Here are some photos showing the visual differences of one of my product components side by side of different materials. The use case performance has been identical, from a functional standpoint. The formlabs parts will be coated in Cerakote C series black. This model was originally designed for FDM printing in mind, but to get it to work as a resin print, I had to split the model and design internal structures with resin printing in mind. Assembly takes just a few seconds after post processing. Some brass expanding threaded inserts for attaching other components, and coarse screws on the back to pull/hold everything together.
Look at how good the seam/joint line is between the two parts - I love it when a plan comes together. I need to look at the suction/compression layer lines that are showing up, however these disappear with a light sanding just before finishing. I just printed the first time with 2Kv2, so still adjusting for elephants foot.
After Cerakote C Series Finish, installed on bike. This was the prototype print (actually all the parts on my bike are the prototypes, lol), so still has elephants foot.
The issue with FDM is that model orientation matters for functional models, the only way to get maximum strength on this model on a FDM printer was having it on its side (so layer lines ran parallel to load forces), lots of supports which resulted in a part that just didn’t look or feel good when handled. I tried sanding (which took a VERY long time), acetone smoothing (deformed too much/inconsistent surface results), I tried a smaller nozzle size (resulting in a 36 hour print), however it just wasn’t good enough results even though I’ve been selling this component for about 2 years now.
I’ve wanted to make this out of resin, at least for aesthetic reasons but post processing. I got the structures dialed as best I could for removing internal supports for heated inserts, but it was a pain. There is still quite a lot of post processing for the resin version, however I just started printing this week with the new split model. I could print this as one single model, however I didn’t want resin to get trapped anywhere in the model, as I have ribbing and boss features for support/load bearing.
To join the seams, I put some resin in a small syringe, applied a line at the seam and rapid cure with a UV flashlight to stop the resin from running off the model. Once the model seams have been closed, I put it back in the form cure for another cure cycle, then sand off (as best I can) to smooth the model out. This is the area that I still need to refine my process. I likely need to have some aggressive grit sandrels on a Dremel to get better results, but I don’t think it’ll be possible to completely reduce the seam line without spending considerable time refining it - it’s already an improvement over FDM.
FDM is great for hobbyists and middle school kids, I don’t think it’s good for much past that. I could never get past its limitations, structural, cosmetic, design, etc and had to move on. I’m so happy I did.
I’ve built a business with FDM, or at least using it for components of a larger assembly. Just like any material/process, there’s a right and wrong application for it. Some things need to be really good, others just need to be good enough.
Same, more or less. For my application there was definitely a wall, and very little that could be done once I hit it. If I could have started out with my current set up many things would have been sooo much easier.
My first sentence in that post was a bit dramatic lol. I’ll admit FDM does have its place, I just have very few fond memories!
