What's new
What's new

Newbie scraper in Japan

Paolo_MD

Stainless
Joined
Apr 6, 2013
Location
Damascus, MD
Homemade scraper - cheaper and better than most of commercial ones

Finally, today I managed to go to Tuckahoe and take a few pictures of my scrapers.

Here is the one I made (my favorite)



At one end there is a piece of 1/4-20 brazed-in to attach the flapper disk



Whereas at the business end I have milled a pocket with a 1" end-mill, providing two points of contact to the blade (even for the finest possible scraping job, the curvature radius of the blade is at least 3-4 times larger)



Another view of the tip (sorry, not very sharp), where you can see how thin is the steel bar




Compared to a 30mm Sandvik scraper, with the bar thinned (but not enough, still way too stiff)




In order to adapt "any" scraper to be pushed with the body, I have made these "adapters" in various sizes. It doesn't need to be a tight fit with the handle.
Both as bluing and as highlighting ink I am very happy with Charbonnel Aqua Wash etching inks




Paolo
 

Paolo_MD

Stainless
Joined
Apr 6, 2013
Location
Damascus, MD
A few general considerations about scrapers, blades, etc.

I started experimenting scraping with tools that are far from ideal: very stiff and short carbon steel scrapers sold by Enco (before getting swallowed by Grainger), Anderson scrapers and, finally both 20mm and 30mm Sandvik ones.

At the beginning I tended to ignore what Richard was saying regarding the importance of having a flexible hand scraper, in order to better control the cut: I was managing to do an okay job with what I had on hand (well, to be honest, the Enco carbon steel scrapers had been put aside almost immediately) and didn't have anything flexible at hand.
During the scraping class I managed to try one of the Dapra scrapers made to use the Biax blades and I immediately realized what big difference there was with my stiff scrapers.

Personally I prefer having a scraper with a wide body (at least 1"), since it is much easier to control the tilt, therefore placing the scraping mark where you intend. You can use it with either large or small blades (grinding a 30mm blade to a 60mm radius is a lot of waste of good carbide).

Blade radius/scraper angle/depth of cut
Essentially, the amount of energy that we can put into a cut is somehow limited. Therefore, if the radius of the blade is larger, the cut will be wider and shallower. With the same blade, if you hold the scraper at a steeper angle, you will produce deeper and narrower cuts, less risk to dig into the surface with the corner of the blade, but you will also get more chatter in the cut.

As suggested by others, use approximately 90mm radius for most of your work and switch to 60mm only for finishing.

By using larger radii, you would increase significantly the risk of digging into the surface with the corner of the blade and your cut would be shallower: what you gain in having to use fewer strokes to cover an area, you lose in having to go over more times to remove the same thickness of material

Regarding why Sandvik and other companies they sell them with a extremely large curvature radius (or even straight), I don't know. Assuming that the blades aren't formed singularly, but rather cut from a long bar, you would have to remove much less material after chopping them off if you sell with a broad radius.

Paolo
 

Bakafish

Cast Iron
Joined
Feb 21, 2022
Location
Tokyo Japan
I started experimenting scraping with tools that are far from ideal: very stiff and short carbon steel scrapers sold by Enco (before getting swallowed by Grainger), Anderson scrapers and, finally both 20mm and 30mm Sandvik ones.

At the beginning I tended to ignore what Richard was saying regarding the importance of having a flexible hand scraper, in order to better control the cut: I was managing to do an okay job with what I had on hand (well, to be honest, the Enco carbon steel scrapers had been put aside almost immediately) and didn't have anything flexible at hand.
During the scraping class I managed to try one of the Dapra scrapers made to use the Biax blades and I immediately realized what big difference there was with my stiff scrapers.

Yeah, I knew these scrapers were overly rigid when I bought them, but I got them very cheaply, about $100USD with no real better alternatives easily available, so I thought that they were far better than nothing. They came with about 10 new replacement blades too, so even if I threw them away this was still a steal.

