When I recently had my lathe apart for the replacement of the countershaft and general inspection, I fixed the broken rack gear housing.  This broken part was known about (it was broken when the lathe arrived), but I had just never gotten around to correcting it.  It worked OK, but the feel was never that of a solid assembly.  Figure 1 shows the broken assembly.  The housing is Zamac, so soldering or brazing were out.  The gear train was swaged in so access was limited.  The area of the break, however was free of any interfering parts.  For these reasons I decided to epoxy a reinforcement to the joint.  In the past I have had great success with the PC-7 brand of epoxy, so I chose this for the repair.

Figure 1

    I used a strip of 0.065" brass for the reinforcement material.  I picked this up at a local hobby shop.  First I bent the end (in a vise) to fit over the leg of the broken mount, then I cut off the piece to fit the leg of the housing.  I cleaned all three pieces to remove any oil.  Next I lightly sanded the mating surfaces to provide a little "bite" for the epoxy.  Lastly I cleaned the parts again.  The PC-7 is a two part epoxy.  I mixed the epoxy, then smeared some in the broken joint.  The parts were then stuck together and more epoxy spread over the entire mating surface of the housing.  The brass piece was put in place while moving it a little to ensure complete coverage.  The brass was then pushed down until the epoxy started to ooze out.  Excess epoxy was then scraped off with a craft stick (handy things to have).
    The whole assembly was then bolted back in place on the removed carriage, while ensuring that everything was still in alignment.  This prevented the mounting feet from seting up out of alignment, and making a wobbly final assembly.  The pieces were then left to setup for 24 hours.  Figure 2 shows the glued up parts bolted in place.

Figure 2

    After the 24 hour wait, I unbolted the parts and used a Dremel with a cutoff wheel to trim the brass even with the housing.  The brass near the small gear interfered with the teeth.  Checking before gluing it on would have been smarter! :-)
    Figure 3 shows the repaired and trimmed assembly ready for installation.  The figure also shows the can for the "B" part of the PC-7 epoxy.  The rack feed now has a smooth and solid feel that it lacked before.

Figure 3

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