Scalpeldashi Blade Styles

Scalpeldashi showing 5 blade styles we frequently use. Handles/blades are, from left to right: Bubinga/#10A, Sandworm Ivory/#40, Summer Sunset/#11, Ultramarine Depths/#10, and Cuttlefish/#16

We get this questions often about what scalpel blades are available, will they fit our sheath, and which is your favorite? This post is an attempt to answer that question.

A common graphic showing just a handful of the huge number of different scalpel blade styles.

To the right is a typical image used to sell some of the more common blade styles. It is far from exhaustive. Blades are available at extremely modest prices, the most common ones are less than 5 cents each if purchased in bulk. More typical pricing is in the range of 7-12 cents per blade for a 100 pack for common styles. Less common styles, blades sterilized by gamma radiation, and stainless steel blades can all be priced a little higher, but are still very inexpensive.

Our seven favorite styles are #9, #10, #10A, #11, #12, #16, and #40. (we offer a sampler pack if you want to give them a all a try) Far and away we use #10A the most, and it is what we supply with every dashi purchased. It is fairly rigid with a fine point, allowing an incredible amount of force to be put behind it. This gives it great precision for accurate work like marking/scoring, but it is perfectly functional for carving, general utility, even opening packages. Its angular style was actually an inspiration for the scalpeldashi itself years back. #11 looks similar, but in practice is very different. It makes sacrifices in rigidity for a more slender blade and even more acute point. It is fantastic for cutting very fine details, particular when accessibility is limited. Both #11 and #16 are sometimes heated, bent/formed, and re-tempered to make specialty tools/cutter heads for unusual applications where sourcing a commercial blade would be difficult. Speaking of #16, this is another good general purpose blade. Wickedly sharp, like all scalpels, with a straight edge and utilitarian sheepsfoot blade it is also great for general purpose but also excels at scraping. Not surprising as it is closely related to a dermaplaning blade. (for those who don’t know, dermaplaning is a common cosmetic procedure where the surface of the skin is scraped and shaved removing the top layer of skin. It is actually rather similar to straight razor shaving in some respects.) #10 is made for slicing, and slice it does. Slicing in softer materials is where we most commonly use this blade. #40 is a double edged blade. Aside from the advantages when piercing or cutting thin slots in material like leather, this blade actually is very useful for EDC. It is a very utilitarian shape, but you get effectively two blades in one. Double the edge retention or keep one exquisitely sharp for critical tasks while you abuse and dull the other edge. #9 is the weird love child of a sheepsfoot safety blade and a chisel. Push cutting in confined space, cutting along a surface but not the surface itself, and scraping are where this blade excels. Genuinely not sure why this blade isn’t more popular, as it is hard to replace. #12

What about sheath fitment though? After all, if you’re going to carry one as part of your EDC, it isn’t much use if you can’t carry it with you. All of the aforementioned styles fit in our standard sheath, though #9 and #12 can be a bit of a squeeze. The reason for this comes down to how the sheath works. You see, most sheaths grip the blade of a knife. Our sheath actually contains torsion bars which grip the scalpel’s bayonet instead. This frees up the design to happily carry a wide variety of blades.

Hopefully that answers the common questions and is a good primer on the subject. Blade preference can be as much about personal taste as application. Thanks to the immense diversity of blade styles available though, there is something for everyone out there.

Product Update - Scalpeldashi

Three chameleon one-off scalpeldashi. From top to bottom: yellow to green, blue to purple, and green to red.

Late in 2019 we promised a shakeup of our popular lineup of scalpeldashi for early 2020. Well here it is! New and better materials, cooler colors, and even tougher than before. And all this while cutting prices, which start at just 25$ for our silicon carbide dashi. (including sheath)

With this launch comes three one-off chameleon dashi. (pictured above) You may recall our chameleon skin finish on our old dashi. This is similar, except now it is no coating, it is swirled through the entire handle! Colors change based on the angle of the light striking it, and the depth and life in the material is impossible to photograph. From top to bottom they are: yellow to green, blue to purple, and green to red. These will be on sale for a limited time.

We’re also accepting orders for custom work, from custom engraving to complete custom dashi to entire custom production runs. If you’re looking for one….. you know what to do. ;)

Airgun Moderator Design, Performance, and Development - Summary of 3 new moderator designs (part 14)

Catch the previous episode HERE.

I've been quietly beavering away on a moderator project all this time, a project which ultimately was a failure. The idea was to create a truly modular airgun moderator where, instead of just stacking otherwise identical sections where all you are choosing is how loud/quiet and long/short you want your moderator to be, you actually change different modules to tune your moderator to your gun. And this is in line with my research on regular non-modular moderators where I determined that different rifles want different ratios of flow delaying and sound absorbing in a given size envelope. My idea was that this could speed up my research because, if I wanted to try a new configuration, I could make a new module and JUST a new module keeping everything else identical. Unfortunately, ultimately, this whole thing was a failure. The first problem was that each module was a bigger pain in the butt to make than a whole mod, so it didn't actually save any time or effort. And as for the design itself, it worked, but not well enough as the connections between sections took up too much length and volume and weight. So, ultimately, I learned a lot but had to abandon it.

This all got me thinking though: why did I start this in the first place? It was because I wanted to shrink the length and weight of the junk I hung on the end of my barrel. So, I struck out in that direction. In this series of tests I was primarily working on two things: 1) making a MUCH smaller mod and 2) making a more versatile mod.

So the interesting thing I learned working on the Mus was that gas diodes actually need to be tuned to a flow and air volume in order to work effectively. Otherwise they act more like a flat baffle. How can I improve on this? Before I used compound gas diodes, a quasi diode inside a full diode. This was about the limit of how small I could make something given the tube diameter constraints. But what if I moved up to a slightly larger tube, one small enough I'd avoid at least some of the large-tube-diameter issues encountered by large OD moderators, but large enough I could fit a gas diode inside a gas diode? So I thought I'd move up to a 40mmOD tube with the same 170mm overall length and see what I could manage. I've nicknamed this size the Gladius.