Personally I prefer having a scraper with a wide body (at least 1"), since it is much easier to control the tilt, therefore placing the scraping mark where you intend. You can use it with either large or small blades (grinding a 30mm blade to a 60mm radius is a lot of waste of good carbide).

Blade radius/scraper angle/depth of cut
Essentially, the amount of energy that we can put into a cut is somehow limited. Therefore, if the radius of the blade is larger, the cut will be wider and shallower. With the same blade, if you hold the scraper at a steeper angle, you will produce deeper and narrower cuts, less risk to dig into the surface with the corner of the blade, but you will also get more chatter in the cut.

As suggested by others, use approximately 90mm radius for most of your work and switch to 60mm only for finishing.

By using larger radii, you would increase significantly the risk of digging into the surface with the corner of the blade and your cut would be shallower: what you gain in having to use fewer strokes to cover an area, you lose in having to go over more times to remove the same thickness of material

Regarding why Sandvik and other companies they sell them with a extremely large curvature radius (or even straight), I don't know. Assuming that the blades aren't formed singularly, but rather cut from a long bar, you would have to remove much less material after chopping them off if you sell with a broad radius.

Paolo

Thanks for your advice, this is very much adding to the consensus. I will grind up a 90mm radius profile and compare how that feels and works in comparison to the factory edges. I was already planning to 3D print some handle cups similar to your nice metal versions. I don't think I'll be doing enough scraping to really justify optimizing the flexibility with the relief cuts in the bar like Robin did, but who knows?
 
Joined
Apr 19, 2006
Location
Manchester, England
I started experimenting scraping with tools that are far from ideal: very stiff and short carbon steel scrapers sold by Enco (before getting swallowed by Grainger), Anderson scrapers and, finally both 20mm and 30mm Sandvik ones.

At the beginning I tended to ignore what Richard was saying regarding the importance of having a flexible hand scraper, in order to better control the cut: I was managing to do an okay job with what I had on hand (well, to be honest, the Enco carbon steel scrapers had been put aside almost immediately) and didn't have anything flexible at hand.
During the scraping class I managed to try one of the Dapra scrapers made to use the Biax blades and I immediately realized what big difference there was with my stiff scrapers.

Personally I prefer having a scraper with a wide body (at least 1"), since it is much easier to control the tilt, therefore placing the scraping mark where you intend. You can use it with either large or small blades (grinding a 30mm blade to a 60mm radius is a lot of waste of good carbide).

Blade radius/scraper angle/depth of cut
Essentially, the amount of energy that we can put into a cut is somehow limited. Therefore, if the radius of the blade is larger, the cut will be wider and shallower. With the same blade, if you hold the scraper at a steeper angle, you will produce deeper and narrower cuts, less risk to dig into the surface with the corner of the blade, but you will also get more chatter in the cut.

As suggested by others, use approximately 90mm radius for most of your work and switch to 60mm only for finishing.

By using larger radii, you would increase significantly the risk of digging into the surface with the corner of the blade and your cut would be shallower: what you gain in having to use fewer strokes to cover an area, you lose in having to go over more times to remove the same thickness of material

Regarding why Sandvik and other companies they sell them with a extremely large curvature radius (or even straight), I don't know. Assuming that the blades aren't formed singularly, but rather cut from a long bar, you would have to remove much less material after chopping them off if you sell with a broad radius.

Paolo

Scraping is definitely a “ horses for courses” job, everybody has their own way of working. Can I just say that I used one of the broader “ Sandvik “ scrapers all my working life, as did my colleagues, and for us they worked fine. Of course the “ Biax “ scrapers were popular also.

I’ve travelled around the UK quite a bit and worked with guys who worked for lots of the big British machine tool makers, I’ve never seen anyone scrape using their stomach or chest. It was always using the arms and upper torso.

Regards Tyrone.
 

