# Scraping my Shars 4" Milling Vise



## macardoso (Mar 29, 2021)

Been working on a steam engine and really been having a hard time holding parallelism on parts where one side is machined and then flipped onto parallels in my milling vise. I finally stuck an indicator in the spindle and tested the vise and found it to be almost 4 thou out of flat with the table in both directions - Yikes!

I bought this vise right away when I got my mill and I think I have gotten away without too many issues because I left the vise overhang the back of the table by about 1". You'll see from the initial bluing that the bottom of the vise is banana shaped and when I recently moved the vise (placing one end on the table this time), it left it crooked on the machine.

Here is the vise. They no longer offer this model, but I think it cost me about $110 eight years ago.




I do not own nor have access to a surface grinder, but I have recently been tooling up to get into scraping so I figured why not try it out.

*Disclaimer: *I have no idea what I am doing and I am not trying to teach others. This is my first or second part I have ever scraped on and I am learning new things every minute. Please be understanding of this in your comments.

Here is the initial bluing using Canode blue. Even with a thick layer of blue, you can see there is only a small contact area in each corner. I didn't measure the actual concavity but I would have to guess it was several thousandths since it took be almost 2 hours to develop this down to a roughly flat surface.




Here is my work setup. The surface plate is 18x24 with blue on about half of it. I have some 2x4s screwed into the table top to act as a work stop. I recently switched from using paper towels to spread the blue to a small rubber brayer and boy should I have done that a long time ago. The brayer makes quick work of developing a flat and thin bluing on the plate.




Couple of things I learned on scraping day 1. I really dislike the canode ink. It seems greasy and smeary compared to the Hi Spot Blue and if it is thin enough to get a good marking then it is almost invisible. I have switched back to using the Dykem for now, but I am looking at sourcing some Charbonnel Concentrated Blue since it sounds like it is a deep pigment and is water washable .

I was waiting on getting into scraping until after I had built a slow speed carbide grinder, however hand sharpening really isn't too hard. My technique is poor enough so far that an imperfect polish on the blade is of zero consequence. I'm finding the carbide blade to dull much faster than I expected causing me to exert a lot more effort to make a stroke. A quick swipe of two on the 1500 grit diamond lapping wheel I bought gets it to be nice and sharp again. I am not sure how hard the vise is (or isn't)

Following Connelly's suggestions on how to slide the part from one side, only a few inches and a few strokes, without any additional downward pressure really does work. Compared with pushing down from the top and rubbing in a lot of circles, I feel the Connelly method generates more consistent blue patterns which are representative of what the part actually looks like.

Digging the corner of the blade into the part is very easy, especially with the unusually large radius of the factory Sandvik scraper blade. I do intend to get this more along the lines of a 60mm radius, but that is a lot of carbide to remove using hand sharpening methods. Im developing the radius a bit more each time I go to re-sharpen. Rolling the corners over on the blade seems to help a lot but I have some nasty score lines in the bottom of the vise.

It is hard to keep the blue on the plate clean and free of chips, dirt, or dust. It is worth the effort to deep clean parts before scraping them. I also cover the blue with a paper towel any time I am not active printing the part.

It is hard to see in the image below, but I have gotten a relatively full bearing contact across the bottom of the vise. Next I need to start measuring parallelism of the top to the bottom. Probably should have been doing that the whole time, but I did try to "scrape straight down" when developing flatness on the bottom. I have been hinge testing the part continuously which did help me find some convexity I had put into the part after some cycles of bad bluing. Now it hinges at the 30% mark on both sides.




I have a fair degree of distrust of the flatness of my no name import surface plate. It is the best that I have though so I will work with it. I can get the part to hinge differently in different places on the plate which is a bit concerning.

I'm not sure to what extent to scrape this vise. I could stop after getting the bottom parallel to the factory grind on the top, or I could lightly scrape the top flat as well in case it too is a banana. I could scrape the sides square to the bottom to account for the rare cases where I use the vise flat on its side. I could scrape the fixed and moving jaws to get them square to the bedways. I could also scrape the tops of the jaws flat, parallel to the bed, and coplanar to each other which would help in the rare cases where I put the jaws on the outside of the vise for oversized parts.

Anyways, it is a start. Can't make this any worse than it was to begin with.


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## macardoso (Mar 29, 2021)

My curiosity was piqued and I needed to go check. After developing initial flatness on the bottom, the bedways are parallel to the bottom within 0.0002" over 4" on the length of the vise and 0.0006" over 4" on the width of the vise. This seems like a big improvement already. 

My next step will be preferentially scraping one side to correct the 6 tenths of non-parallelism, then checking the bedways for flatness, scaping if necessary, then scraping the bottom for flatness on then lengthwise direction.

I don't know what the points per inch requirement is for a vise, but I was thinking I'd keep the bedways at a moderately high points per inch so even thin parallels will sit on high points.


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## C-Bag (Mar 29, 2021)

I have exactly the same vise I also bought from Shars. I dont think I’ve ever checked it but I know I should. So your post is another reason to check it.


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## graham-xrf (Mar 29, 2021)

I have a similar vise, not yet bolted down to the mill. From your experience, I think first, it should get tried on a surface plate.
Thanks for the set of excellent pictures!
I have not tried scraping yet, so your descriptions are absolutely what we need.
I have been gathering the stuff I would need. Like you, for the present, I settled for hand grinding the carbide.




