Parallel Fail! We goofed! Machining & Grinding a 24" Parallel. WW129

[@HughesEarthworks]

Paul is very good at explaining his process. Thanks for sharing John!

[@ello-mz6om]

Do you know Demmeler from Germany? They are pretty big! They make their own Tables and have more than 20 CNCs

[@ello-mz6om]

dei muadr

[@MrLembnau]

my mother used to run a grinder back in the day. she told me that the first thing somebody new in the shop learned is that if somebody yells, you go head to the floor because 90% of the time when someone yells, a part is flying at mach 10 trough the shop.

[@Gottenhimfella]

Just a tip for others: when machining cast iron, it pays to take a sufficiently deep first cut to get well under the skin. It can be really hard on tool edges otherwise. (It's abrasive due to the sand content, and sometimes hard due to rapid chilling). The glazing might have been partly due to the failure to take a deep enough cut, as well as the high rotational speed.

[@ruthpenner6995]

John, talk to and video with this guy every chance you get. He's got the knowledge we want.

[@willw.2294]

I have done parts like you are doing. Since you are starting with a rough casting there are surface stresses within just from the casting process. We would machine all 6 surface and then let it relax a couple weeks outdoors to experience hot and cold or send it out to heat treat it to have it normalized; which is not the same as annealing. Once ready to work on it, begin the grinding using light magnetism or residual magnetism with blocking, just like you did, and grind the working sides and ensure they are square and parallel to each other. Then hand scrape the surfaces to remove high spots and to produce the extreme flatness (less than the .0001" on the indicator), squareness, and parallelism and to create the microscopic pockets so they will hold marking medium (prussian blue, red lead, alcohol, etc.). A parallel for clamping and machining doesn't really need scraped as a ground parallel is going to be close enough for most machining work. Part weight and clamping will also flatten out the parallel's small amount of twist. Where I work, the scrapped parallel is usually a tool for inspection. The ones you find in the catalogs with half moons-scrape marks are for making them pretty; not flat and more accurate. Seeing the scrape marks makes one think it is a precision tool. The Starrett Master level is scraped to make it super flat and to prevent the level from vacuum or wringing itself to the part being levelled. Thanks for sharing in your video.

[@grahamsengineering.2532]

Hey dude. I'm writing this only 5 minutes into your vid. Know you have learned from your mistake which is good. In Australia we call this soft footing. Very important to use the flatest face if possible and then most importantly befor clamping is to shim the work piece or set on Machine Jacks depending on the job. Then you can proceed to clamp it down using a Dial Indicator at each clamp to check for Deflection. Same deal when levelling say a Lathe. You level on three feet first so you don't have soft foot. Then bring the other jacks down checking your levels for deflection so you only just take the weight without twisting the bed of the machine. Levelling things is an art in itself. Happy Machining.

[@FredMiller]

What an Awesome adventure! Thanks for taking us along! Fred

[@jschoenly]

Cabin Fever! Thanks for the shout out John! Hope to have you back sometime! Great to see Paul this weekend as well. Great show and still recovering! Keep up the great work!

[@thunderthormx]

I'm really digging the glasses at 6:50. :P

[@caseyknowles9587]

Great video John...really like seeing different people in their element. Older guys with generations of experience are way cool.

[@christopheronstott2358]

Those gauge blocks he showed you are the bomb !! I use them to set up my bore mics or bore gauges , but let me tell you they are pricey , but they are awesome!!

[@shiro-r4m]

Your glasses are fabulous

[@TomsToolRoom]

Excellent video on grinding a piece "flat"....................It gets super challenging when you grind a really thin piece!

[@broheim23]

John, that is the most informative video I have watched on surface grinding. Thank you for taking the time to record and edit the footage so we can learn from your experience. 👍

[@randelljones4002]

Assumeing that is a raw casting you had made it needs to be normalized before Machineing and or grinding. It has to relax it's internal tensions from being poured. Put it in the oven at 500 degrees for several hours (after supper to bedtime for example) to relieve the stresses. Hope this helps some, keep up the good work

[@drawvenmusket]

Hay Jon, enjoy you class and enjoy the time with the others there

[@thehollowbox]

A tip I've learned for cast iron is to throw a couple of fridge magnets around the mill or lathe. It catches the dust and helps prevent it from getting in your machine.

[@63256325N]

That grinder was fantastic. What a tool! I want one just because....thanks for the video John.

[@Miseries_Company]

Thats good that you know your limitations and take the advice from specialists.

