Making M120 Springs Work (Theorycrafting/Build Recommendations)

Tech Talk
1

Hi all,

So I bought a pair of M120 springs a while back when I started to upgrade my units (J16 and BF P90 V4) and 0 experience/knowledge in upgrading things. That said, I was quickly told by my tech friend that I was basically an idiot and it will literally make my gearbox explode/warp beyond repair and since then I’ve changed to an M95 and M100 spring.

Now that being said months in the future, is there anything I can do with these springs or try to make them work with a nylon gearbox (The only ones available in my country are nylon ones)?

Thanks in advance!

EDIT : Something I forgot to mention is that it doesn’t even cycle on the stock J16 but it can shoot pretty well with the BF P90 V4 (at great risk since the gearbox in that thing is thinner than the one in the Jinming iirc).

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2

I would never recommend an m120 be used in a nylon gearbox. Your tech friend is right in suggesting it will warp a nylon gearbox beyond repair.

In early days before we got metal boxes people would cut down springs to lower the power, but I also don’t recommend this. While it does work, shortening a spring can often lead to other issues.

You could short stroke… a lot. to get the power down but the warping risk would still be a factor. A mate made a m4 pistol out of a gen8, which from memory (was 5 years ago) used a frankentorqued motor which was pretty slow, a dsg gearset and an m120. He did not use it alot though so it may or may not be something that lasts. It was more of a seeing if it would work. Even though it was a DSG, it wasn’t super fast only about 26rps. I’d only try it if you don’t care if the gearbox needs replacing afterwards due to failure!

3

Thanks for taking the time to reply!

Yeah I guess I’m SOOL without a metal gearbox huh? I’ve seen people saying to cut the springs but the whole idea just screams “sketchy” and way more into the concept of “contraption” than I’m comfortable with in modding my units :rofl:.

Are M120 springs alright in a full metal gearbox and stock motor though (will it reduce its lifetime and incur more wear and tear)? I’ve been eyeing the MCX Sijun 89-3 and based on feedback from fellow players the power leaves a bit to be desired fresh out of the box; at least for games in my country (Common FPS is around 300)

No doub’t I’ll probably have to disable the blowback to reduce straining on the stock motor though. Other than that I’m curious on how it will influence the other bits and pieces of the gearbox (assuming all metal and upgraded internals).

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4

M120 is honestly a bit much for cast metal gearboxes. Honestly the only stock gearbox I can say will safely handle it is the metal cyma box, currently only way to get one is in a metal cyma blaster though which is very disappointing.

Because gel is best below 340fps, m120 is something I only use when taking 4-5 teeth off, and is doing over 30rps with more than 350fps which is nuts. It’s rare for that sort of build. An m100 will happily get close to 30rps 330fps with a full stroke, less work involved.

You could cut it down but it is better to just get the spring with the rating you need. Always.

Much more at home in a short stroked high rate of fire CNC box.

5

As @RokSolid commented, M120’s and above are just seriously harsh operating springs.

Every single time that the piston is engaged EVERYTHING is under extreme loads to compress them, then when they release, every single shot uses the piston head like a Jackhammer against your Cylinder Head and the frame of the gearbox :fearful:

They are used in DSG/Short Stroke situations because the piston is only compressing the spring half distance, which would lose FPS in a normal spring, so the bigger springs are used to make up for that loss in spring compression to gain the FPS back again.

As they have a much shorter stroke, they don’t build up the Jackhammer power or speed like a standard blaster would do.

6

Understood, thank you for the explanation and yeah I kinda noticed after switching to the M100 spring on the Jinming (Genuinely appreciate the insight on the short stroke too!). I’ll keep the springs in my box of shame and greed for now and I’ll take a look back if a CNC box ever becomes available here.

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7

This is something I quickly noticed after it cycled once. Seeing that it stopped working I disassembled the box and could literally see cracks and massive wear marks all over. Even the cylinder wasn’t looking good! At this point it’s not a jackhammer but a full on pile driver on the whole box.

The DSG/Short Stroke is something genuinely new to me to be honest hence it never really occured to me. Thinking about it now, pretty obvious since with the short stroke the shorter travel distance + harder spring would just give you more or less the exact same power of a full length one without literally pounding the box apart. The more you know!

Thanks for the insight!

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No worries mate, that’s exactly what we are all here for :+1:

If you have an old JinMing Gen8 Style Nylon blaster, I can give you a good list of parts and modifications that can reliably push 400+ FPS… but in reality, it’s a complete waste of time and effort which has terrible results on accuracy and reliability :roll_eyes:

I can give you details if you are interested in building an unbreakable Gen8 gearbox that will give 300-350 FPS for the rest of your life, but the sweet spot is from 280-320 in reality :ok_hand:.

let me know and I can give you the parts list that won’t cost you an arm and a leg :stuck_out_tongue_winking_eye:

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9

I am in the process of setting myself up to make some videos to help out people with all the things I have learnt over the last 6 years. Hopefully in the next month I can start putting out videos. Making videos is very new to me and will take me some time to get a handle on as time is something I have very little to spare.