You can (approximately) check local flatness if you mount a dial test indicator on a scribing stand, set it down onto the surface, and "walk" it around. A sort of "poor man's repeat-o-meter. For overall corner to corner flatness, you need another reference, or optical instrument. I expect that the granite would have stayed flat somewhat very much better than the vise


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## Janderso (Mar 29, 2021)

graham-xrf said:


> I settled for hand grinding the carbide.


How?
I plan on making a lapping tool, one of these days.


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## macardoso (Mar 29, 2021)

Janderso said:


> How?
> I plan on making a lapping tool, one of these days.


I bought some of these diamond lapidary wheels. They're cheap and cut beautifully. I bought an #800 #1500 and #3000. I drew up plans for a slow speed grinder to use these, but for the time being I lay them on my bench and hand sharpen against them. Thought it would be too difficult, but I am finding it very easy.



			Amazon.com
		


Wishing I just jumped in sooner. I'm just doing a whole machine with geometry checks is very involved, but I am finding the process of scraping for flatness, bearing, and parallelism pretty straightforward.


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## graham-xrf (Mar 29, 2021)

Janderso said:


> How?
> I plan on making a lapping tool, one of these days.


I was just fooling about at a desk with one of those green cutting mats. Trigonometry allowed to figure just how far from the mat edge a pencil needed to be to tip 5°. I taped the pencil down with Duck tape each side. I used a little diamond hone, about the size of a credit card. It has #300 on one side and #1000 on the other. The sort for touching up chisels and router bits, etc.

I used masking tape initially to draw the curve with a school-type kiddies compass, and then rough ground it with the green wheel of my 6" bench grinder. Allow there was an interlude to re-work the wheels and everything so the grinder would not vibrate madly. I plan to re-visit everything about that machine. The actual rough grind took less than 5minutes.

Then, at the desk, I stood the diamond metal hone against a big old V-Block, to keep it upright, set the 20mm wide carbide down over the edge of the desk mat, resting on the pencil. Like this, the angle is always correct. I moved the V-Block and hone together. It worked better letting the V-Block slide around on a piece of paper. When I flipped it over to grind the other edge, the clean line between them developed, and you can tell just by looking at it which side needs "more" or "less".

Crazy simple, and I was watching YouTube, and/or listening to smooth jazz or country music most of the time. Getting two edges up to sharp takes part of an evening.


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## Larry$ (Mar 29, 2021)

I'm a very long way from good at scrapping but I have managed to improve some things using a home made scraper and a jig to sharpen it on my tool & cutter grinder. The diamond wheel on the grinder makes quick work of sharpening. The grinder is high speed but seems to work as well on the scraper as it does on tooling. Actually pretty darned good.


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## macardoso (Mar 29, 2021)

C-Bag said:


> I have exactly the same vise I also bought from Shars. I dont think I’ve ever checked it but I know I should. So your post is another reason to check it.





graham-xrf said:


> I have a similar vise, not yet bolted down to the mill. From your experience, I think first, it should get tried on a surface plate.



I got good results with this vise for 8 years, but it definitely needed work. Hoping to use it as a jumping off point for learning to scrape. The milling machine will be next after I finish the last few parts on this steam engine.


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## macardoso (Mar 29, 2021)

graham-xrf said:


> You can (approximately) check local flatness if you mount a dial test indicator on a scribing stand, set it down onto the surface, and "walk" it around. A sort of "poor man's repeat-o-meter. For overall corner to corner flatness, you need another reference, or optical instrument. I expect that the granite would have stayed flat somewhat very much better than the vise



That's a great idea and I've been meaning to do that. Maybe tonight I can try it out at a few different extensions and get a rough idea of flatness.

Even if it is only true within 0.0005" (it better be a lot better than that) it is still a very accurate tool.


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## graham-xrf (Mar 29, 2021)

macardoso said:


> That's a great idea and I've been meaning to do that. Maybe tonight I can try it out at a few different extensions and get a rough idea of flatness.
> 
> Even if it is only true within 0.0005" (it better be a lot better than that) it is still a very accurate tool.


I binge-watched all the videos about measuring and surface lapping a plate. This is one of those things where you can, in principle, use self-proving methods to get  to any accuracy, though when the plate is within 50 millionths, you can get to the point where you can't improve it, and the more you lap, the flatter becomes your lapping tool instead.

Way, way before that point, you have a plate that will be about 0.0002 in it's worst local measure, and maybe 0.0001 over 80% to 90% of what you would use. Making various versions of repeat-o-meters has the excellent design fro *Robin Renzetti (ROBRENZ)* among them, and various other projects with improvements that acknowledge his version. They are all quite make-able.

The procedures, and what you do to fix I got from *Abom79* "*Lapping my Granite Surface Plate to AA Grade*"




I am quite sure none of us have to do all this to have a surface plate good enough to fix a vise. Most of us rarely need to make something to within 0.0002 absolute. Even if we make a lapped fit to fine limits, it usually only has to fit relative.

Back before pandemic, I scored a nice granite surface plate freebie, on a stand. I plan to use it, but like you, I would rather like to know exactly how it stands up to measurement.