Non-compound Gladius Crown .22 – 81.67

SD Gladius Crown .22 – 61.00

DD Gladius Crown .22 – 65.00

So the above three are all on my .22 Crown, same as always. The non-compound Gladius is basically just a scaled up gas diode, and clearly is not as effective. (this is not surprising) The SD and DD Gladius designs are about equal in terms of performance both with each other and are almost as good as a Pilum. Given the tube OD increase, I'll call that a win, as the point was to “prove” the DD Gladius could be effective on the .22 Crown. But the other point was to make a more versatile design, so what about the DD Gladius on the .30 Crown?

DD Gladius Crown .30 – 77.67

So there was a weird outlier on one of these shots. Keep in mind that each test is sampled by TWO pickups simultaenously, and so when the wind or some other unknown factor on rare occasion throws a weird spike, it can be discarded. Without the outlier removed the average was still a respectable 84.25. So this is a win, in a big way. Keep in mind the Mus averages 82 and 79 for the .22 and .30 Crowns respectively. And the post-peak sound is good on both tests as well. This makes the Gladius an improvement over the Mus across the board. The one area I'm a little iffy about is the post-peak sound, as the Gladius looks comparable to the Mus but despite tinkering with RMS I just don't have a good way to quantify it. It sure sounds good to the ear as well though.

So the Gladius is big, smaller than the Mus, but still quite big. And I wanted small. I started with the Levitas, and promptly rushed to size in a pursuit of ultimate silence. What about going in the opposite direction? After all, most people are willing to pay a serious price in terms of mechanical complexity and dollar cost to cut 6” off the length of their gun by running a bullpup. What good is all of that if you then stick a stonking great mod on the front to quiet it down? So in pursuit of tiny I wanted to see just how small I could go. Remember the TKO was basically a cigar in size and performed quite admirably. So I made a mod the size of a fat tube of chapstick, that weighs 20 grams, and in the spirit of the Levitas I named it the Brevitas. I'm not kidding about the size:

I would have made it skinnier too, but that is the OD of the Crown shroud and any skinnier would have just looked goofy. You might be asking how well such a teeny tiny mod could perform?

Brevitas Crown .22 – 185

Brevitas Crown .30 – 640

Keep in mind that, with the shroud retracted, the Crown .30 meters at 733. Put another way, this more effective than extending the Crown's factory shroud, while being less than half the length. It sounds a little “whooshy,” kind of like a hollywood suppressor actually. This was just a crazy idea, and there is some tweaking I need to do to it. There are also some alternate configurations I want to test. I had no idea if this would work in any way shape or form, but I'm cautiously optimistic about the results of this test. I did cheat though and make the bores a little too tight relative to the projectile, so these numbers may creep up as I enlarge the bores and hopefully go back down as I test other improvements. All in all though, I think this is really cool and really unique. I'm not aware of any mod out there anywhere close to this tiny.

Finally, a gentleman has very kindly loaned me his AAA Slayer to build a mod for. The name is apt: is has a tendency to slay moderators.... particularly in interesting and unexpected ways. You'd expect it to just blow up tubes, and it hasn't done that a single time yet. Instead it has caused all manner of other interesting problems. I've been beavering away at this for some time now, but never had anything worthwhile to show for it until this most recent test.

Slayer .308 ~200 FPE – 608.5

So there are a lot of interesting things about the Slayer, too much to go into here. But one of them is that the tube ping is incredibly loud. You probably saw my previous post on the subject, and that peak is actually from tube ping not the uncorking event. Cool huh? I'm going to continue ruggedizing this moderator design, so this is not a final version, but so long as I'm at or below the air tube ping I'm happy. Unsurprisingly, this mod is all air-handling, there is no room for anything else. I'm doing it in a Gladius size tube to fit the general requirements of the rifle (like accessing the gauge) as the Mus is simply too large.

This was just a quick summary of whats cool I've been working on. Honestly there is just too much to write it all up, but I hope this was an interesting albeit long overdue update.

SALE! - Scalpeldashi

Scalpeldashi, a popular product of ours, we all love them and all carry at least one. We’re changing our lineup for 2020 though, and so we’re putting all our traditional coated polymer scalpeldashi and sheaths on clearance, up to 50% off. Get ‘em while they last, because they will not be restocked!

Out of Office 12/23/19 to 12/27/19

Happy holidays to everyone! We all will be out of the office from 12/23/19 to 12/27/19. During this time period we will not be able to process orders or respond to inquires, please accept our apologies. Service will resume as normal 12/30/19.

Airgun Moderator Design, Performance, and Development - Air Tube Ping; An Interesting Finding (part 13)

Catch the previous episode HERE.

Yes, I’m still here, and I’m still playing with moderators in my copious free time. I spent a lot of time playing with a new piece of technology, figuring it out, and some cool, interesting, and pretty unique things are on their way along with more testing. That is all for later though. Right now I want to talk about something very interesting I discovered regarding tube ping, namely that IT GETS LOUDER. Didn’t expect that? Don’t understand what I mean? Let me unpack.

The above trace is a .308 American Air Arms Slayer. It is a powerful slug-throwing gun running about 200 foot pounds at the muzzle. It is unregulated, runs a tube, guzzles air, and runs some balanced valving witchcraft. All this means that the valve opening and closing events, as well as the total amount of air removed, are relatively violent events in the air tube. Unsurprisingly, this leaves the rifle with a very pronounced “ping” when it fires. Several months ago, I was approached by a gentleman who wanted me to develop a moderator for his Slayer. It seemed like a fun challenge at the time (spoiler alert, its been a pain in the tuchus), so I took him up on the offer. It has been a bit of a roller coaster of hope and failures, but I just finished testing a design which is quieter than the tube ping, and THAT is interesting.

To be clear, I’m only pretty sure of all this, you can never been 100%, but looking at the timeline, other tests, so on and so forth it seems to be the only thing that makes sense. So, in the above trace highlighted in yellow, you can clearly see the “uncorking event,” that is to say the moment when the pellet exits the muzzle of the moderator. It is a bit messy here, because it is all mushed into the tube ping….. which clearly increases in amplitude over time. This might, on first blush, sound a little screwy. How, after all, could the tube ping get louder AFTER the most violent event (valve opening/closing)? If you think about it for a minute though, this actually starts to make sense. When the valve first opens, the air/sound in the tube won't be moving in a uniform wave. The air nearest the valve will expand substantially more than the air nearest the gauge. Similarly when the valve first closes, the air won’t all simultaneously stack up at that end of the tube in a pressure spike because it isn’t all going at the same speed. It takes a couple cycles back and forth for that air movement to coalesce into a uniform sound wave front and thereby reach peak amplitude/intensity. Then, obviously, hysteresis naturally damps it back down to zero over time, in this case a much longer time than was sampled. Look at that happen too. Initially the sound is messy, very messy (look at the area between the yellow highlighting and the teal highlighting), and it actually takes a little time for the wave to coalesce around its primary frequencies. As it does so, it increases in amplitude! I was COMPLETELY not expecting this, but now that I've found it, I thought I ought share it.

