Dial N for MORE Air File!!

please don't be alarmed there's been a bit of an incident here in the garage not exactly sure how to explain what happened but here we are here here we're over here now no one needs to hear about personal drama so let's just try to get through this and move on shout fortunately I've managed to retain control of the human so let's jump right in quite a few viewers express their mild disappointment with me not gone all the way with this thing being a tool tease so succumbing to peer pressure the air file is back on the bench so let's break this thing down we might just find something really exciting inside no I really doubt it and that's why I didn't take it apart in the first place but you never know who's watching right I'm pretty sure it's just a dumb slug of metal with a bunch of holes in it this thing has literally one moving part or does it let's find out despite walking like a duck and probably quacking like a duck this isn't meant to be a tool review or breakdown per se that's effectively what we're gonna be doing my intention is to take it apart and if I understand how it works myself walk you through how it does what it does or how it doesn't whichever the case may be the parts in this error file are all assembled in from the back I know that for two reasons first the body is one solid piece of cast steel and only has two openings on the two ends second there is an exploded view in the manual it's small though and the details are a little hard to make out but you can see all the dashed lines come out the back now the fancy two positions slide switch is just that an on/off switch and how they implemented that is more intriguing to me than the actual filing motion how is it held in place it's just floating on the outside with no screws or cross pins or anything apparent and it appears to be one solid piece metal it's not a plastic switch it might be obvious to some of you tool Tech's out there but I'm not exactly taking apart air tools everyday to have a look at the general shape and function of the tool in particular this law hump in the center so it makes sense to me that once air comes in the back of the tool when it's allowed to pass by that switch it flows to about the center of the body of the tool where then it's diverted either to the back or the front of the air file clockwork to make it reciprocate air comes in the back past the switch to the center where it gets flipped front back front back front back front back until the end of days or you run out of compressed air whichever comes first the tool is off when the switch is in the rear position you can almost think of it like this which is a cork when it's uncork to the air can get through and when you cork it the tool is off but if that's the way it worked as soon as you put air pressure in the back it would just automatically open the switch for you so that's clue number one the air has got to make some kind of a bend through the switch otherwise you're always fighting the compressed air when you're trying to actuate it second clue came from actually using the tool the switch it's got a bit of a rock to it the inside of this if I can get this apart is sort of a very basic shuttle valve sorry about that I was trying to build the intrigue maybe above and beyond what was warranted for an air switch still kind of cool though here comes in the back and can only exit out of that first hole there's not a through-hole here in order to get to the tool it's got to get out of that hole across down into this other one through the rest of this stem and then into that port in the back of the tool there in the back of the switch pocket when the switch is on here in the off position it covers the rear supply air and when it's on it bridges the gap air can come in up and over and fed to the tool there are a couple of or ings in the black switch body let's get into the rest of the tool on the back immediately below the air inlet is the exhaust port the exhaust port has a plastic cap on it that you can swivel around this cap serves to direct or deflect the outlet air the exhaust air is just a little opening here in theory you can rotate it wherever is most convenient going use this thing effectively gushes air straight out the back that opening does a bit of deflection but not very much and it just pops right off I know that because at least in this particular specimen that thing's been popping right off right behind that cap is sintered bronze mesh like a muffler and an internal snap ring holy Cate when things do that okay so there was a cap snap ring the muffler a booby-trap spring another spring up at the front then I suppose this is the cylinder the ported cylinder got holes drilled all the way around in matched sets to here to around a center hole to here and then one right in the middle all right that's a like a roll pin spring pin so the piston is in here I think we can get that out the back the second roll pin and less precision looking back cap this one looks like it was ground with the rope and installed roll pin is almost hard to see and that's where the file is installed the set screw and there's a key here to keep that file I guess from rotating there's a key up at the front pinned in place it's a pretty good fit so I think the key does primarily keeps these ports aligned so the piston can't rotate inside of the housing and I guess keeps your flat files from rotating bronze mufflers by the way serve a couple of purposes first I think is pretty much the same function it would do say in your car helps keep the noise down from compressed air tools it muffles sort of those pressure pulses and second I think they're meant to filter some of that oil out of the air stream so you're not working in a big cloud of nebulized oil you may recognize these more in this form if you work with air stuff same thing sintered bronze these just happen to be on a pipe thread I think that's an NPT thread now granted I'm easily entertained I've always found sintered mufflers like these to be a little miracle of science it's essentially a lot of very