new Folger Tech 2020 Prusa i3 for about a week now and it’s going great. But so far I’ve only printed parts off thingiverse or other sources. Mostly little figurines for my daughter or parts to upgrade the printer. I’ve learned a LOT and have a number of posts planned about it all. But I’m jumping this one out of order because I can’t wait to share it. It’s the first part I designed and printed myself instead of just finding a design someone else already made.
For her birthday last year my daughter got this My Little Pony bubble blower. It’s pretty freaky, the head tilts back and bubbles come flying out of where the neck would be like someone gave Pinky Pie a tracheotomy. It’s the stuff of nightmares.
The worst part though is that the crazy guy who designed this thing neglected to add a fill port. (I’m guessing it originally had one in the butt but some layer said you can’t do that on a kids toy.) So you’re supposed to fill it through the same hole the bubbles come out of. It supposedly came with a special funnel for this…but we never found it. Either it got lost in the shuffle of the birthday party or was left out of our package.
We’ve tried filling it several times…but can’t find any funnels laying around that will fit. There’s a little key in the hole that prevents a normal funnel from fitting so bubble fluid tends to go anywhere but into the pony.
So I fired up OpenSCAD and did a quick search for the best way to make a funnel finding this. It’s a nice little bit of code that generates funnels based on a set of input parameters. Cool. I adjusted them a bit and was able to get a funnel that appeared to be the right size. I then made a little tweak to the code to subtract a small rectangle out of it making a keyway. Quick, easy! Let’s print it!
Well, it wasn’t a perfect print. It wasn’t horrible, but it had some issues. This is ABS and I really haven’t dialed in my settings for ABS yet. I’ve done most of my printing in PLA since it doesn’t stink and doesn’t need as hot of a bed to stick so prints go quicker. But I like ABS as a plastic much more so I’m trying to get used to working with it. I had specified 2mm thick walls for this thinking that would be as thin as I could get away with. the center opening I specified as 3mm so it should have been 7mm across. But came out closer to 8mm. With some sanding I was able to get it to fit. But the double taper design really wasn’t optimal.
The acetone vapor smoothing did polish it up a bit…but it was still a sloppy print and those thick walls bugged me. I decided to push my printer and see how it would do. So I did a revised version.
Wow! The printer pulled it off! The first attempt failed after just a few layers, so I tried again slowing it down 40% to give the layers more time to cool. That did the trick…until it got near the neck – you can see the two ridges where layers messed up – and I had to slow it down another 20%. I was surprised that I got a seam on the bowl part…I had told slic3r to randomize the start/stop positions when I sliced this 🙁 It did on the tube part but not on the bowl for some reason. I should have tried spiral vase mode but was worried it wouldn’t deal with the notch at the end of the print (this prints upside down for support.)
Remember what I said about the wall thickness? I specified 0.8mm. I’ll take 0.83 gladly! That’s over a dozen or so layers – each single layer is very close to 0.8mm, but if I measure the whole bowl section it’s more like 0.9mm due to slight errors in the layers. Still for a half calibrated budget printer I’m VERY happy with this.
There’s a look inside where the two layers slid. I doubt I could have printed this in PLA. First PLA this thin would be too brittle to hold up. Second I’m having horrible luck with overhangs and bridges in PLA so far. I just printed up a cooling duct so hopefully that will help, but I haven’t had a chance to try it yet and knew ABS would work so I just went with it.
So there’s the proof that this crazy contraption works! And that I can design and print a custom part. I’ll try to find time this week to make a few more posts about how I got to this point. There were a few issues I ran into building the printer that I’d love to share with other builders/potential builders and a lot of issues I ran into figuring out how to actually print. But that’s all part of the game with 3D printing!
I’ve got all the parts printed to do a fairly major upgrade on the machine…but honestly I’m having way too much fun just printing stuff to stop and do the upgrade even though I know my prints will be better after the upgrade (and after the upgrade I’ll finish calibrating which will improve print quality even more.)