[@Sicktrickintuner]

Very cool video, never knew so much went into grinding. And warpage I have ran into many times from heat. Welding a table to weld parts on, burned in one side and had it all clamped down and went to pick it up and the 7'x3' twisted like a corkscrew and turned it into a teeter totter making opposing corners lift by 8"! I had to stand on it, and it sprung flat, burned in the other side and clamped it to my frame. Crazy how 3x4x 1/4" angle can bend so easy with bracing through the middle of it all.

[@Steve_Just_Steve]

Wow John, this maybe my fav video you've done, but I love grinding. Paul is obviously extremely knowledgeable and seems like a super nice guy. What a treat to be able to get expert help like that. You should talk him into starting a channel lol. That'd be awesome to get some more surface grinder info in addition to the great content from guys like Stan and Rob. Thanks for sharing John.

[@davidsomething4867]

Takes me back a few years when I was starting in tool making. We had a surface grinder about the same size which I used to use occasionally but mostly used a smaller surface grinder. A work colleague made the mistake of powering down to a diamond dressing tool but the power down locked in place. Never saw anyone move so quick, the dressor held on the magnetic chick but the wheel had a nice groove half inch deep, lol. I was working on the small grinder behind him at the time. Used to do all sorts of thinks like relieve the sides of the wheel so we could grind the stops and other various parts. My favorite task was using a cutting wheel and going through 20mm injector pins in one cut.

[@tylerjones6043]

The brass hammer on a bench does the trick too!! Never gets old.

[@Stephen1455]

That is a brilliant way of describing the twisting of materials John, always had to try to use my hands/fingers/draw a picture, but that is top notch!!!

[@MrCrispinEnterprises]

Hi, You may be interested to know that on a grinding machine such as that the Z axis is actually backwards and forwards, Y is up and down and X is left to right. The spindle orientation normally dictates which axis is which. Cheers. Crispin

[@zedex1226]

NYC CNC the Z axis is parallel with the main spindle. vertical mill, horizontal mill, grinder, horizontal lathe, vertical lathe, doesn't matter. now use the left hand rule with your thumb being the z/main spinle. the longest axis of travel is the x (middle finger) and shorter axis is y (index finger). A rotates about the x axis, B is at 90 degrees to A. there are very few exceptions to this (some machines with oddball work envelopes such as gantry mills will sometimes change up their axis labels with more travel in Y than X)

[@nipz8053]

I left my mark on the back of our surface grinder at work. I completely relate. Great video.

[@landonmiller245]

My favorite video from you! So interesting. I'm a machinist in high school. I have to take a precision grinding class for my automated manufacturing engineer degree and now I look forward to it much more!

[@flatheadronsgarage7345]

The guy is a master. Your straight edge will be a work of art when completed, I'd be happy with it now though. Recently picked up an Abrasive 1 1/2 myself and looking forward to doing work similar to this when it's going, Putting 3 PH in now, Excellent video Sir... Thank You

[@RangerM98]

A thought I had to automate the magnetic release based on hold down power vs spark/sparkout level....could really create accuracy, precision and repeatability as well as not having to rely on manual ability / expertise....CNCs are awesome!....some day I might get around to making some sort of program for that idea!....thanks to everyone involved in this video...it truly was awesome and insightful!

[@TheNemosdaddy]

Enjoy watching your videos. I'm in Cleveland, nice to hear you're close by. Keep up the good work and have fun at the scraping class!

[@sliccreations]

I'm really looking forward to any videos you do on scraping.

[@bstevermer9293]

A camel back straight edge is much wider and has a relief angle cut, so you can spot into dove tails. A large parallel like what your making is very useful.but not as a spotting transfer gage for tool rebuilding. I've found when using a Bridgeport, the table will flex the farther you get it out. The saddle is actually very small for how fare the table can travel . Looks like fun, Richard king is A character you will love the class.

[@matthewcolvin4815]

Really liked seeing the learning experience! Relaxing the magnet is crazy!!

[@billgreathouse1913]

John you are a great student to your trade. You are proof that school ain't just about tuition. I look forward to your videos every week. those jo blocks that you were shown, the first set, I have seen them bought new for Pratt & Whitney at the low price of $11,000. No...... the coma is in the right spot. that being said, I've also seen them for as low as $2500.

[@user990077]

Fascinating. I always learn so much watching your content.

[@BradPow]

cast iron sparks out forever. and it's springy. I spent 5 years in a grinding shop and had lots of flattening jobs for cast iron. a fun challenge at times

[@BradPow]

NYC CNC not normally i find. it depends on the finish needed. ive sparked out mild steel for over an hour with a .003" crossfeed for a satellite imaging part. And I've sparked out parts for just 30 seconds.

