Work towards a finished prototype continues... Lessons in Fusion360 design also keep coming. I have decided that adding the proper nuts and screws will be a last step due to issues Fusion has with losing joints on sub-components. While I think the overall design is going well, I had to go back and basically start some of the components from scratch for the sins I committed early on.
There was a good conversation I had on my last Facebook post with the commenters where I was convinced that a cross bar would be necessary on the X axis assembly. This turned out to be a good thing in more than one way. I was not happy with the prototype when I tried to cause torsion on the Z carriage by hand. The amount of play was surprising (or not depending on how much you think about it). The solution I came up with is the addition of a 500mm linear rail to the underside of the 2020 extruded aluminum cross bar. This has yet to be tested, but I expect it will be enough for the scale of this CNC.
I felt the need to make an obligatory free movement video of the X Y assembly. I get why people are posting these on the Facebook group now.
While I am currently printing PETG parts out for the parts I do not believe will change.. I am still prototyping with (Yellow) PLA. The color is actually growing on me way more than I thought it would. Until I have a working prototype, I will not be providing the design files. This is for a few reasons, please do not ask for the files. A thingiverse "thing" will be created once I am happy that that the design is not a waste of anyone's time. If anyone is interested in the PETG I will be using, please see my post here about the Prusament PETG I have been testing.
I also realized that I would need to take a notch out of the Y axis rear mounts, as the Z carriage would impact these when in the extreme X positions and towards the rear of the Y range. I also beefed these up as I saw some pretty significant warping of the PLA parts where the 12mm bars would be tensioned into place.
The Z carriage design needs to be finished and to include a cable chain mount. It was not optimally designed for 3D printing, so a little re-work is needed. You can see in the pictures that this is not the version in the design and needs to be re-printed. I am also working towards a magnetically connected dust shoe attachment. I think the external electronics enclosure is going to be my last consideration for this project the way things are progressing.
I am pretty optimistic for this project still, but funds have been pretty tight. Even so, I beleive things are moving along nicely.
