Interesting to see things done the old ways vs the easy way out of just surface grinding it to less than .0002 in one pass. What if you don't have a high grade surface plate to use and your plate is off a few tenths to begin with, will they carry over to the scraped part?
Thanks for hosting us, Tom. A fun time was had by all! We also all learned from each other. Don't be too hard on yourself with the metrology. Scraping has "surface texture." Companies like Moore Special Tools would use a scraper's block to check the work on their exquisite machines and to test the scraped masters that tested the machines to millionths of an inch. A scraper's block is an 1" square by maybe 1/4" thick accurate carbide block which is placed between the indicator and the scraped surface while indicating it. In actual usage, your level will be supported by much more area than an indicator point. On scraped work the many equally high contact points are what counts. A gage block might make a reasonable substitute for the scraper's block.
***** Scraper's block: Foundations of Mechanical Accuracy, Wayne Moore, free download at www.totallyscrewedmachineshop.com/documents/FoundationsofMechanicalAccuracy.pdf pages 28-29. Material shown is hardened and precision lapped nitralloy steel, 25mm square, looks to be about 15mm thick.
It is now gone from that site, but you can now download it here: www.hobby-machinist.com/attachments/foundationsofmechanicalaccuracy-pdf.118847/ I would do so soon...
Thanks for sharing. Had to do something like that off shore for work. A fixture and a split clamp collar the wrong ID size but with heavy duty thickness. A small cutoff wheel, die grinder with a 60 grit flapper wheel and a sharpie. I did such a good job they forgot I did it and later ordered the wrong size replacement parts five years later.
Looks like a good time and very entertaining company, thanks for sharing that with us Tom! I'd sure love to hear a little more on the theories behind scraping, or at least your take on it...maybe when you video the decking of the corrosion and the re-scrape? If you get a chance that would fill in a few of the blanks I have about it...on the side, can you believe I can still see much of the factory frosting on my 96 year old SB? That's part of what really interest me about it...I never saw it on the Atlas, so it wasn't even a question in my mind. Thanks again and see ya soon, Aloha...Chuck
Great video on your scrapefest! I might suggest after you machine the level, lap with wet/dry sand paper changing grit size a few times, then scrape for a final flattening. I probably would not use the Biax and stick with hand tools for the best results. Good luck and enjoy!
Gene Elliott If a surface is ground or lapped, the blade of the scraper has difficulty penetrating the surfaces. It just skims off and dulls the blade. When ever possible I try to grind small surfaces prior to scraping so to fast track the scraping to the finishing passes. But before bluing, I use 100 grit sand paper to bread off the shine, then scrape a patch work.
Nice video very informative. I have always been impressed with hand scraping. Seems like hand work and file work were amongst the first skill you learned as a apprentice in the olden days. I was glad to see a picture of the scraping crew at the end, was beginning to think Tom had some scraping pals in the witness protection program.
Gday Tom, That was nice to see some hands on scraping. One guy commented that a surface grinder is an easier way to do it, but hand scraping is more accurate than surface grinding no matter how good the grinder is. Hand scraping is flatter. Actually, one bloke I worked with reckoned that surface grinding is roughing out compared to serious scraping, I agree.
Peter Spence Hi Peter, For small parts a surface grinder would be faster. When you get into large parts or tricky access wheel wear plays a part in just how good a surface grinder can do. Most scraping is done for lube retention on machine tools. Surface grinders cant do that at all. Thanks for the comment. Cheers, Tom
Very interesting video. Now it caused me to have more questions. Once you get one surface flat will is still be concentric to the other side? How do you handle that? Thanks for the video.
Hi Tom great video I have to scrape the ways on my lathe that I'm restoring. Such a big job. Sorry if it's a silly question. Could you recommend a good place to buy some decent scrapers. What to look for and avoid. And how would I tackle the inside V ways. And what tools I would need to start scrapping. I know I need a surface plate. Some blueing etc. Your recommendation would be greatly appreciated.
Would lapping on a surface plate give desirable results? Just trying to wrap my non-machinist head around the concept of scraping. Keep the awesome vids coming.
An interesting method of metal removal. Must be quite an old concept of metal machining. About the only scraping I have done, was when something very stinky got smeared on the brake pedal in Winter and did not notice it until I turned the heat on!
When I'm checking the flatness of a scraped level (starrett 199 for example) or any other scraped tool, I put a gage block between the surface and the probe tip...love your vids! Thanks man!
Tom, my son and I are needing to scrape a bed on our lathe, we have a good understanding of how to scrape but touching up the blade on the scraper has us wondering how others might touch them up. Any chance you might do a vid on how you touch up your blades? Thanks.
***** Hi Larry, There is enough interest in scraping that I will probably make a stand alone video showing some of the stuff first hand. Right now I use an Accu-finish slow speed carbide grinder to touch up the blades. I think you could do a decent job with a simple fixture and some diamond hand held hones. Thanks for the comment. Cheers, Tom
Great video. Have wondered about the process of scraping for a while and this showed several examples of how to do it. One question though. I understand the function of scraping. To create a flat surface that can be used to reference some other surface but how much scraping would be too much? If you have two perfectly flat surfaces they will actually stick together. Almost like being magnetized together due to the intermolecular bonding between the parts. At what point do you call it quits on scraping? 90%, 95%, 98% ?
Enjoyed this one, seeing 'idled' pieces being brought back into use. Could almost taste the rust from the surface plate. Now then how in the world are there (24) thumbs down? Viewers not knowing what they are watching?
