How Surface Grinding Works - Part 1?

funny thing happened on the way out to my garage this morning happens all the time really and by funny I mean not funny to keep these videos to a reasonable length I tend to cut out sections that despite complimenting the content I mean at least I think they do anyway otherwise I want to film them in the first place I tend to cut out sections whose absence might not necessarily take away from the story invariably I'll get a flood of questions about a particular aspect of a project that would have been addressed in the pieces that I cut that just happened in the to piece of I spilled video instead of getting into what I'd planned on for today opto acoustic levitation in the home shop please enjoy this never-before-seen footage about a guy who only bought a grinder yesterday talking to you about grinding okay no so this isn't the mill I just thought while the screws dry on the vise we could take a moment to answer a very popular question that comes up every time grinding is mentioned on this channel it goes a little something like this what they're asking in not so many words is if the wheel wears down as its doing its thing how on earth does a surface grinder get such flat parts and by extension why isn't the part slightly tapered back to front the premise being that the wheel wears by the time it makes it across the surface those are great questions natural questions I assume come from years of people grinding grooves into the face of the wheels on their bench grinders but what might really blow your minds is that surface grinder wheels are actually softer than bench grinder wheels I mean they don't have to be depends on what you're grinding but generally for hardened steel which is the raison d'être for surface grinders the wheels will generally be softer though frankly even hard and soft aren't that black and white when it comes to grinding wheels these things can get complicated just do a quick google search and see how many are available combinations of grits what the grit actually is made of what the matrix is how hard that matrix is how friable it is what color and flavor it might be honestly it's worse than making heads or tails of insert tooling let's have a close look at this wheel in particular the cutting face you see all that chromatic aberration see how it's all dirty and loaded up with metal that right there is the reason we got burn marks on the part let me dress it and I'd like you to keep a close eye on the fresh cutting face as it develops I'm using a little diamond nib to break down the glazed surface to reveal new sharp particles in the wheel see how it's cleaning the back part first and the new face is developing back to front well your intuition is correct the wheel does break down of course eventually you're picking up a small taper a front to back but maybe not as you'd expect okay one minute before I put this away a little safety detail I want to point out and I do realize at this point were three tangents deep in this video but I know I'd kick myself if I didn't bring this up this might be the third or fourth time I say this on this channel when I'm dressing the wheel or when I'm first coming on to a new part that I'm grinding I always come in from the trailing edge this grinder spins this way that might be the opposite from what you're used to seeing this is an old english grinder with the steering wheel on the wrong side in a wheel that spins the wrong direct no offense intended to our English friends out there now the grinder itself doesn't really care but the reason for working on the trailing edge is safety if I were work on the leading edge on the left side in this case again it might be the right side on your grinder if I made some bonehead move with the table while working on the leading edge it could suck the part or the diamond nib under the wheel that potentially could be catastrophic if instead I work on the trailing edge now if I make a bonehead move I mean it's still dangerous the wheel could shatter but the tendency of the grinder would be to kick the part off of the mag Chuck and not suck anything underneath it with that said let's grind a quick little part and cut to the chase okay I think we got a respectable finish there you know for Russian through it no burn marks at least but have a look at the wheel the wear mark for lack of a better description is quite small on the leading edge and isn't the whole face or edge I guess depending on your perspective when a grinding wheel is used this way words are hard the leading edge is what does 99% of the cutting or are the grinding the rest of the wheel still looks as fresh as when we faced it now granted this was a small part but where on the wheel progresses front to back since we're pushing the part in that way the rest of the wheel is still there doing final sizing I suppose although the wheel does break down it doesn't happen as fast as you might expect I mean keep in mind we're only grinding down I don't know a few thousandths at a time maybe five or six thousandths tops for this size grinder with no cooling on finish passes that might only be two or three tenths of a thousandth if you're doing big parts or lots of parts you do need to address the wheel every now and again of course and dressing the wheel does make it smaller not a lot but remember we're talking tenths on this machine so picking back up where you left off can be tricky and as part of the black magic that is precision grinding and while we're here maybe one last thing although it appears it's cutting on its leading edge sort of into the wheel you can't really do any heavy side wheeling that could be dangerous I mean I do it all the time you can probably see that build up in the side of my wheel but it's only for very light dusting of you know small vertical surfaces there are different wheel styles that can take those loads better than this one anyway the screws on the vise should be dry by now well given the non-linearity of time out here in my garage and in my video editing software not sure if that clip raised more questions than it answered but hopefully you found something in there you liked as always smell you later

Channel: This Old Tony

Views: 521,318

Rating: 4.9618406 out of 5

Keywords: surface grinder, norton 5SG

Id: npybvhWYklc

Length: 6min 13sec (373 seconds)

Published: Sat Aug 04 2018

Reddit Comments

[u/MpVpRb]

Agreed

Also Abom79 , oxtoolco and mrpete222 are great

And, if you like quirky, AvE is a bizarre mix of "Uncle Bumblefuck" ineptly hammering on shit and then switching to extremely enlightened and insightful comments on engineering, ending with the line .. "Keep your dick in a vise"

[u/v150super]

TOT is always entertaining a great combination of informative fabrication, and all the dad jokes you can handle. For the ultimate in machining porn, I have to with Clickspring. That guy is just on another level.

[u/nikolaiownz]

as an old machininst... this old tony is just pure entertaining even thoug you already have skills for the trade.

[u/okacookie]

Keith Rucker's channel is good for machine rebuilds of vintage American equipment, and some machining and repairs.

[u/r0773nluck]

Love this guy

[u/fabbricator]

for more grinding content: solid rock machine shop

robin rez.