How do I prevent or mitigate gearbox cracking in the future?

[steverebo]

So if anyone has seen my other threads my gearbox cracked and the piston shot out the front.

 

Out of shear luck someone on this great forum had a spare orion gearbox that they sorted me out for postage and a coffee!!

 

So, I don't want to be in the same situation anytime soon and wanted some advice from you guys on what if anything I can buy or do to help prevent or mitigate gearbox cracking?

 

I have seen these cylinder heads do these help?

 

Thank you all in advance 

Edited February 15, 2022 by steverebo

[EDcase]

Its simple to prevent that kind of problem:

Don't use high speed gears

Don't use overpowered spring

Don't use 11.1v Li-Po

😁

[steverebo]

3 minutes ago, EDcase said:

Its simple to prevent that kind of problem:

Don't use high speed gears

Don't use overpowered spring

Don't use 11.1v Li-Po

😁

But where is the fun in that 😏 

 

In all seriousness I purchased all the bits for a 13:1 build short stroked the gears purxgased q perun v2 and everything and the trigger response is amazing.

 

I do however have a set of 16:1 zci advanced gears but didn't use them because someone told me they are pretty much identical to the stock 18:1 gears 

[EDcase]

The gearbox is a system which was designed to work within a set of performance parameters ie speed & power.

If you change components which alter the working parameters to increase the stresses in operation then you have to upgrade parts which deal with those extra stresses.

 

The gearbox shell is too weak to deal with any increased stresses so that needs to be upgraded...

 

 

Edited February 15, 2022 by EDcase

[Groot]

Radius the gear box and do not put in too big a spring and you will be fine. 

 

If you are planning on going DMR then you are putting stresses on a box that it was never designed to take. So other than going for a good brand of AEG it will or will not split

[EDcase]

Apparently the Orions are already factory radiused

[Skara]

Don't dry fire like a MF:

There is no resistance caused by a BB in the hop unit so the piston will just slam forward with all its force. A couple of shots at the end of the game day to make sure there is no bb left in the "chamber" and unplug the battery.

 

Use PLASTIC Piston heads and Cylinder heads:

Metals aren't very good at absorbing vibrations, the impact from the piston is transmitted directly into the gearbox shell and it'll eventually crack. A damping pad on the cylinder head might help, but depending on your setup it might fuck with your AoE and cause a whole new lot of issues.

 

Make sure your airseal is perfect:

As with dry firing, air leaks will lessen the resistance caused by the air being trapped between the piston head and bb (seated in the hop rubber), causing the piston to hit the cylinder head with more force. Plus you get inconsistent energy output, hop up effect and crap performance. A perfect air seal will let you use a weaker spring to achieve the same energy output, which in turn reduces the stress on the gearbox shell.

 

Radius the gearbox:

Helps, but if you don't do the above you'll still crack it.

 

You can run high RPS builds in pretty much every gearbox shell bar Onions and Ares boxes (for real, Ares gearboxes have the same strength of wet tissue paper).

[steverebo]

10 minutes ago, Skara said:

Don't dry fire like a MF:

There is no resistance caused by a BB in the hop unit so the piston will just slam forward with all its force. A couple of shots at the end of the game day to make sure there is no bb left in the "chamber" and unplug the battery.

 

Use PLASTIC Piston heads and Cylinder heads:

Metals aren't very good at absorbing vibrations, the impact from the piston is transmitted directly into the gearbox shell and it'll eventually crack. A damping pad on the cylinder head might help, but depending on your setup it might fuck with your AoE and cause a whole new lot of issues.

 

Make sure your airseal is perfect:

As with dry firing, air leaks will lessen the resistance caused by the air being trapped between the piston head and bb (seated in the hop rubber), causing the piston to hit the cylinder head with more force. Plus you get inconsistent energy output, hop up effect and crap performance. A perfect air seal will let you use a weaker spring to achieve the same energy output, which in turn reduces the stress on the gearbox shell.

 

Radius the gearbox:

Helps, but if you don't do the above you'll still crack it.

 

You can run high RPS builds in pretty much every gearbox shell bar Onions and Ares boxes (for real, Ares gearboxes have the same strength of wet tissue paper).

Do you think the orion will hold up for a while?

 

I've got some replacement bits in my basket:

 

Gearparts pom piston head

XT steel heat resistant cylinder 60%

XT cylinder head with 2.5mm pad

ZCI 14 tooth cnc piston

XT 21.4mm nozzle 

E&C tappet plate 

 

The gears and bits I currently have are: 

ZCI advanced 13:1 gears short stroked by 2 teeth

M100 piano wire spring

ZCI high toque motor 

Perun V2 hybrid

 

Edited February 15, 2022 by steverebo

[EDcase]

If you want fast trigger response then your best option is to use an 11.1v

[steverebo]

2 minutes ago, EDcase said:

If you want fast trigger response then your best option is to use an 11.1v

I forgot to mention I am using 11.1v 30c batteries as well

[EDcase]

Wow, and that's still not enough!?!?!

 

You might want to analyse your play style 😄

[Druid799]

1 hour ago, EDcase said:

The gearbox is a system which was designed to work within a set of performance parameters ie speed & power.

If you change components which alter the working parameters to increase the stresses in operation then you have to upgrade parts which deal with those extra stresses.