Would love to see a Scrapefest 2, there must be others in the Bay area that are interested in scraping these days. I doubt I'm the only one...After 2 years you might be ready for another one? :-/
It may be too late by now, but machining off your level may release some stresses, making it take many more hand scrape passes to correct, than removing what you need to by hand scaping.....very interesting!.....keep us posted!
Would a steel surface plate that has been worked in a surface grinder be just as flat ? Years ago I took a steel lapping plate that had been thrown out because it had been used to the point of having a bad hollow in the center, trued up the wheel on the surface grinder and ground it what I thought was perfectly flat. What about a Blanchard ground surface? Thanks in advance for any input.
+opticschief Hi Optics, The answer is no it wouldn't be as flat. When scraping we are matching to a master flat reference. The surface grinder can produce flat parts but you have no reference to compare it to. Thanks for the comment. Cheers, Tom
+DSCKy Hi DS, My grinder does not have enough travel to cover the entire length of the level. Good excuse to buy a bigger grinder. Thanks for the comment. Cheers, Tom
Hi Tom. Very strange...the more Oxen videos I watch, the more often items afflicted with weasel snot appear in my shop. Just can't figure it out...?? Keep up the great videos! Carl
Hi Robert, McMaster sells scrapers and the Internet is loaded with information on scraping. Don't need much more than that. Make three small surface plates. You won't need any special measuring gear and by the time your done you will be really good at scraping. Thanks for the comment. Cheers, Tom
Ive never heard of this practice until now . looks interesting but it would drive me insane to make a level surface doing that method . but it looks incredible like metal art . i should give this a shot who knows i might un earth some hidden talent ! . what would be a good starting point ?.
Hi Tom, Sounds like that you just officially launch the new trend among machinists: " Scraping " I have so much to realize before the Big Call hope I'll have time to try it all... Pierre
You guys seemed to have a lot of fun:) I attended a scraping class in sweden with Richard Kind and I can tell you well money spent its so much fun:) I came to think about one thing he told us that's important is to "ring" the part before scraping. Hang the part from a string and tap it some with a hammer or something. I really didn't thing that would affect the work when scraping on really old stuff, but I was wrong:D My first project was an at least 50 year old angle shelf and that thing warped like crazy once I realised my mistake and tapped the piece lightly:) Thanks for sharing! Cheers!!!
On the advice of Tom some time ago I picked up ( not cheap but worth it) a copy of Machine Tool Reconditioning by Connelly, read it front to back, so much info. Currently making my way through a bridgeport requalification.
Very cool Tom, if you scrape til you are blue in the face, will the weasel snot clean it off? I enjoyed this video very much, it is nice to get off the beaten track. Cheers, H
I have 30+ years in the tool shop for first McDonnell Douglas and later Boeing. I am in tooling inspection now. Honestly, I would just leave the level alone if you are happy with the surface. It has been decades since I had to do any scraping but we had to get 90% match between two surfaces, they wern't just flat but multi contoured. Any low spots did not hurt anything just as they will not hurt the level either. I do know the level of crazy we in the trade can get into, The first time I made a wall size book shelf for the home and it was 1/32 out of square it drove me nuts... until I realized it was just a book shelf! By all means do what you feel but if it were mine, I would remount the bubble and call it a day. YMMV! :P OH, BTW, I still have 1/2 a tube of blue and the long hours of bench work it represents and remindes me of, still brings back a yearning to never use it again :P
***** It is nice to have a good surface plate, Reconditioning is as good of a term as any :D Good flat surfaces (when that is what you need) just make things to together better. What do you do if you need a flat surface and don't have one? The answer is to make 3 by scraping, it takes 3 surfaces worked against one another to get a flat plane. If you only have 2 surfaces, you don't have anything, you can match a bowling ball to your shop floor with a perfect fit, 3 surfaces work to prove each other flat. Talk about a pain in the backside! It will make you glad to pay someone else to do it for you!!! :D
This is old still interesting. The overall results that are possible is simply amazing. My mind keeps heading to refine the marking stoning process. I have Ideas but need to get a plate to start fiddling with it. Seems if one removed with cleaner all the color very lightly stoned. Then applied a contrast color using something soft to fill low spots also. Then a light rub on a reference lapping type plate to show and maybe even lower some of them high spots. Alternating hard print flexible removal with hard removal flexible print might clue us in a bit on what is going on to say the least. I saw you sort of doing that on the clean table looking for the polish.
+sideswipe147 Hi Side, You can create a flat plane of any accuracy level by scraping and checking three flat plates together. You check them against one another and slowly increase the bearing area between them until the desired level of accuracy is achieved. The sky's the limit. You do need three so you don't just match one to another. The third plate is the key to producing a flat plane. Thanks for the comment. Cheers, Tom
+oxtoolco cool. thanks for the info. I'm just starting out so I don't have a lot of the needed tools and whatnot. but I do know that a master flat is quite important to have and being able to make one if needed is incredibly valuable information.
Interesting...... although I am not completely understanding the concept of this Scraping method.... A previous viewer asked "why scrape when you can surface grand?" or why not just mill off 2 or 3 thou...? I'm missing something here..... I guess the main question is ... What is the main benefit of scraping vs. milling or grinding? Thanks Tom.. I'm curious....
Depending on how well you do it, a scraped surface can be more accurate than a surface ground or milled surface. Plus, a surface grinder or milling machine will only be as accurate as its ways, which are commonly scraped. Scraped surfaces tend to be a better bearing surface because they hold oil better.