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## macardoso (Mar 29, 2021)

graham-xrf said:


> I binge-watched all the videos about measuring and surface lapping a plate. This is one of those things where you can, in principle, use self-proving methods to get  to any accuracy, though when the plate is within 50 millionths, you can get to the point where you can't improve it, and the more you lap, the flatter becomes your lapping tool instead.
> 
> Way, way before that point, you have a plate that will be about 0.0002 in it's worst local measure, and maybe 0.0001 over 80% to 90% of what you would use. Making various versions of repeat-o-meters has the excellent design fro *Robin Renzetti (ROBRENZ)* among them, and various other projects with improvements that acknowledge his version. They are all quite make-able.
> 
> ...



I've watched all those videos too 

I'd love to get into that, but there is a good deal of expense in making/buying the repeat-o-meter and/or an autocollimator. If I could pay $100 and sneak my plate into a batch getting lapped at a local shop I would totally do that. I've also reached out to a local calibrator to get a quote. Otherwise I've been eyeing up a Shars AA plate for $150. You get the same issue with unknown flatness, but Shars has been good to be and I trust their products pretty well.

I can also tell the quality of granite that mine is made from is inferior to the granite I have seen the plates in the metrology lab I used to work in be made out of. The crystals are quite large. But... It was <$100 and I picked it up locally so I can't complain much. Probably still better than the old Starrett plates I see at the industrial surplus places.


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## graham-xrf (Mar 29, 2021)

@macardoso : You and I seem to be riding the same trail here.
You can get up to tricks to duck having to do the 3-plate method, make up laps, and all that, An ordinary piece of plywood can hold three bolts stable enough to let you know even 0.0001 has touched. It can be circular, trianglar, square, or random shaped like a dog's hind leg, so long as it has 3 pointed  bolts set into nuts on the ply, and all about the same length. Then a central fine thread bolt in a nyloc nut, and put a disc with degree markings on it, and set a pointer, Fancy is to print the protractor. Fine gel pen in a compass also works. This is a "flat" version of a spherometer.

A small type, that can span the surface plate in about 4 or 5 overlapping halves can be used along diagonals, and "Union Jack" lines for local up/down.

The neat trick is to make one that is a bit larger than half the span of the surface. Adjust it down until it only just squeaks to spin.
Leave at that setting, and move to the other end of the plate. If the plate is flat, it will still be at the spin point. With a gentle touch, less than 0.0001 can be felt. There is a 2-bolt version of this also, but the 3-bolt + centre is the "kinematic" spherometer.

I plan to play with one of these 

[Edit: BTW - how big is the Shar's plate? ]


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## pontiac428 (Mar 29, 2021)

I thought an Englander would be quick to point out the Union Flag is only a Jack when it's flown on a ship.  Or so I've been schooled at the pub.

I'm sorry your Shars vise is such a potato chip.  My Shars 5" is so straight that I refused to sell it with my "little" mill.  I'm keeping that vise!   I bought my granite surface from KBC (because the shipping was way cheaper and I had a holiday %-off coupon) but I think their surfaces all come from the same supplier.  I also think the import granite is softer than the pink Starrett surfaces or the hard, slate-colored surfaces you'd see in a commercial shop.  But I'm just one guy, so I don't expect I'll wear it out of spec in my lifetime.


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## graham-xrf (Mar 29, 2021)

pontiac428 said:


> I thought an Englander would be quick to point out the Union Flag is only a Jack when it's flown on a ship.  Or so I've been schooled at the pub.
> 
> I'm sorry your Shars vise is such a potato chip.  My Shars 5" is so straight that I refused to sell it with my "little" mill.  I'm keeping that vise!   I bought my granite surface from KBC (because the shipping was way cheaper and I had a holiday %-off coupon) but I think their surfaces all come from the same supplier.  I also think the import granite is softer than the pink Starrett surfaces or the hard, slate-colored surfaces you'd see in a commercial shop.  But I'm just one guy, so I don't expect I'll wear it out of spec in my lifetime.


I guess my failing was that I was not originally Englander with the island nautical (and somewhat isolationist) mentality. Instead, I was an ex-Colonial from far enough inland not to care. You are right, it is the Union Flag, regardless the Union is now somewhat strained. The "Jack" was on ships. Sailors were also known as "Jack Tars". When I settled in UK, I discovered one is expected to know when it is upside down as a distress signal. There is a slight asymmetry when the Scotland cross of St Andrew is overlaid with the Irish red cross of St Patrick.

There is some argument as to it being called so because it was flown from the jackstaff. Parliament has decreed that "Jack" is shortened reference to "Jacobus" of the Kings James and that the term "Union Jack" can be used on land.

I do want to check out my freebie surface stone, acquired because it was replaced after "someone dropped something on it".




I have found the "ding". Quite hard to spot it without a bit of searching. It hardly looks like that tiny hole will affect anything I would be using it for. It's 18" square and came with the stand. Definitely my vise will be checked out on it!


