Tools

Having just completed a Vans RV9A (G-OPVM) I have a full collection of sheet metal working tools and basic engineering tools. However, the Wittman is metal tubing and wood so back to the shops. I've tried to keep control costs by selecting or making cheaper tools where longevity and limited use allow, but purchasing high quality equipment for the high use equipment such as the TIG welding machine. The TIG welding machine is a Migatronic TIG Scout 160. This is capable of 160 amp DC operation and has all the usual features: HF start, pulse operation etc. Most importantly, it will maintain a clean arc at the low amperages needed for the thin wall tubing in aircraft. The gas is pure Argon which provides the shielding for the arc. The filler rod for 4130 steel is A31 or A32 (ER 80S-D2 or ER 80S-B2). I'm using the A31 which is both cheaper and although slightly less strong should produce a less brittle joint. A simple blowtorch allows tubing to be heated in order to bend it and to stress relieve joints where necessary. The MAPP gas is a mixture of fuel gas with oxygen and provides a much hotter flame than conventional blow torches more on a par with oxy - acetylene. Next are the tools for cutting and shaping the wood, tubing and sheet metal. The 4.5 inch angle grinder is equipped with a 3/64" metal cutting blade and mounted in the stand allows tubing to be cut quickly (and noisily!) at angles up to 45 degree. The bandsaw is equipped with a range of blades: 14TPI M42 bi-metal for tubing and thicker plate, 6TPI for wood, 20TPI M42 bi-metal for thin plate. The pillar drill is bench mounted so the the head can swing over the normal support plate or over the notcher. This simple device clamps tubing securely and using an appropriately sized bi-metal holesaw cuts the tube ends to precisely join with the crossing tube again at angles up to 45 degrees. The bench grinder having done sterling work deburring all the aluminium in the RV9A swaps the soft deburring wheel for a grind stone more suitable for steel. The guide on the belt sander is fitted with a jig for sharpening the TIG electrodes accurately. Finally, working with steel necessitates various fabrications to bend and form the shapes. The first construction is a very simple heavy duty bending brake for forming the various spar mounting brackets. The shaped pieces of angle allow the ends of tubing to be flattened in order to make the ends of the control rods without creasing, and the angle iron allows lengths of tubing to be flattened to the oval sections required in various places.