Paolo_MD

Stainless
Joined
Apr 6, 2013
Location
Damascus, MD
Scraping is definitely a “ horses for courses” job, everybody has their own way of working. Can I just say that I used one of the broader “ Sandvik “ scrapers all my working life, as did my colleagues, and for us they worked fine. Of course the “ Biax “ scrapers were popular also.

I’ve travelled around the UK quite a bit and worked with guys who worked for lots of the big British machine tool makers, I’ve never seen anyone scrape using their stomach or chest. It was always using the arms and upper torso.

Regards Tyrone.


Definitely, in order to make curved scraping marks like, I believe, is rather popular in UK, you need to do "brute force" pushing just with your arms.
And, I guess, for that type of scraping, you would rather use a fairly rigid scraper.

I am just an hobbyist. true, I don't have to put bread on my table by scraping. I also don't have much time to dedicate to it and I need to be as efficient as possible to get my projects moving.
As I said, I was fairly happy with what I was doing before trying a more flexible scraper. By pushing the scraper with my body, rather than my arms, I manage to get much more done before getting too tired and, by using a flexible scraper, I find myself having much better control on the length of the strokes.

For the sake of time, whenever practical and possible, I use a power scraper to do the job. But, once more, I find that Richard's advice of using flexible blades is golden also with the Biax.

Paolo
 
Joined
Apr 19, 2006
Location
Manchester, England
Definitely, in order to make curved scraping marks like, I believe, is rather popular in UK, you need to do "brute force" pushing just with your arms.
And, I guess, for that type of scraping, you would rather use a fairly rigid scraper.

I am just an hobbyist. true, I don't have to put bread on my table by scraping. I also don't have much time to dedicate to it and I need to be as efficient as possible to get my projects moving.
As I said, I was fairly happy with what I was doing before trying a more flexible scraper. By pushing the scraper with my body, rather than my arms, I manage to get much more done before getting too tired and, by using a flexible scraper, I find myself having much better control on the length of the strokes.

For the sake of time, whenever practical and possible, I use a power scraper to do the job. But, once more, I find that Richard's advice of using flexible blades is golden also with the Biax.

Paolo

If it suits you and you’re happy with the results you’re getting that’s all that matters. I’m not saying one method is better than the other, I just find it strange that the methods that seem popular in the US are unheard of over here.

Regards Tyrone.
 

Luke Rickert

Hot Rolled
Joined
Oct 24, 2007
Location
OSLO
If it suits you and you’re happy with the results you’re getting that’s all that matters. I’m not saying one method is better than the other, I just find it strange that the methods that seem popular in the US are unheard of over here.

Regards Tyrone.

I believe that one could translate "popular in the US" to popular with a specific rather vocal "personality" who has a very specific and narrow idea of how scraping should work. If you look at the actual American experts in scraping like Moore I don't think they used flexible scrapers.

It is good to remember with scraping that it doesn't matter how you get there, what matters is the final accuracy. Looking at the available tools, books, photos etc 99% of scraping ever done in the last few hundred years with done with stiff scrapers.

I think that this fixation on scraper flex comes from an over focus on scraping depth and speed. While the depth of scraping cuts might matter for certain specific applications but is by no means general and really isn't really an issue for hobbyists or well maintained and properly designed machines.

The speed of material removal also isn't such an issue if you rebuild machines logically, which means you plane, mill or grind before scraping a badly worn machine so the amount of material removed by scraping is minimized. Better yet you maintain your equipment and scrape it before it gets badly worn.

I have never seen a Swiss made machine with what would be considered "deep" scraping. It is the same story for flaking which isn't used on any European machine I have seen, only overrated drill presses trying to pass as milling machines which due to a combination of poor design and expected lack of maintenance do everything possible to retain oil.


Just give it a try and find a way that works for you and your applications.

Luke
 
Joined
Apr 19, 2006
Location
Manchester, England
When I first started out in the 1960’s most of the old guys had scrapers made out of old files.

Carbide tipped scrapers we’re just coming out at that time.


