BT70 Nose Cones

thingiverse

Collection of BT-70 Nose Cones. Print in ABS or PET-G for the best impact strength and heat resistance. Adjust nozzle size and number of perimeters to balance strength vs weight. Print Settings: Printer Brand: Wanhao Printer: Wanhao Duplicator i3 V2 Rafts: No Supports: No Resolution: .2 to .3 Infill: None Notes: I print these in ABS or PETG for better impact resistance and less likelihood for distortion in a warm car as you will get with PLA. The shoulders present the largest challenge in printing these. If you're using a .4 nozzle, you'll need to print 4 perimeters to prevent the nosecone from collapsing at the shoulder. If you are using Simplify3D, you can print the portion up to the shoulder with 3 (or 2 for lighter, less tough) perimeters, shift to 4 perimeters at the shoulder for a mm or so and then revert to 3 (or 2) perimeters. The horizontality of the top of elliptical and parabolic nose presents another challenge. Without support, they tend to collapse. As the layers print more horizontally, they leave gaps between adjacent perimeters. I have printed some with very sparse (3%) triangular support. The best solution I've found is to create a new process at 4-5 mm below the top with 4 top and bottom layers and 30%+ infill to provide support for the top layers. The bottom layer may be stringy depending on how well your printer bridges, but it's inside the nose cone. I also print the tops with thinner layers to reduce the stepping. Post-Printing: Finishing: I've tried a couple of ways to make these look less like 3D parts. Acetone smoothing will work with ABS. Lately, I just sand and use a filler primer to prepare to paint. How I Designed This: Designed in Onshape Online Cad