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Rob D
09-02-2004, 09:06 PM
Hi All,
Anyone here ever scraped in a machine?
If so, would you be willing to explain or show how its done?

Rob D

Alan T.
09-02-2004, 09:28 PM
http://www.practicalmachinist.com/ubb/Forum11/HTML/000400.html

duluthboat
09-02-2004, 10:19 PM
I doubt there are many old enough to have done much way scraping. For a long time now the mating surfaces on machine tools have been finished by machine. You will still see mills and a few lathes that have scrape marks this done only to put divots in the surface to hold oil and reduce the amount of surface to surface contact. Sometime these scrape marks are still done by a person and a power hand tool that reciprocates and has a scraper on the end. The surface is first machined true, than scraped, than stoned to remove the burs. I’m not sure if machine rebuilders go to that detail any more. Today there are auto pressure lubrication systems that have done away with much of this.

Gary :D

Konstantin
09-02-2004, 10:47 PM
Those are great posts in that link.
Joe Michaels has writer hands.


Konstantin.

duluthboat
09-03-2004, 09:12 AM
LOL!!
I just read that post and it is funny that my only scraping experience is also with large babbit bearings. In my case the main shaft bearings from old Navy Destroyers when I was aboard a tender in the Navy. We would get the bearing halves from the foundry, machine and then scrape the lands where the two halves came together. They were then assembled and set up on a horizontal bar for boring. I still have a few of my scraping tools from back then, each person made their own. Scraping babbit is much different than scraping good steel. The idea is the same but if you take too much in one spot from a lathe bed, you have to bring the rest of the bed down to that level.

I guess this still is not an answer to your question; it’s easy to start running down memory lane. I may have an old text book from the days when scraping was done if I find something I’ll let you know.

Gary :D

sendkeys
09-03-2004, 01:19 PM
My Harb Frt 30864 $1000 mill/drill was a mess ! The ways

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here a post from a old newsgroup might help litle

sendkeys
09-03-2004, 01:24 PM
anyone have a picture of a scraping tool ? really like to see the end of it :)

duluthboat
09-03-2004, 01:27 PM
I'll take a shot of one of mine when I get to work.

Gary

duluthboat
09-03-2004, 06:09 PM
Not much luck with my cheap camera getting any detail. It is a simple flat bar, 1” wide, .12” thick, a piece of carbide soldered to the end, and a file handle. The end is ground square with a slight radius side to side. I have 4 sizes this is the largest.

Gary :D

The Wizard
09-03-2004, 08:59 PM
Hi Folks,

I just thought I'd pop into this thread and say thanks for taking me on a trip down memory lane :) .

I have done a bit of hand scraping in my time and it can be a long and tedious process depending on the part in question and how good the finish has to be.

I had the pleasure of working with an 'old master' at hand scraping back in the early 80's and to see him turn out exquisite 'bird's foot' scraping on a part was a real treat. I was working at the time in the Engineering Dept. of a College in England and this particular gentleman had worked for 30+ years in the tool room of Rolls Royce Motors (yes THE Rolls Royce) before he took early retirement and become a College lecturer until he retired again at age 65. He could work wonders with metal whether by hand or machine and I often wondered if the students really appreciated his skills.

We had students of all abilities on the engineering courses but those on the apprenticeship program were in College full time for the first year. As part of their training they were required to make certain items which they would then be able to add to their tool boxes (tap wrenches, engineers clamps, vices, vee blocks etc.) As part of their training they would also have to do a certain amount of hand scraping in order to gain the experience and prove they were competent in the skill. The item normally used for scraping lessons was an adjustable scribing block and the students would have to hand scrape the bottom face and the 'vee' in the bottom. If the 'old master' was on duty on the day the students had to hand the work in for marking you could tell by the long faces just how many had to go back and re-scrape the surfaces until they were up to his standards....lol.

Ho hum..........happy days........lol.

Larry

sendkeys
09-03-2004, 10:33 PM
Not much luck with my cheap camera getting any detail. It is a simple flat bar, 1” wide, .12” thick, a piece of carbide soldered to the end, and a file handle. The end is ground square with a slight radius side to side. I have 4 sizes this is the largest.

Gary :D



Ahh the pictures were great thank you very much, now im going to make one do some testing :) going to be fun

Thank you again :)

Rob D
09-05-2004, 10:38 PM
Thanks for the input guys.
We have an old south bend lathe I may be getting to practice on.

Thanks again
Rob

BT1
09-22-2004, 04:58 AM
I remember back some 12 years or so ago now scraping in a medium size steel marking off plate as an apprentice.

Yes, shesus...