Oh thatās not good, do you have any more info? Usually a cracked hub wouldnāt cause a flat. Did you drive on the hub without tire pressure, after the flat already happened?
Impossible to say, but itās possible. I can take some pics of it later.
Also, the hubs got up to like 55c while riding
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Thatās pretty toasty, but will happen if printed in black. PETG should be okay with those temps though.
Luckily itās pretty easy to replace a broken hub. 
I still gotta get around to printing my Y-types. Still working on dialing in PETG on my printer and then Iāll have a go at it.
Just briefly skimmed this thread. @Tanuki your designs are very cool, that said, I canāt not share my quick thoughts.
I apologize in advance, but not reallyā¦
DIY 3DP hubs, printed on hobby printers, for continuous use, is one of the most dangerous things Iāve heard of on this forum. I understand that the designs look great in models, but they look like shit when printed from said hobby printers. I would steer clear of this. Good for prototypes at this level and thatās all.
Cheers!
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Thank you for your input. 
That being said, my hubs are in continuous use and are working just fine. And I also donāt think that they look like shit, especially after a bit surface finishing. This comes down to the individual user though, so I get where youāre coming from. This is a print by @ShutterShock, which is really beautifully done in my opinion.
About danger, well, riding boards its pretty dangerous itself, and with my designs having a safety factor of over 10 and me riding them for over half a year now, I have to disagree here with you. I make it very clear though that this again comes down to the individual user, such as riding itself also does. After all, Iām not providing a product here.
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Iām not convinced that theyāre strong enough yet either but are we forgetting the psycotiller hubs that people have run 1000ās of miles on, or the ones that @mishrasubhransu made?
As for looking like shit, thatās just flat out rude lol if your prints look that and thatās totally user error
I get that thereās plenty of 3dp haters out there but I donāt really understand the need to throw more fuel on the fire
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What kind of tires are those?
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@ShutterShock @Tanuki
Please accept my apologies for offending you. I will have no further comments regarding this.
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No offense taken, all good. Everyone has the right to their own opinion, and all I was getting from your post is that you were voicing yours.
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Btw here is the hub that @ShutterShock was talking about, by @mishrasubhransu The concept really is not that new.
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I donāt recommend buying them until they have fixed their valve stem tearing problem. Only got about 20 miles in before one blew, and one of my friends has had 5 blow in the same way out of his 16 tubes
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Cracked hub pics
Hard to see bc itās black but you get the point.
4 walls, 80% gyroid infill, printed at 260c. You can tell it was printed correctly since itās nice and shiny. If you print petg under temp it will come out dull.
Seems to be a strength failure, cracked through most of a thin portion, and traveled into the spoke. Iād probably increase wall thickness, personally.
Due to the position of the melted parts where the tire was, itās reasonable to assume the flat tire was riding on it for a bit before it broke. Also, here are a couple pics of temps
I also went over some railroad tracks at some point before this broke
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Look like you hit some bumps after the flatā¦ riding on the flange is not something that I accounted for, maybe a hard bump while the tire pressure is not that high could lead to failure due the flange hitting the ground. Have you checked the other hubs for similar cracks?
Also Iām still not okay with you not using 100% infill / high perimeter counts. 
Iām not saying that this is the cause, but it doesnāt help either. 
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I would agree that this is a well printed hub. 260C on PETG (I even use no fan) will get it nice and hot with strong layer bonds.
I donāt think the issue is necessarily 3D printing, but rather the type of plastic used. ABS and PETG are pretty strong in the printing world, but still fairly brittle. A more ductile plastic would be a better choice but I realize these are very hard to print with. Nylon (MBS hubs, Flux AT2 enclosure) or polycarb (safety glasses, helmet visors) would be great choices, even HDPE (5 gallon buckets) or POM might work. Something that deforms/bends rather than snaps would be ideal.
I had a very similar failure method with PLA and PETG motor mounts. The layers were well bonded, but it broke across the layers, meaning it was the plastic itās self that broke, not the print. The PETG mount actually cracked twice.
PETG pulleys, where they donāt see impact, seem to last a pretty long time.
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This isnāt the best example, but since youāre printing them, why not make the inner support solid instead of with spokes?
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The other ones seem fine to me, but I havenāt taken the tires off yet. Itās definitely possible it happened after the tire blew, but I also donāt think something like a Rockstar 2 would do that
In my experience, having that extra 20% infill does not make it 20% stronger but Iāll try it anyway
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Ya you make good points. I know Dr Mike has his set printed with PACF
I wanna try some nylon ones when I get the chance. Should be easy on this printer but the material is very expensive.
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