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## Ulma Doctor (Mar 30, 2021)

graham-xrf said:


> I have found the "ding". Quite hard to spot it without a bit of searching. It hardly looks like that tiny hole will affect anything I would be using it for. It's 18" square and came with the stand. Definitely my vise will be checked out on it!


granite surface plates don't raise burrs due to impact, small bits of spalling are low points and don't really affect overall accuracy
a cast iron surface plate will raise burs under the same impact


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## Alcap (Mar 30, 2021)

I’m trying to understand , so over time the vise got bowed, from use or another reason ? If the bottom isnt flat then the bed (? ) of the vise be bowed too ?


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## graham-xrf (Mar 30, 2021)

I hate to say it - but. Check out the bed. Even without a straight edge reference, there are things you can do, with a DTI, and a level.


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## macardoso (Mar 30, 2021)

graham-xrf said:


> You can get up to tricks to duck having to do the 3-plate method, make up laps, and all that, An ordinary piece of plywood can hold three bolts stable enough to let you know even 0.0001 has touched. It can be circular, trianglar, square, or random shaped like a dog's hind leg, so long as it has 3 pointed bolts set into nuts on the ply, and all about the same length. Then a central fine thread bolt in a nyloc nut, and put a disc with degree markings on it, and set a pointer, Fancy is to print the protractor. Fine gel pen in a compass also works. This is a "flat" version of a spherometer.
> 
> A small type, that can span the surface plate in about 4 or 5 overlapping halves can be used along diagonals, and "Union Jack" lines for local up/down.
> 
> ...



I did the poor mans repeat-o-meter last night on the half of the plate which was not covered in Dykem. I have an Interapid tenths indicator. Total reading was about 0.0002-0.0003" so not bad. my indicator base could probably use a light scrape or lapping job to get it sitting real flat too. Next time I clean off all the blue I'll check the other side.



graham-xrf said:


> [Edit: BTW - how big is the Shar's plate? ]



This plate was from JTS machinery in Cleveland - now out of business. It is a no-name import plate 18x24x3. At 150 lbs it was the heaviest I could carry around or lift onto the bench. I need a stand for it.



Alcap said:


> I’m trying to understand , so over time the vise got bowed, from use or another reason ? If the bottom isnt flat then the bed (? ) of the vise be bowed too ?



One word - China. The vise has likely been like this since I got it. My next post will cover it better, but the top was bowed as well but in the opposite direction so it is not bent, just bad grinding.



graham-xrf said:


> I hate to say it - but. Check out the bed. Even without a straight edge reference, there are things you can do, with a DTI, and a level.



Yup, I had to do that. Will write about it in my next post but I couldn't get my measurements to stabilize when scraping the bottom and it was because the bed of the vise was also very crooked.


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## macardoso (Mar 30, 2021)

Did about another hour of scraping on the bottom and I am getting pretty comfortable getting a good bluing. The hinging method helped my identify when I was getting convexity in the middle and I could preferentially scrape to resolve this issue.

In the image below, I am trying to scrape only the areas needed to resolve the side to side taper and the convexity of the bottom.




I worked at this for a while but just could not get consistent measurements on the parallelism of the bed to the bottom. I figured the bed must also be twisted, so I disassembled and cleaned the vise to prepare for scraping.




Here is an initial blue up. Somewhat as expected as there was a lot of raised material around the tapped holes. I wonder if they were drilled and tapped after grinding? Anyways, I figured at this point that the blue on the left side of the picture was just a false reading due to the part being lifted at the threaded holes, but later on I realized that the left edge was significantly raised up in comparison to the rest of the bed.




Since it is hard to get a good bluing on surface ground finishes, I used layout fluid to paint the top surface. I then executed two scraping passes to texture the surface, looking for even scrape patterning and spacing (thus scraping "straight down")




Here is what that looked like.




I spent another hour trying to develop this surface down to flat. Here is a summary of what I have discovered in the part geometry.

Bottom not flat: bottom was concave (banana shaped) by roughly 0.003"
Bottom not parallel to bed: after developing the bottom to be flat, a widthwise taper of ~0.0006" and a lengthwise taper of ~0.0002" were present.
Bed not flat: bed is concave by roughly 0.003"
Bed rails not flat: each rail has a concavity along the length (like a half pipe) of roughly 0.0008"

I made a lot of progress towards getting this flat. Probably would be done by now if I didn't make mistakes - more on that later. I would guess one more hour to get it flat, one hour to high point to decent bearing, and one hour to get the bottom parallel to the top.

Each cycle looks like this:
1) Examine bluing (use sharpie to mark exclusion zones if needed)
2) Scrape bluing
3) Dust off chips
4) Wipe clean with alcohol
5) Stone lightly with a fine india stone
6) wipe clean with alcohol
7) Clean off dust with light compressed air
8) Use brayer to smooth out the blue on the plate
9) Print part with blue

During the latter part of roughing in the bed I got impatient and thought to try a bench stone to hit off the high spots. I only gave it maybe a dozen swipes, but I did a lot of damage in that short action. If you can see in the image below, the outside edges of the bed rails got rolled off very quickly (they were even high before stoning). This is going to require several scraping passes to drop the surface down to the level of the edges that got stoned. Probably cost me at least an hour of work in only 15 seconds - ugh. I called it a night here.




What I learned on day 2 of scraping:

1) It is very easy to get dirt, dust, and grit in your blue on the plate. When you do, you typically have to remove a ton of blue and start over. I had to develop and good strategy of cleaning the part before bluing it. The scraping chips fall into the vise body during scraping and then fall onto the plate when it is inverted. The extra cleaning time is much better than constantly needing to wipe off the blue and start over.

