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Basic Flip Smoothing

Feb 6, 20211469 VIEWS

So you picked up a budget bearing knife as a ‘project’ knife to putter around with and you’re looking for ideas? One thing you can do is polish the bearing works, smoothing both the flip and the close action until you've got some semblance of a noiseless flick open and a smooth, gravity drop shut. This can be done many, many different ways, as many ways as there are to smooth and then polish metal; your humble narrator prefers to use a Dremel, using the following steps. I should probably make some kind of disclaimer statement here - this guide is for people already handy with a Dremel. If you’re not already handy with one it’s best not to learn how to use one while handling pocket knives or other sharp and pointy things. Hand held high RPM rotary grinding tools can be surprisingly violent if they get out of your firm grasp, they can impart an astonishing amount of kinetic energy to small sharp things you're trying to polish, sending them flying further and faster than you might expect. These mistakes can at the least severely mar your project and are entirely capable of permanently maiming you as well. Dremel related injuries aren't for the faint of heart. That said: Most budget knives with bearings are not paired up with 'race' washers, or hardened steel washers with a small ring milled into them where the bearings come into contact with the metal of the liner and the tang of the blade. Some, the better budget ones usually, will have races milled directly into the metal -- this isn't as good as a proper set of races and it doesn't keep out as much debris as that kind of setup, but we're talking about budget knives. But most of the time you're dealing with a more expensive knife before you see the bearings paired with race washers on either side. Mostly in budget knives you're looking at a nylon bearing cage, with steel or ceramic bearings turning against the metal of the frame and the tang of the knife, slightly wearing in a path with time. People see that path and go 'well, ok, it looks like it's wearing in' -- but the path is never going to be as smooth as a properly milled and polished race, for the same way that a footpath is never going to be as smooth as a bobsled run. It leaves little bumps and irregularities -- the bearings aren't wearing their way in. Because they're so much harder than the liner steel, and usually harder than the blade steel, they're just pushing softer metal out of the way. The good news is that you can smooth the path, and even a small difference in smoothness will be reflected in the flip. If you‘ve ever pushed a cart across gravel, then asphalt, then cement, then tile, you know that with rolling objects, even a little change of the smoothness of surface you're trying to roll over makes a big difference in everything from sound to vibratory feedback. The same's gonna be true here. So what we’re going to do is use a little aluminum rouge to polish the running surfaces on the bearing works of a Ganzo D2 flipper - a Firebird FH81. The light polish job will make a noticeable difference in the action of the knife. Before:

You can see that Ganzo has actually milled races in the liners; they’re already polished a bit so we won’t have to hit those too hard. The tang can be cleaned up much better, though. Next, one at a time, put the pieces you are going to polish in a vise:

Load up a felt tipped mandrel bit with some rouge and carefully but evenly begin polishing the area of metal that bearings are running over:

Don't push with it -- Dremels and their bits generally aren't meant for end on pressure in the same way that drills and drill bits are. It's smart to keep the pressure light when doing something like this. And you won't get all the surface in the milled pocket unless you have expertly lathed down your felt bit to fit in it. That said, so long as you see that the polished metal is reaching the area where the bearings are going to roll, you're good. A professional could do this all much better and more cleanly in their shop, mind you -- this is amateur work. But it's going to smooth the flip considerably, all the same.

Shiny! You can elect to buff a little around the detent hole (this makes it slightly easier to disengage the detent ball when flipping the knife open) and further shine the path (this may leave visible marks on the blade, but it will ease both deployment and closing). And if you’re feeling ambitious, even file in a detent ramp with the corner of a diamond file -- a small notch, about the size of the detent ball sticking out from the lockbar, right where the detent ball is striking on it during the closing action. On opening, the detent ball pushing down the ramp gives the opening flip a little boost at the end; likewise, it eases the close because the detent ball 'skates' up the ramp as opposed to catching on the side of the lockface.

If you add one, buff it smooth with the Dremel and some rouge -- from the top, again, staying away from the lockface. You want the detent ball to skate smoothly up and down the ramp.