[@BasementShopGuy]

I believe that the irregular design of the hump back better prevents movement from temperature fluctuation.

[@ntdanny]

note at the start of the grinding the dull orange colour of the sparks that cast iron gives off whereas steel gives off a brighter more yellow spark, you can use this as a way to identify cast iron from steel if you are unsure what you have.

[@JuanRamirez-kt1se]

John, I enjoy your talks on Fusion 360 use so much that I resided to venture into machining. I guess I am hocked. Thanks for the work you do and honoring your grandfather. Keep up the good work. By the way, my birthday is coming up it will be 77.

[@arnljotseem8794]

what a cool friend to have around.

[@anthonyambler9688]

I spent a day as a apprentice trying to get a casting flat doing the exact same thing kept clamping the twist out only for it to come back when realised. One of the old timers took pity on me in the end and showed me how to shim using a indicator so your just getting a tiny deflection when clamped down

[@mikeingram3186]

You should have put the piece on a surface plate after you have milled it. While on the surface plate you use an indicator and shim stock to make the part sit flat. You mark all of your shim stock locations then transfer the shim stock and the part to the surface grinder and turn on the magnet just like normal and grind the piece. In. Once the surface sparked out check the part on a surface plate re-shim and regrind as needed. Doing it this way will allow you to see how flat the part is while not being chucked up. Do note that you only have to shim one side and when you grind the second side there should be no shim stock.

[@WatchWesWork]

That is how I would do it. He didn't help anything by attacking it with that Bridgeport.

[@deeremeyer1749]

You should try learning the differences between "flat" and "level" and "parallel".

[@stephenmcdaniel1941]

Nice vid! On warped or irregular parts I like to use a couple screwyballs (outsidescrewball #16) under the part, and then clamp it to an angle. It keeps the part from getting sucked down on the chuck.

[@dannyoktim9628]

Nice webbing on those parallels, may I suggest if you ever make them again have the webbing stop short about 2 inches from the end. This will give you enough room for a half inch bolt down hole when you need to secure them to your work surface. Good point out concerning the placement of the diamond on the surface grinder!

[@tallbrian100]

Back at my first job I ground 14' stright edges. 1 tenth per foot was the tolerance. They took about 9 hours each to grind. They sold for $4000 each in 1985.

[@craigs5212]

John, thanks for showing one of Paul's catalog pages in the video. I just ordered one of his tramming rings. Been wanting one of these for a long time -- nice coincidence. Have fun at Kieth's don't get too blue.

[@MyShopNotes]

Learn every day. That's where the fun is.

[@TomWalterTX]

There is more learning in this video that I had every realized. Thank You & Debolt Machine. My mind is racing this morning, great stuff! Lautard, in one of his Bed Side Reader Books, shows how to inspect a surface plate. Great tip when buying used (If I ever move, how the heck will I lift that 300# thing!)

[@xanokothe]

I am starting to undestand why grinding is more precise than other methods. The grinder is basic just a wheel, so the contact surface is smaller and average by itself. The table is the thing that moves making it the center point. Really interesting.

[@Keith_Ward]

All of the grains in a grinding wheel are just really tiny cutters that remove really really small chips. Much smaller amounts than anything else could cut, therefore much more precise.

[@samclarke161]

As well grinders you only take off tenths at a time or risk parts flaying off the mag. Seen a few guys do it, scary as hell as it becomes a bullet.

[@deeremeyer1749]

If you don't get that "grinding" is the least precise "machining" process possible because the grinding wheel is constantly shrinking and professionals in the field will only at most claim their processes/machines will "hold" a "tolerance" (as opposed to ACHIEVING A SPECIFICATION) of .001 then you're clearly a noob fool who like all the other noob fools has no clue how stupid all this "precision grinding" propaganda is. Precision grinding HISTORICALLY was NOT and still IS NOT for REAL MACHINISTS a "machining" process and was/is only done by PROFESSIONALS to achieve a certain SURFACE FINISH on "non-precision" parts. You won't find a single surface grinder in a real machine shop equipped with quality machine tools operated by real machinists. They're only needed by fools and noobs like NYC CNC here who fuck up the original machine work with improper process and/or crappy tools and need to "fix" improper machine work with a "pretty" surface the clueless "customer" will think indicates "precision" and "accuracy". Some TURDS CAN BE POLISHED AND THAT'S WHERE SURFACE GRINDERS "SHINE".