2) A rubber brayer does a good job of picking up a bit of dust and grit from the blue on the surface plate. The dust sticks better to the rubber roller than the plate. Keeping the brayer clean and rolling it over the blue at least every few cycles helps keep the plate clean.

3) Bench stones have no place in scraping. A fine india hard arkansas stone or a precision ground flat stone (PFG) is the only option for deburring.

4) You need to rough scrape longer than you think. I keep switching to going after high points long before the surface is flat or geometrically correct.

5) Hinging is really important for determining surface flatness.

6) Carbide hand scrapers require more frequent sharpening than expected. I notice the edge does not cut as easily after 4-5 cycles. 2-3 swipes on 1500 grit diamond gets it back to sharp. I can visually see if the blade is dull by if there is any light reflected from the corner of the blade. Even the faintest sliver indicates dullness.

7) Scraping near edges and holes is very tricky. It is hard to get yourself to cut deep enough just inside from the edge, but not roll over the edge.

I do think that a few more hours will get this *much* better than what I started with. On my next scraping attempt, I expect to be 25% more efficient if I can avoid the same mistakes I've done here.


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## Janderso (Mar 30, 2021)

pontiac428 said:


> I also think the import granite is softer than the pink Starrett surfaces


You are correct sir, based on the information I have gleaned from watching the lapping repair-recertification videos anyway.


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## Janderso (Mar 30, 2021)

macardoso said:


> Bottom not flat: bottom was concave (banana shaped) by roughly 0.003"


.003" is a lot to scrape!
 We measured the typical depth of scrape to be .0002 to .0003" per scraping session, that's tedious as hell. Too bad you don't have access to a surface grinder.


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## macardoso (Mar 30, 2021)

Janderso said:


> .003" is a lot to scrape!
> We measured the typical depth of scrape to be .0002 to .0003" per scraping session, that's tedious as hell. Too bad you don't have access to a surface grinder.


Yeah, i'm really roughing hard for such a small surface and the incremental drop in the surface is quite slow. But it is also pretty neat - in my mind - that I can work a surface into precision (hopefully) without access to some of the more precision machining equipment.


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## macardoso (Mar 31, 2021)

I got another good hour of scraping in yesterday and was pretty spot on with my guess of 1 hour to correct the damage done by the stone.

I now have a nice and flat surface with decent bearing contact. I have a few hollows, but I expect them to fill in as I start high pointing. I am getting about 20-30 points per inch all over with 5 points per inch in the bare sections. All of my contact points are tiny so I only think I have 5% bearing or so. Doesn't quite look like the pictures I see of finished scaping yet.

In the image below I've marked all my high points with sharpie. This both makes it possible to share a picture of the work here as well as helps me when I go to actually scrape this in.

You can see some bare spots in the top left corner, along the very right edge, and a higher distribution at the edges of the bed rails compared to the middle.





What I learned on day 3:

1) A lot of damage can be done to a surface very quickly, and it is very slow to repair

2) A very light rubbing of blue followed by a dry rubbing on the surface plate creates a bunch of blue circles with a burnished (almost black looking) dot in the middle. In the later stages of scraping this makes it easier to see your high points

3) The wide radius of the stock Sandvik blade wasn't too bad to rough with, but I feel I am having accuracy issues with aiming for high points. I have started to develop a tighter radius on the blade but that is a lot of work when shaping completely by hand.

4) I can see my work better with a single overhead light rather than all the lights on in the basement. Makes it easier to get a contrast between the surface and the high points.

I think I will high point for an hour and see where I get to. Would like to see a slightly more even distribution before I call it finished.

Then I get to go back and work on getting the bottom parallel to the bed.


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## macardoso (Mar 31, 2021)

Sitting on hold with a call at work and got another highpointing cycle in (note the tally count on the casting web).

Used Richard King's suggestions from another thread to add contrast (red canode) before bluing. After bluing I rubbed the part on the clean side of the surface plate. Pretty easy to see the high points now.




And with high points marked by sharpie for easy visual




Still have some bare areas (especially under the fixed jaw) but I am getting much better contact. High pointing is slow. I was originally going to do 10 cycles, but it might be more like 5 and see where I get to.


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## macardoso (Mar 31, 2021)

Highpointing cycle #3







Getting a lot more tiny high points. I can tell there are some areas bearing more heavily, especially the inside edge of the fixed jaw (right of keyway, left side of image), top right of image, bottom left of image, and in general the edges of the rails over the inside.

Getting closer. Think I might make pass #5 only hit the high points in these heavier bearing areas. Will see. Hinging on the surface plate is showing really nice flatness.


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## macardoso (Apr 1, 2021)

Here is after highpointing cycle #4. 

I am experimenting with only highpointing the areas where there was lots of bearing to try to even it out. I was taking the very lightest cuts on the surface - probably less than a tenth.




And here is after the blue-up. Notice the middle areas, which were bearing less before and now bearing more heavily. This meant that only the very lightest cut completely changed the bearing pattern, kind of wild. I'm going to selectively scrape only these regions this time, then probably 2 passes over the whole surface and call it quits.




