How did this happen?

[Muffin]

I finally got my parts in for my Classic Amry SD5, I got a EG1000 TM motor and Guarder high speed gear set. I was happy to get it up and running since the original motor had died.
So me and my team met up today for a game and about 2 hours into the day it stopped firing. I was in the middle of laying down fire in full auto until it stopped and just clicked whenever I pulled the trigger. I assumed I had perhaps let off half way through the cycle, but my 9.6 had lots of juice left.
So we head back to the cars where my tools are and I start taking it apart, I attempted to release the anti-reversal latch but it was free, no pressure on it, so once I fully opened my mechbox I descovered this:


Nearly half the teeth of the top gear were ripped out, and shaking around inside the gearbox.
After taking more of the parts out and inspecting them I noticed this:



My gearbox is cracked all over the front end of it. The piston, piston head and all those front end pieces SEEM to be undamaged.
Like I said I just got these parts in and installed them. Everything was installed properly and shimmed, but what went wrong?

[FOX_111]

Classic Army, it's to be expected.

[CupidStunt]

Originally Posted by FOX_111

Classic Army, it's to be expected.

Your wrong there. Check the New thread up about it for proof

[[Avtomat]]

Originally Posted by m102404

Either that or your mechbox failed the transition from adolescence to adulthood...see, it only has one pube...

lmao. . sorry

[Drache]

I had the same crack in my mechbox of my stock TM SG1.....

[SHÖCK]

A sorbo pad may have prevented this attrocity

[Muffin]

I doubt that a rubber pad will have prevented this, nevertheless it is a good investment.
Anyone else had any problems with Guarder products?

[Marriott]

And i thoguht Guarder Gears were steel... That amount of teeth removes is more like what would happen with Cast gears...very odd... What power rating was the gun?

[Luckless]

If they are hardened steel, it could have been a bad heat treatment. The joy of any metal is no matter how high the quality is, there is always a chance of very nasty failure from something just a little wrong.

Hope you get things sorted out. Has anyone tried repairing a mech box with a slightly flexible epoxy? I know there are some used in engineering that will rip chunks out of the steel before the cured epoxy itself fails, yet are still slightly flexible.

[airborneboi69]

whats youre spring %you have in youre gun?

[Skladfin]

just buy a new mechbox now, time to ditch the old shitty one!

[Drake]

High Speed gearset AND a 9.6v batt... either you were using a stock-ish spring and had insanely high ROF (asking for trouble) or you were using high speed gears in conjunction with a stiffer spring (asking for trouble).

The cracked mechbox makes me think it's an upgraded spring.

[Muffin]

The gun has been upgraded, although with what I'm not sure. I emailed the guy who I had bought it from but he said the person before him had done up these upgrades.
I've installed many upgrades on guns for my teamates with springs up to M120 but when pushing my spring back in it didn't feel as stiff. If I were to guess I'd say close to the 350fps mark(its not the stock spring).

[lupo]

Honestly to me it looks like the piston had a very bad seal and just slammed the cylinder head too many times. Pretty common problem it usually takes longer for that to happen but if it was really bad and combined with the highspeed gearset it makes sense.

[Muffin]

Originally Posted by Skladfin

just buy a new mechbox now, time to ditch the old shitty one!

I was thinking of doing that but right now I just can't afford to dump more money into this thing, I'll probably just part it out.