Scraping a Camelback Straight Edge Flat

[Music] hello Keith Rucker machinery dot-org well guys today we're gonna get started scraping in our 18 inch straightedge that I've been working on now for some time I've got previous videos where I showed how I milled all this on my middle machines and then we took it over to the surface grinder I actually grounded in and inspected it it's pretty darn flat right now but we want to get it scraped in so that it's perfectly flat and this will become a reference surface that I would use when I'm scraping in my monarch lathe so this is a brand new casting like I mentioned before that I purchased from Richard King he sells these straight edge castings and basically I'm making my own straight edge so let's get in here and get started doing some scraping I have my work securely mounted and advice here where I can work on it and I got my surface up that I want to be scraping I like to have my surface own scraping up and flat so sometimes you have to move your part around to do this but it's a lot easier to scrape in a flat plane than it is at some angle now as far as the techniques for scraping there's basically two different ways that you can do it first office with a hand scraper and this is a dapper o or by axe type hand scraper this is actually one that I made but it's basically using their design and basically it's just a piece of metal here and it has one of the by axe blades this is the same blades that we're using the power scrapers and you want this to have you know a little bit of flexibility to it when you push down on it you can get a little flex in there on it now this is the cheapest way to scrape you know you can make or buy one of these type of scrapers here relatively inexpensively and it's the time-honored in time you know way that scraping has been done for thousands of years is using a hand scraper and I'm gonna actually start out by showing this but then we're gonna go to a power scraper this is a by ax power scraper and basically this just greatly speeds up the whole process I guess the downside to the power strippers are these are relatively expensive so unless you're kind of in the business of scraping if you're in the business of scraping you got to have one if you're a home shop guy that maybe only does this occasionally or a one-time deal you know it may not make sense to spend the money on one of these I felt like I needed want to be projects that I have going on so I purchased a used one actually and we're gonna show you both methods of doing this we'll start with the hand scraper though so with the hand scraper what you want to do with it is come in here and again get in here on your part kind of push down on it you some people will push this with their hands but you will find that it will get very tiring very quickly it's much better to kind of put this up against your body and use I kind of put it down here I'll make a little cradle down here in my arm and put it down here and come in here and start scraping by hand when you're doing your scrape marks it's very important that you create a pattern I like to go diagonally across the part and then when I come back the next time I'll come back the other way this kind of creates a checkerboard appearance on here is Richard King calls it and that will just kind of help keep things going some people when they're starting you know they may just kind of come in here and randomly pick angles to shoes from get in a pattern stay in that pattern in your criss crossing over your scrape marks and what that's going to happen over time as this fee scrapes in you'll start getting those high points and low points the whole purpose of scraping is not only to get it flat which is we're definitely something we want to do but on a machine surface when you have two surfaces that are going back and forth you want to have some low spots in there for the oil to go to that's the reason we don't just take it right off the surface grinder and go over there and put it under there's no place for the old ago and this will very actually score up very quickly if you just try to use two ground surfaces you got to have a place for the old ago and that's what hand scraping does it gets it flat but you have high points and you have low points and those high points are bearing the weight of your your two parts but then you have those lower areas of the old can actually day in to lubricate Thanks so anyway with you win your hand scraping you know come in with your stroke and pull out you know when we first start a lot of times will tell people do the tap tap tap tap tap because you want that scooping action to kind of come in there and come out again you want to do it in Chris crosses a lot of times I'll actually take a little 45 like a little speed square and draw lines on my part to make sure that I stay at those angles this is where you're going and sometimes you kind of get off line and those will give you some guidelines to go on the other thing about hand scraping is don't be afraid to push down this thing so you know some people say well I'm scared I'm gonna take off too much material you know if you get over here and just really gouge as hard as you can go you're only taking tenths of a thousandth of an inch off so you know a good straight mark is probably four tenths maybe five tenths three to four tenths is probably more average what most people are doing when people first start they're very optimally taking maybe 1/10 because they're scared to really put some some weight into it and remove some material and you can actually see the cast iron starting to come up here on my part was a long cross route so zoomy in here and kind of show you this [Music] now when you first start scraping apart again I'm doing kind of 45s across here