Gena, here's another video from Japan showing these "dancing" scraping guys...the video shows how they use scraping everywhere in their machines: kzbin.info/www/bejne/r2KuqYh5ecdsj7M

You have magic hands and very good work, but is it possible to compare the performance of a MIG and a precision dial gauge with a 0.002 mm level? I am interested in the difference in readings caused by the contact force of the different indicators?

You are awesome, putting so much effort and finally achieving very high precision with limited tools. This is ingenious and a like if people work so hard. I deeply appreciate it. Thank you so much!

I wonder if the age and storage conditions of the vial may affect the shape as glass is a fluid that shifts very slowly so just being in storage for decades may have affected the soviet vial more as I assume its the oldest . When installed in an instrument the vial is often supported by plaster which may reduce the shift in shape due to gravity.Check out Wikipedia optical flats long term stability for glass. probably best if you just measure the accuracy and compensate if needed. (mark whatever you mount it on )

Few realise what treasure Mr. Bazarko and his channel is. Deep respect, Sir.

If you ever tried to scrape steel or eve, Iron you get the same scratches no matter what you do. This is because those metals are a lot more elastic so the microscopic chips don't break, they bundle up at the cutter's edge and gouge the material because they;ve been work hardened by the cutting.

Hallo, Gena; I was watching a video by a Japanese Precision CNC machine manufacturer, and they have many, many scraping operations, even as far as the base of the "tower"... I noticed that some of the people doing the scraping were "dancing", seemed funny, but they had a rounded end of the scraper handle, and had that against their hip, using the body to put the power into the heavy scraping... Looks like a good way to do the deep scraping, and they changed to the "normal" way for final scraping. They measure to 0.0001 mm.

www.youtube.com/@%E6%99%B4%E6%BA%B1

I don't think this was said on the video, and I haven't seen a comment about it, but a key to Gena's accurate measurements is that the tip of the stylus is directly above the front foot. He makes a vertical measurement about as perfectly as one can get, and it reflects the surface topology at that exact point.

I really admire your scientific approach to everything.

Is it possible to make this process less work intensive? I'm thinking bout some guide rail on a fixture above work-piece? Level it once above surfaces to be grind, then run grinding wheel on these surfaces? I'm not an expert, maybe that is a nonsense what I say)

Looks right. You are right to check if your plane is perpendicular to the column. As you could easily scrape the ways perfectly straight but out of alignment with the rest of the machine. Ususally, when scraping for alignment, the shortest axis is adjusted because it is less work. But in this case, the scraping of the ways (the longest axis) will be a lot of work regardless so you may as well do the alignment there.

Interesting work. I'm skeptical of any method that allows you to justify a surface plate that isn't flat. If you don't have a reliable flat surface, why bother with other gages and measurements? In precision, simple and fast measurements will be more reliable. Also, the ability to reverse the part is often useful. So rather than measuring top and bottom, it may be better to leave your instruments set as they are and flip the part you're measuring. In theory, this is nothing. In practice, it can prove your measurements.

One thing's for sure, I admire the patience you have to do all this work by hand.

Very interesting. Nice work sir

I noticed the same thing. just gauling from hard bits in the iron i think. the cutter profile has somewhat of a negitive rake angle so it's more of a push-out-of-the-way-er and on heavy cuts that leaves this scratchy finish.

I only get these scratches when I'm still pressing down on the backstroke. If I stroke forward and lift to go back I get no scratches.

The first thing I thought was that they were coming from the corners. Do you sharpen the blade with enough radius ? Also, not sure it’s the problem, those strokes look very long.

Gena, I have never seen a video with so much high-level technical information as the one you provide! Congratulations. I am a scholar and also a manufacturer of precision equipment for my own use in machine restorations. Your help is fantastic, thank you!

Definitely sharp corners on the carbide inserts edge. I've had the same issue I radius the edges very slightly

Why the AI voice

Дякую за відео. Можливо в направляючу шаржувавя абразив або стружка твердішого металу під час попередньої роботи.

Do you have any alternate ways to contribute, like "buy me a coffee"? 🇨🇦👍🇺🇦

I wonder if the blade geometry was like a planer blade, that is, so that the front of the blade "tilts back" from the surface. __\___, so that the "chips" from the scraping are lifted away from the surface...the straight blade ___/___ maybe actually encourages the accumulation of hard particles in front of it? As you noted, as the blade dulls, the particles tend to "roll under" the rounded edge, instead of being pushed ahead.

The cause for those scratches are sharp corners on your scraper and very long movements. Use shorter and no backwards strokes.

Gena, I wondered if you might get less chatter, or easier cutting, if the blade was at an angle different to 90° to the direction of travel, giving more slicing action to the cut, maybe some of the inclusions would not be dragged along with the blade?? As someone else commented, if the scratches are not a "visual" problem, and not deep enough to allow "dirt" to be embedded, then they may act as small oil channels...

Так я теж помічав такі глубокі задири при інтенсивному шабрінні, як на мене це якісь включеннія в чавуні, які тянуть задир.