precise or you know relatively precise Braun's spheres in this case that are put into a form and then heated so they just begin to melt on their surface and sort of fuse to their neighbor that results effectively in a mesh like the space that's left between those balls serves as a filter and that's very well controlled I don't know why but scientists and engineers are very good at making very precise spheres I don't know what these are but I think they're usually rated on the order of microns 20 40 60 micron filter size now maybe you can see this one on the right is dirtier darker it's got a lot more oil trapped in it I was just in my parts bin it's probably time to throw that away maybe wash it but probably throw it away and this one is brand-new you know what that's not that oily hmm okay hold on just one minute I feel something starting to happen in my brain they may be dim but some lights are starting to come on so here's the piston that came out of there you know what it's not that oily what are you doing here something wrong do not run that a father ninety-one psi oh I'm sorry Chris but that already happened deterministic paradoxes no matter what you do you just cannot avoid the tragedy no no not that I mean it happened last week you got the timing wrong so I hate to bring it up but why you a cat does it does it really matter Chris good point take it easy so no I didn't directly oil this tool some of you caught that in the last video and while you're stinging laughter subsides allow me to explain my garage has two air lines running through it one wet and one dry let's say it is out of my compressor the line is split it goes through a moisture trap and it then splits into two they each have their own regulator but one has an inline oiler the dry line with no oiler is used for general shop air pneumatics projects when they happen and occasionally for the Sprague or painting the wet line with the oiler is for air tools it's also the one I give my neighbor when he wants to blow down his lawnmower and new sneakers now here's where I'm going with this this air tool has no seals the piston and cylinder are hardened in ground so they're relying on those machine services effectively for their air seal now apart from the burr created by the cross pin this thing is a nice fit on the inside nice fit however doesn't really tell us anything so think of it this way it's got to be a close enough fit for the tool to work but it still needs some clearance so the parts actually move when you have a running clearance like this to allow the parts to move well you also have gaps for air to get around this thing needs oil to help fill those gaps I mean it lubricates the parts of course keeps them from rubbing and wearing out but I'm sure it goes a long way to helping with the air seal and although these parts do have a light film of oil on them I'm willing to bet that this thing wants a lot more here's what I'll do once I have this thing together I'll try dripping oil straight down into the inlet and see how big if any difference it makes for now though let's take a look at how it does its shimmying and its shaking now how on earth am I going to walk you through this life sure was a lot easier before they started making three-dimensional tools fortunately since this video you're watching on your screen has already been converted to a 2d representation of a 3d world we might just be able to pull this off you just pause and think about that for a moment would you you're going to have to know a few things simultaneously to get how this works but trust me it's very simple since I'm already holding the piston let's start with that since I'm too lazy to put it down and pick up a different part the piston is cross drilled or a cross ported the holes that you see on the ends that one and that one are connected to the opposite end faces there and there if air makes it into this hole on this end over here this is air this isn't air if air gets in this hole over here dang it it comes out the opposite end same thing for these two pair holes please don't make me run another wire through there so when air comes through these ports on the outside of the cylinder makes it through and into the piston its ported through that hole on this end and out the back turns the piston into a little bottle rocket and shoot it over to this end here the piston is going nice and fast slams into the end of the cylinder which pushes the cylinder in the same direction now that this piston has slid over this port can't get any air and all the air coming in through the cylinder it goes through the other hole at the opposite end that one there which ports it through the back shoots the piston back the other way slamming into the back of the cylinder and driving the whole mess backwards a little bit now of course in this more newer position the air to this hole is cut off this port is revealed air now coming in through the cylinder goes back through across the piston shoots it back the other way slams into the top of the cylinder wall pushing everything forward a bit etc etc and the vicious cycle of life continues so much like my wife and I the piston and the cylinder have an unstable arrangement the holes in the cylinder and in the piston are arranged in such a way that when the air pressure comes in it's never quite happy and it always wants to piston to be on the other side of the couch and when it switches sides the air is still in it happy and wants the piston to go back to where it started that goes on all night until it's out of hot air wait coincidentally some may say fortuitously the files are attached to the cylinder so whenever the cylinder gets a hit either forward or backwards from that piston that's just bouncing off the walls in there at going ape that force is transmitted to the file and the file goes back and forth to so that's basically the whole story right there just to be safe a few more lashes to ensure this horse is really dead the piston isn't keyed to the cylinder it can rotate however at once King it would likely cause it to bind the grooves you