So does Connellys book on scraping. Seems to fetch around £90.
Sure I could've lost it when I had it out of the local library and made a profit.
- Thread starter peterd51
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So does Connellys book on scraping. Seems to fetch around £90.
Sure I could've lost it when I had it out of the local library and made a profit.
To add to the chorus, grind a file down, theyre the right material to start with.
I do have some nice half round ones that I bought as discarded junk once, and used with some micrometer blue theyre very useful things indeed...
If you ever see the frosting marks on machine bedways these were traditionally done with scrapers by hand, although nowadays much more likely to be someone with a biax power scraper as their wrists might be a bit shot by now (its from a bygone age of precision for sure...)
Future toy?
http://www.dapra.com/biax/scrapers/index.html
These Dapra biax scrapers seem to fetch big money on Ebay. Reading around they seem to be a favorite with unscrupulous machine tool "reconditioners" for putting in scraping marks and making a tool look near new or hardly used before selling on.
Yeah, flake it in the worn bits, smear it with eggshell grey over every surface including the tailstock quill etc and call it new
pidgeon chit welder
sticking metal since 1962
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Is it any good getting a file and grinding the teeth off to make the scraper ..you will have a bit of length for pressure
Could you use any long handled wood lathe tools ? .... Resetting the edge using one of the nickel steel diamond inpregnated sharpening strips .
To the gentleman who says using hand scrapers is a dying art and will be lost to that dying generatiion ...I ain't dead yet!
Could you use any long handled wood lathe tools ? .... Resetting the edge using one of the nickel steel diamond inpregnated sharpening strips .
To the gentleman who says using hand scrapers is a dying art and will be lost to that dying generatiion ...I ain't dead yet!
Iain Westland
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me neither pcw!!
peterd51
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Hi,
I saw 'frosting' mentioned in a write-up somewhere yesterday, I think.
how's it done please, cross-hatching?
Regards
Peter
I saw 'frosting' mentioned in a write-up somewhere yesterday, I think.
how's it done please, cross-hatching?
Regards
Peter
Copy paste from chatski :-)
For half moon frosting, imagine the mushroom end of the scraper handle as a clock dial. The tool is used by gently striking the clock dial with a soft rubber maul or the heel of the hand. A right hander firmly grasps the scraper by the snak of the blade (not the handle) and applies it to the work with the left edge held firmly down. He strikes the mushroom at about 4 o'clock with a repeated slightly down handed blows. A series of half moons progress with each blow. The blows have to be absolutely consistant in force and direction.
For me...
It actually reduces the bearing area between mating surfaces accelerating wear and other problems but avoids the stiction between two very very flat surfaces causing jerkyness, someone put it as the engineering equivalent of sticking a banana in the axle when overdone as it becomes cosmetic. Ive seen 5% coverage mentioned as a optimum figure but as always its pretty subjective...
I dont even have a surface plate at the moment (I havent got a workshop floor again yet, so splurging on one isnt on the immediate agenda!), and I havent had my camelback on a master to check its flatness, so Im restricted to a bit of bearing scraping.
For half moon frosting, imagine the mushroom end of the scraper handle as a clock dial. The tool is used by gently striking the clock dial with a soft rubber maul or the heel of the hand. A right hander firmly grasps the scraper by the snak of the blade (not the handle) and applies it to the work with the left edge held firmly down. He strikes the mushroom at about 4 o'clock with a repeated slightly down handed blows. A series of half moons progress with each blow. The blows have to be absolutely consistant in force and direction.
For me...
It actually reduces the bearing area between mating surfaces accelerating wear and other problems but avoids the stiction between two very very flat surfaces causing jerkyness, someone put it as the engineering equivalent of sticking a banana in the axle when overdone as it becomes cosmetic. Ive seen 5% coverage mentioned as a optimum figure but as always its pretty subjective...
I dont even have a surface plate at the moment (I havent got a workshop floor again yet, so splurging on one isnt on the immediate agenda!), and I havent had my camelback on a master to check its flatness, so Im restricted to a bit of bearing scraping.
peterd51
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Hi,
thanks for the info, sounds tricky to get it right.
My new scaper turned up today, it's bigger than I imagined, and looks like a one-handed tool, rather like handling a broadsword!
Anyhow, I'll have a play with it on Saturday on a scrap piece to see what it can do.
Regards
Peter
thanks for the info, sounds tricky to get it right.