Danny Herrera One of the advantages that scraping offers over surface grinding is the ability to align and fit parts relative to each other and do so very precisely and with great control. Precision scraping is done when parts are in the natural state. When parts are ground they are influenced by holding forces and thermal effects, where as in scraping, there are very little of those effects. The scraping methodology is mostly superior when it comes to correcting machine tool geometry. And as Andrew stated, the lubrication evenness is also better with scraped surfaces. As a scraper, we talk in terms of tenths (.0001") with contact points of up to 40 points per square inch (Technique 40).
+Andrew Phillip I can't even wrap my head around how that is possible, the guy is holding the thing in his hand. Edit: I should have watched more of the video before commenting and now it makes sense. Nothing is perfectly flat, ways have irregular wear patterns, heat and clamping forces also confound flatness. So the granite stone with die is a very very flat reference surface and it reveals the imperfections in the surface and the human hand can remove very fine amounts of material with an abrasive, giving a very precise surface.
How appropriate! I just put down my scraper an hour ago and then checked out Oxtoolco and what do I find? Why scraping? To me it does as much to my mind as it does to the the piece of metal. You can keep the Biax (as a tool freak, did I really wtrite that!?) Listening to good music while scraping is relaxing while doing a physical workout. You would otherwise have to pay good money to get that. I just wish I could be there with you.
Einar S Hi Einar, I also find the steady patterning of scraping relaxing. I tried the Biax and yes its certainly faster. One of the attractions of scraping is I can do a super accurate job by hand. To me this is wonderful and still amazing. Thanks for the comment. Cheers, Tom
Hi mate. Sorry, I don't get it, is this scraping meant to be in stead of a surface grind, or is it better. What if you scrape it all flat, but one side is higher than the other. Is this like Sudoku, making yourself crazy, and getting nowhere? What does one remove, the blue, or the blank? Marcel.
Marcel Timmers Hey Marcel, This is not something that can be explained in a short comment. The original level was hand scraped so I wanted to follow tradition. And yes you can produce surfaces that are better than grinding if you want to spend the time. Thanks for the comment. Cheers, Tom
oxtoolco Tom forgive me but are you for real--you have thrown me me a real loop..If you have diamond impregnated grinders that do not wear,the question is how hand work is better than machine grinding..You have totally lost me..regards Ian what happens
+Ian Craig try running an entire bed of a lathe under a grinder? Hand scraping get into places on large machines with ease. Also, you can scrape in alignment and parallelism with the machine in place: even down to accounting for future wear. Flaking can be added to hold way oil on the surface and reduce wear. Proper fit can be made, far beyond normal surface grinder sizes and shapes. Most levels arn't flat on the bottom!
Nice work Tom, but don't be so shy with that scraper. At the print you had at 5:30, hook in to it big fella! The divots caused by the corrosion are just cosmetic and wouldn't affect the function in any way. If they were on a machine way you could say they're "oil retention points". ;)
There is a machine re-builder business just a 1/4 mile down the road from me. Mostly they work on large punch presses, but in their slow time, they will work on small machines. I got a quote to have my Bridgeport x and y axis scrapped in and was somewhat surprised at it being $1600.00 minimum. But as you know, and showed in this video, it takes a lot of time!
Okay, being new in the machinist world, what is the main purpose for scraping? Looks like something I would like to try. Also, are the tools hard to come by? Thanks, John (a.k.a... ShadeTree Machinist)
ShadeTree Machinist Making precise flat surfaces for measuring instruments and machine ways, it is also used to create pockets for oil in the machine ways to prevent stiction. You can make hand scrapers from old files or buy them, there are some nice ones with carbide inserts I believe.
A typographical error is a mistake made in the typing process of printed material. The term includes errors due to mechanical failure or slips of the hand or finger, but excludes errors of ignorance, such as spelling errors.
Tom, Great video, looking forward to more about scraping. What are you using for the contrast agent on the level? I have seen references to red lead, but don't really want to deal with it if I can possibly avoid it.
I practice the Japanese style. Pushing the scraping tool with your waist. Get very good control over the stroke length when doing the final finish scraping
12345NoNamesLeft You do not need to buy, find a place for, and set up a grinder. You do not need to get grinding dust in all your tools. In fact, you need little more than a scraper, a reference surface, and your work. You can make your own accurate reference surface with three hunks of iron and a scraper, but a decent surface plate can save you a whole lot of work...
***** Why is grinding dust even a factor. Scraping is so time consuming, that the effort to clean tool is negligible.As much as I want to support scraping, It has to be said that a quick grinding job will out do a sloppy scrape job. For example the new Taft Pierce blocks and plates, you pay ~50% more to have them scraped, but the inspection tolerance is equal to that if it were ground. Since scraping is a trial and error process, I can tell you that they quit as soon as they meet tolerance. You may as well get the ground blocks then scrap in a patch work your self and save a few hundred.
Hi, I've watched a number of videos on scraping and it seems time consuming, why not just put it in grinder to get perfectly flat surface? Ok,... I just read comments about oil flow, well then why not machine in some optimized pattern like lines on a bias or something?
+junglemap My surface grinder will not cover the length of this level. The larger the surface the more difficult it is to grind it perfectly flat. Thanks for the comment. Cheers, Tom
Wow! Like-It. Thanks’ to all the guys, for making this video possible. And ‘Tom’! As always, thanks’ for taking the time to make this video! And I support this site. ~M~
8:43 - 9:00 probably the best (visual learner) explanation of the basic principle for newbs that exists on UA-cam. Take the errant part to a standard (precision surface plate), transfer the blue Dykem transfer paste to reveal the high spots, then scrape them.
