Tarmo4 - Various Modified Parts

thingiverse

I found that I kept losing the bolts from the front steering knuckle, so I designed the attached with captured nuts to solve this problem. Another issue I had was that the rear steering knuckles were prone to snapping, so I have designed a slightly thicker version that has not snapped on me yet! The steering knuckles can be printed as per the original build guide. After striping the inside of the original drive shafts, I tried using the ones with the PLA end caps. These were much better. However, after upgrading to nylon diff gears, even the PLA end caps started to strip. Here I have designed a drive shaft with a more robust PLA end cap which have so far survived on my Tarmo4. The TPU shaft should be printed vertically with good dry TPU filament. I've been using SainSmart TPU and have found it to be excellent for this. I have created a file with the support already added to the flexible drive shaft for ease of printing. I use 8 shells/wall thickness with 0.2mm layer height. Infill for this is 50%. The end caps can be printed with PLA/PLA+. These will need support adding for printing. I use 3 shells/wall thickness and a 0.2mm layer height with 20% infill. I glue the end caps to the TPU part with LOCTITE 406 superglue. I've had a TPU shaft rip apart without the end caps coming loose - so this is definitely a good glue to use. You will have to see which of the 3 end cap sizes works best for your setup. I use a tight connector and a medium connector, one on each end for my Tarmo4. <h6>Hardware Required for the Front Steering Knuckle</h6> 4 x M3 nyloc nuts 4 x M3 hex head machine screws 14mm Source file is included (FreeCAD 0.19) if you need to alter anything.