XM-18 My conclusions on the way to work the flipper

[Sloop]

It's kind of an oxymoron -- to get the knife to smartly flip, you need a strong detent. The way to prove this is to open the blade to where it is just slightly past the detent and then try the flipper. The blade moves easily but won't flip open beyond 90 degrees. And yet, sometimes this strong detent prevents being able to apply downward pressure on the flipper. Not only does that sharp edge on the flipper hurt my finger, but the blade doesn't budge. IMO, this occasional lockup has nothing to do with the tuning setup on the knife, but is in fact a product of the detent kind of getting stuck in the hole in the blade. On a loading scale, I've measured the amount of force necessary to open beyond the detent and it is close to 1 lb, 13 oz.

From an engineering perspective, the recommended way to flip open the knife (simultaneously pushing down from the top while pushing forward on the flipper) is at odds with pure physics. You are going to get the best mechanical advantage by placing the tip of your finger in the concave portion of the flipper and pulling back fast. Do it in slow motion and you'll see what I'm talking about. However, while this is the easiest way to get past a strong detent, it will not result in the desired snap action. In fact the blade will only open about 135 degrees. This is where I apply a slight flipping action with my wrist, which I am completely used to doing on my big folder, and the blade flys open with a solid snap. The important thing is that it NEVER fails and it is much much less painful on your index finger.
I realize my method is going to create a stir with the XM-18 purests. Putting my flame suit on.

 

[Danke42]

Sounds like a light switch vs. push button debate.

 

[Valyrian steel]

Never had any issues flipping with my XM-18's. Dunno why this is such a big deal

 

[whitty]

Curious. Is this a recently purchased Hinderer or relatively new?

 

[Basp2005]

Mines the new generation. It flips just fine, nice detent. It doesn't act like its on bearings, of course. Wouldn't expect it to. No complaints.

 

[CaptainFuzzy]

I've got a new gen XM24. Sacked the flimsy Teflon washers and threw a nicely polished set of phosphor bronze washers in there. Flips like a dream now. Why RHK hasn't gone to PB is beyond me.

 

[Aussie john boy]

I do push button to open my 18 & 24 both still have Teflon washers I do find the 24 opens better due to weight of the blade though

 

[Sloop]

Curious. Is this a recently purchased Hinderer or relatively new?

YES. But I've worked the heck out of it in the last month to break her in. Also had it apart twice now for adjustment. The first time, I neglected to really do any deep cleaning -- I had just lubed the various parts. On re-assembly, for some reason I was never able to get the blade centered. It favored the scale side. The second disassembly was yesterday and I thoroughly cleaned around all the moving parts, Teflon washers, and pivot holes. Relubed and for some reason this time the blade is perfectly centered.

I understand that the newer knives have a stronger detent. So this time I even added a drop of oil on the detent.

The knife is very smooth, but I still believe my discussion in my OP is correct.

A question: Where does one go to buy a set of phosphor bronze washers? I've seen them mentioned before, but in one post there was a caution about corrosion.

 

[JJ_Colt45]

I've read alot of posts with the OP not liking the action on a Hinderer ... or saying the detent is terrible ...

While I can't speak for them nor have I handled the knife they have to know how it feels or what if any issues it may have ...

I do know my frst Hinderer I thought maybe had too weak a detent or some issue ... then I read a bit about the appropriate motion Hinderer's require to get that smooth vault lock up ...

And within 5 minutes I realised the detent was great ... there were no issues with the action ... it didn't need taken apart cleaned or adjusted ... I just needed to learn a different concept and motion to open it then other flippers.

And now it flies open as well as any flipper I have ever handed. So I always try to advise new Hinderer owners to read and watch the motion it takes and give themselves a couple days with the knife after they know the slightly different motion and pressure ... and I think they may feel like it's a completely different knife.

 

[CaptainFuzzy]

A question: Where does one go to buy a set of phosphor bronze washers? I've seen them mentioned before, but in one post there was a caution about corrosion.

