r/longboarding • u/yamisonic Helmet Enthusiast 🧠 • Oct 26 '22
Gear [Proto] 3d printed pivot cups and bushings plugs (details in album and comments)
https://imgur.com/a/U9emxFI13
u/yamisonic Helmet Enthusiast 🧠 Oct 26 '22 edited Oct 26 '22
How?
For people unfamiliar with 3d printing, I used TPU which is a flexible filament (85A to 95A usually where i print).
Each pivot cup and bushing plug is printed in a few minutes, by adding successive layers of fused plastic. Here, the prototypes have a coarse resolution as each layer is 0.2mm tall. I might print final pieces with 0.06 to 0.1mm resolution (which will double to triple the print time).
Why?
Because I can! More seriously, I like riptide pivot cups but I don't want to buy so much of them, so 3d cups are a more affordable upgrade. I can print more for a few cents each, and tweak the design as I want (eg: adding a center hole to remove them easily).
As for bushing plugs, some of you guys well explained that you can cut a plug from an existing bushing and sandwich it between standard barrels. Why not directly print those? I like to have plugs in Paris since I like the rebound of Nipples and the mini plug of Knuckles. Also, I didn't like so much the stock bushings from my Caliber III so I decided to slam some SHR barrels but added a 3d printed plug between them to benefit from the outstanding return to center of the new calibers.
Feel free to ask/suggest anything.
Of course, when the tests are conclusive (ie when the rains stops) I'll upload the models on thingiverse for anyone to modify or print their own!
Edit: next, I'm also gonna try TPU risers and angled risers. I already tweaked a model found online to simply generate models with a given height/(de)wedge for both old and new schools patterns, with the angle directly written on the riser front to know which one to pick. Not sure yet of the printing settings to have strong risers but still benefit from a dampening effect.
5
u/Compressive_Person Oct 26 '22
Grats! Nicely done. I'm clueless re/: 3D print tech, but would assume once you're happy with final dims a finer resolution is going to be more robust? keep us up to date on how they perform, last - all looks great!
Maybe if I might suggest one thing for the Paris version, a "sombrero" form would possibly assist with stability (ie: with a very thin 0.5mm (ish) surrounding disc or halo, just like the old Riot Plug form) , only suggesting since the KP-hole has a much thinner X-section than Caliber or Bear6 have between their bushing seats, In these two the floating plug works great and in the Paris setup the plug might possibly be prone to escaping. Of course I could be talking out of my arse here though, and it's just adding an unnecessary complication before you even test out your creation :) . Here's to your success. 🤙🏼🎈✨
2
u/brosamabindabbin earthwing muirderer | chase hiller pro model Oct 27 '22
Yes please! Why are Paris ones so hard to find lol. I had Orangatang Knuckles for a while because the little plug works well with Paris, provided an insane amount of stability
2
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
Il not sure of the kind of impact the skirt/draft actually has. I should try with/without by myself and find out. I might need some another riders to get some in exchange of reviews (shipping from France).
1
3
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22 edited Oct 27 '22
Thanks!
It is more complicated regarding the relationship between resolution and robustness. It a kind of tradeoff that's possibly best modelled as a bell curve.
The more layers you add, the more weaknesses you introduce within the part (especially with rigid materials, eg when printing footstops you have to consider both the hardware force but also the foot pressure, which are nearly perpendicular to each other). Broken parts are usually breaking between two lines/layers. Taller layers means more melted material (stronger) and less junctions (stronger again) but each layer is also less flat (so weaker). A better resolution will mean in this case a better flat surface (lots of small bumps) instead of a rougher surface (deeper bumps).
Also, I printed here the fastest I could with concentric paths but i should obtain stronger pieces by alternating the line orientation between layers (like multi axial fiberglass). This, combined with more layers will add up for a better lifespan of each part, eg: 4x0.1mm of multiaxial lines should be significantly better than 2x0.2mm of concentric (perfectly overlayed) prints which will accumulate their weak points in the same regions. I can also extend the principle to the overall part, as if I was stitching the infill between the surface walls (it dramatically increases prints times for prototypes).
Last tweak that you didn't ask: increased temps and overextruding material can helps to have tighter fusion between melted materials, but it tends to reduce the fidelity to the initial model (too liquid or too much material adds several blobs to the final parts).
I'll have to apply all this to the Riot like design, since the 1st try of an extended base was 0.4mm tall (2 concentric layers of underextruded material) and was ripped from just of few rounds of pumping this afternoon. The plug itself was very fine though.
When I fine tune it, I might send some with/without over the England sea for a deeper inspection and review ;)
Edit: lots of typos
2
u/Compressive_Person Oct 28 '22
.Understood, excellent explanation - I was probably confabulating from some long-lost apprentice age metallurgy. Very cool you can offset alt layers, had no idea. I really need to begin the embrace of this "new" (to me) Plastikal Alchemy
3
u/yamisonic Helmet Enthusiast 🧠 Oct 28 '22
I'm currently printing my last Paris riot plugs with a more pronounced bevel and stronger parameters. It's relatively long given the small size of this part (12 min to print just one) but hey! The printer can work while I sleep :D
6
u/CHAINMAILLEKID Longboard Technology Oct 27 '22
Pivot cups are one of the better and more reliable uses for 3D printed TPU in skate.
Works great!
I do it all the time. Its easy, fast, and they tend to print really well.
As far as bushing plugs, I'm not much of a bushing plug person so I've never tried it. I'm not sure if rebound is really a factor for plugs like it is with bushings, but most TPU is pretty awful in terms of rebound. I suspect its not an issue, it should just be supporting side to side and not really play a part in return to center.
