Shermax took a hard hit today

[WattsWheelhouse]

I'm 3 days into my EUC journey and my new sherman max hit the deck pretty hard today at my local outdoor velodrome. I stayed on my feet, luckily. But I broke my 3d printed bumpers off and scraped up the cage, case, and pedals pretty good. Bye bye resale value 😂. Still rides like a champ though. 

So now I'm looking for some more robust protection. I could just print some more of the bolt/clamp on protectors, but these lasted literally two mishaps. Thoughts? Recommendations? Bite the bullet and buy some, or bite the bullet and print some? 

[supercurio]

@Racer13X to be expected when you learn! And I would say even during the 1st year of riding.

Short answer: print your bumpers in TPU.
Something in between from 95A / 40D hardness - no need to go too soft. 2-3 perimeters, 20-30% infill like gyroid.
The toughness of the material will lead to them not only not breaking but being more effective at their job of protection.

Edited July 31, 2022 by supercurio

[WattsWheelhouse]

Yeah I had PLA ones on there, 10 walls for strength and sliding wear resistance. I figured they'd operate like motorcycle frame sliders, but this hit just shattered the bolt areas. I'll reinforce that bit. My printers are deltas with Boden tubes, so TPU will definitely be frustrating. But I'll give it a shot. Thanks for the tips! 

[supercurio]

Ah yes then you can print PLA very fast.. and TPU pretty slow.
Then at least 95A TPU or 98A will be more manageable and still give good results. Walls around 1mm or less in that case.
In worst case you can get some PLA+ blends sold as TPU (even smell like PLA), or anything that ends up tough and a bit flexible. The result won't be as good but it will still work and it might be the best you can print practically.

As you've seen, with PLA the bumper will not bump but transfer the stress then shatter unless it can fail gracefully in the process. And PLA is the least tough, most brittle filament.
Good luck tuning the settings for the prints! I'm sure you can do it with enough patience 😄

Edited August 1, 2022 by supercurio

[BKW]

The SherMax is incredibly robust by itself. Even though I'm not even too familiar with the robustness of other EUCs, I'd still argue the sherman is the toughest.

[WattsWheelhouse]

11 hours ago, ETAonTheEUC said:

The SherMax is incredibly robust by itself. Even though I'm not even too familiar with the robustness of other EUCs, I'd still argue the sherman is the toughest.

Yeah, that's one reason I got it. I'll tell ya, I'm testing out those roll bars, and my protective gear. I now wish I used wrist guards when I was skateboarding way back in the day! What a hand saver! 

[WattsWheelhouse]

On 7/31/2022 at 7:57 PM, supercurio said:

Ah yes then you can print PLA very fast.. and TPU pretty slow.
Then at least 95A TPU or 98A will be more manageable and still give good results. Walls around 1mm or less in that case.
In worst case you can get some PLA+ blends sold as TPU (even smell like PLA), or anything that ends up tough and a bit flexible. The result won't be as good but it will still work and it might be the best you can print practically.

As you've seen, with PLA the bumper will not bump but transfer the stress then shatter unless it can fail gracefully in the process. And PLA is the least tough, most brittle filament.
Good luck tuning the settings for the prints! I'm sure you can do it with enough patience 😄

Through much trial and error I was able to dial in some decent TPU settings, and printed bumpers and power pads! TPU is amazing. It feels weird to pull a rubbery print off the bed! I've still got some blobbing here and there, but I think that's due to retraction settings not being perfect. TPU retraction is tough to nail down on a delta with a long Boden tube.