After reading and watching videos on scraping I was wanting to ask why go through all the work of scraping if your main goal is oil retention. Could similar results be made by grinding small grooves into the surface and then grinding or machining to remove any irregularities caused by grooving? Please enlighten me......Rick.
For starters, "oil retention" is not the only, nor even "main" goal.
As to alternatives - a good deal of expensive professional research has been done to find automatable / lower labour-content, and as important - more easily and highly
repeatable results, yes.
Photetching, and micro-machining have been compared to legacy hand scraping and flaking.
So far.. the old methods have "won". That doesn't mean folks should cease looking for improvement.
One of the more obvious approaches, though not cheap, has been to change the lubricant and provide constant positive pressure appropriate to it being a constant "flush" as well as lube. Another is to make different choices of materials, usually with one of them being sacrificial AND easily replaced as an assembly. Google "wear strips" and find miracle plastics and the Bronzes - some with graphite plugs
One issue of the "old way" being that any flaked depressions good enough to retain oil well will also retain the particles of fretting corrosion. No surprise than a fair percentage of machine tools do NOT leave the factory with any hand-scraping nor flaking of any kind, and never did. For those, it is a field-repair technique, if-even.
Not to forget, too, that whole generations of modern machine tools no longer use the traditional sliding vee, flat, or box "ways" throughout, or even "at all". Some are on rolling-element linear bearings.
Hand scraping "may" still be on the menu. Their SUPPORTS have to be put into near-as-dammit perfect alignment and/or restored to it after corrosion and such have done the dirty. The class of grinding and lapping equipment that put them to rights at the factory is seldom portable to a field location, nor is the worn machine itself easily or economically transported.
Hand, or power-assisted (Biax) scraping and flaking are VERY "portable", so live-on as a viable field repair technique.
Ironically, it is "hobbyists" who flock to it and have become major supporters of keeping scraping alive and well as a skill. Hobbyists, retirees, and small-shop owners tend to be "the ones" who see value in restoring "old iron" for fun - or simply earning a crust with the best they can
afford.
Major companies are as like to simply scrap a worn machine and buy a new one because the costs have been amortized several times over, and a new one is expected to be more productive and/or better suited to the changing workloads.