This naturally leads to some interesting ideas on the design of depingers; they don’t have to break up the wave front to function, they simply need to stop it from forming in the first place. This suggests entirely different avenues of design, some in the same vein as existing designs granted, but others completely novel.

Cool stuff eh?

Out of Office 11/28 - 12/1/19

A very happy Thanksgiving to everyone! In observance of this holiday, and giving thanks to our friends and family, we all will all be out of the office from 11/28 to 12/1/19. During this time period we will not be able to process orders or respond to inquires. As a small thank you, we’re offering a 10% discount, site-wide, just enter the code “9ULZASI” at checkout.

Project - Scope Throw Lever

The concept is far from new: magnification rings on scopes can be stiff to actuate, thus a throw lever to increase the mechanical advantage and grip is an obvious accessory.

A small objective 1-6x scope I think is underappreciated in the realm of airgunning. It is well suited for close range hunting/shooting, but still has the magnification to reach out for some longer shots. It’d be a great fit on an FX Dreamline Compact for example, or many of the popular super compact bullpups. In this case we’re looking at the AIM Sports Alpha 6 1-6x24 30mm Riflescope. It is a very nice little optic for an airgun and <100 yard work on varmints of various flavors, and it has a bunch of other nice little features. It’d be an especially good fit on an Edgun Leshiy though, where the small (24mm) primary objective would allow it to clear the somewhat inelegant upward bulge of the Leshiy’s integral shroud without sacrificing size on the ocular. It has a handful of other nice little features as well. But this blog post isn’t meant to be a scope review.

And so, needing a throw lever for this scope and with no obvious commercial option, we set about making one. And if you’re going to build something, why not improve it, add a bit of flair? In this case we made the throw lever and ring from 20% carbon fiber reinforced nylon, a fantastic material and way overkill durability-wise, for this application. We also added two glow elements though. These are only visible from behind the scope, so they won’t alert whatever you’re hunting, but mean at night it is easy to locate your throw lever/know your magnification.

Custom throw lever for a clever little scope? Done!

Put a trit on it - Spyderco Autonomy 2

Tritium vial holding GITD insert for a Spyderco Autonomy 2. Seen here with our arc lighter

As part of an ongoing project to get tritium on literally everything, we embarked on a (short) journey to get one on the Spyderco Autonomy 2. Not satisfied to place it just anywhere though, we went with the fire button, making its location easy to find and the entire knife to orient even in the dark. Holding the trit is a GITD insert, for double the glow.

Project - Borescope down a Smooth Twist X barrel

First, an obligatory safety message: airguns are dangerous, and should be treated with the same safe handling practices as firearms. Do not replicate what was seen/done in the above video. Please note the rifle was degassed for this, for safety reasons. Even still, this violates several best handling practices and should not be copied.

So what exactly are you seeing here? Well, this is a .30 caliber Smooth Twist X barrel on an FX Crown. Note that the camera starts rotated approximately 90 degrees clockwise from vertical, and so the brass transfer port actually appears on the right hand side.

0:00 First you see the bolt probe, slowly being retracted, and the magazine indexing a pellet. Note how rapid/violent that is. It really chucks that pellet sideways surprisingly forcefully. No wonder groups shrink when pellets are single loaded as opposed to magazine fed.

0:13 The pellet starts to be fed forward. Again keep in mind the camera’s rotated perspective. The pellet slowly noses its way forward.

0:21 The pellet visibly engages the rifling here, showing slight deformation at the points. Notably, this is key to good accuracy on most airguns and firearms, firing the projectile before it has engaged the leade will tend to result in poor accuracy.

0:36 We’re just examining the bore here. Note this barrel has not been cleaned at all recently, so lead buildup should represent normal use. The majority of the bore appears quite smooth, although far from flawless as there are clear tool marks of some sort at various points. Notable is the leading of the lands, while the grooves appear remarkably untouched.

1:07 Now we’re at the choke. I would recommend you pause the video here, click the little gear in the bottom right hand corner, and set the playback speed to 0.25 (1/4 normal speed) and watch the whole thing carefully, potentially multiple times. It is VERY interesting. Its significance is difficult to fully discern, but the leading certainly suggests the pellet goes from riding the lands to being constrained by the entire bore in a very short distance. There is also, at least the appearance, of the lands getting wider toward the muzzle within the choke.

1:14 Out of the bore and into the liner system. Visible here is the liner retention tubular bolt and the inside of the internal shroud brake.

So what all this means is very much subject to interpretation. There is a great deal of speculation regarding the Smooth Twist and Smooth Twist X systems, how they are similar to and different from conventional rifling, etc. So here it is, a solid video showing a peek behind the curtain of what exactly is in the bore. Hopefully it is interesting, if not otherwise useful.

Light of Xiuhtecuhtli - Teaser

Just a little teaser of the LoX as we work on it here. Long exposure photography makes it easy to “cheat” beamshots, a 5 minute exposure in an area with little light pollution will make even a 5$ zoomie look impressive, however video is another matter entirely. The necessary frame rate and ISO make it much clearer if you’re cheating the shot. In this case, this 9 second clip was filmed on a potato quality cell phone camera. In short, yes, it is just that bright.

Project - Scalpeldashi Pocket Clip

Chameleon skin scalpeldashi w/ carbon fiber sheath and titanium pocket clip

It is all too common a refrain in the flashlight world “well that is great, but does it have a pocket clip?” We got a customer request for exactly that, rather than carrying it as a neck-knife or keychain-knife, they wanted a corner-of-the-pocket carry system.