Clean it all THOROUGHLY with degreaser. Pro tip; spent rouge, which turns black, likes to collect in corners and in the detent hole in particular. It’s a mild abrasive, so you don’t want it staying in the works -- if you forget this step, you'll just have to take it all apart again later, and clean it again otherwise because the flip will feel gritty. Take the time and clean it thoroughly the first time through. Q-tips help. So does rubbing alcohol. At times I've found myself even needing to use a sink. Clean the entire piece very well, dry it, then lightly wipe with your preferred knife oil. When you're done with all the pieces, put it together:

Flip it. Drop it shut. Mind, especially the first time you do it, that you get your digits well clear, because it's going to come down a little faster than you're used to. Anyway, here's a clip of the freaked FH81 action in action: https://youtu.be/jgTuVrcHx1g Not bad for a budget knife, huh? This is all stuff that you can easily do on a budget knife without worrying about throwing off an exact tolerance -- if you tried to do it on a high quality knife, something built to an extremely fine tolerance, you'd be as likely to roughen the flip as you would be to smooth it. But if you have a work knife or a beater or something with an inexpensive set of bearings in it, you'd be surprised what a difference a simple bit of polishing can do for the smoothness of the flip. Anyway - enjoy your Dremel freaked, effortless, whisper drop closing budget knife. PS If you're sitting there going 'maaaaan, no use to me, I don't have a Dremel' you can do all this without one. You just need several different grits of sand paper, some rouge or lapping compound, at least one thumb, and a lot of patience. Maybe a couple dowel rods. The truth is there's many other tools out there, like a drill press, that can be adapted to use in this fashion -- and many of them would be better for the task! But likely if you own them you know all this already. I use a Dremel because I have one at hand, I suppose you could say. :)

(Edited)

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Mar 23, 2021

7 Tips for Budget Knife Enhancing -- If reading any of this has motivated you to start taking apart and improving your knives, that's great. I'm going to leave you with a few last tips that will help you immensely on your journey, at least if your experience turns out to be anything like mine. 1) Get decent tools. You will need Torx T6 and T8 drivers. You will want a six piece set or better, though, because you'll occasionally encounter other sizes, like T5, T7, T10 and so on, but you can BANK on needing T6 and T8. More than one of each in fact -- they regrettably break or strip with extended use, particularly if used incorrectly. I recommend starting with a set of Wera, Felo or Wiha drivers with long handles, and at least one of the shorter and fatter drivers with sockets and replaceable bits, and a couple sets of bits to fit it. The short ones are easier to get a steady grip on, and having a steady grip both makes it easier to use and harder to accidentally round the bits or strip the fasteners. You may want to add Torx Plus drivers and bits, especially IP6 and IP8. Torx Plus fasteners are frequently mistaken for regular Torx fasteners and unfortunately quite easy to strip with a Torx driver. But they're less common when you start out so if you have limited funds you'll do better in the beginning to get extra Torx drivers or bits instead. 2) Get a modding mat. These are silicone mats that lay flat on your desk, usually with a lip around the edge to prevent things from rolling onto the desktop. You can find many that are made for knives. Some of them are very nice but generally speaking, a mat for soldering small electronics will be better for most of your purposes and quite a bit cheaper to boot. The bigger size you get, with the more little pockets and spaces for tools and screws and so on around the edge, the more useful you're going to find it. Look for larger options with one or more magnets embedded in them as these are great for keeping loose parts together on an occasionally chaotic workbench. You can of course get one of the ones marketed to knife people for knife breakdowns if you prefer. It'll be fine. The ones marketed for knives are priced higher with very little to show for the difference, though -- two cents from your humble narrator. If you're on a budget it's impossible to beat the soldering mats. 3) Keep the floor area clean. Because, and I can promise you this, sooner or later you'll be down in it looking for the screw or washer or pin you just dropped on the floor. Probably more often than you'd like. And the natural tendency of workshop floors is to get cluttered fast. This is a very good reason to do this work in a place where there's no carpet on the floor. Trust me. 4) Get an adjustable light. Flashlights are useful but sometimes you need both hands free. An inexpensive 'workshop' setup with a regular bulb and socket, a wire clamp and a reflective aluminum shade can do nicely for not much money. 5) Grab a pair of 4 power reading glasses. Even if your eyes are good. It makes working with the smaller parts much easier and when disassembling or reassembling the knife it makes it a lot harder to miss important details, which can be extremely small on a pocket knife. It also makes it easier to make sure you have a screw properly lined up before threading it back into the knife, avoiding messing up the threads and so on. Having these glasses at the workstation will make fine detail tasks a lot easier as well. A lot of cheap reading glasses at the store are like 1.5 power, maybe 2 power. The four power ones are super thick by comparison but they'll let you see details you'd otherwise miss. 6) Make mistakes. I did. It was how I learned many many things. It's important to understand that when you're learning stuff on your own, getting it right the first time frequently doesn't teach you anything useful, whereas making the mistake definitely lets you know what to avoid next time. In life and at the workbench, mistakes are far and away your best teachers, if the least merciful. The sin isn't in making them, it's in making no attempt to learn from them once they occur. 7) Be ready for those mistakes to occasionally cost you a knife. Sooner or later, you're going to damage a knife. Quite probably more than one. Often only cosmetically, or largely so. Sometimes you will degrade its performance one way or another. In the extreme you may render it unusable or too dangerous to use. That's the price of diving into something like this and being willing to learn through trial and error. Fortunately the great thing about budget knives is that they're budget friendly. If you screw up a knife you like, buy another one and keep the old for spare parts. Chalk it up to the knife school of hard knocks. All this is to say, I suppose, that if the thought of ruining a budget knife trying to improve it is so upsetting to you that you'd really hate to do it, or the cost of occasionally replacing one exceeds your current means, that this is probably not the best hobby for you! OTOH if you can live with that, go at it. You might be astonished at how much you end up learning and how good you get at optimizing your pocket knives to your own preference. The EDC community is due to sunset any day now. I've been informed that this thread and some others may be retained, but I wouldn't necessarily expect that to last long, and in any case I don't expect to be able to update this thread much longer after tonight. It would have been nice to get a chance to record more research here and demonstrate more techniques, but that's life. But if you start taking apart knives yourself and get good at it -- it will take a while, so have patience -- then take the time to pass it along to other people as well if you can. That was and always has been the point of these Drop guides many of us have authored. Best of luck keeping your action glassy smooth, now...