I have two companies interested to help out once I get it off the ground, so I have plenty of motivation for it.

Short stroking is definitely on the list to feature. And while it is more to the advanced side of tech work, it isn’t something that is hard to do or grasp. Often not needed, though in short barrel blasters it can greatly improve efficiency and optimise the setup with little loss of fps.

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Ah, the misguided quest for extreme FPS… :joy:

I just recently went through all of my harder hitting blasters and downsized piston springs to drop the FPS to below 300, the target being about 280.

Best example is my CYMA XM-177 which was pushing 340+FPS… couldn’t hit a 3" target from 5 metres away with it. Dropped it back to 270 and with the Rizer working like it should it’ll hit a torso sized tree consistently at 18-20 metres. Some inconsistency in elevation accuracy but I put that down to gel size variation and hopup interaction. Windage accuracy has improved out of sight with an average spread of about 15cm.

That 3" target at 5 metres can now be hit 100% of the time with a dialed in red dot.

Seriously, for me the object of the exercise is to hit what I’m aiming at as consistently as possible. If I can get 90% of my Ultra Elites pinging off my target at 270FPS, I’ll take that over 90% of my 340FPS gels missing it by a metre all day every day. :joy:

I’m not sure when we decided that 300+FPS was the desirable outcome… because it just isn’t. Over springing stresses your gearbox shell, wears your bearings faster, robs you of any accuracy and makes your expensive Rizer or DB hopup redundant.

I don’t see the point. :man_shrugging:

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Never did as far as I remember, was just a tinker thing if you can and want to.

I never even bothered all of mine are near smack on 280-300fps and that’s the way I like them. Each to their own :+1:

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I always found that high FPS was an UNWANTED result from doing simple upgrades that were for no other reason than to build a reliable quality blaster and nothing more.

Back when people were in awe at something 300FPS when OOTB blasters were in the 170-220FPS range…it wasn’t any Rocket Surgery magic to find 300-350FPS through simple air sealing and minor tweaks.

I’ve always tried to keep builds to the 270-300FPS range for the ultimate performance, but to achieve this always meant DETUNING the components to try and stay at those output levels.

My mad scientist journey with the “little pig” nylon Gen8 punching 450+ was just a shits n giggles exercise to see how far the boundaries could be pushed.

Was that sort of FPS good for anything…
Hell no, but it was a fun challenge to see exactly how far the envelope could be pushed and learn the weak points of the engineering for reference in future builds.

This is the reason I enjoy this hobby so much, to be able to apply engineering, physics and electrical skills to achieve amazing results in many different applications.

Still haven’t found another hobby to replace it yet, so probably get back into the RC Buggy building like I used to do years ago… but still not as fun as Gelbasters :pensive:

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@DocBob I remember that time when getting something to be reliable at 300fps meant you were a god among men! How far this hobby has come!

When I teched for a retailer I seen some poor choices! A guy come in, with an LDT HK416, that just keeps warping gearboxes, breaking everything, sick of fixing it can you do it and make it last.
I ask him “what do you want out of it?”.
He says, "I play outdoors, I want 300-330fps, good range and accuracy, with a bit faster rate of fire and snappiness. (so what everyone wants really!)

I say of course that’s easy, quote him up and crack on. Gearbox comes out and it was indeed warped! It’s locked up with the piston right at the back, undo some of the screws and twist the spring retainer and BAM! M140 spring and retainer launches into me! M140!! in a nylon ldt box! Undervolumed massively cause he has extended the barrel but not changed the cylinder, done no air seal work… When I asked what fps he was getting? 310fps! From an M140! And the look of despair when I say ideally that spring would be able to get well over 450fps with his long barrel… and it is pointless!

Poor man just kept buying gearboxes, banging this big spring and a high torque motor in them with no other effort. We have all made learning decisions, I did too early on but I enjoyed the journey :slight_smile:

Anyway, got the thing going with an m100, doing consistent 330fps and shooting decently accurate, he was happy and I only seen him to buy more gels from then on. Lovely!

The thing I find is accuracy becomes harder above 300, and very difficult over 340fps. It can be done, but everything has to come together and work out for it to happen, and then it still wont be as accurate as something doing 270-300fps.

Barrels must be very sturdy and stable both inner and outer, airseal and volumes must be bang on, and you may go through a few different hopups before finding one that works well. It is expensive and time consuming. Now and then you jag one that just works like you hope, but for the most part its alot of trial and error combined with experience and knowledge. And while it can hit a person size target at 30m, so can the thing doing 270fps with a hopup! Sure the 380fps beast can reach out another maybe 5 metres, if they see it coming they will just move, and if they don’t you will need a good burst to ensure one gets on target. Easier to just get closer with less fps, and the blaster will last longer.

