FILENAMES: round1.jpg round2.jpg round3.jpg round4.jpg round5.jpg round6.jpg DESCRIPTION: These are pictures of the process and machinery used to build up worn shafts by welding so that they can be machined back to original condition. Posted by Matt Maguire . Matt provided the following description: ======================================================================== There has been some discussion on rec.crafts.metalworking about using a lathe for shaft welding, so I thought I'd post some pics of this very thing. To weldors this practice is called "ROUNDABOUT" welding ROUND1.JPG - Is a pic of my own roundabout machine, it is capable of 500 amp continuous duty on shafts (like a lathe), or it may be turned on the headstock with a 22" table affixed and used to bore weld. As the spindle turns a cam and microswitch are used to "step" the torch over, a variable timing circiut is used to control the step amount determined by bead size. The spindle is DC variable speed to allow for correct surface travel speeds. I am considering building a dedicated SAW shaft machine similar to those by Gleason or Vulcan for automitive type work but I never seem to have the time. ROUND2.JPG - Is a pic of a roundabout machine (1200 amp cap.) at E.M. Smith & Co. Peoria, IL. SAW (Submerged arc welding) a wrist pin from a National 4000 ton forging press (28"dia. x 52"L). Parameters were 7/64" wire (Weld Mold #535) step over 3/4" running about 375amps. You wouldn't want this thing on your toe!!! ROUND3.JPG - Is a pic of the same machine with open arc (mig) process, pulse welding a super alloy on a shaft for a chemical plant. Tri-mix gas was used with 1/6" wire. The weldor was running about 280amp background and 800amp peak, stepping over about 7/8", making a very flat bead profile. This process will "microwave your butt", leathers, vasoline, #15 shade, #4 glasses and a plywood barrier for the operator! ROUND4.JPG - Is a pic of a Gleason Subarc crankshaft weldor set for plain shaft welding, the part in the machine is a tamping toolholder (4340AQ at 390BHN). A seal diameter was overlayed with .045" 4340 wire, it's been so long I can't remember all the parameters. The weld chemistry and properties control with this machine are awsome. I also thought I had some pics of the whole machine alas...(I'll probably find the darn things after I post this). ROUND5.JPG - Is a pic of a shaft welded with my little machine, parameters were ..045" wire (E70T-S3) set at 150ipm 21V = 180amps, the surface travel speed 17ipm and step over a touch less tham 1/4". ROUND6.JPG - Is a pic of a bore welded part, E70-T again but the part is ductile iron! The process, weldor mods. and such to do this would take too long to explain (the power supply slope settings took months to work out). Hope this is useful to anyone considering shaft overlay or bore welding. BTW - a lot of help is available from Lincoln Electric on this subject. Matt Maguire