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reswright

3852

Mar 22, 2021

Krudo Vice after pivot freaking and Skiffs: https://youtu.be/LORylulta1M It's actually broken in even further since this was done. Just lovely to flip.

reswright

3852

Mar 10, 2021

Polishing Supersteel Pivots Most decent knives with bearing cages should be coming with at least one if not two sets of races per cage - one against the frame and one against the tang, for each side. Cheap bearing knives usually lack both sets, and sometimes have a thrust washer instead of a set of races, but in all but the highest end knives the bearings are usually left to turn against the bare tang, with maybe a race milled into it. This is a problem on two kinds of knife. The first is the kind that's just been cheaply done and they haven't polished up the bore at all, and there's grinder marks all over the place. And some of them can be deep - too deep to polish out, like so:

That's from the grinder head either just parking on the metal while it was still running, or the piece took a hell of a bump during grinding. So the second kind of knife that has an issue here is on the opposite end of the spectum -- a supersteel knife where the manufacturer has decided that the bearings can turn directly against the tang. With supersteel that's a problem because it's usually more roughly milled on a production knife than a knife with softer steel coming out of the same facility. Not because it's done sloppily, but because it's hard steel . The harder the steel, the harder work it will be to polish that pivot face, and the more working on it will wear out tools and consume things like grinder heads and belts and sandpaper. And the longer it takes and the more money it costs to work and so on. Which is to say that factory processes that might produce a glassy smooth finish on something like 440C aren't going to be quite as effective on a hard supersteel and at a point they're willing to call it done and leave some grinder marks in their piece S35VN pivot:

M390 pivot:

See the swirls? To the bearings, those are like corduroy fabric. It gives a rough graininess to the flip compared to the same setup running against a race. And because it's supersteel it's hard to smooth them down. If you try the regular technique you'll just get frustrated and end up with a really ripply surface because your rouge isn't enough to smooth it. So to do these pieces I use a three grit approach -- white rouge, green rouge, then red rouge, in that order. White's a little more abrasive, red is least abrasive and most polishing.

Think of it like multiple stage sanding where you're going from 400 grit to 800 grit to 1200 grit and so on. The white rouge knocks it down, the green levels it and the red finishes the polish. After: S35VN:

M390:

The difference in actual smoothness has an outsize impact on how much you 'feel' the flip. With a perfectly smooth race you're losing less energy to bearings wearing through swirl marks and the difference is, the flip's smoother and quicker. You can adjust the pivot better to hit that magic point where you can snap flip things but there's zero rub and zero blade play.

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mdeous

230

Mar 12, 2021

Re sharpening, yep I also feel like a lot of people who spent decades improving their freehand skills don't want to admit that (and that's probably a very unpleasant feeling to see your precious experience being replaced by a machine), I've seen many answers to questions about a guided system like "it's good but it will never give as good results as years of experience" without ever being able to explain why. I definitely think a guided system gives superior results, but on the other hand there's something really satisfying on getting great results freehand, and I'll probably continue doing it from time to time.