right now I know from my grinding that this thing is within probably six tenths of being perfectly flat if you don't know or you got more than that you really just kind of get here just start scraping panting scraping because what Richard calls it just going really hard to get a good place to start with I don't want to do that on this part because I know I'm already fairly flat but we're just going to come through here do that when you get through going in that direction you'll come back through here and create that crisscross and I'm probably not actually pushing down my parts moving around a little bit on the vise here I probably should secure that but when I power scraping in a minute it won't matter but anyway you kind of get the idea we're making those Criss crosses that's hand scraping I'm gonna go ahead and go to power scraping because it's just so much faster and I need to get this done hi guys I got my buy ax power scraper so this thing basically when you turn it on for that scraping and it's the right angle and everything here you put these blades in you know one thing this I get asked well can't you just use some other machine to do what this does and yeah you could probably find a little reciprocating something to create that action but really what you need is to be able to adjust the length of that stroke depending on what stage of scraping you're in this one's got a little set screw in here and you can adjust that length of that stroke right now I've got to set on about a 3/8 inch stroke which is kind of for making finishing passes again we've already kind of got this down pretty close so I don't want to make just great big huge strokes when we get into finishing you know we're gonna take it down to a really really fine stroke you know around an eighth of an inch long to a quarter of an inch or somewhere long and there eight to sixteenth actually so having that ability to adjust the stroke is very important now with this by acts you just kind of come in here and and I usually again make a little cradle than my arm and let this rest in here you want to be kind of data at an angle and when you're working this thing you want to just kind of move your whole body side to side as you go across it and let it do the work now when you're doing scraping one of the things that Richard always tells us make individual scrape marks so you want it to come in and make an mark you don't want to your next one to be on top of it you don't you want it just be an individual mark and you want to work in individual lines so you just start making a line and let those individual scrape marks develop I'll also point out that I just took a Sharpie pen and again little speed square here and went along and put some lines on here at 45 degrees across my part and that's going to help me stay where I need to be and keep my lines in the right orientation anyway that's good just come in here and [Applause] all right we got one direction done now we're going to come back and go in the other direction we made really two passes here and we're starting to already see that striping pattern come in there now if you run your hand across this you're going to feel a lot of little burrs on the surface there and we want to knock those birds down and to do that I'm just going to use a stone and we're just going to lightly just knock those burrs off I'm not trying to stone this surface down I just want to get those burrs off before I take it over to my surface plate so before we take it over to the surface plate the blue up first thing I want to do is I want to just take a little Windex and hit this and just wipe it off now this is going to be more important later on when you're got the blue from the previous bluing on there we don't clean right now but it's still a good practice I've deburred it we're going to do that and then the next thing I want to do is come in here and I'm just taking some connote yellow and this is just going to look like a mustard container but it's a water soluble dye in this yellow and we're gonna put a light coat on here before we blew it up and what this does is it just kind of helps take the sheen off of what you just did and it's going to be real important when you come back on the next scraping you can see your scrape marks your new scrape marks so we're basically taking that sheen off of there and really kind of helps you see what you're doing on that particular pass because after a while things just start running together so if we rolled that on grab a paper towel here and we're just going to wipe it off now but still there's you really can't probably see it very well but when you start scraping you'll see those nice clean scrape marks on there and you kind of have this little yellow on there that just takes that sheen off so let's go get our surface plate prepped and we'll blue this up for the first time over at the surface plate now and we need to go ahead and get this prep so that we can start bluing up so any time I first come in and start using the plate for the day I want to make sure it's good and clean and you can just take your hand and rub across this and I actually clean this plate earlier today and I can already feel with my hand little specks of dirt and stuff that's gotten on this just in the last little bit of time so every time I come up to this plate I'm gonna wipe it with my hand but to start with it's good to go ahead and get a good cleaning on it so you need to give you some type of cleaner they make a surface plate cleaner this works just fine I'm just using Windex here 4:01 any type of cleaner will work just fine I'm going to squirt it down we'll take some paper towels and just wipe it off now I've already cleaned this up from the last time I blued it but if you have blue on here you