What I learned on day 4:

1) Whatever your distribution of high points is after the roughing phase will continue through highpointing. The highpointing increases the bearing contact all over, but the relative distribution remains the same. So I would say keep roughing until you have an even distribution of high points all over.

2) The hinge test is very sensitive at determining flatness once the surface is moderately well finished. My one partial high pointing pass noticeably changed the hinge test results.


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## macardoso (Apr 1, 2021)

After Highpointing Cycle #5







A bit of selective scraping did a lot to improve the distribution of high points. I'm taking one final pass on the surface and calling it good.


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## macardoso (Apr 1, 2021)

The bedways of the vise are done. Did a quick check of the moving jaw to see how it fits up and yeah... gonna be scraping that too.







The moving jaw is very rough on the surface and all the contact is in the middle of the bed rails. I feel like one or two slides of the jaw and my beautifully scraped surface will be all scored up.

I'll scrape this in. Might need to add a groove to the corner so I can get the blade in there. I won't go for as pretty of a surface. Maybe 10 ppi instead of the 30-40 I got on the bed. Then I still need to finish the geometry on the bottom (half done) and get it parallel to the bed. This is a lot of work!


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## pontiac428 (Apr 2, 2021)

macardoso said:


> This is a lot of work!



It's just a little vise, he thought, it'll be quick and easy!


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## macardoso (Apr 5, 2021)

OK Got a good chunk more progress done last friday.

Below is a progression of rouging in the moving vise jaw and finishing. I did not go to the same level of finishing as the bedways as It is my understanding that this is not needed for semi-static scraped surfaces.

The milled surface is broken up (blind scraping) for better blue transfer



Initial contact is quite poor



After a few more roughing passes I have contact down the length of the slides



The right slide is showing much better area contact than the left, thus I scraped the high areas on the left.



Using the bedways to print the moving jaw



Getting better all-over contact



Lighter blue is helping make more educated decisions about where to scrape



Very light bluing near the end of highpointing 



And this is where I called it done.



And a beauty shot of the scraped bed and moving jaw.




What I've learned since day 5:

You can rough pretty judiciously at first, I think I am too easy on it still and take a long time to get through the roughing
Determining flatness on parts with protrusions above the planar surface is tricky, hinge test cannot be used
The hydrodynamic bearing generated between two scraped surfaces is incredible, I totally get why we do this! 
Printing a part using another scraped part as a template feels a lot different than rubbing on a granite plate. The blue acts like grease if used in anything but the thinnest layers and smears a LOT compared to the granite. Also it seems to develop less obvious burnished spots which is annoying when trying to highpoint.


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## Janderso (Apr 5, 2021)

It appears you have learned volumes these last few sessions.
Looking great.


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## macardoso (Apr 5, 2021)

Also I bought a tube of Charbonnel Etching Ink - Concentrated Blue. I bought it since some had touted the benefits of being water washable. Unfortunately I did not buy the version labeled as "AQUA WASH" and it is definitely not water soluble.

In general I like the Charbonnel as an alternative to Dykem Hi Spot blue. It feels quite a bit like the Hi Spot blue (much more so than the Canode). The color density is excellent. It does have a few notable differences. First, it is more "tacky" where the Dykem is more "greasy". It is a bit harder to develop into a thin film but once it is, it seems to hold up much better to repeated printings than the Dykem. Once a thin layer has been developed, it seems to smear less than the Dykem for metal to metal printing (have not yet tried the surface plate).

It does not clean up as easily as the Dykem using a dry paper towel (more sticky) nor is it tremendously soluble in Isopropyl Alcohol (IPA) which I use generously to clean the Dykem. Interestingly, a small amount of Charbonnel thinned in IPA leaves a super matte film on the surface. I might pick up some yellow ink and thin with IPA to use as contrast.

The Charbonnel (non-AQUA WASH) cleans up super easy with WD-40, and that can be cleaned with IPA. One extra step.

The Charbonnel is also about half the price of the Dkyem Hi spot (per oz)


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## Janderso (Apr 5, 2021)

macardoso said:


> Also I bought a tube of Charbonnel Etching Ink - Concentrated Blue. I bought it since some had touted the benefits of being water washable. Unfortunately I did not buy the version labeled as "AQUA WASH" and it is definitely not water soluble.
> 
> In general I like the Charbonnel as an alternative to Dykem Hi Spot blue. It feels quite a bit like the Hi Spot blue (much more so than the Canode). The color density is excellent. It does have a few notable differences. First, it is more "tacky" where the Dykem is more "greasy". It is a bit harder to develop into a thin film but once it is, it seems to hold up much better to repeated printings than the Dykem. Once a thin layer has been developed, it seems to smear less than the Dykem for metal to metal printing (have not yet tried the surface plate).
> 
> ...


I remember how difficult it was to get the blue thin enough. Richard had us add a bit of windex to thin it as I recall.
I bought the water soluble in blue.


			Restricted Access


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## macardoso (Apr 5, 2021)

So all I have left on this vise is to scrape the bottom to be flat and parallel to the bed. 

After the roughing that I had done prior to the bed, the surface seems to be within 0.0002" of parallel over the whole length of the vise. This should be moderately easy to correct. Again for the bottom of the vise I do not feel the need to get the same points per inch as I did on the bedways.