(Edited)

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mdeous

230

Mar 12, 2021

Re polishing (the threads management really sucks here...): I see, thanks. I have to say the results you had with your blades is quite impressive! I've been thinking about getting a dremel for a few things, if the results are worth the effort (which you seem to say are) I might give this a try.

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reswright

3852

Feb 27, 2021

Added a detent ramp and dropped some Skiffs into my Spydie Smock:

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reswright

3852

Feb 20, 2021

Smoothing a Crossbar Lock Flip This is the WithArmour WA-080, a relatively inexpensive crossbar locking knife.

WithArmour usually has decent build quality; the WA-080 is indeed built like a tank but unfortunately it has a lot of drag on the flip: https://youtu.be/2jNesd7xDwU This knife, unlike the ones so far in this thread, turns on Teflon washers - which there’s very little that can be done to improve. But it’s a crossbar locker, and a lot of the drag comes from the crossbar rubbing on the round edge of the tang during the flip. That, we can smooth!

So dust and dirt can embed in Teflon, and you can see a little wear from that has already occurred. Clean the washers well then set them aside. You can also see the edge of the tang, where the crossbar slides, has only a little shine to it. Little dull. and speaking of the crossbar, it’s a little gritty too:

all these surfaces can be polished. Smoothing them will reduce drag during opening. The tang, you can sand and buff, or use the side of a Dremel felt head and some rouge, which is what I’ll do:

After polishing the side of the tang:

For good measure I cleaned up the area under where the washers sit. It won't have a really noticeable effect but what it'll do is take any more little bits of blade coating that were gonna pop off and stick into the teflon, and get them out of the way before that happens. Moving on to the crossbar: This piece, especially being press fit together so that it can't be broken down, is too hard to properly Dremel polish -- trying would probably leave the surface uneven. So I’ll use sandpaper and aluminum rouge:

Time consuming by comparison but it works. The pivot barrel gets the same treatment. It was in pretty good shape but I have it here, might as well smooth it a bit.

Not a huge difference, really, but it’ll help a little. Back together:

Did that improve the flip? https://youtu.be/czBJQco3KfQ Yes! As you can see the pivot’s about the same when the crossbar’s pulled back but the amount of drag has dropped notably on opening with the thumb stud. I wouldn’t call it glassy but I’ll take the improvement.

(Edited)

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reswright

3852

Feb 14, 2021

Freaking the QSP Leopard

Bought one of these a while back because I liked the geometry, but out of the box the flip was wretchedly hard on the fingers. Works before polishing:

After polishing:

action now: https://youtu.be/zrEgG8Eq3to

@method_burger - I like my Leopard now.

(Edited)

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reswright

3852

Feb 17, 2021

That sounds about right. Not a lot to be done for that flipper tab - I suppose grinding away part of the liner and scale might give a little more room to get on the tab, but the tab's always going to be too small and angled an awkward way. I was just kinda happy that I could flip the thing open without fighting it and without my fingertip feeling hard used in the process.

method_burger

563

Feb 18, 2021

reswrightyeah, theres a lot going on with this knife, thats a huge positive. the scalloped liners are such a nice touch i wish all liner lock knives did that. and they go and ruin it with that weird flipper tab. wouldve easily been a 10/10 with like 3 slight changes (flipper tab, back backspacer, and the weird pointy bit on the butt of the handle) qsp missed a home run with this

reswright

3852

Feb 12, 2021

Was smooth, now is glass

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reswright

3852

Feb 12, 2021

Freaked Assassin in which your intrepid narrator freaks his double dyed Harnds Assassin.

The Harnds Assassin has been one of my favorite budget knives for quite a while. It’s got a blade I really like in nitrogen Sandvik and despite the long blade, a sweet and easy flip.

but I really can’t leave well enough alone. Getting it apart is complicated by an internally bolted frame which unscrews from the opposite side that the pivot does, but it’s easy to figure out once you know that bolt is there.

As you can see they properly milled in races. Also, note those bigass ceramic bearings and how many they fit into that cage - about 2 more than ‘normal’. Hat tip to Harnds. That’s why the flip is smooth already - but it’s also why freaking the works still has room to make an impact. one Dremel polish job later:

Back together.

Action: https://youtu.be/mGMJvaONZIA Pretty happy with that, actually. There you are, Drop. The Assassin is even faster and quieter after a light polish job on the bearing works. No idea why Drop’s never tried to source Harnds but they make great knives.

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