At 8:00 ! No that's not how you use the marble !! You're supposed to put sandpaper on there ! You'll make dips in your marble and it won't be straight anymore !!
Looks like fun. I would have soiled diapers if someone got close to my surface plate (if I had one). I saw some other youtube videos on scraping. They were really good. The dudes that made the scraping videos (I forgot author, title) did it for a living and even give training seminars in their shop. They resurrect ways of beat machines, and other stuff. One thing I picked up is that they were very methodical. Not that it is horribly difficult.; just takes patience.
Thanks! I can figure out a heck of a lot just by looking at this! Mostly... scraping is a bunch of work. Then add skill, spinkle in some luck... Yikes.
+oxtoolco My dad always said that the difference between the pros and the amateurs is that the pros recover faster from their mistakes. You learn a lot from your mistakes. Mostly, you learn that you hate having to do things twice.
Hey Tom, That was an interesting video! I'm glad you managed to "scrape" it together! Do you have a name for your group yet? Scrapers R Us, Scrape That Scrap, Have Metal; Will Scrape . . . At the end, you said you scraped your brains out. That must have been a rather gory situation. Will you be reinstalling your brains for the next session? Thanks for the video and allowing me to tease the hell out of you! (A word of caution: don't scrape anything in your house! I would imagine the Mrs. would get upset and you would be sleeping on your lathe bed!) Scrape your ass off! Oxen Dave
+Widg3t's Widgets It is the process of taking an uneven surface back to a flat state. We do this on ways and anything that requires a truly flat surface. The other process of scraping is "flaking." This gives some voids for oil and what not to flow between two flat surfaces. If you place a couple gauge blocks together with a bit of oil between them, they will stick. Flaking will prevent this, and let things move smoothly.
My .02 Don't bother machining it, it's a level base needs to be straight/flat. It's not a bearing surface . (Moveable part)A small low is not going to affect any thing when used as a levle. . . But if you wanna show your friends a perfect piece take a pencil eraser and dab a touch of blue over it ;)
+B Stevermer Hi Steve, The original Pratt and Whitney levels had scraped soles. The ground bubbles on these are sensitive enough to pick up a few tenths over their length. The scraped finish sure looks cool as well. Thanks for the comment. Cheers, Tom
Good work Tom, and if anyone else wants more info on technique, check out Nick Muellers work on UA-cam. (He may go as MuellerNick on YT). Several groups of us have done an intro to scraping weekend course in Melbourne, Australia, over the last couple of years. It was a great course. Rob
I'm not sure about that R. A. and at the moment I am away from home and only have limited coverage, so can't research it for you. If I get a chance I'll see what I can find out ,but it will be well into next week I think before I expect to be able to reply with an answer. Nicks videos were clear to view and I don't recall any watermark issues when I saw them, but it would be at least twelve months since I have seen any of his work. Regards, RT.
Interesting to see things done the old ways vs the easy way out of just surface grinding it to less than .0002 in one pass. What if you don't have a high grade surface plate to use and your plate is off a few tenths to begin with, will they carry over to the scraped part?
Good looking flat surfaces there guys! Hey I heard that comment about me and my wife! LOL
Abom79 that was me abom79! your wife's reaction made my day!
i had a great time meeting Tom and the others. Scrapefest was a bunch of fun!
Enjoyed the video, great day in the shop
I am scheduled to attend one of Richard King's scraping classes next month. It should be fun.
Thanks for hosting us, Tom. A fun time was had by all! We also all learned from each other.
Don't be too hard on yourself with the metrology. Scraping has "surface texture." Companies like Moore Special Tools would use a scraper's block to check the work on their exquisite machines and to test the scraped masters that tested the machines to millionths of an inch. A scraper's block is an 1" square by maybe 1/4" thick accurate carbide block which is placed between the indicator and the scraped surface while indicating it. In actual usage, your level will be supported by much more area than an indicator point. On scraped work the many equally high contact points are what counts. A gage block might make a reasonable substitute for the scraper's block.
***** Scraper's block:
Foundations of Mechanical Accuracy, Wayne Moore, free download at
www.totallyscrewedmachineshop.com/documents/FoundationsofMechanicalAccuracy.pdf
pages 28-29. Material shown is hardened and precision lapped nitralloy steel, 25mm square, looks to be about 15mm thick.
The link you provided no longer functions, do you have a digital copy or another source. I can't afford the actual book!
It is now gone from that site, but you can now download it here:
www.hobby-machinist.com/attachments/foundationsofmechanicalaccuracy-pdf.118847/
I would do so soon...
Thanks so much, had to make an account but now I've got it. Lots of other useful documentation on the website also.
Thanks for sharing. Had to do something like that off shore for work. A fixture and a split clamp collar the wrong ID size but with heavy duty thickness. A small cutoff wheel, die grinder with a 60 grit flapper wheel and a sharpie. I did such a good job they forgot I did it and later ordered the wrong size replacement parts five years later.
Looks like a good time and very entertaining company, thanks for sharing that with us Tom! I'd sure love to hear a little more on the theories behind scraping, or at least your take on it...maybe when you video the decking of the corrosion and the re-scrape? If you get a chance that would fill in a few of the blanks I have about it...on the side, can you believe I can still see much of the factory frosting on my 96 year old SB? That's part of what really interest me about it...I never saw it on the Atlas, so it wasn't even a question in my mind. Thanks again and see ya soon, Aloha...Chuck
You guys must have the patience of a saint, this is one thing I could never do.
Interesting work, Tom. Scraping is almost a lost art. I enjoyed this.
