Balloon Boat V3 - Compatible with Mini Figures

by k-eye Feb 5, 2018
Download All Files

Thing Apps Enabled

Please Login to Comment

Hi K-eye,
What size is the hole for the exhaust? I need to drill it out due to using stupidly supports.

Hi Sausage7,

sorry for my late answer. The exhaust is about 2.5 mm.

Hi, I have a problem with this. I use cura and, when i check the slice i notice the software fill the air hole in the pipe. I have to set something in cura to take it open? thanks

Hi, I don’t use cura, but maybe you have to check your support settings. Support should be „off“.

Support is off. Which slicer do you use?

I use Simplify3D

Comments deleted.

Muy bueno tu trabajo, felicitaciones! Guarde este archivo para imprimir mas tarde!
GENIO !!!!

Thank you very much. I hope you'll have fun with your boat!

Thank you for this thing! Thumbs up to you!

  • Sent from 3D Geeks: Thingiverse Browser for Android

Bellissima e divertente
Prusa mk3
2h30 minuti circa

Comments deleted.

Help! I can't get the pegs to print correctly! I tried the model with the spout in the back and the pegs were too big. I tried a 20% size reduction for peg sizes, but my lego pieces still don't work. My son is really frustrated.

I‘ll try to upload a version with even bigger pins. But I haven‘t got much time at the moment. So you‘ll have to be patient...

Hi Keye, I actually don't need bigger pins. I just need advice. When I opened the file in my dremel software it said the boat was too big to print. I told the program to auto reduce. The boat I printed had pins that were 5mm wide. Then I reduced the boat by 20% to make the pins 4mm, which ended up making the pins to small and close together to fit regular american legos. What would you advise me to do to print it off correctl?

If you reduce the size, Lego won‘t fit anymore. Downlad the smaller version, maybe it is ok for your Dremel.

Any chance of posting the 3.1-smaller sketchup file...importing the stl was a nightmare result.


I will upload it in the next days.

That would be awesome! Thanks...

Comments deleted.

Hey there! Love the boat. My son was so excited to load up his legos, but they keep falling off. Any idea how to make the circles a little larger to attach the legos? The spacing appears to be correct, but the radius is a little small. Thanks again! Great design.

printed 3.2_final
Prusa i3 MK3
.2mm @ 15% infill

Try to scale the model a little bit up (maybe 101 or 102%). I used original measures, so i think it is becuase the shrinking of the material.

Comments deleted.

thx for the model.
I have a small air leak on the top. As a result, impossible to inflate the ballon directly with the tip.
Printed with the recommended parameters.

Made this on my cr10s! Cctree pla. Came out great! Kids thought it was fun!! Nice work!

What brand is your balloon? Can't seem to find any large water balloon in the state.

Sorry, I don‘t know. It‘s just a balloon :)

Thanks for the design. Our daughter is enjoying a lot.

Hey, super-cool design, thanks!

Printing it now, and the air passage looks really small - I'm thinking I would have made it bigger through the passage and just constrained the ends to restrict the flow - that way strings and crud that get in the long tube wouldn't change the flow as much, and if the holes come out too small they're easier to drill out.

What do you use for design software?

Hi, I‘m using SketchUp. The tube is that small, so you can print the boat without support - and support wouldn‘t be very helpful there ;)

I've had good results printing much larger (round) openings without support: https://www.thingiverse.com/thing:1807378

Folded Tabor Pipe

Of course a round tube is possible here too w/o support. But I decided to design it the way it is, because I thought it would be more air tight.
The printer prints straight lines now, otherwise (with a round tube) the tube will get much more „single lines“ and will be much more affected fr air leaks.
It is no problem to design a round tube. If you want me to do it, just tell me. But imho it isn‘t worth it.

Oh, no need - first we have to get a balloon to try on it as is ;-)

I just bought a Lulzbot Mini printer two days ago. Until then I knew nothing about 3d printing. I printed out two of your Version 3.2 boats and everything about them turned out PERFECT! No leaks, they putt-putt around the tub really great and the mini figures fit perfect. I'll be sending them to my 5 year old granddaughter who loves all her bathtub toys.

Great, I‘m pleased the design works for you.

Can I also print the balloon?

Just a joke (-:

Print came out great, no leaks, floats fine. My problem is my minifigs dont stick. Gonna try another with lower flow rate maybe.

Thanks for the boat, kids love it.

Wanhao i3, Pla, 220/60, 4 walls top/bottom/sides.

I gave this a print today (v3.1_stl) and did notice some air bubbles coming from the top.
So i took my wife's clear nail polish and put a layer on top of the boat. And it looked like it helped a bit.
now don't tell my wife....

Well already finished, not done and the truth was a failure, the air comes out everywhere and the water enters the same, the ship sinks. I have printed it with 4 layers on top and 4 layers on the bottom and 4 contour layers. I have printed it in PLA

What was your infill? I used 35%...

Is it possible to create a shorter one? My printer only has a 10cm x10cm printbed. If i rotate it by x 90° and z 45° there is only a liitle overhead at the front. So i think, if the boat is one or 2 rows shorter, it will fit into my printer.

Comments deleted.

Smaller version is now available.
Hope it will work for those who need it.

Today I‘ll post a shorter version and one without pins.

does your slicer allow you to scale the model?

Unfortunately scaling is not an option. The pins will become to small, also the chminey and the air tube.

Yes, but then the mini figures doesn't fit and all the fun is gone...

nice... it is gonna makes me breathless...literally...anyway i am gonna make 2 for the kids anyway thats for sure, could You consider to make a refill value to reinflate the ballon ?