I plan to stop here, but there are more parts of the vise that could use attention. In particular:

The fixed jaw, scraping for good contact on the mating surface, flatness on the jaw mounting face, jaw mounting face orthogonality to the bed surface, and top parallelism to the bed ways.
The moving jaw, scraping the top for parallelism to the bedways and jaw mounting face for orthogonality to the bed ways.
The vise body, scraping the sides for flatness, squareness to bedways, and squareness to the fixed jaw. Scraping the internal moving jaw guide rails for flatness and parallelism.
Reworking the moving jaw bosses. I notice in some areas they are a loose fit to the vise body guide rails and tight in other areas. Reworking the guide rails will leave them even looser. This can cause the moving jaw to yaw sideways when a part is clamped off center. The cast bosses could be machined away and a bronze guide boss could be added, machined, scraped, or ground to a snug fit between the guide rails
Adding ball oilers recessed in the top surface of the moving jaw to feed oil to the moving jaw. Alternatively, I can be better about occasionally lifting the moving jaw to add oil to the ways and slides.
I don't feel these items are immediately necessary as this vise will be quite accurate for my needs upon the conclusion of the scraping of the bottom surface.


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## macardoso (Apr 5, 2021)

Janderso said:


> I remember how difficult it was to get the blue thin enough. Richard had us add a bit of windex to thin it as I recall.
> I bought the water soluble in blue.
> 
> 
> Restricted Access



Thanks for the link! I personally like the thickness of the concentrated ink. It is some work to develop the thin film, but once it is there, it stays put. I feel like I'm constantly adding more Dykem to keep the same blue thickness on my plate. Just my thoughts after a few hours of trying it out.


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## Winegrower (Apr 5, 2021)

Excellent write up.  And I am realizing that a Kurt vise is a much better value than I thought.


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## macardoso (Apr 5, 2021)

Winegrower said:


> Excellent write up.  And I am realizing that a Kurt vise is a much better value than I thought.


Yup, I'd tend to agree. This is what I have so why not make it better!


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## pontiac428 (Apr 5, 2021)

Wow.  You really jumped in with both feet on this one.  I probably would have found somebody with a surface grinder to rescue it, but you've clearly learned a lot from the experience (and shared it).  Thanks for the writeup!


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## jwmelvin (Apr 5, 2021)

This thread has been amazing. Inspiring and intimidating together. Thank you.


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## macardoso (Apr 6, 2021)

Remeasured the vise last night, this time using a gage block to bridge the highpoints. This made a huge difference in the ease and repeatability of measurements

Parallelism in Transverse Direction: 0.00030" over 4"
Parallelism in Longitudinal Direction: 0.00035" over 8"
TIR Parallelism: 0.00050"

Noticed my indicator base is not all that flat. It too will need to be scraped if I'm going to have ease in measuring my work.


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## macardoso (Apr 6, 2021)

Took a moment to take better readings over the whole vise surface.

I used a tenths indicator on a stand in a fixed position. Once the indicator was zeroed, I did not touch it for the entirety of the measurement. To measure, I slid the vise under the indicator stylus and then took a clean gage block and slipped it between. I took a minimum of 3 measurements or as many as were required to get the measurements to settle. All readings were interpolated between the graduations to the nearest 1/5th tenth (0.00002").  Between 3 successive readings, I went back to the zero location (top left of vise, center of way) and made sure the indicator repeated to zero. Care was taken to not measure over the sharpie numbers as these would influence the measurements by 1/2 tenth or more. A total of 48 measurement locations were sampled.










To better visualize the data, I drew a to-proportion grid in excel and plotted the values (in 0.0001") then heat mapped the whole surface. The origin measurement is marked as a bold 0.0.




Here is the same chart using single color gradient.




This is all overkill for a vise but kind of fun. The overall taper from top left to bottom right corner will be corrected by scraping the bottom of the vise. The convexity in the middle might be convexity remaining from scraping the top surface, errors in my measurements, or non flatness of my surface plate. I'd like to finish roughing and high pointing the bottom, then repeat this chart hoping for deviations <0.0002" all over.


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## MrCrankyface (Apr 7, 2021)

I'm really enjoying following this along, thanks for sharing with such good writeups!


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## NC Rick (Apr 9, 2021)

While it sounds like a lot of work, there are a lot of lessons in metrology and old school ways to achieve spectacular accuracy.  You should have started with a good vise ;-). Seriously, thank you for taking the time to bring us along.


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## macardoso (Apr 9, 2021)

NC Rick said:


> While it sounds like a lot of work, there are a lot of lessons in metrology and old school ways to achieve spectacular accuracy.  You should have started with a good vise ;-). Seriously, thank you for taking the time to bring us along.


While it is a lot of work, it is rather relaxing and I can get into a flow. I’ve been listening to Liftoff (audiobook on the early history of SpaceX) and 3 hours can fly by without me noticing. The hardest part is actually understanding the geometry of the part. Detecting bow or twist in the surface is moderately tricky to measure when the error is only a tenth or two. My first job was in a metrology lab so I have some patience for taking my time while measuring a part.