Great video on your scrapefest! I might suggest after you machine the level, lap with wet/dry sand paper changing grit size a few times, then scrape for a final flattening. I probably would not use the Biax and stick with hand tools for the best results.
Good luck and enjoy!
Gene Elliott If a surface is ground or lapped, the blade of the scraper has difficulty penetrating the surfaces. It just skims off and dulls the blade. When ever possible I try to grind small surfaces prior to scraping so to fast track the scraping to the finishing passes. But before bluing, I use 100 grit sand paper to bread off the shine, then scrape a patch work.
I learned scraping as a wee lad. I could scrape my knees and elbows with the best of them. Tee Hee.
Great video Tom.
Nice video very informative. I have always been impressed with hand scraping. Seems like hand work and file work were amongst the first skill you learned as a apprentice in the olden days. I was glad to see a picture of the scraping crew at the end, was beginning to think Tom had some scraping pals in the witness protection program.
Tom I can't wait for the more in depth tutorial on scraping.I love the concept of high precision with minimal machinery.
Craig Spakowski Scraping and lapping are both "cool" for that reason.
Gday Tom,
That was nice to see some hands on scraping. One guy commented that a surface grinder is an easier way to do it, but hand scraping is more accurate than surface grinding no matter how good the grinder is. Hand scraping is flatter. Actually, one bloke I worked with reckoned that surface grinding is roughing out compared to serious scraping, I agree.
Peter Spence Hi Peter,
For small parts a surface grinder would be faster. When you get into large parts or tricky access wheel wear plays a part in just how good a surface grinder can do. Most scraping is done for lube retention on machine tools. Surface grinders cant do that at all. Thanks for the comment.
Cheers,
Tom
Great video. I'm taking a class from Richard King in a couple weeks to learn scraping and rebuilding. Your scrape-fest has me excited :)
Funny, just yesterday I was wondering to myself when you were going to post a scraping video, and there we go!
Very interesting video. Now it caused me to have more questions. Once you get one surface flat will is still be concentric to the other side? How do you handle that? Thanks for the video.
Tom, I would surely love to see a video or two on HOW to do this. Great video.Thanks!!
Hi Tom great video I have to scrape the ways on my lathe that I'm restoring. Such a big job. Sorry if it's a silly question. Could you recommend a good place to buy some decent scrapers. What to look for and avoid. And how would I tackle the inside V ways. And what tools I would need to start scrapping. I know I need a surface plate. Some blueing etc. Your recommendation would be greatly appreciated.
Would lapping on a surface plate give desirable results? Just trying to wrap my non-machinist head around the concept of scraping. Keep the awesome vids coming.
An interesting method of metal removal. Must be quite an old concept of metal machining. About the only scraping I have done, was when something very stinky got smeared on the brake pedal in Winter and did not notice it until I turned the heat on!
it's cool to see videos on machining. I did like it.
When I'm checking the flatness of a scraped level (starrett 199 for example) or any other scraped tool, I put a gage block between the surface and the probe tip...love your vids! Thanks man!
Hi Michael,
That is good for seeing the average local surface. Thanks for the comment.
Cheers,
Tom
Tom, my son and I are needing to scrape a bed on our lathe, we have a good understanding of how to scrape but touching up the blade on the scraper has us wondering how others might touch them up. Any chance you might do a vid on how you touch up your blades? Thanks.
***** Hi Larry,
There is enough interest in scraping that I will probably make a stand alone video showing some of the stuff first hand. Right now I use an Accu-finish slow speed carbide grinder to touch up the blades. I think you could do a decent job with a simple fixture and some diamond hand held hones. Thanks for the comment.
Cheers,
Tom
oxtoolco
Thanks Tom, hoping you have the time to do another video on scraping. As usual, we always enjoy your vids.
Could you tidy the level on a surface grinder?. Would like to know a little more about the blades you used,, never scraped before. Rob
Great video. Have wondered about the process of scraping for a while and this showed several examples of how to do it. One question though. I understand the function of scraping. To create a flat surface that can be used to reference some other surface but how much scraping would be too much? If you have two perfectly flat surfaces they will actually stick together. Almost like being magnetized together due to the intermolecular bonding between the parts. At what point do you call it quits on scraping? 90%, 95%, 98% ?
Looks like a good time! I hope you will cover some of the techniques in a future video.
All The Best!
Mike
Enjoyed this one, seeing 'idled' pieces being brought back into use. Could almost taste the rust from the surface plate.
Now then how in the world are there (24) thumbs down? Viewers not knowing what they are watching?
Would love to see a Scrapefest 2, there must be others in the Bay area that are interested in scraping these days. I doubt I'm the only one...After 2 years you might be ready for another one? :-/
It may be too late by now, but machining off your level may release some stresses, making it take many more hand scrape passes to correct, than removing what you need to by hand scaping.....very interesting!.....keep us posted!
Would a steel surface plate that has been worked in a surface grinder be just as flat ? Years ago I took a steel lapping plate that had been thrown out because it had been used to the point of having a bad hollow in the center, trued up the wheel on the surface grinder and ground it what I thought was perfectly flat. What about a Blanchard ground surface? Thanks in advance for any input.
+opticschief Hi Optics,
The answer is no it wouldn't be as flat. When scraping we are matching to a master flat reference. The surface grinder can produce flat parts but you have no reference to compare it to. Thanks for the comment.
Cheers,
Tom
+oxtoolco What about grind first, scrape second... good approach or bad?
+DSCKy Hi DS,
My grinder does not have enough travel to cover the entire length of the level. Good excuse to buy a bigger grinder. Thanks for the comment.
