9 replies to this topic

[nehebkau]

So I know this is not a big deal but it's something that just struck me. Lots of classes are using jump jets, not just for getting into firing positions or getting over tough terrain to take a tactical position but to provide another access of combat movement. For as little as .5t you can add add another level of targeting difficulty to those you are fighting (and as well to yourself when you target)

What I am saying, is that jump jets are quickly showing their strength as an offensive, active combat, weapon not just for lights but for the heavier mechs that can mount them. This got me thinking, shouldn't there be a trade-off for using them in combat, besides the very low weight and critical slot cost of these items? It just seemed to me that jump jets should be producing a bit of heat when they are being used -- and the bigger the jump jet the bigger the heat it makes.

What I suggest is that jump jets produce heat over time for their use, dependent on the size of the jump jet. Light-weight jump jets, like those found on lights, would produce almost no heat but the huge engines required to jump a victor would produce quite a bit of heat.

It seems to me that there is really no difference between a giant flame shooting out your butt generating heat and a flamer shooting out your hand in regards to their heat production -- in fact an internal nuclear powered thruster would produce more internal heat than a flame-thrower.

So, begin the polarization of comments : "I love JJs -- this sucks" or "I don't use JJs -- this rules" and the "I use JJs but don't want to say so therefor I'll say I don't to give my argument more weight then say the idea sucks".

Seriously, though, doesn't it make sense that an internal jet, fusion or plasma engine would produce internal heat? (Even if it is something highly improbable like compressed air, the act of compressing it produces waste heat)

BTW I do use JJs on some mechs and not on others.

[Coralld]

As much as I am for JJ balance, there are currently enough threads floating around about this that people can post in.

[Firewuff]

Technically JJ are more likely to cool your mech as you are explelling hot material out of your mech even if it would show up on hear vision like a torch.

That said a small heat gain of 25% you get with a flamer might make it a more balancing factor. More JJ the faster you heat up. Would also curbppop tarts as it adds heat.

[Colonel Fubar]

And I want a Mech Pogo Stick!

[Gryphorim]

Actually, I like this Idea, that JJ's increase heat. I'd say though, do like the flamer and make them so, whilst being very hot to run, they cap out at 80% heat. That way you can use them for a tactical retreat, but not for poptarting.

Edited by Gryphorim, 20 February 2014 - 12:41 AM.

[Mekwarrior]

What about air cooling while falling of some of the heat used in the jump? Or you could jump jet off a mountain to dissipate heat.

If they did add jump jet heat, I'd like to see the ability for jump jets to recharge while in the air. It seems silly that they can only recharge while on the ground.

Edited by Mekwarrior, 20 February 2014 - 08:02 AM.

[BourbonFaucet]

They did in the TT to the tune of a minimum 3 points + 1 per hex beyond 3, if I remember correctly. It'd really cut down on PPC poptarts, at least, not sure about ballistic ones. Might be a nice addition to have some heat generation.

[Nothing Whatsoever]

Well, MWO Jumps Jets burn too long and have a limited thrust in comparison to their description in the Tech Manual.

Here's some stuff on Mech Jump Jets

Spoiler

By harnessing the power of a 'Mech's fusion engine to superheat air or another suitable fluid, Jump Jets allow a BattleMech to briefly overcome gravity and rocket short distances over the battlefield.

Operational Details

Jump jets work in a similar, albeit more limited, fashion to the fusion rockets installed on Aerospace Fighters. Inside a magnetically shielded reaction chamber buried deep inside the 'Mech, an electron beam superheats a reaction mass and expels the expanding gases through nozzles located on the back of the 'Mech or in its legs. Reaction mass is commonly provided in the form of air forced into the reaction chamber by a system of turbo-compressors, but most 'Mechs have a small amount of alternate reaction mass, usually in the form of hydrogen, water or mercury, in order to facilitate operation in a vacuum and to reduce the wear on the jets from superheated oxygen when in an atmosphere that contains it^[2]. The reaction mass provided by an atmosphere is effectively infinite, but the supplementary reaction mass carried on-board is limited by the number of thruster assemblies installed unless additional tankage is added to the 'Mech^[3].