Best Regard and great job
Mr Witzel

Oh, nice! I need them in my bathroom!!!

For those having issues with making it airtight, you might consider more top layers, but hotter temp and possible more extrusion could help as well. You can also adjust line width up to 0.48mm even with a .4mm nozzle. And consider using ironing in Cura 3.2, I think that will definitely seal horizontal surfaces.

I gave this a try, but it leaks massively. Like there's no way you can blow up the balloon. To test where the air was coming out, I filled the balloon and then attached it and then put the whole thing under water and watched for bubbles. And there were a LOT! It is the Lego bumps that are doing it.

I was going with 0.2mm and I was sure to have 5 layers top and bottom so that should have been enough. I'm using Cura as my slicer and I'm wondering if there's something about the Lego bumps that throws off the "top" layer setting. It seems like the very top of each bump has a pinhole in it. I'm not sure though... with thousands of bubbles coming out, it is hard to tell exactly where from. I'm going to look at the sliced model very carefully in the morning, but I think I'll just try this again without the Lego feature.

I had two out of three leak exactly the same as you describe. It does seem like the "studs" are where it comes out mainly, and looking at the design they are "hollow" inside and wish they were solid. However, the air shouldn't even be getting into the hull cavity in the first place. I am tempted to dissect the ones that leak to see how that is happening.

Good point. If this were traditional manufacturing, I'd say the mistake is the square angles of the tube that's holding the air. "seams" should be avoided. But does this translate to 3D printing? Probably not so much. The issue is probably a lot more basic... that 3D printed objects simply aren't airtight :)

That is exactly where I suspected the leak was too, but I performed an autopsy and at first was surprised to find where it was, then it made sense. On this one, it actually happened where the tube goes up the chimney. Looks like at the layer where the deck starts, it starts under-extruding there for some reason, and there was a square tube layer that basically had no adhesion. Maybe because it starts doing more travels, or maybe the square tube layers start cooling too much while it is doing the deck top/bottoms, or both. Not too sure how to work around that during the print. I might try to fix my other leaker by drilling down the chimney just past the deck layer and printing a round tube to glue in.

I did some searching regarding "3d print airtight" and it sounds like it is just a hopeless cause. 3d printed items are simply... porous. Granted, for this type of thing, we don't really need airtight. We need air-sorta-tight. Which is why it works sometimes for some people with some settings. I think the design could be improved. More walls around that tube would help. 100% infill probably would help (but man, what a waste of plastic).

I am not so sure about that, as I print stuff all the time that hold water such as vases and hummingbird feeder usually with just 3 perimeters that don't leak, but I guess that is "water tight". Also, I switched to another balloon boat model where the pieces are separate and the chimney looks like a corncob pipe, and those are all coming out "air tight".

water is much much (keep going) larger than air. Like I said, we just need "sorta tight" so it can work, it just can't leak as bad as it is. I'm sure this can be fixed.


Very good job! My grandson will be crazy about this boat! Is it possible to get the original design file (if possible under Fusion360) and not only the stl ? I would like to make a remix of the v3.2, either splitting the air conduit in two and installing a mobile central rudder, or installing two mobile side rudders. I would also like to reserve some internal space for some ballast weight that I plan to insert during the print, so the boat would sit deeper in the water, increasing the efficiency of the propulsion.

Thank you so much !

Hi, I can add the .skp-file from SketchUp, where I designed the boats. Maybe this evening or tomorrow.


Thank you so much ! I will keep you updated from my side !
Ok, I found the way to edit .stl files with Fusion 360. I added two mods to your "Classic" :

  • two mobile rudders
  • ballast weight

Printer setup is the same than the one you recommend (infill15% and perimeter = 3)

Hardware needed :

For the rudders: 2 rudders, 2 M2 x 13 screws, 2 M2 flat washers, 2 M2 nuts, 2 tiny droplets of thread lock
For the ballast : 4 M5 nuts

See picture 1 for the rudder installation.

I created 4 wells inside the hull in which I fitted 4 M5 nuts as ballast (see picture 2). The nuts must be inserted when the machine is printing layer #28. No need to pause the machine. I added a drop of cyano to secure the nuts, but I think this is overkill.

This design is yours, Keye, if you want to upload it. Thanks !

Hi, how do you edit an stl with fusion 360? Been trying to work this out for a long time without success, any advise would be greatly appreciated. Thanks

Just printed one, I'm disappointed, the air leaks (a lot) from somewhere inside the boat.

Same thing with mine, the air is leaking (a lot) inside of the boat and then up thru the deck too. It was at .28 layers though, so trying again now at .2 at added another (4) top/bottom layer. Will report back later!

Using .2 layer heights and 4 top/bottom is air tight!

Thanks for your report. I‘ll add this in the print settings.

Unfortunately, I did a second one at .2 and it also leaks a lot, so not sure why that happens.

Ok, that‘s not nice. But it is not a problem from the file, the print itself is the problem.
The filament-lines are not tight enough connected. Try to reduce resolution to 0,15mm (but for me on Flashforge 0,2mm is just fine) or use another filament.
Sorry, I hope you‘ll get it to work.
Did you see the *.skp-files? It is a lot easier to manage them on Sketchup than transform and edit stl-files.

Comments deleted.

Thank you

Good job ! But you could made even count across (not 5 pins but for example 6 if do you understand :)

Comments deleted.

You‘re right. Maybe in V4 ;)

this week i‘ll upload V3.1 with an equal amount of dots. and a version with a smallers chimney, so the print will be a little faster...