What Happens to Hand-Scraped Guideways After Real Work?

Added: 2026-05-10

[00:00:03][music] >> Hello. About 1 year ago, I rebuilt the X-axis guideways of a 3B722 surface grinding machine.

[00:00:20]The guideways are 3 m long.

[00:00:23]Their straightness was checked with an autocollimator very carefully and repeatedly.

[00:00:30]The scraping work was performed with an accuracy of approximately half of 1/100 of a millimeter, meaning the error over the entire working length remained within 5 microns.

[00:01:01]After the repair was completed, the machine returned to normal operation.

[00:01:06]I used it for grinding precision parts and tooling.

[00:01:10]The results were very good. Grinding errors were only a few microns over a work piece length of about 1 m.

[00:01:22]The machine worked for several months.

[00:01:24]>> [snorts] >> Unfortunately, later a problem appeared.

[00:01:28]The main high-pressure oil supply pipe cracked.

[00:01:32]Because of this tiny crack, I had to partially disassemble the entire machine.

[00:01:38]To repair the pipe, it was necessary to remove the table from the guideways.

[00:01:44]There was simply no other way to reach the damaged section.

[00:01:49]I also had to disassemble the lubrication station.

[00:01:53]At the moment, the 10 kW motor, the oil pump, and part of the oil piping have been removed.

[00:02:01]So, the machine now looks seriously dismantled.

[00:02:05]However, there is also a positive side to this situation.

[00:02:09]We now have a rare opportunity to inspect the condition of freshly scraped guideways after several months of real operation.

[00:02:20]To see how the scraped surfaces look after actual use, I invite you to join me in this inspection.

[00:02:28]I myself am very interested to see how the working surfaces have changed, how operation affected them, and how well the guideway geometry has survived after many hours of machine work.

[00:02:50]And for this, detailed measurements are not even necessary.

[00:02:55]It is enough to simply inspect the working surfaces and examine the condition of the characteristic frosted scraping pattern left by the scraper.

[00:03:07]So, what do we see?

[00:03:09]The scraping marks have been preserved very well.

[00:03:13]Moreover, they remain fairly uniform across all working surfaces.

[00:03:19]The guideway surfaces show no new damage.

[00:03:23]In some places, individual scoring marks can still be seen, but these are old defects that existed long before the repair.

[00:03:33]At some point in the past, the machine operated with a failure in the oil supply system, essentially running dry, and that caused deep damage to the guideways.

[00:03:45]During the rebuild, I chose not to remove these old scars completely because doing so would have required removing too much metal.

[00:03:56]At this point, they no longer affect the geometry of the guideways and therefore do not create any practical problems during operation.

[00:04:05]The X axis linear motion system of a machine like this operates under extremely demanding conditions.

[00:04:12]The table performs thousands of movements from one end to the other.

[00:04:17]Sometimes the total travel distance during a single hour of operation literally reaches several kilometers.

[00:04:32]At the same time, this design has one major advantage, continuous oil supply between the working surfaces.

[00:04:41]The uninterrupted oil flow creates a stable oil film.

[00:04:46]And during movement, it also forms an oil wedge, which greatly reduces guideway wear.

[00:04:54]In fact, these guideways have only completed their initial running in period and are fully ready for further operation.

[00:05:03]Moreover, I even hope that their geometry has become slightly better over time.

[00:05:09]The highest microscopic peaks of the surface relief have partially lapped together and the working surfaces have adapted to each other even more precisely.

[00:05:22]At least, I am very satisfied with how the guideways look now.

[00:05:27]In my opinion, they have been preserved extremely well.

[00:05:31]I have already repaired the damaged oil pipe.

[00:05:35]The guideway inspection for both myself and for you, the viewers, is now complete.

[00:05:41]And now it is time to assemble the machine again.

[00:05:45]I hope that very soon it will return to work once more.

[00:05:49]Thank you for watching and goodbye.