I used to do work for a Swiss company called “ BUSS AG “. They made extruders for the plastic and food industries. Inside the gearboxes they had phosphor bronze slideways and sleeve bearings with some of the deepest scraping I’ve ever seen. How they got really deep scraping inside a 10” sleeve bearing was a bit of a mystery. I suspect the scraping was done with pull scrapers as the pattern was all small 3/8”squares.

They weren’t a machine tool building company but their gearboxes were built to the same standard as a lathe headstock.

Regards Tyrone.
 

Mcgyver

Diamond
Joined
Aug 5, 2005
Location
Toronto
As someone doing it as an interest rather than vocation, my projects end up being on the smaller side (think goodness!). So what works from me wouldn't for the person scraping a 20' planer with one of the hip rubber pads.

Anyway, some of my favourite tools I've made are shown below. Short blades easily controlled and some but not a great deal of flex seem perfect for smaller benchtop projects or even smaller assemblies of larger projects. Contrary to many, I usually like a large radius. It almost finds the high spots itself lol. Other than the Biax, I haven't found a commercial tool I like as much as the home made ones.

I was given my start in scraping by wonderful Englishman who was the perfect mentor. He managed to guide you in such a way that you half figured things out for yourself and half because of his guidance. It was probably in fact 95% his guidance, but it was a good way to mentor....like sales 101, make it the other persons idea for for the win. Old Dave ended up giving me his Biax, camel back and other other reference flats...miss that guy.

Whidbey's point is excellent - there are lots of ways to come at this and what counts is the finished result. Different shapes and sizes that have worked for me:


ELUjEdi.jpg


yHwQAJm.jpg


whnUCKn.jpg


HyilUCp.jpg
 

Bakafish

Cast Iron
Joined
Feb 21, 2022
Location
Tokyo Japan
As someone doing it as an interest rather than vocation, my projects end up being on the smaller side (think goodness!). So what works from me wouldn't for the person scraping a 20' planer with one of the hip rubber pads.

Anyway, some of my favourite tools I've made are shown below. Short blades easily controlled and some but not a great deal of flex seem perfect for smaller benchtop projects or even smaller assemblies of larger projects. Contrary to many, I usually like a large radius. It almost finds the high spots itself lol. Other than the Biax, I haven't found a commercial tool I like as much as the home made ones.

I was given my start in scraping by wonderful Englishman who was the perfect mentor. He managed to guide you in such a way that you half figured things out for yourself and half because of his guidance. It was probably in fact 95% his guidance, but it was a good way to mentor....like sales 101, make it the other persons idea for for the win. Old Dave ended up giving me his Biax, camel back and other other reference flats...miss that guy.

Whidbey's point is excellent - there are lots of ways to come at this and what counts is the finished result. Different shapes and sizes that have worked for me:


ELUjEdi.jpg


yHwQAJm.jpg


whnUCKn.jpg


HyilUCp.jpg

Wow, that's quite a collection. I can see they have very large radii similar to mine. Very encouraging words, I'll do my best with what I have. I have enough spares that I can experiment a bit too. Sorry for your lost mentor.
 
Joined
Apr 19, 2006
Location
Manchester, England
As someone doing it as an interest rather than vocation, my projects end up being on the smaller side (think goodness!). So what works from me wouldn't for the person scraping a 20' planer with one of the hip rubber pads.

Anyway, some of my favourite tools I've made are shown below. Short blades easily controlled and some but not a great deal of flex seem perfect for smaller benchtop projects or even smaller assemblies of larger projects. Contrary to many, I usually like a large radius. It almost finds the high spots itself lol. Other than the Biax, I haven't found a commercial tool I like as much as the home made ones.

I was given my start in scraping by wonderful Englishman who was the perfect mentor. He managed to guide you in such a way that you half figured things out for yourself and half because of his guidance. It was probably in fact 95% his guidance, but it was a good way to mentor....like sales 101, make it the other persons idea for for the win. Old Dave ended up giving me his Biax, camel back and other other reference flats...miss that guy.