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Well I dunno about that. My RC buggy aint bad at all. :stuck_out_tongue_winking_eye:

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Nice work :+1:

The very first advice that I give to anyone looking for bigger springs, batteries, motors, hardened gels etc is to simply fix the air seals!

I tell them all the time thing… adding bigger springs and all the other bullshit will achieve absolutely bugger all if all the air pressure is leaking like a sieve from every single orifice :roll_eyes:

#1 priority for any Gelbaster is to fix air seals first before touching anything else.

When I was reviewing all the brand new blasters OOTB with supplied batteries and gels, I would Chrono stock performance, then strip, fix seals and reassemble/test.

Would always see an increase of 40-50FPS from this simple work with all the factory parts sealed properly and nothing else.

As you said, if I seen someone getting 300 FPS with a M120 spring, you knew Syra away that their air seals and VE were absolutely shit house :rofl:

Quality parts gave big FPS gains, but they were fitted for reliability and efficiency, not high power output… that was the side effect that had to be dumbed down through VE and ported cylinders etc to lower the FPS to the desired level :ok_hand:

You might remember that I always purchased at least two of every single model blaster that I owned, to be able to keep one in 100% original condition in its box for the collection, and the other to tear apart and test which mods gave the best results in overall performance.

I truly believe that hopups are definitely limited to a certain FPS range, where too fast or too slow greatly reduces their effectiveness.

As many tests proved that some hops became useless at certain levels, even though they were brilliant at lower speeds.

This relates to your other comments about trial and error when assembling parts.
NOTHING is designed to fit or work together :face_with_symbols_over_mouth: hence the need for a huge stockpile of thousands of different parts :roll_eyes:

This is why I still have a storage unit piled high with big boxes of brand new and 2nd hand performance parts even though I don’t have any Gelbasters to put them in!

Every single build was planned on paper, required parts for each build were ordered and I wouldn’t get the customer’s blaster until all of the parts had arrived.

How many times half of those parts simply wouldn’t work together inside those Blasters was infuriating, stalling the build and requiring digging through my pile of alternative parts to try and get a good combination together, or having to order more parts in the hope that they might fit the job causing more delays… but there’s nothing that can be done to avoid this as you don’t know what you’re facing until you have the parts right in front of you!

Sounds like I’m having a whinge, but that was actually the enjoyment of overcoming these setbacks and being able to end up with a good quality product in the end :white_check_mark:

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That’s it and what I got taught by a few good people. Efficiency. But also if you want to go ham, well it’s your blaster do whatever the fk you want. Just don’t kid yourself or know/research what you are doing.

17

This is the most true thing in gel ball. Tolerances and specs are wank, everything is a wild card of will this work with that.
Also how I ended up with 30-40 pistons in my cupboard! Springs gears nozzles, trigger switches… you name it I have multiples of it! And most of it only works well in one or two things that I may never see again :face_with_symbols_over_mouth:

Building for efficiency is the best option, always. That is why my vector with MK cnc box is 24rps @ 310fps, it used 800mAh to go through a whole game day and 4 litres of gels! The brushless helps sure, But the rest of the build is very much set up to be efficient over power, and that is the “outdoor” setup, two screws and the spring can be dropped down to 240-280fps depending on the spring if the field and rules are a bit tighter. It is quite versatile now. :slight_smile:

18

Yeah, I’ve got a healthy collection of ugrade parts that don’t work because they’re poorly made. Cylinder heads and nozzles, mostly. As someone who worked extensively with CNC machinery, I can tell you that CNC doesn’t guarantee functionality or accuracy. It comes down to the data file and the machine setter, and knowing Chinese QC and manufacturing practices, it’s a crapshoot.

It’s a bit of a trap for new players… you install upgrade parts expecting them to be an improvement and more often than not, they’re not. Plenty of my blasters run a mix of alloy upgrade parts with nylon OEM parts because that’s what gives the best result… counterintuitive maybe, but it is what it is.

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19

My favourite was metal gear sets.
Didn’t matter what brand, even though they were top quality expensive sets and not cheap cast parts, had wildly different tolerances that made them sometimes impossible to be able to use :face_with_symbols_over_mouth:

It was most common that the axles were too wide, which meant zero ability to shim anything, and would lock up solid as soon as the gearbox halves were screwed back together🙄

Alignment between teeth on the sector gear and piston racks being way off each other, pin holes in cylinder heads drilled in the wrong place, tappet plates or the plate runner channels in the gearbox being too tight to slide freely, tappet plate not having enough space to fully cycle having Airsoft travel in front of the gearbox limiting proper cycling and many many more :face_exhaling:

Great fun!

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I’ve had the same. I have a box of tappet plates, box of pistons, box of nozzles cylinder heads springs retainers gears bushes and bearings motor towers gearboxes the list goes on and on.

I guess eventually instead of modifying everything to fit I just bought more variety of parts. Now I try to just use the right part for the right thing, but still end up modifying parts to suit! It never ends!