Busted Tachyon slab screws!!!

OK Here is the scoop :)

Sorry for the late reply, Christmas, family and all.

I will be getting a package from Micortech which will contain replacement screws and bushings for any missing or lost pieces you guys may get. Microtech would rather see the actual knife but we know that in many cases that is not feasible and probably not necessary as a missing slab screw does not render the knife useless.

So send me an email with your address and any missing part you may have and I will do my best to get them out to you.

Now keep in mind that when you remove these screws you will need to replace them using more Loc-Tite.

For the record I have not been able to duplicate any of the problems seen here other than my own knife getting a bit loose (pivot) after hard play and no Loc-tite.

I checked about 12 knives still in box and only one showed signs of a loose screw. So for a first attempt I think Microtech did a pretty good job!

Let me know what more I can do.
 
Originally posted by Mike Turber
Let me know what more I can do.
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Keep them coming, and shorten the amount of time to the release date of the 4" blades models.... ;)

In case you have't heard it enough, I think you're doing a banged up job.... Now about those 2 bronze bushings and the bottle of Barcardi you owe me...:D :D :D
 
I've had mine totally apart three times now. Have mirrored polished the screw heads and pivots and reassemmbled with no problem. I use blue loctite ( medium ). A couple things to remember;

1. Make sure you degrease the screw. I use acetone or brake cleaning fluid from a spray can. I follow this with compressed air to blast out all residue. Just a little dab will do you!

2. When you loctite the pivots, use a toothpick to apply just a bit on the inside of the pivot and not the screw itself. If you use too much it will be squeezed out into the pivot joint and then you get to do it all over again. I know, I did it:eek:
 
Just another couple of words. I took apart and re-assembled (3) of them last night. Two with no problem at all..., and then
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.., the same sort of problem Chuck mentioned with excessive tightness to the point I was sure more force would cause ~~>
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.., me sitting at the computer writing to Mike! I did get the third one completely disassembled using a heat-gun, and all three re-assembled nicely.

As Chuck also mentioned.., I did look closely with both 10X and 30X magnification, and on one knife, found absolutely no signs of locking residue of any sort. The other two both had obvious visable residue from some Loc-Tite type material.

I found no excessively "loose" screws, and one of these knives has had at least 4-5 hours of manipulation.

Sooooo, it looks like everyone's experiences are valid, and MT needs to do a little "In-Service" on assembly of the Tachyon. I think we've heard enough inconsitencies to make this a valid request.., not to be taken as a "cheap shot" at all. They are great knives and I like 'em!
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"Hunters seek what they [WANT].., Seekers hunt what they [NEED]"
 
Hey, with this practice, maybe we should include a Time-trial of disassembly and reassembly of a Tachyon in the Bali Games. Along with Best Ariel and Best Freestyle. For those of us more mechanically inclined.......:D :D
 
Hey guys, i know i'm jumping in here a bit late but i've also experiences some of these problems. First of all i've already lost my latch screw and have another coming from Mike. It had come out once, i found it and put it back in but without loc-tite, and after flipping for a matter of minutes it was already gone again...for good.

I also noticed the other day while manipulating that one of the slab screws was close to falling out on its own without having tryied to loosten or test the tightness of any of the screws. When i finally get some loc-tite, should i go through and give every screw a dab just to be safe?
 
Tachyon is,in many ways, unlike anything MT has done before. A few start-up glitches are expected. So far, I'd characterize what we've seen as very, very minor.

I've said it before and I'll say it again, the balisong design is deceptive. It seems very simple, two handles, a blade, maybe a latch. But, it is, in fact, a rather complex design. Consider, for example, the recent introduction that I still call "The Chinese Sidewinder." Consider the problems that Roton has had with Monarch. I shouldn't tell you this, but I will, even the first prototype I saw of Gemini had a minor little problem that was quickly corrected. But, even an experienced and qualified maker like Darrel Ralph (who has made a few balisongs in the past) screwed up. Mr. Dobruski's first one had a rather nasty little problem that he has since corrected. (BTW, even the first prototype of Tachyon I saw had a minor little dimensional problem that I won't discuss since it's been corrected completely.)

If the worst problems that MT has are inconsistencies in latch position (which I actually consider a feature) and inconsistency in application of thread locking adhesive (ranging from none to way to much), then I still think they've done an outstanding job. Outstanding!




If you are a Tachyon owner, you should realize four things: First, some of the screws, especially the latch screw but also the slab screws, are very small, boardering on jeweler's screws. You can easily, especially with the Torx head, apply enough torque to break the screw head off if, for some reason, the threads aren't willing to move. Second, some or all of your screws may have way to much thread locking adhesive, enough adhesive to keep the threads from moving at torques well above what will break the head off. Third, without thread locking adhesive, some of the screws, especially the pivot screws, may work their way out. If this happens, the knife may spontaneously disassemble itself in your hand. That could cause some problems. Forth, some or all of your screws may not have any thread locking adhesive. So, it would be a good idea to check.

