Yimkin | Adventures in 3D printing

More for fun than any other reason, I thought it wouldn't hurt to print off a 1:10 scale model of the Yimkin chassis and maybe it will come in handy at some point. If it's new to you it's possible to print a CAD model in 3D by building up the model using thin extrusions (layers) of PLA plastic.


The images below show the process with the first images of what the CAD drawing looks like (in yellow) once it's been imported into the printer as a .stl file. As you'll see it's an Ultimaker printer and its first job is to work out how much 'scaffolding' will be needed to support the shape while it's being printed. This is printed at the same time but using a separate extruder and is made from PVA plastic (like the wood glue).


Once the printing is in process you just have to sit and wait and watch as the model emerges. There's a shot of the model on the printer with the chassis in grey PLA and the scaffolding in white PVA. Then again on the workbench as a complete unit. At this point the whole thing is submerged in warm water which dissolves the PVA and leaves you with the finished model.


In this case the printing was done over a couple of days but in total the print time was 25 hours. Mainly due to the intricate shape and amount of scaffolding to ensure it kept its shape. You can see the various options you can play with on the printer to get the optimum performance.


Things learned; anything that's too small at 1:10 scale is not printed out. So as you'll see the suspension pickup points have been omitted. Anything that is printed but is realistically still too small can be very fragile. In this case the diagonal bracing at the back of the chassis - which needed to be repaired by hand. Similarly anything that is too slender can warp. In this case the top right chassis rail.


One of the other projects 'on the list' is to use a 3D scanner to recreate the Standard 10 hubs in CAD. As these would take an age to model. If this works out it may be worth printing out sections of the chassis at 1:5 scale just to see how everything moves in practice ... or just to have on the workbench.