The inclusions also depends on what part of the melt they used when they casted the frame ( the most pure part is in the middle of the container they used to poor the casting with. Since slack gathers at the top and the more solid heavier parts when to the bottom. Leaving the middle nice and pure) it also depends on how fast they cooled the casting since to fast cooling creates white cast iron/white cast iron particles/pockets ( which we don't want. We want gray cast iron) but also particle I'd they had stability ( so no sand parts/grane got discharged from the mold and is sitting in the top of the casting and the get dragged as it's scraped) and pre heated to a pretty high temp so it don't shock cool and gets to cool down as slowly as possible Maybe also try a Japanese style scraper ( there scrapers use there hips to deliver the force instead of the arms. Since the legs and hips are way stronger there is also more controle over the scrapping action. Plus they also have a even shallower angle of attack when they scrape ( about 87ish degree from the surface of interest )

The only time I've seen significant scratches is when I catch, accidentally, the corner of the blade (left-most, right-most sides of the blade). You are human, not a machine, you get tired, and once every now and then you press on the edge of the blade more than what you hoped for - you might get a scratch! You also insist on using extra flat blade profile on you blade, which gives you extra sharp corners to scratch with, with no excuse for error in blade control. I also noted that your hand scraper is a short one (really short!), there are hand control issues with that; longer-handled scrapers are a little easier to control and fatigue you much less, since you crape with your entire body, instead of your elbows. But that's personal choice, also you might not have room to maneuver with longer handle. My main/favorite hand scraper is almost 50cm (20 inch), as comparison. This is all from my own experience and observation. I have no scientific proof. As other people have mentioned in comments, and your ChatGPT research agreed, it might be harder cast iron chips sticking to edge of the blade, like to a magnet.

Soviet cast iron quality?

Interesting observation! While IMO the inclusion is the most likely , there could be two other possibilities too: grits from grinding embedded themselves in the cast iron, and the carbide slowly chipping and contributing particles.

Beautiful work, Gennady. I think you're right, inclusions of harder material

Tham you Gena 👍‍‍🌟👍‍‍

Iron carbides is my guess as well. I would also guess that, if viewed under high magnification, the scratches would point to rolling abrasion. This would support the hypothesis. As for the chattermarks - They are inevitable. They are also the reason why there must be an appreciable angle between the cutting stokes when scaping. It is to avoid exacerbating the chatter from earlier passes. love the videos, Gena. Much love.

Most of the likely issues I can think of have already been mentioned. But I'll add an unlikely one. Maybe it's a built up edge on the scraper. en.wikipedia.org/wiki/Built_up_edge As far as I know it should not happen with cast iron but maybe :)

if it is cast iron they will be very high carbon, crystalline iron. As its being scraped out of the main body of cast iron it is leaving scratches as theyre pushed through the iron rather than scraped out of it.

Большое спасибо. Полезно.

I too suspect it’s carbides . Cast iron tends to be inconsistent, and I’ve often encountered very hard embedded grains. On my Chinese milling machine, there were many hard grains . It was so badly machined from the factory that I had scrape over 1mm in sections . I made a straight edge from a cast iron street drain grate, and that was surprisingly a better and nicer cutting cast iron than my Chinese milling machine .

Так потом получается ещё и стол пришабривать.

Советский чугун непредсказуем. Не японский.

I would think that if you magnified the scraper stroke you would find a massive number of scratches, to me they would be considered oil reservoirs. Almost every machined surface winds up with long scratches and there not a deal breaker unless you are trying for a museum piece that looks unused

👍👍

The technique of long continuous scraping strokes during the heavy scraping will drag those inclusions along the entire length of the stroke. Shorter strokes during fine scraping liberates those inclusions faster. Try short strokes for the heavy scraping passes to see if the scratches are shorter. That is why you don’t see them with a Biax machine.

A possible reason that you see less of the scratches when you have a sharp blade is that the cutter is able to slice through some of the inclusions rather than dragging them. Good video.

My first thought was iron carbides. Cast iron has been described to me as something of a concrete made out of metal, with grains of much harder material suspended in a matrix of relatively soft iron, and most of it's higher carbon content resides in these discreet grains, but I'm no metallurgist. I've also heard that the shape of these tiny crystals have a large effect on the properties of the material, like the difference in fragmentation between white and grey cast, or with rounded nodules accounting for the workability of ductile iron.

In my experience, I've had noticed this phenomenon in mild steel as SAE1020 or SAE 1045, not only in cast Iron, but I never noticed it on Brass, and yeah, once I'm doing some machines, I have scraped lot of brass

Does Moore type scraping get around this scratching issue?

Impressive energy ..for heavy defects I use a dremel , easy to remove 0.1 mm per cut , just need to ink ( trace ink blue and touching blue) not the full surface to visualise abrasive ''touching'' and that less boring than scrapping by hand

Great. I didn’t get the graphite lubrication thing at the beginning and what is it for?

This AI talk sucks.