Cheers,
Tom
Hi Tom.
Very strange...the more Oxen videos I watch, the more often items afflicted with weasel snot appear in my shop. Just can't figure it out...??
Keep up the great videos!
Carl
I would love to get in to this some day. No Idea where to start though.
Hi Robert,
McMaster sells scrapers and the Internet is loaded with information on scraping. Don't need much more than that. Make three small surface plates. You won't need any special measuring gear and by the time your done you will be really good at scraping. Thanks for the comment.
Cheers,
Tom
Thanks! I appreciate the help. Have a wonderful day,
Very interesting. It would be useful to have some general tips on how this is done correctly. Thanks.
Uncanny you would post this today. Enjoyed, would like to see more of course.
Colin ;-)
Ive never heard of this practice until now . looks interesting but it would drive me insane to make a level surface doing that method . but it looks incredible like metal art . i should give this a shot who knows i might un earth some hidden talent ! . what would be a good starting point ?.
Where did you get the rubber roller for spreading out the bluing? Got a scraper from McMaster, but couldn't find a source for a roller.
YCM30cnc Try an art supply store. It's called a brayer. Printmakers use them. Dick Blick no doubt carries them.
Hi Tom,
Sounds like that you just officially launch the new trend among machinists: " Scraping "
I have so much to realize before the Big Call hope I'll have time to try it all...
Pierre
So is the point of scraping removing corrosion on parts that would be hard to disassemble and grind?
You guys seemed to have a lot of fun:) I attended a scraping class in sweden with Richard Kind and I can tell you well money spent its so much fun:) I came to think about one thing he told us that's important is to "ring" the part before scraping. Hang the part from a string and tap it some with a hammer or something. I really didn't thing that would affect the work when scraping on really old stuff, but I was wrong:D My first project was an at least 50 year old angle shelf and that thing warped like crazy once I realised my mistake and tapped the piece lightly:)
Thanks for sharing! Cheers!!!
On the advice of Tom some time ago I picked up ( not cheap but worth it) a copy of Machine Tool Reconditioning by Connelly, read it front to back, so much info. Currently making my way through a bridgeport requalification.
Very cool Tom, if you scrape til you are blue in the face, will the weasel snot clean it off?
I enjoyed this video very much, it is nice to get off the beaten track.
Cheers, H
I have 30+ years in the tool shop for first McDonnell Douglas and later Boeing. I am in tooling inspection now. Honestly, I would just leave the level alone if you are happy with the surface. It has been decades since I had to do any scraping but we had to get 90% match between two surfaces, they wern't just flat but multi contoured. Any low spots did not hurt anything just as they will not hurt the level either. I do know the level of crazy we in the trade can get into, The first time I made a wall size book shelf for the home and it was 1/32 out of square it drove me nuts... until I realized it was just a book shelf! By all means do what you feel but if it were mine, I would remount the bubble and call it a day. YMMV! :P
OH, BTW, I still have 1/2 a tube of blue and the long hours of bench work it represents and remindes me of, still brings back a yearning to never use it again :P
*****
It is nice to have a good surface plate, Reconditioning is as good of a term as any :D Good flat surfaces (when that is what you need) just make things to together better. What do you do if you need a flat surface and don't have one? The answer is to make 3 by scraping, it takes 3 surfaces worked against one another to get a flat plane. If you only have 2 surfaces, you don't have anything, you can match a bowling ball to your shop floor with a perfect fit, 3 surfaces work to prove each other flat. Talk about a pain in the backside! It will make you glad to pay someone else to do it for you!!! :D
This is old still interesting. The overall results that are possible is simply amazing. My mind keeps heading to refine the marking stoning process. I have Ideas but need to get a plate to start fiddling with it.
Seems if one removed with cleaner all the color very lightly stoned. Then applied a contrast color using something soft to fill low spots also. Then a light rub on a reference lapping type plate to show and maybe even lower some of them high spots. Alternating hard print flexible removal with hard removal flexible print might clue us in a bit on what is going on to say the least. I saw you sort of doing that on the clean table looking for the polish.
Enjoyed watching thanks.
so how do you make a master flat surfaceis... if you dont have a master flat surface to go off of?
+sideswipe147 Hi Side,
You can create a flat plane of any accuracy level by scraping and checking three flat plates together. You check them against one another and slowly increase the bearing area between them until the desired level of accuracy is achieved. The sky's the limit. You do need three so you don't just match one to another. The third plate is the key to producing a flat plane. Thanks for the comment.
Cheers,
Tom
+oxtoolco
cool. thanks for the info. I'm just starting out so I don't have a lot of the needed tools and whatnot. but I do know that a master flat is quite important to have and being able to make one if needed is incredibly valuable information.
Interesting...... although I am not completely understanding the concept of this Scraping method.... A previous viewer asked "why scrape when you can surface grand?" or why not just mill off 2 or 3 thou...? I'm missing something here..... I guess the main question is ... What is the main benefit of scraping vs. milling or grinding? Thanks Tom.. I'm curious....
Depending on how well you do it, a scraped surface can be more accurate than a surface ground or milled surface. Plus, a surface grinder or milling machine will only be as accurate as its ways, which are commonly scraped. Scraped surfaces tend to be a better bearing surface because they hold oil better.
Danny Herrera One of the advantages that scraping offers over surface grinding is the ability to align and fit parts relative to each other and do so very precisely and with great control. Precision scraping is done when parts are in the natural state. When parts are ground they are influenced by holding forces and thermal effects, where as in scraping, there are very little of those effects. The scraping methodology is mostly superior when it comes to correcting machine tool geometry. And as Andrew stated, the lubrication evenness is also better with scraped surfaces. As a scraper, we talk in terms of tenths (.0001") with contact points of up to 40 points per square inch (Technique 40).
