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King Arms 8mm V2 Gearbox

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*note, bear with me on these pictures. Photoshop is currently down on my PC, so had to use other editing programs.

 

 

This gearbox is listed around $40 to 60 dollars depending on where you go. It has 8mm bearings which is nice, suggesting that it is stronger than 7mm. Comes with what seemed to be a high end switch and tappet plate.

It has reinforced sections around the gears as shown.

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We tested this gearbox on Aug 14th. A list of parts is mandatory to explain the outcome.

 

Guarder Silent piston head

Guarder Cylinder

Guarder Cylinder head

Deep Fire Titanium teeth piston

Systema Super torque Helical gears

Systema Magnum motor

Systema m170

 

The platform was a CA M15a4, with stock hop up unit and mad bull bucking.

 

After carefully shimming the helicals and test firing, it was off to the range. The distance was very nice, shooting well over 240ft with .30s and the CA stock 509mm barrel. With a 2400Mah battery and a Systema Magnum the ROF was about 15 rounds a second. After coming in from shooting we decided to take a look at the wear. There was little to no wear on any of the parts, however we had to grind down a section of gearbox due to grinding issues with the helicals (See 1A). We than attempted to rear wire it, which in my opinion is harder than other gearboxes. As noticed in this picture (See 1B), there is a random hole in the back of the box which makes the wires sit rather loose, and then are proned to "pitching" when closing the box.

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We also had problems with our anti-reversal latch. We tryed a systema, guarder, and a "XYT" brand, all grinded with the spur gear. We eventually grinded down one of the anti-reversal latches. After installing it back into the body we noticed something rather shocking.

 

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We checked the other side and...

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Now, I have gotten a few comments referring to our idiocity of putting a 170 in a V2. However, we have been running a Classic Army stock V2 box with a 160 chroning at 500FPS for at least 15,000 rounds with no cracks. A "reinforced" gearbox should not crack with less than 500 rounds through it, despite spring strength. Most people will stick a 120 in their boxes, and eventually even they will crack, but this is simply a foreshadowing of that outcome.

 

Over all this box looks nice, the performance was good, however the durability is below poor. I would not recommend this box ever, unless you are using a M90 spring.

 

The next gearbox we are going to review is the Systema V2. The walls near the cyilnder are almost twice as thick as the King Arms box, and we are predicting that it will last alot longer.

 

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Your review is biased and unbalanced. Thus your recommendation of not using a King Arms box is utter nonsense.

 

To disprove my statement you would need to accomplish the following -

 

1 - You must review 3 more King Arms gearboxes and install the same components each time under the same test conditions.

2 - You must review those same 3 boxes(should they survive) under a high speed 400fps application to test not only strength under high stress, but also strength under high cyclic rate.

 

To further my low opinion of your biased review is the following -

 

1 - I have now installed no less than a dozen of these same gearboxes. Here are some of the "Big power" examples -

Box 1 - 500fps at 29RPS | Magnum motor - 12v 40amp NiMH ~ 5000 rds as of last month

Box 2 - 500fps at 27RPS | Magnum motor - 12v 30amp NiMH ~ 2000 rds as of last month

Box 3 - 410fps at 28RPS | Magnum motor - 10.8v 40amp NiMH ~ 9000 rds as of yesterday(this was opened tonight to confirm)

Box 4 - 390fps at 26RPS | Magnum motor - 10.8v 30amp NiMH ~ 4500rds as of last weekend

 

2 - I have personally tuned my SR-15 to 600fps and cycled well over 1000rds through it in that same box at nearly 25rds a second just to see if my piston and gears would last. Guess what they did! :)

 

So in conclusion, until you review more than one, and a miscast one at that, gearbox you should not post your "review" for all to see. Or at the very least post a disclaimer stating you only reviewed one gearbox and anything you write for us to read should be taken at face value.

 

Oh and for anyone else who likes doing reviews of one item at a time and saying it's poor please think before you post. It's entirely possible you just got one bad casting/molding and the majority of the others will make out just fine.

 

Cheers :)

Edited by sc0rp10n
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In that light, they are obviously proned to "bad casting/molding". Therefore I still will not buy another, nore advise anyone else to either.

 

Seems to me your post lacks credibility. Where are your parts lists? Pictures? Anything to even slightly show that your not just rambling.

 

And I guess anyone who has a review about a gun, a optic, a pair of boots, a bag of bbs, or any thing else on this forum is also considered "utter nonsense"... Right? So you can only say something is "poor", only if you have three of them? What if I rated the king arms box great, would you have sh*t all over me for not reviewing three of them? I didn't think so.

