Short version: My first attempt at repairing a damaged shaft by shrinking a repair tube over the damaged area.
The guys at the battleship gun facility asked if I could fix a shaft. An area about 2.5" long and 1.25" OD was badly pitted where water had collected under a bronze bushing. They wanted to fill it with JB weld and sand it smooth but thankfully they asked what I thought. I had read a couple of discussions where people sleeved damaged areas by heat shrinking a tube over the damaged area and didn't think it sounded difficult so I told them I could fix it with steel. I got them to order 6" of 1-3/8" OD annealed 4140; off to the races.
The shaft had to be turned down to clean up all of the deep pitting. The final pass ended up reducing the OD from 1.253" to 1.043". I cut 2.75" of 4140 off of the bar, faced the ends and starting boring it out. At 13/16" I went from drills to a boring bar and brought the ID to 1.042 based on the tables in Machinery's Handbook. A quick check confirmed that there was an interference fit. An application of propane torch heat turned the steel sleeve blue so at that time I dropped it over the machined area of the shaft. It dropped home with a nice "clink" which was very satisfying. After just a few minutes of cooling I was able to turn the OD of the sleeve down to blend to the original OD of the shaft. It was still a little long so I cut it down from the long end to match what was left of the original length of the 1-1/4" portion of the shaft. At that point it was ready to recut the keyway slots so I lined it up in the mill and recut the slots to match the originals. Deburr and done!
The guys at the battleship gun facility asked if I could fix a shaft. An area about 2.5" long and 1.25" OD was badly pitted where water had collected under a bronze bushing. They wanted to fill it with JB weld and sand it smooth but thankfully they asked what I thought. I had read a couple of discussions where people sleeved damaged areas by heat shrinking a tube over the damaged area and didn't think it sounded difficult so I told them I could fix it with steel. I got them to order 6" of 1-3/8" OD annealed 4140; off to the races.
The shaft had to be turned down to clean up all of the deep pitting. The final pass ended up reducing the OD from 1.253" to 1.043". I cut 2.75" of 4140 off of the bar, faced the ends and starting boring it out. At 13/16" I went from drills to a boring bar and brought the ID to 1.042 based on the tables in Machinery's Handbook. A quick check confirmed that there was an interference fit. An application of propane torch heat turned the steel sleeve blue so at that time I dropped it over the machined area of the shaft. It dropped home with a nice "clink" which was very satisfying. After just a few minutes of cooling I was able to turn the OD of the sleeve down to blend to the original OD of the shaft. It was still a little long so I cut it down from the long end to match what was left of the original length of the 1-1/4" portion of the shaft. At that point it was ready to recut the keyway slots so I lined it up in the mill and recut the slots to match the originals. Deburr and done!