know you may have to really get the old blue off you know at the end of the day or beginning of a new day or even during the day sometimes you need to just clean your plate off and start over so let that dry off it just takes a couple of minutes here or a minute or so and you'll start seeing that color change that's the water evaporating off and again I'm just going to take my hand and I'm going to rub across it because that paper towel that I just use it has lint in it and even that little you get a little specks on there I can feel it with your hand it's amazing what you can feel with your hand you know this is this is clean now so let me get some blue so I'm using just a connote blue this is a dye spotting blue again it's very similar to the person blue or some people use docum the nice thing about this stuff is this water soluble you can go to the sink and clean it up you know with person blue you often stay blue for several days anyway I really like this stuff I'm just gonna start just like a painter and we're gonna get some here in the middle of the plate and that becomes our palette that we'll work off on I've just got a little sponge roller here and we're just gonna kind of get us a area here that we can get blue off up to actually blew the table up now when you're doing this you don't want a really thick layer blue you want to be really thin you want to be able to see through it so you know this is something this is basically where I can go back and get a little bit more I'm going to be blueing up down here on this edge of my table again I'll wipe it and we're just going to transfer some of that blue down here to it we have pretty long stroke here strength I can see through this layer and it may even still be on a little bit too thick I've also got a little roller here one thing about this connote is is they grind it up and you get sometimes you can have a little bit of grit in there this kind of helps crush that up so I like to just roll it it also helps spread it out a little bit thinner on the plate all right we've got a nice area here and I'm gonna take my hands I'm just gonna kind of wipe across it and make sure it's clean I'm gonna do that every time I come over here yeah a little blue on my hands no big deal now let's get our part and put it on here see what it looks like we have the straight edge that's where we're here and I'm gonna just put it down onto the plate and now I'm not gonna push down on this I just want to kind of slide it back and forth that will transfer some blue I can tell from the sound of this that I've definitely got some hot spots in here the other thing that's really important is to hinge this part and to hinge it what I mean is you're gonna err on the end and you just take your hand and you move it back and forth and I can see it's pivoting on this corner right here now ideally when it's flat it's kind of pivot about 1/3 in from each side and right in the middle right now it's tipping right here on this corner that tells me that's my high spot and over here it's pivoting somewhere kind of over in this area so I got two hotspots on the ends and we'll flip our plate over and I'm gonna zoom in here where you can see this and it kind of confirms what we just saw when we pivoted that we were definitely seeing high spots on the ends and what we see here we see blue on those ends what happened is is when I was scraping this I didn't do a good job of getting all the way out here to these ends and it's showing right now when I'm blue in this I'm also Guinea a little bit of blue along this edge over here again probably where I'm not getting out to those edges so what are we gonna do I'm gonna do is I'm gonna come in here and we're gonna make some crosses just like we did before but I'm going to focus on these edges and try to clean those up because I didn't do a good job of that last time and then this rinse and repeat I'll Windex it clean it off will stone it we'll put the yellow back on there and then go blue it up again so let's get in here and knock these hot bullets off [Applause] [Applause] [Applause] [Applause] I want you to see where I'm at now I've actually gone through a couple more cycles of the scraping and as I talked about you know we started out high on the ends and as we do this I've just been working on the areas that are blue this area in here is still a little bit low and again I'm not talking about much I tried I've got a piece of 1,000 thick shim stock and I can't get it under here so I know we're we're talking about tenths of a thousandth of an inch high but we're slowly bringing it down and I've worked it in now so we've actually got blue making contact all the way out here and kind of all the way in here I've still got a little bit of a belly that kind of goes in through here and I use the term belly somewhat lightly because again we're talking about ten thousandths of an inch but it's coming in we're making progress I'm just going to keep on going all I'm doing here is I'm making crosses I'm still making crosses just like we did before but I'm only scraping the areas where there's blue and I'm not just trying to hit the blue points you know I'm making contact in this whole area in here it's not a lot of contact yet but I'm not worried about getting my points per inch up right now I'm just worried about getting contact all the way across right now so I'm scraping down these whole blue areas and just going back and forth and continuing to work it in until we get contact all the way across I just wanted to show you guys this because you saw the last one I did one pass between that last time I believed it in this one and all of a sudden everything just starting to come in you know I don't have a whole lot of points to contact yet again but what's important is is