If you haven't noticed it, several weeks ago I added an article on thread locking adhesives to my website. You can read it by clicking here
 
Chuck, excellent article on thread locking adhesives. Thanks. I work for a defense plant where we design and manufacture avionics equipment for military aircraft. We specify the red Loctite on our engineering drawings, the others are very rarely used. Our equipment has to withstand the vibrations and shock of weapon recoil without coming apart. Loctite is a great product and your article goes way beyond normally supplied user instructions.
 
Coming from a world of safety wires, lock washers, cover plates, paint indicators, replacable rivets, or any other primative method of keeping a screw from unwinding, Loctite is a miracle. It's cheap, it works, and a little dab will do ya. Use it whenever you break a thread and don't want it to come back out. Personally I think using it on the slab screws are overkill, since there are 6 of them in each handle. But if you're the lazy type, use it and forget it. Otherwise keep those torx drivers handy, you'll need them if you remember to check those screws every now and then.
 
Safety wire, lock washers, thread locking adhesives, etc., it's all a matter of tradeoffs.

Lock washers, especially those that are captive to the screw or nut, don't cost much and don't involve much if any extra labor. But, they chew up the surfaces pretty badly. This means that they are not suitable for hardware that's going to be assembled and disassembled many times. Some forms of lock washers also wear out with repeated reuse. And, to really use lock washers correctly, they need to be compressed to the proper torque which means controlled-torque tooling.

Safety wire is very expensive, especially when labor is accounted for. And they are physically ugly. But, that ugliness is one of their greatest features. It's called inspectability. An inspector can look at a series of bolts and say, "Yup, that one's got its safety wire. That one does. That one does too. But, this fourth one clearly doesn't." And, in safety-critical applications, that's very important.

Safety wire is completely reworkable. You can assemble and disassemble as many times as you want to. But, it does require a skilled technician and some special tooling.

Safety wire, by the way, may be something at some of you have never heard of. It's a bit of an exotic technique. It's used some in high-performance automotive applications. I've seen it on natural gas pipelines. But it's mostly an aircraft thing.

http://www.tpub.com/air/2-30.htm
http://www.rx7turboturbo.com/robrobinette/safety_wire.htm
http://www.ultralightnews.com/pilotslounge/safetywire.htm

Removable rivets are nifty and have the advantage of working from one side. But, they require special tooling.

Thead locking adhesives are cosmetically perfect. If the adhesive is properly applied, you won't even know that it's there. You can buy it in a custom color to match your product's surface color so that if any little extra does squeeze out, it won't be noticable. This is a double-edged sword, though (knife content). On the one hand, this keeps your finished product looking very clean (very Microtech). But, on the other hand, it makes it impossible for an inspector to visually assure that the fastener was correctly installed.

The amount of locking affect you get depends on the formulation of adhesive you use. But, it also depends on the amount you apply. For consistent results, the amount of adhesive you apply has to be carefully controlled. If you consult Loctite's website, you can see that they not only sell the adhesive, but they sell elaborate, and expensive, factory equipment for properly applying exact, metered doses.

Thread locking adhesives are not substitute for proper torque. If MT is going to allow field disassembly and reassembly of Tachyon, I'd like to suggest that they publish specifications for torque on each of the three screw types. Most of us probably don't have access to torque-controlled screw drives. But, at least we can get some idea of how much torque to apply. Even if you can only borrow a torque-controlled driver for a few minutes, you can "get a feel for" how much torque to apply. I think you'll discover that you're probably grossly over torquing your screws.

Thread locking adhesives do leave a hard residue on the parts when disassembled. That residue can build up and can interfer with proper reassembly. So, it needs to be removed. The best way to remove it, sometimes the only way to remove it, is with nasty chemical solvents.

Of course, the other problem that thread locking adhesives have for some applications is that they are heat-sensitive. On engines and breaks, this often makes them completely inappropriate.
 
Thanks Chuck. I was just sharing my joys at the advantages of Locktite, but that was a great job of explaining the other methods of screw retention.

That's just some of the stuff you need to learn in getting FAA licenses in Airframe and Powerplant... And mandatory on motorcycle components if you ever decide to race them.

Just one correction: Lock washer, the flanged type not the nut type, were often used in areas that require frequent disassembly, as long as the screw/bolt isn't serving in a vital operational function. The bend in the washer when compressed provide tension against the thread matings, so that they would not have any free slack and the screw would not start unscrewing itself.
 
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