Prusa Mk 4

Tony, glad you went outside your temperature box.  For the PlanePrint their design is based on a tight range of wall thickness ~0.5mm. And because of the gyroid infil some of the wall is double layer.  With a non-gyroid infil e.g. a vase mode print more of the wall is single layer - thus my testing to see if I could get something more like 0.8mm or 1mm to make the parts more robust and allow for a lower percentage of infix-ribs.

Actually, if there is a wee gap in the TODO list for the house I really would like to take the PlanePrint outer form and recast it with vase-mode ribs and see how they compare.

Just imagine what "spares" are going to be like when we are all electric. Virtually everything in the drive train is likely to be unique for every model let alone the manufacturer.
Gone are the days when Ford UK made just 3 engines. 4 cylinder "Kent" from 848cc to 1600cc and the V4 & V6 "Essex" from 2000cc to 3000cc.
All so simple!
  

The big problem I have with ABS is distortion due to shrinkage as the print gets thicker.
I suppose a fully heated cabinet would reduce the problem but a standard A8 would need some reconfiguration to get all its electronics outside the cabinet so its PLA for me!

I finally got some hours to go back to that idea of turning the Gyroid filled Rise Nano wing into a vase mode printable (a clean void within the wing) rather than the gyroid + stringing.

Remember ages ago I took the Clarke Y airfoil for several simple wings and was able to design in a set of spars to form via vase mode printing. I found it yielded a fairly stiff wing.
Clarke Y has that flat base so it was straightforward to setup simple shapes needed.

Well the Rise Nano from Planeprint has a not-at-all simple airfoil, indeed it seems to transition to quite a few different shapes as it progresses from the root. Planeprint recently moved to using a gyroid fill for most of their parts.

 

I am really really chuffed - after a half dozen tries I figured out how to drive freeCAD to take that original STL and create some useful variants.

Say you had a complex wing form (as an STL file) but wanted to create an alternative wing that used a CF spar and ribs that you could cover yourself?

I base this on a YouTube video I found that discusses out to take a boat hull and create a set of bulkheads.  I will probably make the steps I describe below clearer if you have a look at this video:  Here is one path to create a set of ribs that exactly match that complex wing form.... a similar set of steps could take a STL fuselage so you could create matching bulkheads...

In freeCAD open up a new document, go into the Part workbench. First step import the STL file

 

Highlight the mesh and choose the option to convert the mesh into a shape

 

A pop-up asks about 'sewing the shape' stick with the default.

 

The next step is to convert the shape to a solid

 

The mesh is huge so there are an over-the-top number of polygons. There is an option to make a copy of the solid which is 'refined'.

To make a set of ribs you need to create a set of surface-like entities. I tried several ways that didn't work and went back to the YouTube suggestion using the curves workbench (this is an add-on) and something called an ISO curve mesh that can be applied to a face. 

First step is to create a cube that is slightly bigger than the wing. 

 

The next is to highlight a face of the cube and apply an ISOmesh to it. One dimension is zero and the other I made 16 so as to get 15 evenly spaced lines.

 

Hide the box (via space bar) and then that set of lines can be extruded - I did the extrude 120mm.

 

I am being called to dinner so will continue this post later.....