we're getting blue now almost over the entire par so I may still have a little bit of a belly in here if anything this edge up here which was high on the last passes I just scraped down it's now just a little bit low so I'm really close here we're gonna make another pass we're probably going to hit pretty much all out I'm gonna try to stay out of a few little areas in here in fact I think what I'm going to do is I've got a little Sharpie pen here I want to stay out of there I want to stay out of there so we're just gonna try to avoid these when we're scraping and it got a little bit of a hole in here you know maybe maybe a little bit up in here and you know maybe a little bit right in here but everywhere else I'm pretty much making blue so what I'm gonna do is we're gonna come in here again and make another set of crosses I'm gonna stay out of these areas and we'll blue it up again see we're out all right in the past I've been really doing more roughing so I've been doing basically two passes at once so I've been going in both directions I'm getting down a little bit closer now so I think what's gonna go in one direction I'm gonna take a something here and just kind of put down where I remember okay I was going in this direction so next time I'll know to go the opposite so let's take it out we'll clean this up blew it up and see where we're at well I made a few more passes over there and what I'm to the point now is I've got pretty much contact all the way across yes it's heavier in other areas and some but I have got contact from one into the other so I'm kind of getting beyond that the stage of scraping that I was in I'm ready to kind of start fine tuning this and getting it more flat and so forth so we typically start looking at the number of points per inch as being a guide as to you know where we're at and to do that you can use a little gauge this is actually one that Emirates and made a 3d print and it's got a one inch square hole in the middle this is the one that dapper uh sells basically this one additionally has some radius is on there for grinding your your your cutters but they both do the same thing I kind of like this orange one because it really you get that that contrast in colors but what you want to do is just lay this on here and look down in that hole and count the number of points now some points or maybe a really big point some points might be little points you're not really looking at the size you're just counting the total so let me zoom you in a little bit tighter kind of show you I'm talking about hopefully you can see this but you know we've got one great big area right here that's one point and this will be tiny one up here that's two so we're gonna count all these points and there's a lot in this one so I'm just going to go one two three four five six seven eight nine ten eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty one twenty two points that's pretty good but it's not that all the way across so we come over here and we just kind of pick a random spot music movie over on this one I'm getting one two three four five six seven eight nine ten eleven about twelve so I have gone across this and done this in multiple places across my straight edge and I'm averaging anywhere from about it's somewhere between twelve and fifteen I would say on average yeah I've got some areas where I got twenty I got some areas where I may actually be a little bit below twelve but I'm guessing probably 12 15 points per inch is kind of on average of what we got across here so when you take Richard King scraping class it gives you a little book and it has some really good guides in here on on what to do at different stages we've kind of been at the finishing crosses we started out like I said where we had less than a thousandth inch of variation across there so we've been doing the crosses going back and forth so we're now down to 12 to 20 PPI and we're wanting to change our strategy here a little bit and there's two things I want to do number one in the areas where I have a lot of contact we're going to continue using some crosses just in those areas but then we're also going to be going in here and doing what he calls dive bombing so you're just going to kind of hit an individual point and kind of knock those individual points down and the other thing I need to do is we need to shorten up the stroke on the on the scraper itself so we've been at about a 3/8 inch stroke we need to get that down to between 1/8 and 3/16 a little bit shorter stroke when we're finding tuning now we're getting where we're we're trying to get this things really dressed in so we're gonna again dive bombing and crosses but with a shorter stroke on our power scraper all right so we're dive bombing in crosses again where I have just a few points I'm just going to hit the high points where I've got some larger areas will do crosses in there come in here I got a point here we just kind of going in [Applause] get individual points to find to break them up [Applause] [Applause] slow it down a little bit I'm getting a few more strokes in there that I really want [Applause] these bigger mark what you really want to do is kind of break them up into smaller marks so you didn't have a big mark here that leave one point per inch but when you come in here and break it up I can turn that into three or four points per inch and that's even better basically I'm just making the blue go away I'm dive-bombing them you know in this area where I got a lot of contact I'm doing my props [Applause] and we're just gonna work all the way across until we find up get them all done [Applause] remember you know we're trying to get individual straight marks an individual lines we're really not finding the crossover you know if you're going any dive by my