see cut into this thing serve two purposes first it lets the air get to the ports no matter how it's turned around inside of the cylinder the area between these ribs fills up with air and the ports are the only way in or out second there is less surface area between the piston faces itself and the inside of the cylinder let's take a quick look at how the air makes it through the air file body itself through the cylinder walls to the piston and back out again and when I try my best here but I don't know how well you're gonna be able to see down inside of this thing but we're looking in the back of the cast body of the air file the proctologists view if you like that's the threaded port where the air line at just feeds into the switch and up in the ceiling there is a small elongated port which would be the air into the whole mechanism once the switch is turned on down at the end maybe you could just make it out is the key that keeps the cylinder from rotating there is nothing on the floor and there's too long exhaust slots that come out the back towards where that air muffler was so keeping that in mind what we just saw let's take a look at the cylinder body again to get our orientation straight there is the slot that rides in that key so this is key to the body of the air file in this position unlike the piston inside of this this can't rotate so let's call this the top side this is where we saw that small elongated Port air can now get into the cylinder here and feed the piston on the sides there are exhaust holes there's two sets of two their top two sets of two there that align with the long exhaust grooves that we saw these allow air to escape from inside the cylinder so the piston can actually move into that position now maybe interestingly there is a single hole on Center at the bottom you may be wondering out loud well this old Tony what does that hold for well that's why we're talking about this part isn't it let's go back to the top so you just bought yourself an air file your compressors ready to go and you plug in your air line you may or may not have oil dip beforehand you flip on the switch and the inside the cylinder floods with air the piston is just hanging out mine in its own business it could be anywhere inside of this chamber but let's say just by chance when you flip that switch this piston happens to be right on center you're probably thinking now what are the odds of that well I can tell you from firsthand experience it happens quite a lot when it starts off in the middle the two grooves on the end can't get air right they're sealed off by these two polished grooves towards the center you flip the thing on and the air file stalls in that situation you want to be able to bleed that air out otherwise you'll never get out of that stalled position and that is what this hole is for see it spans that middle groove and if the piston isn't moving and that area is being pressurized it can bleed out the bottom now what happens in practice is you flip the switch and it's stalled you instinctively sort of give it that little shake that shifts this piston one way or another just enough to get the air into one of the two working areas and start the filing action on top of the breakdown requests from the first video more than one viewer asked if there were a room for improvement inside perhaps it could be tuned for a better performance give it more scoop as they say not having done a full laboratory analysis i'ma have to say no probably not first of all everything is hardened so you're likely talking new parts if you wanted to experiment I haven't measured this out but maybe you could grind a hair off each end of the piston get a smidge more oomph or blend some nitrous into your air line of course but right out of the gate I don't see much in terms of low-hanging fruit there were however quite a few comments that stuck out from people that actually use these things about them being helpful in hard-to-reach areas or small areas with limited access for full normal file strokes or polishing in small corners for example and I think I mentioned that in my first video came to that same conclusion for the money I still think it's worth having around as an option I mean you know why not despite it only seen use maybe once every couple of years had it cost more than fifteen dollars though I likely wouldn't feel the same way about it all right let's try this out some cold rolled steel just like the last video I think that was cold rolled steel I did Lube this before putting it back together but I let this run a little bit so I don't think there's that much oil in there at least comparable to the first test I think that's comparable to before let's try with the ton more oil yeah I don't know it's hard to say maybe a little bit better it could very well be psychological though I am making a mess now well I think that's it for now folks truth be told 20 minutes later I'm now not really sure why I made this video but here we are however for the six of you that are still watching I have a big announcement after years of waiting I recently and finally took receipt of a long awaited addition to my humble garage a new machine that quite frankly really brings this air file into perspective but will put them head-to-head in their own video signing off for now I hope you found something of interest in this video and as always he's a good kid he's a good kid this video brought to you in part by the generosity of clickspring making a gear since 76 BC

Channel: This Old Tony

Views: 573,800

Rating: 4.9543128 out of 5

Keywords: air file, harbor freight, tool breakdown, reciprocating air tool

Id: Mv1BdL_0U4Q

Length: 18min 25sec (1105 seconds)

Published: Fri Aug 03 2018

Reddit Comments

[u/slovenlygnuut]

My good lord I love this old tony, he feels singular in the YouTube machinist world.

[u/FrenchFryCattaneo]

How come die filers and air files aren't really made anymore? There's plenty of times I need to work on inside corners where a die grinder won't work and it seems like the only air file I can find is the harbor freight one.