Because of the heat produced by jump jet activation and limited on-board fuel, jump jets can only maintain thrust for a few seconds. A far cry from flight, jump jets nevertheless allow a 'Mech to make short leaps sufficient enough to outmaneuver 'Mechs not similarly equipped or bypass obstacles and unfavorable terrain^[2][1]. Care must be taken when jumping, however, as jumping causes heat buildup with even the shortest jump generating more heat than running, and damage to a 'Mech's gyro or leg actuators and joints can cause a 'Mech to fumble upon landing[4]. Owing to the inability of liquids to be compressed, submerged jump jets cannot be used lest the extreme pressure rupture the jet's casing^[2][4].

Attacks by a Jumping 'Mech

Jumping makes a 'Mech harder to hit, but the accuracy of weapons fitted to the jumping 'Mech is also adversely affected^[4]. In addition to standard weapons fire, a 'Mech with jump jets can perform a combat maneuver known as Death from Above, which involves it jumping into the air and attempting to land on an opponent. A successful DFA has the potential to crush an opposing 'Mech's head, but the maneuver risks damage to one's own 'Mech even if the attack is successful^[5]. Another attack that has been known to be performed using jump jets nicknamed the "I Am Jade Falcon" maneuver uses the jets in a 'Mech's legs to torch an adjacent hostile^[6].

So, what we should have is more thrust with a shorter burst and a longer cooldown between bursts so that it's harder to use them as frequently in combat as we currently can.

Distance should also be standardized where each JJ provides 30 meters, possibly set a different heat value when they are used, and maybe also tie the acceleration to reach that height to the number of mounted Jump Jets and/or engine rating and mech weight.

Further details in spoiler.

Spoiler

So height could be like this:

• 1 JJ - 30 M
  
• 2 JJ - 60 M
  
• 3 JJ - 90 M
  
• 4 JJ -120 M
  
• 5 JJ - 150 M
  
• and so on

That would give the SDR-5V the ability to jump to 360 M with 12 JJs, for example.

Setting the heat value could be 1 heat per JJ, or whatever is fair to set.

Jump Jet acceleration could be tied to the Engine Rating and weight of the mech, so that a light with an XL 300 can accelerate faster than an Assault with an XL 300 for example.

Then we can tweak the shake to where having too few Jumps Jets from the max that can be mounted, increases screen shake.

So a CTF-3D has stock set up of 4 Jump Jets, so mounting only one limits jump height to 30 M and has a shake penalty of +75% to a standard value for screen shake.
Mounting two reduces the penalty to +50%, three reduces penalty to +25%.
Mounting the four, there still will be screen shake and no penalty, but it is slightly reduced from where it currently is, since the mech was designed to use that number of Jump Jets.

The same should work for Jenners 1 JJ, 30 M but 80% penalty. 2 JJ 60 M, 60% penalty and so on to the max value.

Mechs that can mount a higher max than their stock loadout of Jump Jets should still get any height bonus like the SDR 5V or VTR-9K, but the penalty for mounting less should be calculated from their stock numbers.

[MeiSooHaityu]

Sounds like a good idea. I kind of like it better than my limited JJ fuel idea (which I had posted in a few threads). Similar in that Assaults and Heavies would be more limited than Lights when it comes to jumping.

The heat idea would be easier to implement and a bit more fair in a way.

I approve.

[Coralld]

I can see this possibly working, especially if PGI makes it so that all JJs provide the 6m jump height like they are suppose to, because currently in MWO the first JJ you put in gives you 3 to 4 times that and all others afterword are 6m.
So, if all JJs provide 6m jump height this means not only would they have to add more JJ which requires more weight for more lift but they would also be producing more heat.

Edited by Coralld, 20 February 2014 - 12:27 PM.