point and you miss it don't worry about it don't try to go in just dig out a hole just go on blew it up and catch it on the next run it's not careful you will dig a hole and we don't want to dig holes and looked over this might drive it and just miss any like that one this is where that yellow really helps because you can tell where you've been and where you haven't been that's good for now well I've continued scraping on and we've got really looking pretty nice now we've got pretty good coverage across here I check this out this is roughly 20 points per inch and I'm gonna estimate that is somewhere between 20 and 30 percent coverage which is for a machine not bad I'd probably like to get a little bit better coverage for a machine surface it's not done yet on a straight edge though I really want to get it up to about 40 points per inch a lot more bearing points and a little bit closer together than this so at this point we're again kind of going to change our strategy I'm gonna put a different blade into the back straight one has a larger radius on it let me show you what we got here so this blade here has about a it's a 60 radius I believe is what that one is and yeah 60 radius and the idea here is with that larger radius as I'm actually scraping the partners coming in contact it's going to be much smaller and my goal here is when I come in here and scrape this again I got on a real short stroke a real narrow cut that I'm making and all I'm gonna do is just come in here and kind of dive-bomb these blue points I'm not gonna scrape anything that's not blue at this point I'm just hitting these I'm just gonna come in here and I just kind of go boom boom boom boom boom and hit those go dive in and come right back out I'm not making long strokes like I watched before boom boom boom so we're gonna do that and basically what I'm doing here is we're not trying to eliminate all these points I'm just trying to cut them up into smaller pieces in the same time that should lower these down and hopefully bring in some contacts and some of these areas in between as well because they're all really really close you know they're probably all within a couple of tenths of being on the same plane but of course we're just hitting the highest points right now so anyway let's go in here they call this sometimes the technique for tea method to get 240 points and that's what we're trying to do here [Music] all right so we're gonna bring it over to the plate now and first thing I want to do is just kind of blew it up I can really feel it kind of second down to the plate which tells me it's getting pretty flat now when when you're blew it apart it's you don't want to just push down real hard on this thing you just want to kind of go back and forth it's not really that important how you go back and forth some people like to go in circles some people like to slide Indians some people go in figure eights that's not important what's important is is that you move it across the surface of the plate and transfer the blue onto the high spots of the part and again as always we're going to hinge it and it's going about here about here which is about 30% which is just what you want to see that telling me that it's not high in the middle it's not high on the end so it's fairly flat so let's pull it off now and yeah we actually increased our coverage there a good bit so that's a take this over to the Vice now and I'm going to repeat that process and we're just going to keep doing this until we get the total number of points down to where we want them all right we're going to come over here now to the plate again I've just went through another cycle and we're gonna glue this thing up again and hinge it make sure everything is good I'm gonna do something little bit different this time though after I've done that I'm gonna take a peek and we've got good coverage on the bottom but what I want to do is I want to find the highest of my highs so I'm gonna take it over now on to an area of the plate that doesn't have any blue on it and I'm gonna rub it on there and the idea here is is that it'll actually take the blue off of the very very highest points on the on the bottom there and it'll kind of polish them and I'm gonna see my extreme high points so now when I turn this over and you're probably not gonna be able to see this on camera because you have to really get in here look but some of these little we're gonna have a little polished area in the very center of the blue and that's my highest of my hives again we're talking again a ten thousandth of an inch higher and I this time I'm just gonna go in and I'm just going to hit those I'm not gonna worry about the other blue areas in here I'm just going to hit those very highest points and again we're just trying to bring down bring in some of these areas where we don't quite have the area of contact that we're looking for so I'm gonna do that and we'll be back again so here's what I've done I literally got down here real now at a low angle and I was looking across here for the shiny points and I just took a Sharpie pen and I just touched each one of those little high points that are on there and there's a lot more blue in here than what he just sees high points but these high points for the highest of the highs and again what I'm going to do now is I'm going to come in here and all I'm gonna do is I'm just gonna go in there and dive-bomb each and every one of those little dots it took me a little while to do that but it's a lot easier for me to see that because the the shiny points you really kind of have to get the light just right so I was literally having to get down there and look at it to identify all those and there's a couple of ways you can do this I'm probably gonna use the power scraper and again