Perfectly worded and perfectly describes the reason why so many have problems after they’ve ‘up-graded’ their guns(especially TM’s) .
Eloquently put good sir 👍.

[Speedbird_666]

3 hours ago, steverebo said:

Out of shear luck someone on this great forum had a spare orion gearbox that they sorted me out for postage and a coffee!!

 

Should be in post tomorrow mate. Hopefully it'll tide you over until a better shell can be sourced.

 

As I've said in other threads, I know E&C shells work from first hand experience, but getting hold of one is difficult in the UK at the moment as you've found. 

 

I know Retroarms are producing Specna-branded gearbox shells, but they cost as much, if not more than a complete Specna CORE gun. 

 

Another option is to buy the cheapest Specna CORE gun for around £100, gut the GB out of it and sell off the externals. A faff, but a feasible option? I've not heard anywhere nearly as many issues with the CORE series internals. 

 

 

[steverebo]

24 minutes ago, Speedbird_666 said:

 

Should be in post tomorrow mate. Hopefully it'll tide you over until a better shell can be sourced.

 

As I've said in other threads, I know E&C shells work from first hand experience, but getting hold of one is difficult in the UK at the moment as you've found. 

 

I know Retroarms are producing Specna-branded gearbox shells, but they cost as much, if not more than a complete Specna CORE gun. 

 

Another option is to buy the cheapest Specna CORE gun for around £100, gut the GB out of it and sell off the externals. A faff, but a feasible option? I've not heard anywhere nearly as many issues with the CORE series internals. 

 

 

Cheers buddy! 

 

Has anyone tried FPS Softair cylinder heads and pistons they are advertised for HROF

 

[Skara]

I run their poly piston heads. They work fine at 30ish rps

[Rogerborg]

You can get "bracers" that wedge in front of your gearbox to brace it against the shell, e.g.

 

https://www.aliexpress.com/item/32215233163.html?spm=a2g0o.9042311.0.0.75234c4dcmkYQz

 

V2/M4 only, and they only work with old style dial hop units, not the rotary units (Maxx, ZCI, Specna).  They rely on friction from two tiny grub screws to hold two other tiny cylinders in place, so are interesting bodges that probably don't really address a problem that should never have been there in the first place, but, you know... airsoft.

[steverebo]

I am hearing conflicting things about the rubber dampener at the front of the fps cylinder head preventing cracking and actually speeding it up?

[Skara]

What's not clear about using polymer cylinder and piston heads?

[steverebo]

Ive decided to go for the lonex pom mushroom head piston head and rocket silent cylinder head as supposedly these absorb a lot more than standard and reduce the risk of cracking.

 

Now I am just debating whether to stick with my 13:1 gears or swap to something less stressful

[EvilMonkee]

Buy a GBBR

[Lozart]

21 hours ago, steverebo said:

Do you think the orion will hold up for a while?

 

 

How long did the old one last?

[steverebo]

3 hours ago, Lozart said:

 

How long did the old one last?

3 games 0900 to 1600 so I'm hoping that was just a lemon and the one I'm receiving will hold out longer.

 

I have purchased the lonex pom mushroom head silent piston and rocket silent cylinder head which I am hoping help reduce some of the shock. 

 

I'm going to grab a retro arms hop u it as it is more stable than the plastic ZCI one I am using and has a rubber washer nozzle end which in theory should also help reduce shock plus my ZCI hop unit has terrible fitting with my maple leaf barrel it wobbles all over the place.

 

Also hoping the different design of the retro arms feed tube might help with my feeding issues and be ready for the retro arms split gearbox when I get the money together to grab one 

Edited February 16, 2022 by steverebo

[Lozart]

Honestly, with the setup you're trying to run I doubt it's going to last all that much longer. They're just not good gearboxes.

 

In terms of all the things you're changing I'd be amazed if you don't constantly have some issue or other purely because you seem to be intent on slapping in whatever you can lay your hands on and hoping it works together which as you are finding out, isn't always the case.

 

I wish you luck.

[steverebo]

31 minutes ago, Lozart said:

Honestly, with the setup you're trying to run I doubt it's going to last all that much longer. They're just not good gearboxes.

 

In terms of all the things you're changing I'd be amazed if you don't constantly have some issue or other purely because you seem to be intent on slapping in whatever you can lay your hands on and hoping it works together which as you are finding out, isn't always the case.

 

I wish you luck.

It was all stock bar the gears and mofset till this happened as the stock compression set was fine and had no issues but it all got totalled when the gearbox cracked.

 

I tried to get a slot with luke from negative airsoft to fix it but he has a backlog of 3 months so I'm trying myself and hoping it works out 

[Lozart]

1 hour ago, steverebo said:

It was all stock bar the gears and mofset

 

So all the bits that make it go faster than it should then?

 

This is entirely my point and it's a general one not aimed specifically at you - if someone had said "I want to put 13:1 gears and a mosfet in my Specna Edge so I can make it go BRRRTTT is this a good idea" then we could have all said "no" or "well you can but don't be surprised if it breaks" and saved a great deal of cost and heartache. It's the same as the endless "just bought this is it any good?" posts.

 

Like I say though, best of luck. My personal advice would be get it going with the replacement box you got on here and the standard gears and keep it as a backup gun. Then go buy a better one to fuck about with.