+Andrew Phillip I can't even wrap my head around how that is possible, the guy is holding the thing in his hand.
Edit: I should have watched more of the video before commenting and now it makes sense. Nothing is perfectly flat, ways have irregular wear patterns, heat and clamping forces also confound flatness. So the granite stone with die is a very very flat reference surface and it reveals the imperfections in the surface and the human hand can remove very fine amounts of material with an abrasive, giving a very precise surface.
+The Eternal Hermit Hi Hermit,
Well said. Milling and grinding do not necessarily produce flat straight geometry. Thanks for the comment.
cheers,
Tom
Hi, what kind of cutting tool you use on the tip of the manual scraper?
How appropriate!
I just put down my scraper an hour ago and then checked out Oxtoolco and what do I find?
Why scraping? To me it does as much to my mind as it does to the the piece of metal. You can keep the Biax (as a tool freak, did I really wtrite that!?) Listening to good music while scraping is relaxing while doing a physical workout. You would otherwise have to pay good money to get that.
I just wish I could be there with you.
Einar S Hi Einar,
I also find the steady patterning of scraping relaxing. I tried the Biax and yes its certainly faster. One of the attractions of scraping is I can do a super accurate job by hand. To me this is wonderful and still amazing. Thanks for the comment.
Cheers,
Tom
Hi Tom !
Nice initiative !
You said you scaped your brains out !
... was that these small chips laying all around ;-))
Keld Sørensen Hey Keld,
Well at least we didn't scrape our asses off. Thanks for the comment.
Cheers,
Tom
oxtoolco Ha, ha, you asked for it yourself ;-))
Tom: Very very nice !!
So are you going to buy a "old or new" BIAX, or just stick to "by hand" ? :)
so what stones are used to knock the burr off?
jeff
+DRIFTMOTIVE Hi Jeff,
I use a 320 grit bench stone to catch the little fuzzy burrs. Thanks for the comment.
Cheers,
Tom
+oxtoolco alright thanks for the reply
Hi mate.
Sorry, I don't get it, is this scraping meant to be in stead of a surface grind, or is it better. What if you scrape it all flat, but one side is higher than the other. Is this like Sudoku, making yourself crazy, and getting nowhere? What does one remove, the blue, or the blank?
Marcel.
Marcel Timmers Hey Marcel,
This is not something that can be explained in a short comment. The original level was hand scraped so I wanted to follow tradition. And yes you can produce surfaces that are better than grinding if you want to spend the time. Thanks for the comment.
Cheers,
Tom
oxtoolco Tom forgive me but are you for real--you have thrown me me a real loop..If you have diamond impregnated grinders that do not wear,the question is how hand work is better than machine grinding..You have totally lost me..regards Ian what happens
+Ian Craig try running an entire bed of a lathe under a grinder? Hand scraping get into places on large machines with ease. Also, you can scrape in alignment and parallelism with the machine in place: even down to accounting for future wear.
Flaking can be added to hold way oil on the surface and reduce wear. Proper fit can be made, far beyond normal surface grinder sizes and shapes.
Most levels arn't flat on the bottom!
Nice work Tom, but don't be so shy with that scraper. At the print you had at 5:30, hook in to it big fella!
The divots caused by the corrosion are just cosmetic and wouldn't affect the function in any way. If they were on a machine way you could say they're "oil retention points". ;)
There is a machine re-builder business just a 1/4 mile down the road from me. Mostly they work on large punch presses, but in their slow time, they will work on small machines. I got a quote to have my Bridgeport x and y axis scrapped in and was somewhat surprised at it being $1600.00 minimum. But as you know, and showed in this video, it takes a lot of time!
Okay, being new in the machinist world, what is the main purpose for scraping? Looks like something I would like to try. Also, are the tools hard to come by? Thanks, John (a.k.a... ShadeTree Machinist)
ShadeTree Machinist Making precise flat surfaces for measuring instruments and machine ways, it is also used to create pockets for oil in the machine ways to prevent stiction. You can make hand scrapers from old files or buy them, there are some nice ones with carbide inserts I believe.
Thanks for the info. That makes since.
ShadeTree Machinist **SENSE. The word "since" is used to denote a passage of time, eg "He hasn't ridden a bike since he was a boy."
666alikat But do you know the word "typo"?
A typographical error is a mistake made in the typing process of printed material. The term includes errors due to mechanical failure or slips of the hand or finger, but excludes errors of ignorance, such as spelling errors.
Tom,
Great video, looking forward to more about scraping.
What are you using for the contrast agent on the level? I have seen references to red lead, but don't really want to deal with it if I can possibly avoid it.
I practice the Japanese style. Pushing the scraping tool with your waist. Get very good control over the stroke length when doing the final finish scraping
Sending a gallon of elbow grease for part 2.
More of a "scrape in" than a scrapefest!
Shadon HKW thought you would offer to run the dog under your grinder. But the shipping cost would kill the joy.
+Matthew Tinker A scrape along?
That was interestingly confusing. Is this technique still in use today?
Thats another thing Tom-- you casually showed a dial indicator that registered a tenth of a thou on a scraping----to me that is wild....How..
Ian Craig Hey Ian,
Its all smoke and mirrors and some CGI. Thanks for the comment.
Cheers,
Tom
Why scrape instead of grind?