just go in there and dive-bomb them some people will actually use the hand scraper here and just bump scrape them they'll just literally put the point of the scraper you know right on the point that they want to do and then take it and bump in the scraper and scrape it with your hand and just hit those high points but once we do that hopefully we're going to be pretty darn close to being done with this thing so let's get in here and dive-bombed these real quick and see what it looks like all right yeah this is blue enough really nice you know I'm still not a hundred percent satisfied where I'm at but I'm at a point now where we're gonna probably stop on this side and I'm gonna flip over and start working on the dovetail up underneath this edge here in same process as we just did we're gonna work on that surface it's very likely that as we remove some material off that dovetail that it could change the bottom you know just a little bit so I'm not going to take it all the way down I want to go ahead and get this dovetail scraped in and then we'll come back and check the bottom and kind of go back and forth between the two until we get both of them spotting out just where we want to but this is this is really this is really pretty darn close in fact it's probably good enough as it is but I'm gonna try to get a few more points of contact in there before we're done so anyway I start working on the dovetail so for this dovetail edge I've got a little jig a little fixture here that I actually cobbled together when I was working on my 36 inch straightedge but it works good on this one too a little bit long but we're gonna leave it like it is but basically I want to work on this as flat as I can so basically I just took a piece of wood cut a couple of 45s made a cradle that this thing kind of sits down in I clamp this down to the bench then I clamped my part to this little riser in the back here there's two little supports by there and that gives me a fairly rigid work surface here that I can now scrape on and I'm scraping flat rather than an angle you can scrape at an angle but it's difficult anytime you get off of anything that's flat so we're trying to make it as easy as possible so we're gonna come in here and I'm probably not gonna show all this just simply because you've seen the process we'll start off with making fairly long strokes and doing crosses again this has been ground in so it should be pretty close we'll blew it up and just go through the same steps that we did before until we get our area of contact that we're looking for over here here you go guys all finished I've spent probably another hour and a half scraping the dovetail in and then after I did that when I flipped it over the bottom side I'd actually kind of come in just a little bit so I was blowing up in the back but not in the front it took about one or two quick passes on there and we were back covering up completely and then I checked the front again and everything looks good so a point in case there you know when you're doing something like this when you get surface flat and you remove some metal on the other side it's probably going to move a little bit again we're talking ten thousandths of an inch here very tiny amounts but when you're scraping that can make a difference but anyway this is done I'm down to it's probably 35 to 40 points and probably about 30 45 percent or 30 to 40 percent coverage as well on there which I'm happy with this is going to be fine and you know the thing about a straightedge is is every time you use it the first thing you'll do is you'll go blew it up on the table check it out and you may have to go in there and fine-tune it but each and every time music because it will move it's going to move with temperature change it's it's just going to move period over time so don't ever just trust that it's right your surface plate is your calibrated surface you always check the the straightedge to the surface plate and then you can use a straightedge as your reference surface so anyway I'm very happy with results I thought it turned out real nice now I need to build me a little box to store this in so it doesn't get damaged and protect it but that would be a project for another day so there it is and there was a quick demonstration on scraping that was just a very basic introduction there's a lot more to it than really what I covered there and I'll probably be doing some more scraping videos along and along and hopefully you can pick up a few more tips I will just say up front guys I am by no means an expert on scraping I've been through a couple of classes I know the basics obviously was able to get this thing flat within you know fairly flat anyway it says it's within thirty five forty points on here so I'm happy with that I can get the job done an experienced scraper could probably do it in about half the time but I can still do it in because I'm still learning but the the techniques and practices that I use I think will work anybody there you go that's my disclaimer I guess and like so we'll be doing some more scraping projects down the road and you'll probably get to see this straightedge in action soon when I start scraping in are finished scraping in the dovetails on my lathe over here so with that that'll be a wrap thank you guys for watching as always leave me a thumbs up if you like what you see if you haven't already please subscribe to the channel and we'll talk to you next time Thanks [Music] you

Channel: Keith Rucker - VintageMachinery.org

Views: 85,425

Rating: 4.9208703 out of 5

Keywords: Machine Shop, Machinist, Vintage Machinery, Metalworking, Keith Rucker, VintageMachinery.org, Hand Scraping, Power Scraping, Biax, Darpa

Id: s7yVMl81GOA

Length: 42min 29sec (2549 seconds)

Published: Fri Nov 24 2017