DIY surface plate (out of curiosity)

[Richard King 2]

Felix.....today we would never scrape steels as scraping steel generates slivers and they HURT and hard to get out of your fingers. My Dad worked at Northern Ordinance during WW 2 where they had 50' x 50'floor plates they set navel guns on to calibrate. My dad said they would set on boat cushions on their butts and scrape for weeks using 4' x 6' cast iron plates and lap scraped using autocollimator's and precision levels to get is as close as possible.

I have step scraped large machines up to 50' L x 12" W beds using an 8' cast iron camelback straight-edge and plate A real pain in the butt doing that. Alex, Ted one of my assistant teachers at PMC in Taiwan trained at that Japanese company and said after a day of scraping bent over he could hardly straighten up and walk. Imagine working months bent over. Ted now scraped my way and using hand and power scrapers.

Here is a web-site we set up on scraping I taught classes at PMC over 2 years in time over 20 years...

https://www.facebook.com/TaiwanScraping http://scraping.pmc.org.tw/ and another Japanese site that PMC has on their web site http://www.yasda.co.jp/takumi/takumi01.htm

 

[Bob Korves]

Need an aoutocollimator AND a repeate-o-meter to do it right. Well, at least that is what Standridge Granite uses...

 

[TakeDeadAim]

Felix.....today we would never scrape steels as scraping steel generates slivers and they HURT and hard to get out of your fingers. My Dad worked at Northern Ordinance during WW 2 where they had 50' x 50'floor plates they set navel guns on to calibrate. My dad said they would set on boat cushions on their butts and scrape for weeks using 4' x 6' cast iron plates and lap scraped using autocollimator's and precision levels to get is as close as possible.

I have step scraped large machines up to 50' L x 12" W beds using an 8' cast iron camelback straight-edge and plate A real pain in the butt doing that. Alex, Ted one of my assistant teachers at PMC in Taiwan trained at that Japanese company and said after a day of scraping bent over he could hardly straighten up and walk. Imagine working months bent over. Ted now scraped my way and using hand and power scrapers.

Next time you ask a question like this ask it in the general Machine Reconditioning forum please. I want to talk about normal scraping and not a "what if " questions. Thanks

Here is a web-site we set up on scraping I taught classes at PMC over 2 years in time over 20 years...

https://www.facebook.com/TaiwanScraping http://scraping.pmc.org.tw/ and another Japanese site that PMC has on their web site http://www.yasda.co.jp/takumi/takumi01.htm

I think his question was about normal scraping. What has changed is the way machine tools are built, used and the fact not much machinery (especially large stuff), is reconditioned any longer. If, as an example, a large boring mill needed to be reconditioned it would have to be done much the same way we did it back in the 70's and 80's and that often meant sitting on a boat cushion for weeks on end lifting heavy cast iron straight edges into place to mark ways that were smaller than the straightedge itself.