So, I found a source of low cost 316 stainless steel printing (SLM process from JLCPCB.com). Ordered some tests as I want to use if to a little device. But of course I got side tracked and put in some quotes for bike lugs. $15 for a lug to fit a 44mm head tube and 38mm down tube. Ooookay? 
This thread is going to be about brainstorming ideas of how to make best use of this process with the end goal of making a real life frame some time later in the year.
I think the easiest way to start is just make plain old lugs, drop outs, fittings, etc and braze it up. This is cheapest and there is minimal guess work as everything has been done before. Downside is the need for at least a minimal fixture, and torch (which I do have). Maybe there is a clever way of integrating fixture features into the prints? Pins and stand offs perhaps that allow it to just be laid down on a flat bench top.
Alternatively we could bond it. To me though the trade offs are a bit of a draw. Still need to heat the epoxy to cure, fixture, etc.
There are also things to be wary of when printing stainless, not unlike casting it. The minimum unsupported wall thickness is about 1mm, but large thin geometries can warp. So we may need to add structural removable supports (increasing costs) and "fatter" sections that can be filled with a semi hollow lattice. This is much easier to do with an internal lug as opposed to the traditional overlay.
Anyone have some ideas to add in here?
Inner and outer sleeve with integrated head tube. (about $100 including the top tube half of course). Potential issues with this one cleaning up inside the gap between the inner and outer sleeves. Also if they warp the tube may not fit.
![Image]()
Traditional lug (about $15). Potential issues here are really just deforming, but 316 can be moved around a little to bend it back into shape as well. My understanding is normal cast lugs aren't always perfectly round either and need massaging.
![Image]()
This thread is going to be about brainstorming ideas of how to make best use of this process with the end goal of making a real life frame some time later in the year.
I think the easiest way to start is just make plain old lugs, drop outs, fittings, etc and braze it up. This is cheapest and there is minimal guess work as everything has been done before. Downside is the need for at least a minimal fixture, and torch (which I do have). Maybe there is a clever way of integrating fixture features into the prints? Pins and stand offs perhaps that allow it to just be laid down on a flat bench top.
Alternatively we could bond it. To me though the trade offs are a bit of a draw. Still need to heat the epoxy to cure, fixture, etc.
There are also things to be wary of when printing stainless, not unlike casting it. The minimum unsupported wall thickness is about 1mm, but large thin geometries can warp. So we may need to add structural removable supports (increasing costs) and "fatter" sections that can be filled with a semi hollow lattice. This is much easier to do with an internal lug as opposed to the traditional overlay.
Anyone have some ideas to add in here?
Inner and outer sleeve with integrated head tube. (about $100 including the top tube half of course). Potential issues with this one cleaning up inside the gap between the inner and outer sleeves. Also if they warp the tube may not fit.
Traditional lug (about $15). Potential issues here are really just deforming, but 316 can be moved around a little to bend it back into shape as well. My understanding is normal cast lugs aren't always perfectly round either and need massaging.
