Square tubing checker

thingiverse

NOTE: Needs revision/remixing! Purpose: To verify the parallel nature of square tube surfaces. Background: I am constructing a precision linear delta, which utilizes square stainless steel tubes as vertical ways. Whitworth's three-plate technique can produce one side of the tubing flat but may not ensure it is parallel to the opposite side. This machine mounts a dial indicator for measuring the opposing surface's plane-ness relative to the flat surface I scraped. The flat surface rests on three skate bearings, and a spring tab at the top keeps the tubing pressed against these points. Vitamins needed: 1. Dial indicator 2. M6x20mm bolt 3. 2 M5x50 mm bolts 4. 2 M8x40 mm bolts 5. 3 608 skate bearings 6. 6 8mm washers Construction: 1) Print the three pieces: indicator mount, top, and bottom. 2) Assemble the three skate bearings into the base using M8 bolts and washers. 3) Connect the indicator mount to the top and the base using M5 bolts, which pass through all three pieces. 4) Secure the dial indicator to the indicator mount with an M6 bolt. 5) Mount the base on a large stable workbench. Instructions for use: This procedure trues three pieces of square tubing (A, B, C), each having four sides (A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, C4). 1) Use Whitworth's three-plate technique and a hand scraper to make sides A1, B1, and C1 all flat. 2) Run A, B, and C through the device with the flat side (A1, B1, or C1) down. The dial indicator will measure the relative error between side 1 and side 3 along the tube's length. Use a hand scraper to reduce the error. 3) When sides A3, B3, and C3 are all parallel to A1, B1, and C1, use Whitworth technique on side three, then repeat test two to ensure we are still parallel. 4) Repeat steps one through three for sides 2 and 4. This should ensure opposite sides are parallel but does not guarantee the tubes are square; they could be parallelograms in cross-section. Print Settings Printer: MyKossel 1010 Rafts: No Supports: Yes Resolution: 0.2 Infill: 25%