There are lots of different types of clips possible, but in this case we went with a 6Al4V titanium deep carry pocket clip and stainless hardware. It carries light and out of the way in the pocket, it is exceptionally convenient, and looks good too. It all worked out rather smashingly.

Chameleon skin scalpeldashi w/ carbon fiber sheath and titanium pocket clip

Product Spotlight - Scalpeldashi

Bocote Scalpeldashi

Just how sharp is a scalpeldashi? Really the question is more along the lines of: just how sharp is a surgical scalpel blade? Very sharp is unsatisfying, so we embarked on a brief journey to vault a couple common cutting tests namely hair, printer paper, and newsprint. For this testing we used exclusively Swann Morton #10A blades, the blades we supply on our dashi.

Printer paper, this one is all too common. There are some tricks here though. The first is that paper has a “grain,” that is to say it cuts more easily in one direction than another. So when watching people’s tests here, look for ones which change direction, either rotating the sheet of paper or starting at one angle and shifting to another as the cuts progress. The next trick/challenge is technique. There is a technique to cutting printer paper that makes it easier. We know this from conversations with people such as Cliff Stamp who demonstrate this. Unfortunately we have no such talent, so if this works, it is all down to the blade. Finally is sharpening technique. In this case no technique is applied, the blades are of course virgin fresh out of the package, however in general the best edges for cutting paper are very sharp but applied on a coarse stone to leave a “toothy” edge which can keep the paper from slipping away. Cutting then at an angle and drawing the edge through makes cuts easier. That is two more strikes against this blade style passing this test, as the blade is very short and the edge itself is highly polished and refined. The paper used for this test was Staples 20 pound copy paper.

Bocote scalpeldashi shown cutting printer paper (Swann Morton #10A blade)

Of course, since you can probably see these gifs as you scroll, you already knew the answer before getting here. The lack of blade length made this slightly more challenging, mostly because cuts had to be very precise. Too deep or shallow and the cutting edge slips off the paper ruining the cut. It worked great though.

Next up is newsprint/thin glossy magazine print. This is apparently different/harder to cut than printer paper? Same challenges apply, but now to super super thin flexible paper. This specific test was done on a semi-gloss Cabelas’ flyer. The flexibility of the paper definitely made it more of a challenge to hold and maintain consistent depth on the blade. Largely though, it was about the same as printer paper which is to say no problem.

Bocote scalpeldashi seen cutting newsprint (Swann Morton #10A blade)

Finally, there is hair. Shaving is trivial with one of these blades, but shaving sharp knives are a dime a dozen anyway so that is no great challenge nor anything special. The real trick is whittling a hair. This is where things get a little more prickly. All the men of STO have short hair, hair too short to test. The ladies available and willing to donate to the cause have fine blonde hair, which doesn’t show up on camera. A dog, owned by one of our partners, has just the finest softest imaginable hair, which both doesn’t show up on camera and is too fine to be cut. There is a third option for hair sourcing from men with short hair, and those hairs are easily whittled by one of these scalpel blades as it turns out, but they aren’t *cough* suitable for a family friendly venue as such. So this one you’ll just have to take our word for, the scalpel blades will whittle some human hairs.

And that is a wrap, a little almost-science applied to some common sharpness tests to demonstrate just how sharp one of our scalpeldashi can be.

Two one-off scalpeldashi showing their strontium aluminate powered glow-in-the-dark elements

Light of Xiuhtecuhtli - Update

The Light of Xiuhtecuhtli, or LoX, illuminating a mountain about 4.3 miles away, despite first having the beam reflected off the surface of a lake. To be fair, this isn’t a huge accomplishment, as at this many candela the LoX is actually rated for ______ ANSI throw distance.

You didn’t think we’d forgotten about the Light of Xiuhtecuhtli, the most powerful flashlight in the world, did you?

A big thank you to everyone who reached out after reading our initial announcement to provide design input, or simply to be put on the inquiry list. This has shaped our plans for the LoX regarding design direction and of course price. To be clear though, we’re not going to HMG Sturmgewehr this project, we have not and will not take a penny until the production design is complete. If you’re interested in adding your name to the list though, please reach out via the contact form in the top right hand corner. When the light is ready, everyone on said list will be given an opportunity to purchase one at a discounted price.

Light painting with the LoX. This was a 30 second exposure at F11, giving just the briefest of moments to wave the light back and forth across the landscape to “paint” it with light. Note the point is a quarter mile away, and the far side of the lake is a mile away. More than a few insects were roasted as part of this process.

So where do things stand? Well we think we are about 90% of the way to the final electrical and optical architecture. Test mule specifications stand at 54 million candela (54,000Kcd which roughly converts to 54,000,000 lux@1 meter. There are severe limitations to measuring at 1 meter though, read our Test Protocols page to understand why.) and about 6,000 lumens.

The process from here is primarily about converting this light into something as beautiful as it is exceptional. Much like we’ve done with the optical design, we have every intention of taking our time and ensuring every last little detail is just the way we want it.

Just a few of the evening’s casualties. Note this is just a rough test mule for the overall architecture of the light to test the critical performance aspects, thus the hodgepodge of parts, it does not in any way represent the style choices of the final product.

Testing this light most recently revealed something somewhat unexpected: this light is an insect killer. The beam is so intense, so powerful, insects are not only drawn to it from miles around, they’re killed simply by flying through it. It was a calm night when we were doing photography, and you could see on the lake surface drops, like rain, beneath the beam of felled insects. All lights will attract insects, and some of our other lights are powerful enough to harm them if they fly close, but we’ve never seen the likes of this before. A simply inestimable number of insects falling out of the sky and into the water as far away as we could see. And not just small insects, many of them are quite large, some as large as your fist. The above photo was taken hastily with a cell phone, we didn’t realize the bezel was full of insects until we’d carried the light back and were about to pack it up. Surely there must have been more before we jostled/carried the light around?

Just something to keep in mind regarding this light, these power levels mean it is not a toy and should be treated with care and respect.

Project - Silent Laminar Flow Fan

I'm not the kind of guy to spend $500 on a blow job at Walmart..... even if it's from a guy named James Dyson.