[@zachaliles]

DEEREMEYER1 show us on the bear where the surface grinder touched you.

[@TINRFD]

Yeah, surface grinding is more about the "feeling" and hearing, than dialing in a value...learned that in the past, too.

[@titus142]

Those are some sweet ass safety glasses.

[@papahajek5383]

Table droop can cause the high center from milling to grinding. Just depends what you are seeking as far as over all tolerances and what you are using it for.

[@waynep343]

i just imagine your shop in a few weeks with machinery all torn down while you scrape the ways to perfection. got to get your surface plate lapped though. loose machinery bugs me no end. but it cannot be avoided sometimes.. thanks for a great video

[@lawrencekimmel352]

I always loved machining cast iron.

[@sbirdranch]

Joe Blocks! I have an old set of these with Pratt and Whitney's name on them. Didn't expect to get that out of this video. Big thanks to Paul.

[@GeofDumas]

wow! that fine feed would come in handy so often. what a nice machine

[@GeofDumas]

NYC CNC can't disagree with that. I just mean for the sake of speed. that kind of adjustment can be done on my old Boyer Shultz but only slowly and very carefully

[@occamssawzall3486]

NYC CNC Ya. But give a carpenter a crappy chisel, bent nails and broken hammer and I don't think you're gonna get fine cabinetry... The quality of the tools are still essential.

[@Gkuljian]

Speaking of scary grinder stories. I had a machine tool instructor who was working on a grinder with his teacher, when the wheel exploded and took the guys scalp off, killing him. Well one night when I was working in the tool crib, sharpening endmills, we went out to the grinding room to cut off the end of a milling cutter, and just as that short piece of endmill came off, it wedged the wheel, and exploded. We looked at each other like some ghost had just passed by, and decided to let him live another day.

[@jonburne]

I love these videos where you show where you goofed and how to you came to fix it. Keep up the great work and never forget; everyone goofs, it is not just you ;) .

[@nder12345]

ice one John. Its a pain in the ass to get castings parallel. I cant wait for the scrapfest footage I attended a 2 day scraping class here in Australia unfortunately we couldn't afford to fly richard across the pond. I assume you did this before getting your new grinder. One tip is place a thin rubber sheet under the job between the magnet it helps it pulling flat

[@titter3648]

Clamping the ends with some sort of cam action clamp pressing against each other on each end will probably get rid of the twisting problem. But then it will have very little sideways holding force so you need to use minimal tool pressure if you are going to mill it.

[@andrewgiles6192]

John rocking the 70's disco safety glasses :D

[@zed65656]

Glad it turned out ok in the end after all.

[@davidbird4771]

If you run a cupped length of wood through a thickness planer, the rollers flatten out the cut and the blades remove a thickness of material. When the stock emerges, thinner, but still cupped. You have to flatten one side on a jointer first and then thickness the material that is flat on one side to get the other side flat and both sides parallel. When you took the twist out of the parallel with the clamps or magnet, you did essentially the same thing as thicknessing a cupped board. You should have shimmed the piece stable on the table without changing the shape or twist and the first grinding of the top side would have flattened it and then could have been used for reference to flatten the opposite side.

[@SIMIKINGMOTO]

Man this safety glasses at 6:48 LOL :D

[@Mtaalas]

This is a great video, young machinist learning from the older and experienced one... :)

[@bigjarn]

The hump back is a definite purpose flat straight surface used to check lathe ways and other machine surfaces.

[@cavemansmancave9025]

So funny. I was going to ask you for Paul's name. I couldn't remember it and misplaced his business card. DOH! We have a few small one off parts to get turned around quickly. I got busy (I was at Sam's shop) and didn't get to ask and here it is. So, thanks. 😊 John

[@sblack48]

Regarding a camelback vs a parallel is that the camelback is much deeper. Stiffness is proportional to the square of the depth. The rib is going to be thinner on the camelback than the 2nd parallel side so the whole thing will be lighter and stiffer. If you are working in scraping all day everyday that parallel is going to be exhausting to work with. Also, I think if you use that parallel in the shop for mill setups etc it will not keep its precision. A precision straightedge should be used for scraping and otherwise kept in a box or otherwise kept away from dust and chips. And my Grandma had glasses like that! Great video.