I picked mine up on eBay for 6 bucks. Once you've got the size measurements (pm me if you want em, I'll send a pic of the bag) I'm sure you could order them from any of the online knife supply stores. As far as corrosion goes, I use FrogLube and that seems to keep everything pretty corrosion free. I also live in the dead center of the country and live nowhere near a body of salt water. But the PB washers make it VERY smooth.

 

[Sloop]

I picked mine up on eBay for 6 bucks. Once you've got the size measurements (pm me if you want em, I'll send a pic of the bag) I'm sure you could order them from any of the online knife supply stores. As far as corrosion goes, I use FrogLube and that seems to keep everything pretty corrosion free. I also live in the dead center of the country and live nowhere near a body of salt water. But the PB washers make it VERY smooth.

Thanks for the info. I may just try a set of PBs. Seems to be a mixed bag of how people like them. But, having disassembled my knife two times now, it is becoming quite easy to do, so experimenting will hurt nothing.

One thing I haven't quite figured out yet is why in the XM-18 the Teflon washers are two different outer diameters?

 

[REK Knives]

Your issue can be fixed it just need detent work and to be dialed in. If it is too strong from getting stuck in the hole then either the lockbar tension needs to be adjusted or you need a new larger detent ball (I prefer to install ceramic) and dial in the action that way. Last thing I recommend is to round the point tip of the flipper tab, hinderers are bad about this.

 

[whp]

I ve never thought about corrosion issues with pb washers. I wonder how often pb washers corrode in humid climates. I live and work fairly near the salt water. If teflon washers are more durable in my climate, they are fine with me. To me, the xm 18 flips fine.

 

[WhiteShampoo]

I've got a new gen XM24. Sacked the flimsy Teflon washers and threw a nicely polished set of phosphor bronze washers in there. Flips like a dream now. Why RHK hasn't gone to PB is beyond me.

Rick likes the knife to be able to handle mud, grit, etc., and the Teflon washers supposedly handle that better than phosphor bronze washers do. Teflon also doesn't require as much lubrication as phosphor bronze does (it is naturally more "slick" than phosphor bronze). Rick doesn't care if the blade flies open with a flick of the finger, he cares about reliability and performance more than anything else (which makes sense considering his history). I state all that not to start an argument, just sharing what has been stated in the past.

 

[Sloop]

Your issue can be fixed it just need detent work and to be dialed in ............... or you need a new larger detent ball (I prefer to install ceramic) and dial in the action that way.

Last thing I recommend is to round the point tip of the flipper tab, hinderers are bad about this.

I assume the ceramic detent ball installation would void the warranty?
Also, rounding off the tip of the flipper would cause damage to the beautiful dark gray finish of the blade (my XM-18 is the special Legion model). Otherwise I would have already had my Dremel out.

Thanks for the suggestions. However, I am convinced now that my knife is perfectly in-spec for flipping ability. And will only improve with more break-in.

 

[Sloop]

Rick likes the knife to be able to handle mud, grit, etc., and the Teflon washers supposedly handle that better than phosphor bronze washers do. Teflon also doesn't require as much lubrication as phosphor bronze does (it is naturally more "slick" than phosphor bronze). Rick doesn't care if the blade flies open with a flick of the finger, he cares about reliability and performance more than anything else (which makes sense considering his history). I state all that not to start an argument, just sharing what has been stated in the past.

I am still wondering why the two different outer diameter Teflon washers?

 

[Officer's Match]

I am still wondering why the two different outer diameter Teflon washers?

Probably to maximize surface area for stability (larger one won't fit lock side IIRC).

 

[WhiteShampoo]

I am still wondering why the two different outer diameter Teflon washers?

Don't know for sure, my only guess is just so you can't see the washer through the space between the frame and the lock, because you can see a little of the phosphor bronze washer when they are installed. However, with that said, the phosphor bronze washer isn't glaringly obvious or anything when installed. CRK gets around this problem with their oversize washers by machining the washers with a cutout where the lockbar would be.

 

[Sloop]

Thanks to both of you for your reply. Next time I disassemble the knife, I will be sure to examine the washers closely on reassembly.