The issue with the Dyson fans is that they’re pretty inefficient, loud, and not what you’d call cheap. So if you want to get blown in your sleep without disturbing your significant other, a better solution will be required. This project was embarked on with the explicit goals of being:

• Silent (won’t bother you or your SO while sleeping)

• Ultra-low energy consumption (remember ultimately the point of this is to cool you off, so a fan which eats a hundred watts or more may feel cool to sit in front of, but is ultimately generating a fair bit of heat)

• Focused and smooth air (so it can blow on you, but not your SO who doesn’t like it, again minimal disruption. We’re going for a gentle Hawaiian breeze here.)

• Inexpensive (it is a total experiment, so starting with a couple hundred dollars in parts just to see if something is viable stinks!)

• Adjustable for all angles (so you can aim it EXACTLY where you want it)

So objectives set, how to go about it? To solve this, we’re going for a quick and dirty project here, completed in a day thanks to rapid prototyping. Best to start with a base. Designing impellers and fans is a bit of a process, so lets go with something off-the-shelf. Computer fans are notoriously inexpensive, efficient, reliable, and well documented regarding their performance and noise level. I went with a Thermaltake 200mm case fan, two of them actually, for all of the above reasons. The exact model number is CL-F015-PL20BL-A.

And if you wanted silent air at a cheap price alone, you could very easily just build a mount for these and call it good. But bladed fans deliver their air, not continuously, but in pulses. They also tend to spread their air out quite a lot, producing turbulent flow. The optimal would be, not turbulent, but laminar flow. So the next obvious step was to set about building an integrated laminar flow head w/ mount for the Thermaltake fan.

Thanks to the miracle of rapid-prototyping, this head was ripped out quickly and fit first try. Note the dovetail at the bottom. Tripod ball heads will point in all directions, and cheap ones are available for a song, so an Arca Swiss clamp seemed like an obvious choice rather than trying to fabricobble some sort of head. I should note though that, if you had one kicking around, one of those old school adjustable desk lamps with the coil springs on the side would also work well for this application, concealing the wires as well.

So at this point you might be saying something along the lines of “great, but that isn’t laminar flow, that is just some vague stumpy ducting. What gives?” Right you are, in the famous words of Brittney Spears though “I’ve got a plan.”

So you want a whole bunch of smooth parallel thin walled tubes. What better way to kill two birds with one stone than to use soda straws? I know I’m doing my part to help us use the 6 bajillion straws Americans allegedly consume per year. (it is approximately 500 straws per fan, if you were wondering)

Having shoved all the straws together, I encountered my first problem: the relatively short duct required the straws shoved in and compressed rather forcefully. This meant the friction fit holds them in place, just as I had intended, however it also means they have a certain flare outward at the top. Not good. The other problem, running the fan, is that apparently these Thermaltake fans are absolutely piss poor at positive pressure applications, even ones as mild as this.

The flare at the top was an easy fix, just a retaining ring can be press fit around the sraws and nicely constrains them. Problem solved.

The pricklier problem of the thermaltake fans has to do with blade velocity, blade geometry, and ductwork. I could run the fans harder, I could design new blades, but the low hanging fruit is to clear the MASSIVE almost 3mm gap between the blade tips and the fans. A surprising amount of air can be felt exiting the intake side of the fan through precisely this gap.

This one took me two tries to get toleranced correctly, and even still there is about 0.5mm of under-utilized space so I could hit it a third time for even more performance. Allegedly the increase in performance is exponential as the blade tips approach the ducting. This, for now though, mostly resolved the problem.

So how does it work you might be asking? Well, as far as flow goes an inexpensive (read as inaccurate) anemometer I had kicking around measures the output as about 3.5mph at the output (straw) side. Compare that to the 5mph one of these fans, unmodified, produces on the same (again, innacurate) anemometer. Perhaps more importantly is the subjective impression, which is that even 7 feet away there is still a distinct gentle and very smooth feeling breeze. The whole assembly runs in almost complete silence.

The other question is, of course, one of power consumption. Looks like two of these fans running together is 6.7 watts, or about half one of those crappy “save the world” LED lightbulbs which outputs an advertised 60 lumens and you almost believe them. So that is pretty good.

So there it is, cheap, quick, smooth air wafted silently from any angle all for less power than the vampire draw of all those phone chargers you have plugged in all around the house. In the immortal words of George Bush “mission accomplished!”

Project - Hasselblad XPan Body & Rear Lens Caps

You may remember, around this time back in 2018, we built a replacement lens shade for the Hasselblad XPan. For those not already aware, Hasselblad are the makers of some of the finest film cameras ever made. The XPan is a discontinued panoramic 35mm film camera, which is to say it uses the archaic standard of 35mm film, however it takes non-standard exceptionally wide (panoramic) exposures with it. 35mm film cameras have overwhelmingly fallen by the wayside in favor of their digital counterparts. Take the Nikon F5, arguably the greatest 35mm SLR professional camera every built; in 1990 they were sold for 3,000$ each new. Now on Ebay such a legend can be had for a mere 300$. Unusual gems such as the Hasselblad XPan though are bucking this trend, and skyrocketing in price. Their accessories are too, as they’re being snapped up by collectors and users alike. So last year we made a replacement lens shade for a friend of the company, an otherwise expensive and somewhat fragile original component.

Well said friend of the company has been greatly enjoying his XPan and lens shade, so much so he returned asking for two more exotic and discontinued XPan components: body and rear lens caps.

To my knowledge, both of these components were never sold as separates either. The rear lens caps in particular came as part of an unusual bubble-style container in which the lenses themselves were sold. The rear lens cap had an odd external locking system, which attached it to the container bubble. It is common to see container bubbles, SANS REAR LENS CAP, available for sale on Ebay as well. Apparently these are another functional collector’s item in short supply.

Thus we once again set out to replicate the form and function of said caps, which I think was a solid success. The body cap has an alignment notch, and functions much as one would expect. The rear lens cap though is more of a triumph, fitting to, not just the lens, but the original container bubble.

More functional replicas of irreplaceable parts for camera obscura? Done!

New Product Option - Bocote Scalpeldashi & Sheaths

Scalpeldashi and sheath in bocote over phenolic

We take a break from our (apparently) regularly scheduled blog posts on airguns to introduce a new product option. Our popular and practical scalpeldashi now is available in bocote. Bocote is an exotic hardwood with an absolutely stunning yellow and black grain. This patterning is all natural, no stains or dyes of any sort are added, which makes it all the more spectacular. For this limited run, we’ve also done up a handful of sheaths to match. What a beautiful and exotic combo!