[@namecollision]

The reason for the "camel back" straight edges is to prevent them from bending under its own weight. Things you think are solid, aren't. Rich set up a bridgeport table on a work bench and indicated it with his KingWay tool. Then he had all 10 of us stand at the other work bench. Our weight on the concrete floor was enough to move the indicator a couple tenths. We were not touching the workbench. Your parallels are so nice and flat it will almost be a shame to scrape them. Then again, scraping them to exactly the same height will be challenge. A fun project for me was doing a 6" angle plate. It took awhile, but I got all surfaces flat, parallel and perpendicular within a 2~3 tenths. It still amazes me that can be done with hand tools. Andy

[@chrisstephens6673]

Indeed, a camel back and a parallel have different purposes. In short, one is a straight edge the other is for packing.

[@larsmark]

Haha, I just love those old lady glasses you have at Pauls shop 😅

[@brucec954]

Interesting "parallels" to wood working (wood typically has lots of twist and movement). Normally you start by jointing (never heard of a metal jointer), and then make it parallel in a planer. However, when you have a board wider than your jointer, you shim it on a thick flat board and run it through the planer. So I would think you could easily shim it on your Bridgeport table and then mill it.

[@gordo3di]

This is a really cool video. I'm loving just learning more.

[@TomMakeHere]

I've got a lot to learn about grinding Great video

[@JasonDoege]

Shimming seems like one option, but I think that if you clamped it properly you would not clamp out the twist. Put a piece of copper wire across the parallel under one of the holes and copper bb under the other hole and clamp down on the holes. Basically that would be 3-point clamping that would introduce no new, nor take out any old, twist. That would allow you to fly-cut the existing twist out of one side and then you could clamp normally when you fly-cut the other side.

[@CalebKraftmakes]

I've done hot glass and had to deal with the stresses and relaxing that happen as it cools, I never even considered that it would be an issue with cast iron. I guess it is pretty much the same thing though.

[@chrisstephens6673]

Not just cast iron, ordinary rectangular cold rolled mild steel will warp if you only machine one side.

[@johnhomeyer2093]

Stress relieving will really help out on that

[@giuliobuccini208]

There was no way to clamp the piece at both ends hanging it "on the air"? Maybe some 123-blocks with screws pushing at both sides of the vertical faces of the bar? (I.e. applying a transversal force at bar's ends and keeping it lifted up from the table surface).

[@mikenixon9164]

Good video John is this what caused you too buy a grinder?

[@886014]

John the reason for the camel backs is because they're stiffer per weight. You mentioned several times the weight, now imagine lifting that weight on and off a machine dozens of time to spot a way etc. The other thing you will discover in Richard's class is the effect of heat and just how much metal moves. Scraping is a whole different level of precision. Sorry but I only really post videos on KZbin to pass them on to people I know, but on my channel you can see a short 18" camel back I scraped "flying" on my plate. My 3' camelback won't quite fly because of the tolerances in the plate, but it comes close. Yes yes I know, I need to get decent videos up! Paul did a very good job of grinding that parallel. Now the bad news. It didn't need to be that accurate before scraping, and you could have taken out than wind with a Biax in relatively short time. Rich will have a Biax (power scraper) to show you in the class. Also the first thing you will do is scrape off that nicely ground surface before it even hits a plate. A well ground surface won't spot properly and will be just one big useless smear. The chances are Paul got them so close you won't do much scraping on those parallels, so you may want to take a smaller piece of cast with you and practice scraping it square. Rich should be able to show you how to self-prove a block to extremely square on all sides using just a surface plate and dial indicator. Good luck with the course, enjoy it, be prepared to say "wow!" a lot ... and say hi from Pete in Oz.

[@886014]

Good idea John. However you have a very good eye and hands, and an attitude of perfection, so I think you'll pick up scraping very quickly. To be honest I know even Rich agrees that basic scraping isn't very hard. But scraping to alignment is another thing entirely and much more difficult. So if you get a chance to scrape something to square (for example) try to jump at the opportunity even if you personally feel you haven't fully mastered the scraping technique. Scraping well is just practice, but getting shown how to then align something is gold. A cheap angle plate makes a good crash test dummy.

[@bcbloc02]

Machining gets you close, grinding or burnishing gets you real close. :-) Your parallels were likely fat in the middle from the knee rocking on the Bridgeport. Holding less than .001 over several foot length on a knee mill can be a real challenge. I did a video about that called "how to do precision work with a worn machine"

[@occamssawzall3486]

bcbloc02 How much of that video has to be cut due to cursing? Lol

[@motormaker]

John. That surface plate is filthy. My mentor would have kicked my ass back when I was an apprentice if I was checking parts on a dirty granite plate. Any metal transfer or oil, or grit, or plain old dirt will make your job harder than it needs to be.