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Trust me, Scorpion here holds more credibility than most "airsmiths"

 

He is called by people around the country to tune gearboxes, and has been highly praised, not only by his team, but by the local airsoft area, and those who have sought his services across the states.

 

I have personally been there, watching him test and test, and check each angle and new item to check durability and standards. I would go to no one else with internals work, ever.

 

His time and expertise are well placed to assess doubts in your review.

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The 3 different problems we had with them, (Cracking, anti reversal latch, gear grinding) is a clear statement that it is not just, "bad casting".

 

And according to your friend, your only allowed to review something if you have had 3 of them. I guess every review in this section would be described as, "biased and unbalanced" and "utter nonsense".

Edited by nativeofsandiego
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well, place it this way, you have seen one piece, not a large amount of them. Someone might have a problem with a computer, it could be totally specific to his, and he will rant to the world that the entire series is bad.

 

Now, if more people had your opinions, there could be some credibility. Seeing as how you have had experience with one box, and he has done multiples, there might be more backing from his words than yours.

 

Totally defaming a product for one specific individual item does nothing to truly tell the product.

Edited by Sinner101GR
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Incorrect! How can you even say they are prone to bad casting when I just gave you 4 examples of GREAT casting? Are you even reading what you're typing? :)

 

No I wouldn't have *suitcase* all over you, because we would be sharing the same opinion. However I would still have posted, though in that case to reinforce your point of their quality design. Also I obviously was posting on this review because it's a gearbox. You are reviewing a piece of material that is cast and sent down a line with thousands of the same item cast over and over. You sir, through that very post right there are proving my original post correct. I am merely giving you more reviews than the single one you provided. But to be fair let's cite your examples for comparison...

 

~A gun, well maybe there could be a bad one, but as this item requires many working parts to function at the same time it is a review more of the craftsmanship of the assembly, not the build quality of the specific components. Again if you went into detail here you would be going after more casting flaws or possible CNC errors.

~ An optic, sorry to bring more bad news, but this falls under the AEG category. Again you are measuring the parts used as well as the craftsmanship of assembly. This review should be given at face value and should ask for other reviews in case this item has a bad lense or a miscast body. Remember this is Asia here folks, do it cheap and do it fast! ;)

~ A pair of boots, now that is a good review! Provided they're fairly compared to other boots of the same quality level and caliber of craftsmanship. I think you could actually do a boot review as a stand alone. Good choice here!

~ A bag of BBs, oh c'mon! Are you serious? 1 bag? Of the millions of rounds out there? And you want to review 1 bag? Yeah....no.

 

EDIT - Oh and about this stuff here "The 3 different problems we had with them, (Cracking, anti reversal latch, gear grinding) is a clear statement that it is not just, "bad casting"."

 

Here's what went wrong, as I've seen it on many gearboxes, get ready it might blow your mind!

1 - Systema gears are usually just a tad thicker than any other gear set known in airsoft. Thus they have to be shimmed on average .1-.2mm higher in the gearbox than say Prometheus gears. Oh and isn't it ironic that all I've used in my builds are Prom gears and I've had no issues while you used Only Systema in your one and had clearance issues with the anti-reversal? Hmm...that might be biased to assume that all systema gears are manufactured just slightly differently. Maybe if someone had tested over 20 sets in the past 2 years he'd have an idea. Oh wait, I did that! :D

2 - Gear grinding? Uh, I don't see any burn marks on the bearing so I'll assume the shimming was ok. So that means you're talking about the grinding on the trigger stop from the sector gear. Where you took that section out... Yeah that's standard issue for ALL Systema Helical gear sets. That's why if you ask any dedicated Airsmith he'll tell you that you don't and shouldn't ever need Systema helical anything. With all the new shims, Teflon treatments, ceramic bearings out there you don't need anything but a Prometheus torque or high speed gear set to turn anything 500fps and under.

 

As I predicted you took it personally and not for the objective criticism I was trying to provide. I was hoping you'd see it as a review of your review from a fellow airsofter, but somehow that got lost in translation. So please, again, think about what you are saying before you type it ;)

 

And as requested, parts lists -

 

Box 1 - 500fps at 29RPS | Magnum motor - 12v 40amp NiMH ~ 5000 rds as of last month

 

Full guarder cylinder set

TM piston - TM piston head (ported, shimmed, drilled for lightweight and Teflon coated with over sized o-ring)

Prometheus Torque(standard) gear set

AB+RF MOSFET system wired in

Prometheus MS150

 

Box 2 - 500fps at 27RPS | Magnum motor - 12v 30amp NiMH ~ 2000 rds as of last month

 

Full guarder cylinder set

TM piston - TM piston head (ported, shimmed, drilled for lightweight and teflon coated with over sized o-ring)

