Panhard Cylinder Liner Rebore Update 3

Yet again, I could only manage a few hours on the Panhard stuff, but I have finally cured the machining issues I had reboring the liners.

This is the set up as it stands now, long tooltip holder, modified LH boring bar with indexable CCMT insert, but unfortunately the longer tooltip holder fouls the boring bar micrometer body, so I cannot take a direct measurement using it at the moment. A little tweak with a Dremel should solve this, but I’ll do it another day, when I make a sleeve for the anvil, so it contacts the lower cutting surface of the new indexable insert.


On examination the bore was truly round, had a good consistent surface finish and measured 86.03 mm at the top, middle and bottom. I have eliminated the chatter that caused the rippling to the bore last weekend, by using the larger tooltip holder, but I got a slight scoring at three points afterwards. However, a slower feed speed, as well as tightening the spring loaded gibs, and increasing the pressure on the boring bar sleeves to eliminate the sliding play stopped any further occurrences.

Interestingly the original induction motor runs lot cooler with the vacuum pump motor coupling, which has a rubber cush drive rather than a leather or felt pad, and even with the increased loadings and therefore additional effort required to move the boring bar ,through the slides, there is no increase in temperature.

The ripple to the bores was caused by me inadvertently using the shorter tooltip holder, which is really made for the smaller bores sizes. The grub screw which is designed to lock the tooltip holder in position, was in fact gripping the adjusting plate, and so the tooltip holder was vibrating and moving on the screw adjuster.

Considering I didn’t have a manual, or know of any other person with one of these, losing just one liner to teething issues is a good result.

Here is the test cylinder after honing, but not washed yet though.



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