Okay, this is better, I have to admit. When I created the first Lazy Susan mechanisms (previously posted here) I was pretty pleased with myself. And, to be clear they are designed for low speed and work very well. But I have received a few comments about using conical bearings and I could not resist the temptation to see how much better it could be. Of course, we can assume conical bearings will work better but given the limitations of 3d FDM printing and my preferred 0.2mm layer height – the question is how much better and is it worth the effort.
The short answer is… it works way better, especially in smaller-diameter mechanisms. In this case, I designed a 180mm outside diameter mechanism. It uses 36 conical bearings.
Very unscientifically, I did a spin test (no load) of this new version 2.0 design (with conical bearings) and the original design with straight pin bearings. As you can see in the video I made, the new version 2.0 spins approximately (or at least) 5 times further than the original design. That is significant.
The earlier design and the new v2.0 design are very similar as can be seen in the image above. However, the conical bearings reduce the inherent friction and inefficiency of the pin bearing in this application. However, the conical bearings require the top and bottom surfaces (contacting the bearings) to also be sloped. And, this presents a problem when using a 0.2mm layer height.
In the image below I am trying to illustrate the problem of creating a low-slope surface with FDM printing. This means the conical bearing is not well mated with the top and bottom surfaces but for sure it is better than the original design. As the diameter of the entire Lazy Susan mechanism increases the problem gets worse and therefore the benefit of the conical bearings declines. For a smaller thrust bearing it would be significant though and as I am planning to build a project with a smaller thrust bearing I will be sure to use conical bearings for that.
Strangely, I did not perceive a significant reduction in the amount of sound produced by the new v2.0 design. That seems counterintuitive. I mean, less friction and easier rolling, should produce less sound. But nonetheless, v2.0 is definitely better.
I have made the 180mm and 230mm versions.
- 180mm ring requires 36 pins
- 230mm ring requires 40 pins
I also improved the way I am printing the bearings. In this version, the individual bearings snap off of the print carrier cleaner and should work well with no post-printing cleanup.
Printing
I have tried to make my main print settings visible on the Cura screenshot but in case they are difficult to read I have summarized them again here…
Material: I choose to use PETG for its durability and flexibility.
My Setup:
Nozzle = 0.4mm
My Settings:
Layer height = 0.2mm
Line width = 0.4mm
Wall count = 4 (1.6mm)
Infill = 40%
Support:
Designed to print without support.
Print Orientation: As shown in the screenshot(s).
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