Scalpeldashi and sheath in bocote over phenolic

Airgun Moderator Design, Performance, and Development - The Final Mus Test+ (part 12)

Catch the previous episode HERE.

So there are a couple things to wrap together into this test. The first is the highly anticipated tests of the DonnyFL Emperor and Ronin. I believe I'm correct in saying that the EMP is the largest commercially produced airgun moderator out there, being substantially larger than the Huggett Magna and heavier and larger diameter, although a smidge shorter, than the Clague .30 (previously the largest moderator tested) I've put these tests below, however I'm also going to insert them into the big test so anyone looking for more info can find them all in the same place. These tests were done on the Crown .22 running 32 foot pounds, just like all the others.

The second thing is to test the final Mus revisions. This is the culmination of months of trial and failure, but finally I have a design I'm happy with so this will be generating its “final” numbers. I mentioned this before, but I've abandoned optimizing it for .22 as I just don't know how I'll ever get it to beat the Pilum, but this rev. should work great on .30 and I'll also test it on the .22 just for fairness.

The third is addressing the complaints of unfairness regarding the Clague .30, and that it ought be tested on a .30 like it was intended. I don't think these claims have a great deal of merit, that it'll suddenly change directions and be an outstanding performer when dumping almost three times as much air down the bore, but I'm prepared to give it a fair shake and a chance to shine.

Donny Emperor

Sound – 81.0
Mass (grams) – 436.6
Volume (mm^3) – 536,804
Length (mm) – 266
Diameter (mm) – 50.69
Exit OD (mm) – 8.55

THIS MODERATOR WAS TESTED ON 6.1019, SEPARATE FROM THE REST OF THE MODERATORS TESTED HERE

The first thing that jumped out at me about this wasn't the size, it was the weight. In fact it was so heavy, I had to pull the core out and weigh it in parts as it was maxing out my scale. For those who don't speak metric, that is a whisker shy of a pound. It also is the only thing I've yet tested which is heavier than the Clague, and although it has a larger bounding volume it is a little shorter. Internally this, and the Ronin, differ from the other Donnys I've handled in that, instead of three chambers of varying sizes and two baffles, these have multiple chambers of identical size and far more of them. The Emperor also now has wire mesh around the outside of the felt as well, and it is held closed with zip-ties rather than the usual black masking tape. There also appears to now be not-insubstantial space between the outside of the core-wrap and the tube, effectively creating a permeable barrier between the inner core and an outer chamber of sorts. It may seem like a small detail, but this could have a substantial impact on ultimate performance, causing these designs to perform much better than their diameter would suggest. Fit and finish is otherwise identical to the other Donnys, as described above.

Before I leap into testing, I want to note that this Emperor was marketed and sold for .22/.25, but Donny said these came out a little on the snug side for .25 so really it is best as a .22 can. This is probably because, with a couple stacked tolerances and such a long mod to amplify any tolerance issues, you want that size exit hole to quite large to reliably clear a .22 pellet. The point I'm trying to get at though is that this was very much NOT made for .30.

My initial reaction to this design was surprise, and in a good way. Given all my testing with large diameter designs, I was expecting this to be much much louder than it actually sounded. Maybe it sounded a bit like a Huggett Belita but without the ring of the Huggett? What I'm getting at is, if you didn't know it was an enormous moderator, you'd never guess it by listening to it. It didn't seem to have that sound of very high peak and low subsequent sound you (or rather I) expect from a large diameter can. Another thing I want to note here is that the muzzle is substantially farther from the shooter's ear than with other designs, and the face is much wider, so it is possible some sound attenuation to the shooters ear occurs based simply on the form factor. Put another way, this can moves the “muzzle” of your gun almost a foot further away from your ear than no moderator, and then casts a significant shadow. Given that your muzzle may have only been two feet away from your ear to start with, this is likely not inconsequential.

So how did it actually do? Not bad really. Again I was expecting armageddon, something up in the Clague range of mid hundreds. To be below 100 was great, in fact this design was almost as good as normal sized moderators. Looking at the traces, there is clearly less residual sound than many other smaller designs, but it isn't dead silent either. It is enough that, if you were to measure with an unsuitable sound meter or a phone, you might get erroneous numbers suggesting it is quieter than say a 0dB. Given this design's length and weight I can't exactly call this result great, being almost as good as a design a quarter its mass, but it sure is a heck of a lot better than I'd have guessed.

Donny Ronin

Sound – 103.6
Mass (grams) – 267.7
Volume (mm^3) – 325,562
Length (mm) – 160.5
Diameter (mm) – 50.82
Exit OD (mm) – 8.11

THIS MODERATOR WAS TESTED ON 6.10.19, SEPARATE FROM THE REST OF THE MODERATORS TESTED HERE

I covered above, on the Emperor, the internal and aesthetic observations of these two. Beyond that, they are largely similar to the other Donny designs I've tested from an aesthetic perspective and are covered in greater detail above.

I also want to note that this design was sold for .22/.25, not .30. I too would expect this exit OD to be too tight for .30.

My subjective impression on how this design sounded was “peaky,” that is to say producing a peak which is much higher than you'd expect given its draining sound. That isn't to say it sounded quiet, because it really didn't, but having passed my initial surprise given the performance of the Emperor I guess this sounded neither luxuriously quiet nor ostentatiously loud. It definitely has the kind of sound delivery which would make it hard for an untrained ear to judge how loud it actually is, if that makes any kind of sense. I do worry I've listened to too many moderators at this point, and so my subjective impressions are starting to diverge substantially form what a lay-person would perceive, however this is why hard data exists.

Well, for those who say this sounded quieter than the Sumo, I believe them because it is..... barely. We're probably within margin of error here, but on a previous day the Sumo averaged 108 and the Ronin averaged 103.6. Of course both of these are substantially louder than smaller diameter designs, but there it is. I suspect, although could easily be wrong as I have been so many times before, the design alterations of the Ronin will give it a further edge over the Sumo on higher flow guns.

