...I think... :/

Anyways.... if you wanted to make this work, youd need a Heckofalot of work on it -.-

Not only am I famous, but I inspire Hipster...ness... Yeah.
~Tsu

In this game you need to take the offensive. No one will buy that low damage but knocback crap. Besides such knocback would break combos or bother your nearby allies. Really, you make it sound like it functions exactly as a shield bump, but also takes up an extra weapon slot.... And there already exists a weak sword with huge knocback, its called Leviathan Blade--> plus its free if you do missions

i cant see why would i want to craft such useless not-new thing, when there are better alternatives that do the same already for free.

The main issue with this thread is how a horizontal jackhammer does everything you claim; do you swing it like a blunt weapon or pound the internal organs out of something in front of you? I found this page which is essentially your post but the two make no sense together. Yours makes it sound like something you swing like a two handed club, the other an illogical melee weapon designed to break through armor. What is it best at, knockback or damage? Is it supposed to be used like this, a two handed weapon? I can understand a thin and long hit box; we already have that for the second and third swings for rapier swords.

The basic attack knocks the enemies away, yet we already have shield bumping. This is not a first person shooter. Shield bumping does not damage for a reason.

It is not intended to be a main weapon yet can one-shot most enemies; this alone makes it too overpowered to exist. I can understand if it can one-shot some of the weaker T1 enemies in the first few floors, but nothing after that should be able to kill in one hit except some charge attacks of weapons of the next tier star ranks.

It may seem like it at times, but most threads I am able to read; the "I hate the energy system" and "I want pets/dual wielding/free CE/other stupid selfish whining" threads tend to melt onto each other sometimes, but this thread is not one of them. I understand you want the mechanics of this weapon but keep in mind the golden rule of all equipment: it must not be overpowered. Everything overpowered is instantly shot down and picked apart by vultures who necro the thread to spite others. I can understand a jackhammer, but Autogun essentially already does the effect this weapon appears to do but as a melee weapon. Assume when using content from other games as reference no one knows how it works; no one knows what you mean. The basic attack as an elbow bump makes sense but will not be implemented due to the existence of shield bumping. The charge attack seems to activate the piston battering, destroying enemy armor; does this break monster shields (Gremlin, battlepod, et cetera) or just damage in rapid succession? The first would be overpowered, the second is already done through Autogun.

Suggestions not being implemented in the game? Have you seen Polyps and Howlitzers, or the +2 charge on the Volcanic Demo Suit? Almost all of the content, including Lockdown, came from suggestions. The threads may be buried under all the "I want free elevator use", "I want lower prices", et cetera fodder threads but they existed and were taken to the front lines. Suggestions matter. I believe Shadow Lairs came from here from bored veterans. I remember the Howlitzer thread.

Is this what you meant for the weapon? If so, this is the most overpowered thing ever. You can run up to anything and one-shot everything and Spiral Knights has no ammo restriction, only clip sizes. Nothing in the game will ever work like this. Never.

@OP:
First things first,
Allow me to ASSUME that your weapon's normal attack is mainly for KB, whereas the charge attack is specialized to take out immobile enemies with ease.

If you don't know how this animation would work, go play an old WWII FPS. You know, the good ones nobody hears about.
Irrelevant.

Charge attack is whatever pilebunkers do. The jackhammer function. Very high damage, much higher than Troika's 2nd hit. Also pushes.
Remind me how you are going to hold the weapon with your hands, given that it is relatively large?
Also, doing 'very high damage' and 'pushing' contradicts each other, unless the knockback is extremely minimal or the damage is dealt in a single hit, which goes against the 'jackhammer function'.
Welcome to weapon mechanics 101.

The knockback only gives the thing enough time to charge before the enemy comes back.
If it doesn't have this, it'll be extremely weak and nobody would use it. Shield can't push constantly, nor can they damage.
As with most swords' normal attacks; this is not my main concern.
And it won't be "extremely weak" if you scale the damage up a little.

The Pilebunker would add an interesting game play style for those who don't want to press M1 and then shield cancel as their main attack for slow swords.
You will need to depend on your shield eventually. That's why they were implemented in the first place.
And if you are using slow swords, you are at risk of being more vulnerable to attacks. Consider that into the design of the weapon if possible.

Everything is but a variant upon itself.
The examples you use are in the same line. Not the point; you're suggesting a new line of weapons altogether.

Unfortunately, you're making a Troika clone with a new charge attack mechanic - it essentially has the same function as a Troika; i.e. KB and high damage to a single target upon a charge attack.
Granted, one of the lines can inflict fire, but this is a marginal concern.

Want me to reword everything I said up there in a more simple wording? Fine. You guys won't listen anyway.
See? That wasn't too hard to understand now was it?
You're invited to attack our arguments, not to commit argumentum ad hominem on us by implying that we are stupid.
Similarly, I dismiss your idea as uncreative, but I have no right to call you 'stupid' because one idea was bad.

And don't rage like that. You're only making yourself seem very immature.

TL;DR

Not at kentard the topic