Prometheus Torque(standard) gear set

AB+RF MOSFET system wired in

Prometheus MS150

 

Box 3 - 410fps at 28RPS | Magnum motor - 10.8v 40amp NiMH ~ 9000 rds as of yesterday(this was opened tonight to confirm)

 

Full guarder cylinder set

TM piston - TM piston head (ported, shimmed, drilled for lightweight and Teflon coated with over sized o-ring)

Prometheus High speed gear set

AB+RF MOSFET system wired in

Prometheus MS120

 

Box 4 - 390fps at 26RPS | Magnum motor - 10.8v 30amp NiMH ~ 4500rds as of last weekend

 

Full guarder cylinder set

TM piston - TM piston head (ported, shimmed, drilled for lightweight and Teflon coated with over sized o-ring)

Prometheus High speed gear set

AB+RF MOSFET system wired in

Guarder SP110

Edited by sc0rp10n
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As I predicted you took it personally and not for the objective criticism I was trying to provide.

 

Seriously?

Your review is biased and unbalanced.

 

utter nonsense.

 

my low opinion of your biased review

 

That sounds like objective criticism to me! (Sarcasm in case you missed it)

 

 

First off, what are you talking about? You took specfic examples from my generic meaning (boots, optics, etc) and began to critique and analyze as if you were going to finish with an over solution that will prove my post wrong. Missed it completely my over zealous airsofter, YOU said only reviews with 3 example would be credible, no specifics... My response, any one who reviews anything is an idiot under your paradigm, why? Everyone who ever writes a review is biased if they haven't had 3 of them.

 

Second, do YOU even know what your posting? A Full guarder cylinder set in every box, and yet a "TM piston - TM piston head" in every box. Not sure how your fitting two pistons, and two piston heads in everybox (since every Guarder cylinder set I have ever seen has come with a piston, and a piston head). But hey, it must be possible since you have done 5 gearboxes! Man, thats more than anyone ... EVER!

 

Also, all of your examples included springs less than 170s. You apperently have ZERO experience with 170s in King Arms 8mm boxes. Why are you even posting? Seems to me you are lacking the experience required to be posting in this thread.

 

How can you even say they are proned to bad casting when I just gave you 4 examples of GREAT casting?

It's entirely possible you just got one bad casting/molding

 

Oh and by the way, I gave you one example of "bad casting" because mine broke! In case you missed that also.

Edited by nativeofsandiego
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Just lol! Boy you're a feisty one, I'll give you that, but if you note your sarcasm it takes away from the value. Shall we take one more swing? I think so :D

**Notice the use of smileys, I'm having fun and I hope you are too!

 

I obviously noted TM piston and piston head to describe the fact that the guarder components would have been replaced. Thus my specific notation of said TM parts. Tada the answer is obvious!

 

Let's see what else did you say...oh yes. I do like how you've just now noted, 7 posts later about the fact you have "Oh and by the way, I gave you one example of "bad casting" because mine broke! In case you missed that also. ". Thank you for clarifying that. That's all I was saying. And now that we are in agreement we can both go about our upgrades our own ways. I sure hope to meet you one day on the field. I bet our guns would be pretty darn close in power. Heck it might even happen, you're in TN right? I'm just up the road in Ohio. :)

 

EDIT - I just saw that part where you're trying to nitpick my comment. Sorry you're wrong there too. I specifically quoted you and your king arms box. You're the one who said all reviews. Oops you failed on that one :(

Edited by sc0rp10n
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Box 1 - 500fps at 29RPS | Magnum motor - 12v 40amp NiMH ~ 5000 rds as of last month

 

Full guarder cylinder set

TM piston - TM piston head (ported, shimmed, drilled for lightweight and Teflon coated with over sized o-ring)

Prometheus Torque(standard) gear set

AB+RF MOSFET system wired in

Prometheus MS150

 

(etc)

So TM pistons and piston heads are the way to go? Care to elaborate on why? Just curious. :)

 

Oh, and thanks for the input for this thread, it's stuff like that we can learn something from. Very interesting.

Edited by Utty
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So TM pistons and piston heads are the way to go? Care to elaborate on why? Just curious. :)

 

Oh, and thanks for the input for this thread, it's stuff like that we can learn something from. Very interesting.

 

 

I'd be glad to, but all I do is a repeat of what Corvid and our fellow high speed "gurus" have been doing before me. In fact I happened to learn at almost the same time they did :)

 

I don't want to take this thread off topic so you have a PM in bound!

 

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TM pistons are fantastic because they seem to have the perfect blend of nylon and whatever the hell else they use in their formula for maximum durability.

 

The pistons seem to "give" but at the same time remain just rigid enough to absorb any and all shock they receive from the sector gear. They're an incredibly great product.

