Another video of planing of the same Bridgeport table ways that was recently posted. This is a conglomeration of video segments put together by Fitz Acheson, some of which are contained in the other videos. Rees Acheson
i wonder about extending the stroke a little farther and installing some kind of chip brushes before and after the cutter.. or a flexible tube air nozzle so the cutting edge is not running into previous cuttings either on the back stroke or further tool strokes. i was wondering if you had ever thought about mounting a grinding head of some kind on the tool post.
You've mentioned earlier that one difference between the original rack and gear performance vs. the hydraulic upgrade was a visible pattern in surface quality. Are there any quirks or drawbacks to going hydraulic? I have an old Sanford surface grinder that was outfitted with hydraulics, but they aren't all there. Pondering whether I should fix up the hydraulics, or go another route...
I just read your comment. Most surface grinders that used a rack actually used two of them, each half a tooth staggered. The pinions were likewise staggered. The result was that there was much less of the tooth action showing up on the the finished work surface. I am pretty sure what is going on is that the teeth sliding in and out of mesh tend to lift the table slightly on its oil bed. Staggering the racks more than halves this effect. As for my planer, it had a single rack with quite a large pitch and so the effect was larger. Converting to hydraulic removed the effect. After my planer was originally made, Gray invented the straight rack with a helical pinion set ant an angle. This produced a helical effect where there was always a tooth in the various degrees of mesh and so no marks. Quirks? Well the obvious one is that you may have to make room for the cylinder. But a possibly unexpected one is that the sudden table reversal needs to be dampened or the machine may walk around on the floor. In the case of a surface grinder an accumulator would dampen the reversals. And since there is no heavy cutting load like a planer, the accumulator should not have ill-effects But certain valves that move slowly through the cycle might ease the reversal. Rees