My new scaper turned up today, it's bigger than I imagined, and looks like a one-handed tool, rather like handling a broadsword!
Anyhow, I'll have a play with it on Saturday on a scrap piece to see what it can do.
Regards
Peter
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Our fitters use two hands, one on the blade to control it
peterd51
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Hi,
the Connelly book is available on the internet, published in 1957 I think. I'm not sure if that means it's out of copyright (50 years?) but as I'll not be keeping it on my PC I figure it's the same as brrowing it from the library...
I scanned through the first 100 pages on Friday and fully read any relevant pages on doing the job. Wasted about four hous on Saturday hacking at a piece of steel and getting it wrong. Ground it all off on Sunday and had another go, much better.
Interesting stuff, not as 'tedious' or 'boring' as I imagined from reading the book. In fact three hours sailed by on Sunday and I didn't even notice the cold until I had to move my feet.
Having said that, I'd not fancy it as a full-time permanent job!
Regards
Peter
the Connelly book is available on the internet, published in 1957 I think. I'm not sure if that means it's out of copyright (50 years?) but as I'll not be keeping it on my PC I figure it's the same as brrowing it from the library...
I scanned through the first 100 pages on Friday and fully read any relevant pages on doing the job. Wasted about four hous on Saturday hacking at a piece of steel and getting it wrong. Ground it all off on Sunday and had another go, much better.
Interesting stuff, not as 'tedious' or 'boring' as I imagined from reading the book. In fact three hours sailed by on Sunday and I didn't even notice the cold until I had to move my feet.
Having said that, I'd not fancy it as a full-time permanent job!
Regards
Peter
N
naughtyboy
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got a couple that got years ago for modding dies and formers for plastic extrusion.
bl££dy good bits of kit used them numerous times over years
bl££dy good bits of kit used them numerous times over years
Which scraper did you go for in the end?
A carbide edged one will last far longer between sharpenings.
Is the full Connelly book on the internet? Last I looked it was only a sample of 100 pages or so. If it's the right hundred pages it's very useful as it deals with the general methods and metrology. The rest of the book dealing with operations on specific machine tools and how to get the work surfaces square and plane to each other tends to be a bit repetitive.
Weldingartisan
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I don't see how you can scrape a flat surface with a triangular scraper, I use mine for internal bearings or deburring. I would use a half round (badly!) for flat surfaces. W/A
Never seen anyone hit a scaper with a mallet or anything else either.
Never seen anyone hit a scaper with a mallet or anything else either.
peterd51
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Hi,
'two handed' would be my answer...though I'm probably holding it wrong!
I found it works if I put my right hand around the main shaft just up from the cutting edge, and hold just up from the pointed end between left hand fingers and thumb. Holding it at varying angles I found I can take off small areas under some control.
The result is flat-ish...it'll work until I can buy the correct item at a reasonable price.
TBH I'm only interested in getting the job done...doing it the accepted way up to 'exam' standards isn't really required.
Regards
Peter
'two handed' would be my answer...though I'm probably holding it wrong!
I found it works if I put my right hand around the main shaft just up from the cutting edge, and hold just up from the pointed end between left hand fingers and thumb. Holding it at varying angles I found I can take off small areas under some control.
The result is flat-ish...it'll work until I can buy the correct item at a reasonable price.
TBH I'm only interested in getting the job done...doing it the accepted way up to 'exam' standards isn't really required.
Regards
Peter
Scraper
Hi
Just joined this evening an old git retired.
When I served an apprentaship we made scrappers out of files. We did not grind them to shape, we heated a file to cherry red, let it cool down, this should soffen it enough to be able to cut with hack saw or what ever, also to shape to what ever is required. Then reheat to cherry red drop at 90 degrees into oil this will then harden. Polish with emery and heat to a straw colour this will temper. You can then sharpen on grinder.
I have one that I made like this 55 years ago and still going strong.
Hi
Just joined this evening an old git retired.
When I served an apprentaship we made scrappers out of files. We did not grind them to shape, we heated a file to cherry red, let it cool down, this should soffen it enough to be able to cut with hack saw or what ever, also to shape to what ever is required. Then reheat to cherry red drop at 90 degrees into oil this will then harden. Polish with emery and heat to a straw colour this will temper. You can then sharpen on grinder.
I have one that I made like this 55 years ago and still going strong.