 

I havent had any issues with the version 2 king arms boxes that ive installed down here in Florida. Granted, im sane enough to realize that the version 2 gearbox design is FLAWED so i dont go thinking ill get a ridiculous amount of rounds out of a high fps version 2 box.

 

Native, if you're going to test another king arms box go ahead and radius the cylinder windows next time.

 

Also, i have a king arms version 3 box running 345 fps 23 rounds per second that has seen more than 100,000 rounds now. I use this thing hooked up to a drum magazine and 3 minute long bursts are not uncommon. I have yet to see any fatigue in the gearbox or improper wear cycles anywhere in the gearbox.

 

The reason why i mention this is because the version 3 box is regarded as an extremely strong platform, the version 2 is not.

 

You basically demanded ferrari performance out of a kia.

Edited by Magsz
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im sane enough to realize that the version 2 gearbox design is FLAWED so i dont go thinking ill get a ridiculous amount of rounds out of a high fps version 2 box.

 

You basically demanded ferrari performance out of a kia.

Now, I have gotten a few comments referring to our idiocity of putting a 170 in a V2. However, we have been running a Classic Army stock V2 box with a 160 chroning at 500FPS for at least 15,000 rounds with no cracks. A "reinforced" gearbox should not crack with less than 500 rounds through it, despite spring strength. Most people will stick a 120 in their boxes, and eventually even they will crack, but this is simply a foreshadowing of that outcome.

 

I am running a stock CA V3 gearbox for only 500 rounds, but happy to report, no cracks.

 

I will not buy another King Arms box, simply because the Systema is just as good (better in our trials) for the price.

 

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Which leads me back to my previous post.

 

CA radiuses the corners of their gearbox. King arms doesnt.

 

Still, having said that, its less costly to radius the cylinder windows than it is to have 8mm bearing holes drilled...

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Couldn't you use a key hole file to radius it?

 

You can radius any gearbox by hand quite easily. Its alot harder to drill out holes for bearings if you want everything to be aligned properly. Not everyone has access to a drill press.

 

The point that i was making is that radiusing is easy, going from 7 to 8mm's isnt so the king arms product is NOT worthless.

Edited by Magsz
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Radiusing the gearbox explained in the following link. It's in Finnish, but the pics are more than self-explanatory: http://juoksuhauta.net/stories.php?story=mecha

 

Gearbox radiusing is an effective method to reduce stress around the gearbox "cylinder window" corners, which are the frequent (only?) points of failure. It is not a 100% sure way to prevent a gearbox from cracking, but it does reduce the risk significantly.

 

As much as I agree with Sc0rpi0n that you shouldn't draw too hasty conclusions based on one cracked gearbox, you could have gotten heads to turn much more easily with a softer approach.

 

Gear grinding is related to the Systema gears you were using. At specific gear ratios, you need to mill out a chunk of the gearbox - and it's even advised in the Systema instructions, at least with the FTKs that have those gears (like the M160 G3 FTK).

 

I've seen some boxes (like G&P) take very hard punishment even without radiusing, but it's a good heads-up that this King Arms box was blasted (even though it's just an individual case), so radiusing is probably a good idea if you get one.

 

-Sale

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When you start a reply with this review is, "biased and unbalanced", you are injecting a personal opinion and therefore you made it personal but I'll step back a second and agree that I should have presented the review for what it was; A SINGLE DATAPOINT. In reality and to be mathematically correct, for a sampling to be statistically significant, you need no less than 16 datapoints. This applies to any type of statistical sampling from computing CEP's to determining failure rates. If you really want to get silly, the sampling can only be determined by changing one variable at a time, which gets really hard since there's a wide variation in the quality of airsoft parts from even the same vendor, so using your logic, and given the strictest requirements for determining a truly valid sampling, your review is as worthless as mine.

 

Let's get civil and reasonable. I provided some insight into my experience with a single King Arms gearbox, coupled with your Four successful tests, that is a 20% failure rate for King Arms boxes, which by any standard is too high to consider them a good investment at this point.

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sorry to be offtopic again, few more pix concerning radiusing, hopefully a bit more explanatory here. again, sorry no English, but I think it will be clear from the pictures what is it all about and how to do it.

 

btw. thank you for the reviews - both native and scorpion, i actually think your discussion was pretty useful ;)

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I'm surprised it took as long as it did for radiusing to be mentioned. Yeah the OP was a bit biased in his but that's understandable as it needed filing to go together properly and then broke almost instantly :P And if the gearbox isn't radiused, get that file out even if your putting an M90 in there :)

 

As for getting 3 of the same product before to passing judgement on something? :D I'd like to see someone suggest that to... ohh say the guys in the WA M4 thread. :P

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