As a small aside to these two Donny tests, I expect someone will point out that, while these designs may have been bored for small-calibers, they were intended for higher power air handling. To this end I screwed them to my Crown .30 (80 foot pounds) and ran some dry-fire shots through them. The results were erratic, but far from flattering, producing the highest peak of the session at 220. I wouldn't read into that though, because I also ran a couple other designs dry for the purposes of comparison and discovered that dryfires cause moderators to behave very strangely. In short, a dryfire test of a given moderator may or may not be representative of its performance with projectile, and you'll have no way of knowing until you test it properly. :/

---

Mus

Mus on FX Crown .22 pushing 32 foot pounds

Mus on FX Crown .30 pushing 80 foot pounds

Sound – 78.8 (80 foot pound .30 cal Crown VP), 82.0 (32 foot pound .22 cal Crown)
Mass (grams) – 120
Volume (mm^3) – 333,794
Length (mm) – 170
Diameter (mm) – 50
Exit OD (mm) – 8.4

I just can't tell you how happy I am to have reached this point. I keep harping on it, but really this Mus design was one hell of a slog. From my original test back in March, I've been pounding my head on this wall trying to figure out why large diameter designs don't work well, and how to overcome it. I haven't figured out the former, but at least for higher power guns I've cracked the latter. Good riddance. :P As I noted in my penultimate Mus test, this winding path ultimately lead me to a concentric chamber design. A compound blast baffle deflects the majority of the initial flow and pressure to a pressure reservoir. This then slowly feeds the gas diodes which further delay the flow. Finally the dampers provide the final sound attenuation before exiting the muzzle. The only other thing I want to draw attention to about the design is that I took great pains to keep it light weight to maintain the rifle's balance and minimize POI shift. Physically it is very large, 170mm long and 50mm in diameter, but it only weighs 120 grams or 4.2 ounces. If you read my comments on the Trident and why I liked it so much, you'll notice I really put a premium on weight, especially when hung out there on the end of my barrel.

As far as performance goes, I think it performed well. It isn't quite as much of an advantage over the Pilum QD as I'd have liked on the .30, but it does sound noticeably better. Some of that is down to the quieter draining sound, there is just less noise post-peak going on here. In a weird way you can think of this design as basically a longer moderator which got smushed and so the initial sections were pushed to the outside which make room for more sound damping toward the muzzle end. It is rather giggle-worthy to shoot something this powerful and have it be this quiet. On the .22 it is noticeably louder than what I usually run, a Pilum DD, but not outrageously so. In both cases you can see the trace has a lot less going on after the peak than both Pilum designs it is “competing” with.

Beyond that I guess I don't know what to say other than that I'm just so relieved it is over. Somehow this one started losing some of the elements of fun and became a bit of a slog. So, for now anyway, I think I'm probably going to take some time to step back from airgun silencer design. After all the point of this is fun, and so when it stops being fun you ought take a break. At some point though, there is one more thing I want to specifically “debunk” which is the all-to-common-refrain of “loudest part of the gun is the hammer slap.” This might be true for the shooter, but if so it is only because your face is inches from the hammer and feet from the muzzle; measured at an equal distance the muzzle sound is definitively louder and I want to do some testing to, not just show it, but quantify it. Remember sound attenuates substantially with distance, doubling it will cut 6dB. It'd also be cool to see just how loud the target impacts are with various calibers and backstops as compared to the gun itself going off given, say, a range of 75 yards.

View fullsize

Performance summary for all moderator designs tested to date.

---

Clague .30 on the Crown .30cal running 80 foot pounds – 115.6 – Note that this trace is on a different scale than the above. Color me surprised though, the Clague DID meter substantially better with a bigger slug running down its bore but....... there is a HUGE, round, face-swallowing but to that: it sounded like a cross between star wars blaster firing and high tension steel cable breaking. It'd be freaking awesome if it were intentional, and not trying to be quiet, but it is and so I'd call it flat out unacceptable. Appalling might be another word for it, it sounds like a bad silencer sound-effect from a Hollywood movie. The only other design which resonated this badly was the unbranded moderator which I believe was from Wolf. (the manufacturer was unclear, I don't want to throw Wolf under the bus here) I almost want to shoot a video of this to show to people, as it is so weird and distinctive. I did wonder if this sound might be caused by some sort of pellet-baffle interaction, and so I tried a few dryfires through it..... nope, still resonates. It is just so weird, I don't know what else to say. So for the people who thought the .22 test was not representative of the Clauge, I hope this addresses your complaints? :/

Airgun Moderator Design, Performance, and Development - The Semifinal Mus Test (part 11)

Mus moderator on an FX Crown

Catch the previous episode HERE.

So I'm still blundering around with this Mus design. At the moment I've entirely given up trying to get a large diameter can to work well on my .22 Crown. I'm just not going to beat the Pilum, it isn't going to happen. The Pilum is too well optimized for what it is doing to overcome the large-diameter-can disadvantage. I've gotten close-ish, but I'm flat out of ideas and nothing has any promise in terms of beating it.

On my .30 Crown though is a bit of a different story. I've still tested what feels like endless designs that are louder, but I think I'm homing in on something that'll match or beat the high-power-optimized variant of the Pilum in, not one, but two critical respects. First is, obviously, cutting the peak. At this point I don't hold out hope for beating it by much, but beating it by a whisker is something I can live with. Why? Because the second factor in how quiet a moderator sounds is post-peak-noise level. This is where some of my better Mus designs look to have an advantage over the QD Pilum. There is no escaping it, the QD Pilum is amazing at cutting the peak given its diminutive size, but given how much air it eats it still has a bit of a “whoosh” to it. So even if I can just barely match or beat the peak with the Mus, using that extra bit of space to improve post-peak-damping might just be the key to getting a not-totally-worthless large diameter design.

There is something else I want to add here, and that is I've tried a LOT of different designs to get to this point. Large baffles, small baffles, near baffles, far baffles, baffles inside baffles, tubes inside tubes, complex flow paths and geometries the likes of which you can't imagine. All failures, in one way or another. So this test here represents just a teenie weenie tiny fraction of the number of designs I've tested to try and make a working Mus. There are vastly too many failed designs and bad ideas to write up and try to explain them all. Basically, what I'm trying to say, are two things:
1) Well meaning comments suggesting “you should try....” no, I've already tried it. Intelligent and well thought out suggestions are always welcome, but realize if you're about to suggest something based on conventional wisdom, CFD, acoustic flow analysis, or a vaguely conventional design please understand it has already been tried. There have simply been too many attempts to document, that doesn't mean I've been lazy in my designing, only in my expounding.