12345NoNamesLeft to get extremely flat surfaces
12345NoNamesLeft
www.okuma.com/handscraping
12345NoNamesLeft No heat, no clamping force, don't have to bring the part to the machine etc
12345NoNamesLeft You do not need to buy, find a place for, and set up a grinder. You do not need to get grinding dust in all your tools. In fact, you need little more than a scraper, a reference surface, and your work. You can make your own accurate reference surface with three hunks of iron and a scraper, but a decent surface plate can save you a whole lot of work...
***** Why is grinding dust even a factor. Scraping is so time consuming, that the effort to clean tool is negligible.As much as I want to support scraping, It has to be said that a quick grinding job will out do a sloppy scrape job. For example the new Taft Pierce blocks and plates, you pay ~50% more to have them scraped, but the inspection tolerance is equal to that if it were ground. Since scraping is a trial and error process, I can tell you that they quit as soon as they meet tolerance. You may as well get the ground blocks then scrap in a patch work your self and save a few hundred.
Hi, I've watched a number of videos on scraping and it seems time consuming, why not just put it in grinder to get perfectly flat surface?
Ok,... I just read comments about oil flow, well then why not machine in some optimized pattern like lines on a bias or something?
+junglemap My surface grinder will not cover the length of this level. The larger the surface the more difficult it is to grind it perfectly flat. Thanks for the comment.
Cheers,
Tom
Wow! Like-It. Thanks’ to all the guys, for making this video possible. And ‘Tom’! As always, thanks’ for taking the time to make this video! And I support this site. ~M~
8:43 - 9:00
probably the best (visual learner) explanation of the basic principle for newbs that exists on UA-cam. Take the errant part to a standard (precision surface plate), transfer the blue Dykem transfer paste to reveal the high spots, then scrape them.
i too have a scraping project :) have scrapers and book.....need more elbow grease !!
A true labor of love!! .. this is only for the Die Hard Machinists!!
i would be more concerned about the high spots more so than the low spots.
At 8:00 ! No that's not how you use the marble !! You're supposed to put sandpaper on there !
You'll make dips in your marble and it won't be straight anymore !!
Looks like fun. I would have soiled diapers if someone got close to my surface plate (if I had one). I saw some other youtube videos on scraping. They were really good. The dudes that made the scraping videos (I forgot author, title) did it for a living and even give training seminars in their shop. They resurrect ways of beat machines, and other stuff. One thing I picked up is that they were very methodical. Not that it is horribly difficult.; just takes patience.
Thanks!
I can figure out a heck of a lot just by looking at this!
Mostly... scraping is a bunch of work.
Then add skill, spinkle in some luck...
Yikes.
+Mark Richardson Hey Mark,
The real trick is cutting down on the luck part. Thanks for the comment.
Cheers,
Tom
+oxtoolco My dad always said that the difference between the pros and the amateurs is that the pros recover faster from their mistakes. You learn a lot from your mistakes. Mostly, you learn that you hate having to do things twice.
We also learn to cover our tracks better. Thanks for the comment.
Cheers,
Tom
Loads of mind bending fun! You want precise? We make it precise! Thank you Tom! :o)
O,,,
Hey Tom,
That was an interesting video! I'm glad you managed to "scrape" it together! Do you have a name for your group yet? Scrapers R Us, Scrape That Scrap, Have Metal; Will Scrape . . . At the end, you said you scraped your brains out. That must have been a rather gory situation. Will you be reinstalling your brains for the next session? Thanks for the video and allowing me to tease the hell out of you! (A word of caution: don't scrape anything in your house! I would imagine the Mrs. would get upset and you would be sleeping on your lathe bed!)
Scrape your ass off!
Oxen Dave
+Widg3t's Widgets It is the process of taking an uneven surface back to a flat state. We do this on ways and anything that requires a truly flat surface. The other process of scraping is "flaking." This gives some voids for oil and what not to flow between two flat surfaces. If you place a couple gauge blocks together with a bit of oil between them, they will stick. Flaking will prevent this, and let things move smoothly.
cast iron is nice compared to carbide burrs and some grinding tools.
My .02
Don't bother machining it, it's a level base needs to be straight/flat. It's not a bearing surface . (Moveable part)A small low is not going to affect any thing when used as a levle.
. . But if you wanna show your friends a perfect piece take a pencil eraser and dab a touch of blue over it ;)
+B Stevermer Hi Steve,
The original Pratt and Whitney levels had scraped soles. The ground bubbles on these are sensitive enough to pick up a few tenths over their length. The scraped finish sure looks cool as well. Thanks for the comment.
Cheers,
Tom
ooh, a scrape fest, not a scrap fest like I thought :D
the title cracked me up!!!
Moshik Galimidi Hi Moshik,
Thanks for the comment.
Cheers,
Tom
Good work Tom, and if anyone else wants more info on technique, check out Nick Muellers work on UA-cam. (He may go as MuellerNick on YT). Several groups of us have done an intro to scraping weekend course in Melbourne, Australia, over the last couple of years. It was a great course.
Rob
I'm not sure about that R. A. and at the moment I am away from home and only have limited coverage, so can't research it for you. If I get a chance I'll see what I can find out ,but it will be well into next week I think before I expect to be able to reply with an answer. Nicks videos were clear to view and I don't recall any watermark issues when I saw them, but it would be at least twelve months since I have seen any of his work. Regards,
RT.
With all the wondrous machines available this seems slow and tedious.
was taught this in a school for navy. that guy with auto scraper is cheating
I think I could do that
Those chips suck that's for sure.
And uhh umm ahh and ya boom haha still haha reinvoke and uh so aa uhh