3D Printed Lugs For Your Custom Bike

We haven’t heard much about 3D printing using stainless steel as the medium, but that’s exactly what’s going on with the lugs used to assemble this bicycle frame. They’re manufactured using LaserCusing, which is a brand name for parts produced using Selective Laser Melting. The video after the break gives you an overview of what it takes to clean up each of these parts.

The laser melts metal power to solidify areas needed in the final part. Just like the hobby printing we’ve seen on the RepRap or Makerbot there are structural supports necessary to complete the print job, and these need to be removed after the laser has done its work. This is where the majority of the labor comes in. You’ll see a ton of waste material pulled out of the cage-like lug, and we’re sure there’s no shortage of filing and polishing to finish up. But wow, what an interesting result. We just need to figure out if anyone has found a cost-effective way to hack together one of these metal-powder printers.

[vimeo http://vimeo.com/34293503 w=470]

[Thanks Tommy via Oleksiy’s Comment]

39 thoughts on “3D Printed Lugs For Your Custom Bike

    1. You’re kidding about the sharp corners, right? Sure I’d question the materials strength too, but if you are worried or are clumsy enough to get hurt on one of those corners, you should’t ride a regular bike.

      1. Exactly. Campagnolo made some cranks in the 70’s that had a sharp edge in a high stress point. That developed cracks and eventually the crank would snap. I managed to snap one in a sprint from a standing start. It was simply stunning how fast I was flung to the pavement.

  1. I always wonder how loud hipsters would scream to OSHA if they were _forced_ by their employer to ride a fixie bike without adequate brakes on both front and rear wheels and an exposed drive train that can’t freewheel and doesn’t have a guard to protect the chainring from eating your pants leg.

    1. Then again not very many employers required to provide workman’s compensation would have such things in there fleet. My guess is that the couriers that use no brakes, free wheeling bikes are considered self employed independent contractors.

  2. So I don’t want to crap on this, as it is a cool use of the technology… but…

    I’m an engineer and it just so happens my main areas of application are A) carbon composites and B) rapid manufacturing technologies. So, as a daily HaD reader when I first glimpsed this I was excited.

    But the nodes he has created for this bike are about the opposite of what you would want to engineer for a node in a carbon tube truss. Those nodes have sharp ends- stress concentrations which are a huge problem especially in sintered parts as they are more prone to crack initiation at stress risers due to the additive material process. The other design error is the artsy pocketing around the bond area to the tubes. You need a large amount of surface area for the bond to adhere between the node and the tube- pocketing this area completely is not a good idea- thickness reduction yes, full pocketing losing bond area and thus bond strength is a no. I would call the durability of these joints into question. It is a cool art project, and showpiece, but I would not ride it a lot.

    I knew that it was going to be a disappointment from an engineering standpoint when i saw the parts being modeled in Rhino. You don’t engineer components in Rhino. You make art school projects in Rhino.

    1. I’m an engineer and I specialize in injection mold and plastic part design, and I cringed at the workmanship here. I saw all the same errors you did and just was shaking my head most of the video.

      I think the builder should focus more on best machine practices and less on video editing.

      Cool? Yes. Structurally sound design? Nope.

    1. Unlikely a bead could be laid by TIG to this level of detail, certainly not MIG. Hard to beat the high precision of a laser and finely ground metal powder. However, it might have been just as easy to investment cast but would have still required all the handwork/cleanup in the end.

      1. BatonRouge, I’m a PhD student at Cranfield University in the UK and we’re working on exactly the technology you describe. A major problem with laser sintering/melting is that you can’t make really large structural components, since it would take forever to build them. Using arc deposition processes, you can greatly increase the rate at which you deposit the material. As Kieth says, you can’t lay a weld bead to the same level of detail, but this doesn’t matter too much on larger, less intricate components. For most potential applications (eg. structural aerospace parts) you would want to finish them by machining anyway. In fact, one of our projects at the moment is to integrate the arc deposition process with multi-axis grinding, so the two operations can be done conveniently on the same machine.

        There are a lot of potential issues in terms of metallurgy (microstructure, inclusions) and residual stress, many of which can be largely avoided by using the right process conditions. I’m confident though that this will one day be used as the large-scale equivalent of laser deposition processes.

    1. Also, I understand all the skepticism as to the structural integrity of the glue and sharp corners but it seems that he has been and will continue to do analysis of such things. Read some of the comments to the video.

      Stuff like this makes me wish I was in school for engineering instead of computer science but then I think about all the physics, chemistry and math involved and realize I made the right decision. ;)

  3. Prior to reading a comment to another Hackaday article stating that all 3D printing was done using plastic, I read a news article about a replacement lower jaw that was printed in Stainless Steel, so I went looking for the particulars. A nice video on “3D metal printing” at you tube, most likely a long time before that process will be available at a shop near you.
    To me this bike looks show queen,not a daily rider.

  4. The machines I have used for sintering 3D Titanium parts have a base cost of around $800,000 right now.

    There are only a few applications where the parts made via additive sintering are cheaper than their counterparts machined from titanium billets. There are a few large advantages: 1- no programming a CNC to do complex 5-axis parts that would normally require special skills, softwares, and tooling. 2- ability to do ‘impossible’ geometries- hollow parts, webbing or ribs on the inside of parts where you could never machine or cast something like that. and 3- time. A part can be printed complete in a few hours and need a simple dress up remachine when it’s done verses the many many hours of programming a CNC or days/weeks for castings.

  5. seen this exact bike on a TV show called “Fanboys”(Steampunk Edition) and this bike or one pretty much identical to it was transformed into a cool steampunk bike. the reason i think its the same, is that the one on tv had identical parts and styling as the one in the pic there. kewl beans.

  6. I am by means an expert engineer, but I’ve got an idea. Driving the laser itself would present it’s own challenge, but couldn’t someone use a stepper motor with a large ammount of steps, and combine it with a transmission to switch between reduction and multiplication gears? The goal would be a fast carriage movement speed to get to the area of printing, and then switch gears to enable a higher degree of control while using the same motor inputs? I thought of the turbulence the transmission would cause and I thought you could reinput the current position of the print head by using a laser to measure the distance between the current position and the point of origin. Using transmisions I belive achieving the level of CONTROL required for this type of printing would be entirely possible. Next the fine layer power spread, a perfectly leveled surface would obviously be required and an insanely accurate stepper motor to spread the next layer. But all in all, this seems possible to do with average parts and the correct modifications. Project time?

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