2) This test is meant to whittle down just the last few factors as the culmination of an immense amount of research. If this doesn't work, or at least if it doesn't point directly at the final solution, I'm going to give up on the large diameter concept entirely.

So far I have never tested a large diameter design, mine or anyone else's, which performed well. As we speak I have the final two pillars of “large diameter moderator performance,” at least as far as the general airgunning community is concerned, on their way to me: the DonnyFL Ronin and Emperor. If they perform well, I'll eat my shoe and bow to the master. If they don't perform well, or if they're actually tube-within-tube or another form of sub-tube design, then..... I told you so? I guess I'm not expecting them to perform well both given the performance of the Sumo, and the summation of all the other testing I've done, but I've also been so wrong about so many things at this point really I'm prepared for anything. Crow is pretty tasty when you've eaten it enough.

All three of these designs are some flavor of concentric chamber design. A blast baffle/s deflects the majority of the initial flow and pressure to a pressure reservoir. This then slowly feeds the gas diodes which further delay the flow. Finally the dampers provide the final sound attenuation before exiting the muzzle.

Mus SD – 137.6 – Clearly this didn't work. That single diode just needed backup on an 80 foot pound gun.

Mus SD AS – 86.4 – Just a single diode still, but now with a compound air stripper. This shows some real promise, but also shows room for improvement.

Mus TD – 93.6 – Three diodes standing alone. Again this shows some promise, but isn't good enough.

I chose to highlight these three tests because they really illustrate where I ultimately went with the design. I'm afraid I've been bad about posting, so I'm writing this conclusion and posting these tests “in the future” and am about to dig into writing up the next phase of..... well of everything. More commercial design tests as well as the final Mus test. I also have received some, well lets call it “feedback,” that I was unfair to the Clague .30 in my original test; the design was intended for a .30 cal FX, not a .22 cal FX, thus testing it so under-bored is akin to “dryfire testing it.” While I'm somewhat dubious of these claims that it'll magically become quiet when dumping several times as much air through it, if gas-seal with the pellet as it passes through each baffle is critical to the design, it may well perform more adequately given lower expectations for suppression with higher power rifles. And since I have said FX .30 cal, giving it the fairest possible shake by testing it as-intended is the least I can do.

Airgun Moderator Design, Performance, and Development - The Edgun Leshiy (part 10)

Catch the previous episode HERE.

So this project had a bit of an up-and-down. As mentioned before, this Leshiy is here by the grace of a very generous AGN user who goes by Custard. These cores are 3D printed, prototypes are done in ABS simply because it is easy to use and inexpensive. They also don't have to print perfectly, because they're just tests after all, and on all our designs we use a series of precision reamers to ensure the bores are precise and consistent. For a finished version to put in Custard's gun and ship back to him, we want a perfect print to do it in 20% carbon fiber reinforced nylon. This material is, in our humble opinion, one of the best possible options for silencer cores as it is very strong, light weight, solvent resistant, and impact resistant. It really is fantastic stuff. I should add that Glock's “magical” polymer frames are also made of nylon, it really does have great material properties.

So what happened and why am I bringing up all this? Well as you'll recall the previous test results were excellent. The small wrinkle was that there were a few little print flaws here and there which ought to be resolved before moving to nylon and printing the “final” core. So I made a couple little tweaks to fix the print issues, and confidently printed out a carbon-nylon core. Putting it in the gun I was expecting quietness..... which is not what I got. By ear I could tell it just wasn't right, way too loud. I didn't even need to meter it. I was more than slightly disgusted that just a few minor design tweaks had caused such a performance shift, I mean really. We would later meter this core, just for giggles, and discover it was averaging 155. NFG.

So this launched a frenzied, and not well documented, series of design tweaks and tests to try and figure out where the magic went (the original test core worked just fine, and still metered in the mid-teens) and how to stuff it back into the design. Yes, silencer design can be just this annoying and fickle. This process resulted in a dozen small tweaks, and ultimately the loss of a baffle. This circles nicely back around to the original test which, turns out, also performed better with just 3 baffles. Go figure. So, below, is the final series of confirmation tests on this project. And the rifle is already on its way back to Custard.

Factory Leshiy Configuration – 260.3
It is loud. We've been here. It is also inconsistent, unusually so, sometimes throwing numbers down in the hundreds other times throwing numbers over 300. In all my testing the highest number it ever threw was 364, the lowest 196. The average from the entirety of testing was 256.8, and the standard deviation 41. If you're wondering though why some test are a little high and others are a little low, this is why. That inconsistency means if you're only pulling 3 shot averages one shot low or high can really skew things. I feel this total average is very representative of the gun's capabilities in the factory configuration.

Final rev. core – 112.0
We lost a baffle here and also lost 3 points off the average of our previous best test. That is insignificant though because, even though this is an average of 8 samples, the standard deviation was 11. It is, to my ear anyway, a significant improvement in sound attenuation over the factory configuration so I'm happy with it. We didn't quite crack 100 (average) as I'd hoped, spending another two months trying to shave another 12 points off the average would be no fun so what is the point? There is also something else......

Extended Shroud/350mmBBL – 87.0
We wanted to test this configuration, not just confirm assembly/fit. For those unaware, there is a popular kit out there which takes minutes to install that gives the Leshiy a longer barrel, longer shroud, and more power. Turns out our new core works very well with it, as it comfortably cracks the 100 mark. Standard deviation was even 6.8. Being slightly less volume constrained obviously helped, but the other thing we did was take a special cut piece of foam that fits inside the spacer/shroud and around the barrel, and shoved that all the way to the back of the shroud. This way, as we learned testing on the Crown, sound would be less apt to reflect up and down the tube. And, thanks to my core design, the damper is essentially “built in” as it comes in contact with an angled rather than flat face.

So there it is, the Leshiy and new core are on their way back to Custard as we speak, along with our sincere thanks for letting us have a play with this system..... and thats enough of highly eccentric volume constrained systems for a while now. :P