I will take this as a lesson. The vise was one of my earliest machining purchases (along with my G0704 mill). Got them when I was maybe 19? Back then “accuracy” was probably a good +/-0.025”. Given that, the vise served me well. Now I want to work in the tenths range and find myself wanting more accurate tools than I have.

Think I’m going to call the vise done. Will post an update when I get some free time.


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## macardoso (Apr 12, 2021)

Vise is done! Here was the day or two leading up to finishing it.

Continued work on the bottom, scraping for flatness, bearing, and parallelism to the bed.



Measurements of the bed surface indicated about 2 tenths of convexity in the surface. More careful hinging also seemed to indicate this, although difficult to tell once it is this flat.



More scraping on the bottom to remove the wedge from side to side - about 2 tenths. Using red canode as contrast.



Light scraping for increasing bearing. This surface is less critical to me for fineness of surface.



Here is how my bench looks while scraping (a bit more cleaned up since I have the extra pieces of the vise pulled out in this photo). The surface plate takes up about 1/3 of the bench, some 2x4's provide good blocking to hold the vise in position while scraping. The diamond lapping wheels on the left are used for hand sharpening.

The vise nut (black slide at the very bottom of the photo) has rough milled slides, which seem of sufficient quality for the job they do. Unfortunately both slides has dings which were the only bearing points as shown by the wear pattern. I stoned these slides with a sharpening stone and got better contact. They are too small to bother scraping, nor is the inside edge of the vise of ground or scraped quality.




Starting to fit the vise back together. I took a full hour to deburr and edge break all the components as well as give it a deep clean.



There is the half ball to reduce jaw lift. Mine seems to be better than a lot of the import vises I see people talking about in this regard, however the cast socket that mates to the ball is rough cast and not super smooth.



Here is the vise assembled.



And back on the mill.



I would have to guess I put about 40 hours into this vise, although I wouldn't call all of that time super productive.

The surfaces are flat and parallel within 0.0002 all over, but most areas are within 1/2 tenth. The jaw lift adjustment screw can be tightened MUCH tighter than before without binding which is a testament to the improvement of the bedways and moving jaw slides.

The screw was cleaned as was the thrust bearing (lots of chips in there). The Chinese must have invented the class 4B thread for the screw retaining jam nut (visible on the left side of the vise in the image above) as a special for this vise. The nut was loose enough that it slid over the major diameter of the threads on the screw for about 1/2 of the length, and just barely threaded for the rest. It is retained with 2 setscrews which crush the threads underneath and probably contribute 95% of the strength of that fastener - what garbage.

Here are a couple more things I learned:

-My Interapid DTI (0.0001") is not very repeatable in the sub-tenth range of measurements. I think any influence (dust, heat expansion, stickiness in the indicator movement, etc.) contributes to measurement error at this range.

-Determining convexity, concavity, twist, etc in the 1-2 tenth range is difficult, at least with my surface plate and measuring tools.

-My indicator base needs to be scraped, it is not flat enough to be reliable in single tenths measurements.

-Changing the inclination of the scraper reduces the cut width and is useful for more accurate high pointing.

-As a righty, scraping 45 degrees to my left is easier than 45 degrees to my right. My body gets between my hands and the work and makes the posture more difficult. Don't know the solution.

-I purchased a 30mm optical flat ($20) to bridge high spots rather than the gage block. I might break it but I think the larger contact area will be preferable to the gage block.

-I still want to pick up the AQUA WASH version of the Charbonnel. I don't find the high spot blue to be *that* messy though.

-My surface plate has a 2" x 1" divot along the back edge, roughly 0.0008" deep. Was never lapped flat - ugh. I have to avoid this. Otherwise my poor man's repeat-o-meter readings using a DTI on a base gave deviations no greater than +/- 0.00015. This is probably sufficient for my needs at this point.

-Part of my inaccuracy when mounting the vise on the mill comes from bending of my 5/8" thick aluminum tooling plate (last photo) as the clamps holding the vise are tightened. Now that I know the vise is true, I can contribute all the error to my machine and workholding setups.


All in all I am very happy with the outcome. I took a cheap vise, all I could afford at the time, and turned it into a much higher precision tool which should last me a long time. The 40 hours spent on it also taught me some scraping fundamentals which I will carry forward with me to my next scraping projects (a CI parallel, a CI surface plate, and hopefully a dovetail straightedge and eventually my G0704 mill).

I want to thank everyone who contributed and has answered my questions.

-Mike


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## Optic Eyes (Apr 12, 2021)

You would have done better with the original sandvik blade, and starting with a triangular file and ground straight edge, in this case 6 to 8 points is good enough with
even distribution, the vice doesn't move


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## macardoso (Apr 12, 2021)

Wanted to make one additional comment. Jumping into scraping doesn't need to be too intimidating. Just going for a flat plane is simple enough and the effort is not extraordinary. Just scraped my indicator holder this afternoon in 45 minutes - granted it was much flatter than the vise to start. Entry costs are also moderately low:

Grade B plate - sized for your work: $50-100
Scraper (Sandvik): $90
Diamond lapping discs (800, 1500 grit): $10 each
Hi Spot Blue: $15
Indicator + stand (cheap one to start): $50
You can even skip the scraper and lapping discs and use a file and a bench grinder. Your work will be rough and it dulls fast, but it does work.


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