[@zedex1226]

it's so much nicer to use when it's clean. height gauge and gauge blocks glide like air hockey pucks and don't stick or jitter anywhere. I clean "my" knock around shop floor granite with rubbing alcohol and a paper towel at least once a shift and comet once a week.

[@colinsmith1410]

This is what I love about your videos John, I always feel like we are learning at the same time. Still trying to get my head around the twist in a cast part. Very interesting stuff. Keep up the good work. (nice T-shirt by the way ;) )

[@siggyincr7447]

For something that is supposed to be extremely accurate, you would have wanted to stress relieve it after casting. No idea if this was done, but it would have eliminated most movement due to machining. I've heard that you could also increase wear resistance and speed up the aging process, normally high precision tooling needs to sit for months/years to reduce residual stresses after any sort of heat treat, by cryogenic processing, essentially cooling the thing down to some extremely cold temp with liquid nitrogen.

[@Awesomeman1987]

the accuracy of that machine is so friggin insane. it was like 10 passes for like 2 thou. jeslus

[@mistijim]

Sweet safety glasses.

[@wireflight]

dude, if you started filming this video in your at-home shop, wow! that's totally sick! and if you got lucky enough to film where you work, well that also awesome. keep the vids coming; I don't have that sort of resources (yet?) but it gives me a better idea of what I need and how to achieve the results I want.

[@paultavres9830]

I had a 1966 chevy truck with 283 V 8 We rebuilt the engine and found the block was a buried aged block that chevy aged buried before machining So the process is not anything new There is a lot you can learn of old timers I spent 10 year in truck manufacturing (working in machine shop body shop mechanic depts ) was like going to college for 10 years while getting paid Then became a apprentice truck technician Were I spent 27 years I learned a tremendous amount of knowledge from others machining engine blocks building engines machining parts building drive shafts electrical trouble shooting becoming a bumper to bumper technician (now retired for 10 years and still getting paid ) Funny thing is the older you get the more you realize what you learned from others

[@aly-tek7190]

Awesome. Perfect timing, I am just bidding on that exact same surface grinder :D

[@OleTheRealG]

we had the very same at school, its great! At work we have a newer model also :)

[@h2opower]

Get some glass for the table for the end checking as they are nice and flat.

[@lincolnmetal1]

threw a large piece of 4140PH, about 3 pounds, on a surface grinder...turned the magnet off to check the flatness, got a little distracted and forgot to switch it back on...earned an arrow pointing to the dent on the back stop with my name for that one...the worst part was balancing the new wheel, took forever.

[@Stephen1455]

We did it differently, we ground a warped/bent part with reduced magnet strength, but you had to use the highest blocks and be on all 4 sides? I even did a thing my boss called float grinding, a plate on 4 ball bearings with magnet and full blocking scared the hell out of me!!

[@jessefoulk]

wow. I enjoyed this episode.

[@JimTaylor42]

For parallelity, after grinding one side flat, is it best to turn the part end-to-end when the other side is ground, or not.

[@SpeedOfDark186Kmps]

I wouldn't clamp the thing down from the top. I'd use a vise. Of course, it's likely that it would still cause a similar problem without shimming though. Beautiful parallel. No doubt that it will get used.

[@cheeto4493]

My first thought was if it could be mounted by the holes in a way not to induce twist (maybe between rubber pads). and then machined very lightly. Understanding lightly to be so little pressure not to induce a wave across the part from the hanging points.

[@Cinnabuns2009]

The first place you start with something coming in to the shop for machining/grinding that is unqualified IS the surface plate. Especially if the part is long, cast or anything thing else that can introduce a lot of variables. If your surface plate is no good... well... that's another issue entirely.

[@alby2317j35]

the Superfly insert is a sumitomo? that coating is for cast iron . for steel of P class sumitomo have"acp200" for materials under 700n/mm2 and "acp300" for harder materials ... "acp300" works well in stainless at half cutting Speed required for normal tool steel

[@chrusb7765]

If we had a surface grinder in a open shop like that, here in Los Angeles county, California, the AQMD and CAL-OSHA would have us closed until we had a grinding room built. LOL

[@johnhomeyer2093]

Lol that sucks

[@cornnatron3030]

lol love the fancy designer glasses .

[@niceandcloudy]

DeBolt is the man. You are too Saunders...

[@RangerM98]

AWESOME video content Bro!...thanks

[@jeremys5904]

Basic woodworking knowledge that is just common sense...to me at least.