3D printed bike

Haha, cheers. plenty has happened in AM world in 9 yrs so I thought itworthy of further attention.
We have a 3D Print thread for printing Thingiverse files in FDM and printing lugs etc is such mature technology nowadays it hardly warrants a place in the Concept bikes thread!

That’s so cool. So often mad web like frame designs claim that they want an organic look, but this is something else.

While we're on the subject of printing lugs and dropouts, here's a few more examples...
Tom Sturdy uses AM lugs to optimise build time.

Plain cut tubes TIG welded to printed titanium lugs is a good effort at DfAM (Design for Additive Manufacturing) the process is repeatable and can be scaled and easily automated/controlled.
Mass customisation at £4500 for a titanium frame.

I really like it too.
As far as metal printing goes, this is as affordable a process as it gets and they've designed the structure/form to suit the process....
https://www.youtube.com/watch?v=Aqj8Vok1bKM

I can imagine that with the addition of topology optimisation you could create something that performs really well too

That's super interesting, I wonder how much the price is able to come down as things get cheaper. It's a bit rough and ready looking considering what £4.5k would get you from other builders tho!

Cool video. Interesting to see that the chunks are welded together by hand tho (understandable). Wonder what it would look like when the frame failed - compared to normal tubing it seems like it would be hard to spot when it was going wrong.

There's not many people using topology optimisation on whole bike frames at the moment. I guess that's because full frame printing is still not economically viable.
This academic paper has a few references to optimising a frame but it's only being used as a case study to pitch one GPU architecture against another, but it shows what a conventional diamond frame might look like if optimised....

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Indeed, If I was shelling out for custom I think I'd still want the artizan touch...
I guess that unless one of the big manufacturers decided that mass customisation is the way to go, it's never going to come down low enough to compete with a carbon moulding

I think the stainless example Rik Van Looy posted earlier looked much nicer, the titanium
one still feels like a home made prototype and finish isn't much better than that old Charge
bike from 2012.

Hopefully you'd need to break multiple webs before catastrophic failure so you'd hopefully see the problem coming!

I guess the other side is that if you did want to go down the 3D printed custom route, you may be able to get things that a traditional frame builder wouldn’t be able to do in terms of something that is wildly custom. Although I don’t imagine that’d cost the same as a classic 2 triangle frame.

Agreed - I think that AM has the potential to enhance the artizan appeal of custom bikes rather than reduce it....
If you look at this seat lug by Rob Quirk it's nicer than what you'd expect on a custom TIG welded road bike....

That is very nice! Has a nice flow to it too. The sturdy looks a bit Mad Max next to it.

Similar story with Prova Cycles - AM design flexibility being used to add value for the wealthy customer....

https://www.provacycles.com/ is well worth a look, especially if you like smooth dropouts, silky seat lugs and metal/carbon frame combinations...
Really using AM to enhance the craftsmanship

Agreed, I think the design of Sturdy lugs lends itself to minimum post-processing.
As-printed finish will cut build times.
Finish on Quirk and Prova lugs above require more artizan attention.
If you look at what the lugs come out of the printer looking like, it'll take time/money to get them up to the silky smooth finish that most punters expect from a custom frame

That lug set above is by Metier bikes. Jamie White wrote this about titanium printed lugs (for bonded carbon frames)....

The advantages of 3D printing lugs rather than machining them are:

1. You can design features that are impossible to machine.
   complex internal cable runs, integrated cable stops, brake mounts, cutouts to minimise weight &
   internal sleeves so that the carbon tubes are bonded on both inside and outside.*
   
2. Zero waste.
   The Ti powder in the print bed that does not get made into the part is reused.
   
3. Complete customization.
   I use complex cutouts and patterns that look nice (I think) and lighten the lugs.
   I can rapidly accommodate new industry “standards” ( 148mm rear hubs, dual-mount Shimano road brakes (like on the Trek Émonde)
   I can modify standards for a particular purpose, e.g. putting a custom Syntace-derived derailleur hangar on a gravel bike.
   
   

The disadvantages of 3D printing lugs are cost and tolerances:

1. 3D printed Ti lugs are expensive, and so only make sense on one-off, fully custom boutique bicycles and you won’t see them on production bicycles for a few years
   To compare printed and machined/welded lugs for Ti/carbon frames, Ballpark is currently $10k USD for a Metier frame vs. $6,500 for a Firefly Carbon-Ti
   
2. The tolerances on 3D printed parts are way worse than on machined parts.
   I get around this problem by designing the Ti parts a little bit proud and reaming them or hand-finishing them to machined tolerances, depending on the joint.
   
   

If you're then comparing full carbon custom frames with C-Ti lugged....
The advantage of Ti lugs is that C-Ti frames can be easily repaired:
joints can be unbonded to replace a damaged tube. You race, you crash: If you’ve ever cracked a carbon frame and had to send it off for repair, you can appreciate a fast, easy repair.
I keep standard tubes on-hand for quick repairs. Depending on your point of view, repairability might be part of “sustainability”.

Metier lugs are DMLS printed in Titanium using an EOS printer.
As with the Sturdy they have minimal post-processing...
Plenty more close up pics here: https://cyclingtips.com/2017/03/photo-gallery-2017-nahbs-custom-bikes-part-3/

I think the combination of bare carbon and printed lugs looks quite good

On the subject of labour intensive artisan finishes here’s a photo from bastion insta showing their lug polishing process

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I guess hand polishing is the only option for lugs as vibratory or drag polishing will mean polishing the bond/weld surfaces too.

One of the most interesting projects in this space is this one marketed by Reynolds.

Mirada Pro did the development (part of Innovate2Make, now with Progressive Technology Group).
The frame was welded by Superted

The lugs are of particular interest as the design was developed using topology optimisation and they really showcase the Design for AM principle that complexity comes for free.
Topology optimisation was done by Evotech CAE who've been involved in a few different bike projects

This was a 2018 project but I think it's pretty much the state of the art at the moment for titanium printed lugs

more info on Cyclist and Bike Radar

https://www.pinkbike.com/news/the-3d-printed-moorhuhn-is-now-available-in-full-titanium.html