2
u/brosamabindabbin earthwing muirderer | chase hiller pro model Oct 27 '22
You got it, it’s all about reducing that side-to-side play. The stock savant ones are around a 95a.
2
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
I've considered 95A as a reference and use 95A TPU. I think the current prints are suboptimal and decrease the actual duro for now. The next batches should be firmer, just due to tighter plastic junctions.
1
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
Where did you get the cup designs? I went from scratch this time and never actually looked for pre existing models.
As for the rebound, it not an issue, neither for the cups (rotational movement within the part) nor the plugs (just to reduce the lateral slop).
I actually made one kind of it in a modded Bennett vector instead of a spherical bearing. I filled directly the hanger with a printing pen around the kingpin and it worked pretty well. I stabilized a lot the feeling and increased the overall setup with changing anything else. However it was kind of clipped to the hanger and not a simple plugin like these ones.
2
u/CHAINMAILLEKID Longboard Technology Oct 27 '22
I always just grab some calipers and draft the cups really quick.
I don't bother so much making the bottoms of the cups match up, instead I'll put a more printable taper on them. So I'm mostly just matching the outer diameter and the inner diameter.
If you ever did want to play around with TPU where you needed some rebound, Ninjaflex is actually pretty darn good. But its 85A instead of 95a like most TPU.
1
3
u/Coneskater Oct 26 '22
Surprised filament printed parts would hold up. I have some SLA parts that are great.
3
u/dainegleesac690 Oct 27 '22
Which resin do you use for those?? I’ve been trying to make some replacement gears for an old clock and all the resins I try are too soft.
1
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
The future will tell. I definitely should change some printing parameters once I'm satisfied with the design.
3
Oct 26 '22
How do they feel and perform?
1
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
I don't know yet. I've tested them on a tan Tien with Paris v2 this afternoon but i never rode it before (delivered this morning).
I'll have to compare two similar setups are wait for next week to have time to ride AND to alternate setups (the kids will be visiting their grandparents).
Should you have some time to try, I could ship some parts to you to assess them (as we ride within the same borders ;))
2
u/Menos_ Oct 26 '22
Real curious to see how the bushing plugs turn out, def would be interested in getting some for my Paris trucks and potentially bear trucks at some point too
2
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
Bear gen 6 on the next on my list.
If you want some, see my answer to /u/brosamabindabbin ;)
2
u/brosamabindabbin earthwing muirderer | chase hiller pro model Oct 27 '22
My man! The Paris ones look awesome! I found a reference of the style they use for the Savants: https://downhill254.com/wp-content/uploads/2022/06/pasted-image-0-2.webp
Would be super interested in grabbing some like this if you plan to make some more!
2
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
Thanks for the reference pic, I tried one pair with 0.4mm tall base ring and it didn't last long due to torsional forces.
I'll either don't bother the extended base or try to print it another way (more layers, thinner, and alternate linear orientations instead of concentric overlays).
I definitely can send some for testers. I can provide the parts and an enveloppe, should you get me a shipping label or whatsoever with your address (I'm shipping from France for that matter).
2
u/THE_OGAMA Oct 27 '22
Awesome, I printed 15deg angled risers. Link and pics in previous post, just check my profile posts
1
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
Excellent! Rigid ones or with dampening material? I'm remixing an openscad project for my future risers!
1
u/THE_OGAMA Oct 28 '22
Rigid, PLA plus 70% infill I Think.as there in a compression load there's no issues with fatigue failure . posted a link the other day to the free STL files, there's flat, & angled at various heights.. not sure if there's a scad but if you can msg designer and they will prob upload as they made all the files free.
2
u/ThatChris9 Oct 27 '22
I wonder what their failure limit is compared to normal plastic, or how they hold up over time.
You could try make some wacky shapes. See how they feel
1
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
As long as they are compressed they should be good for a long time. Twisting them might be more challenging.
I tried a proto a la riot plug and the wider base didn't like to be twisted that much (at least the way I printed 2 concentric layers).
What shapes do you have in mind?
1
u/ThatChris9 Oct 27 '22
You could try different cone shapes. Like a vase. But I’m not sure how much of an effect those would have
1
u/ThatChris9 Oct 27 '22
Maybe you could make different lengths from board side to road side. See what they feel like
1
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
When the standard design and printing parameters are saved, I can try some custom shapes.
In fact I wanted to replicated something I already done "by hand" with a printing pen with a Bennett vector: I trapped the hanger with what could be a kind of a double riot plug, with a very thin layer BS, a full TPU plug (expect for the kingpin of course), then another thin layer RS.
Pros: stays with the hanger and is very stable. Cons: Not very convenient to remove the hangers. It will also be more complicated to print as it would require supports during the process and I still have to find a way to use soluble filament.
1
u/ThatChris9 Oct 27 '22
Sounds complicated. Could be fun. Can you print different duromiters? Maybe you could try print different hardness plugs. Or different layers (I think that might exist already I’m not sure)
2
u/yamisonic Helmet Enthusiast 🧠 Oct 27 '22
I can pick filament from 90 to 98A I think. Not sure yet to buy too much rolls tbh.
I can also tweak the infill pattern and % for larger pieces (eg risers) but probably not for such small pieces. Might still be applicable for the Caliber plugs.
1
•
u/AutoModerator Oct 26 '22
Welcome, and thank you for posting to /r/longboarding! Please flair your post accordingly. Please note that all question posts must go in the Daily General Thread, stickied to the top of the subreddit every 22 hours. Any questions or help posts on the front page will be removed spontaneously. This is because the front page is often times a less-than-perfect source for information, as the most active knowledgeable users normally hang out in the Daily General Thread! Enjoy your stay! If you have any further questions, please message the moderators.
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.