Whidbey's point is excellent - there are lots of ways to come at this and what counts is the finished result. Different shapes and sizes that have worked for me:


ELUjEdi.jpg


yHwQAJm.jpg


whnUCKn.jpg


HyilUCp.jpg

I had a scraper like the one second from the left in the last photo. It was a bought one made by “ Moore & Wright “ . It was pretty disappointing, more of a paint scraper than a machine tool way scraper.

Regards Tyrone.
 

drcoelho

Stainless
Joined
Feb 19, 2017
Location
Los Altos
Yep, small gantry CNC. Japan has lots of challenges. I'll document that build in the appropriate forum as I get started.

View attachment 344013

If I were doing this, I would lose the cast iron plate, and just purchase a commercial granite plate, manufactured flat to AA grade. Not very expensive for this size, good thermal characteristics, and flatter than you'll get doing scraping.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
My scraper that I have not used in years is about 24" long and one that you put on your shoulder and bump with your hand or with a soft hammer. seems nobody mentioned that kind. Yes, it is a little tricky because if you don't hold the blade right it can corner dig.
 

TGTool

Titanium
Joined
Sep 22, 2006
Location
Stillwater, Oklahoma
My scraper that I have not used in years is about 24" long and one that you put on your shoulder and bump with your hand or with a soft hammer. seems nobody mentioned that kind. Yes, it is a little tricky because if you don't hold the blade right it can corner dig.


Is that for normal material removal? I've heard of a technique like that for flaking the crescent moon pattern. If removing material it would seem more like pull scraping but with more power behind it.
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
I've chose to let my students answer the questions here. The question about Sanvik scraper blades came up and we discussed all of this years ago. I spoke to BIAX Germany and they gave me the name of the Sanvik Tech support in Poland where they buy their carbide blades. Below is my letter to them and their answer.

Dear Sirs,

I teach hand scraping and one of my students asked why you grind all
your blades to a 300 Millimeter radius? Do you recommend this is for
roughing and of the buyer scrapes smaller points or when finishing the
scraper re-grinds the blade to a smaller radius?


Do you have any information on sharpening your blades and hand scraping
using your hand scraper?

Thank You for your time.

Richard King
King-Way Scraping Consultants

handscraping.com
[email protected]
______________

Hello Richard,

We just sell the scrapers and blades and they have a standard radius. We
don't provide devices to re-sharp the blades, also the scrapers and blades
are standard items.

Sandvik expects the person to grind the blade to the desired radius for the material which could be many things besides machine tools way scraping..

Kind regards,
Marcin Golec
Technical specialist
Sandvik Polska Sp. z o.o.

+48-22-6473880 ext. 940
+48-607-377-532
+48-22-843-21-36
[email protected]
Sandvik Coromant
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
I've been hand scraping for over 60 years and have tried everything from a sharpened file, an Anderson, Sanvik, a Swiss Biax design, home made scrapers. of all lengths and stiffness. In all my years of scraping cast iron, steel, bronze, Moglice and Turcite I have found a stiff handle is harder to use and the flexible handle is the way to go. I was taught by a Journeyman Scraper (my Dad) who was taught by a German immigrant who was also a hand scraper by trade. I used to handscrape 10 hour days for weeks, I was being paid to scrape and we looked for the most efficient way to make $$ and go home at the end of the day with-out cramped hands and arms. Handscraping is a CRAFT and like other crafts there are many ways to do it. I have said for years, "I don't care how you scrape, as long as you can duplicate what I do in the same amount of time and get the same quality. I can hand scrape 40 PPI, can you?
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
QT: [I've heard of a technique like that for flaking the crescent moon pattern.}

Yes, that was the effect, I could take stock hip pushing it. Actually, I don't know where my blade is and I wanted to scrap in my CI block.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
QT: {You may not know this, but the Japanese were taught to hand scrape by Germany.}
My grandfather a typical old Krout machinist said the Dutch and Germans were the leaders in the machine tool industry.
 








 
Top