V 1 Mechbox
 

Hello guys.

I've been having fun upgrading a version 1 mechbox.
Styrak sold me metal bushing, piston kit and a 110 prometheus spring. PS he is a great retailer.

I put everything together.
Some dremel work for the bushing.
New head, new piston and new spring.
Close and try...
Gears turn and just stop...
I loosened the screew for the mechbox (had a problem like that with a version 2 and it solve everything).
Thing turn better but no complete cycle.
Try a few time... now some smoke came out of the motor.
So I stopped.

I tried to crank the gears by hand and I couldn't crank hard enough to do a full cycle.

So now I'm not sure where I should look for the problem.
I the dremel one side tooth on the cylinder because it would backup in the gears.

Thanks for any help

Check that it's properly shimmed (remove compression parts, screw the mechbox down, and see if you can spin the gears easily, they should do a rotation or a few rotations), or use a bigger battery.

Have you properly shimmed it yet? What battery are you using (mini, large, voltage, brand?)

Just a question.

How the Hell did you manage to get the gearbox back together? I swear you need to have 4 Right hands to close the damn box.

Everything moves fine until I get to the final compression part.

The motor move to 40%
By hand I can get to 80% (just can't turn the gear 180 to the stopper)

Battery is the mini 1400 Tenergy

I used a flexible potato knife just under the firing switch to hold everything. Then I put the cover on from back to front and slowly remove the knife.

And voila

First of all, that's a mini battery so it probably doesn't have enough power.
Secondly, Tenergy batteries are crap so it definitely doesn't have enough power.

Get a bigger/better battery.

+1

And you might need a new motor if a better battery alone doesn't cut it.

What do you suggest as a battery?

Considering the FAMAS has a custom High Speed motor for high rate of fire; it's just not designed for anything other than the stock (280 fps) spring. I'm gonna tell you flat out that the motor can't handle that spring for long.

Get a stock spring (M90) and keep your rate of fire, or an aftermarket motor like a G&P M120.

What do you suggest as a motor?

OK then so I'm going for the G&P M120
Anyone you would recommend or a place to buy one?

www.airsoftparts.ca kicks all kinds of ass. Also www.redwolfairsoft.com or www.ehobbyasia.com.

You will need to modify it, though - the original FAMAS motors are not compatible with newer guns:

http://www.airsoftcanada.com/showthread.php?t=29452

Will the V1 MB hold up to an M120?

Well I got an aftermarket G&P M120 motor. But as you can see in the picture... it doesn't fit.

http://www.securenet.net/members/jeremiel/motor.JPG

So now what????

Actually, unless its a super old FAMAS, it should have an updated EG560HT which provides more torque (similar to a regular EG700). Extra ROF is provided by the gears (basically high speed gears): therein lies one of the problems with upgrading a FAMAS.

That being said, I've upgraded a FAMAS to run a PDI 140% spring and it barely dented the ROF (~1000 rpm instead of 1100). The fact that in this instance the gearbox had to be loosened to crank properly leads me to believe something happened at the shimming level. It's also possible the bushings aren't seated right / too high / too loose (dremeled to fit.. that's kinda WTF-ish, if a gear's center axis is off the mark by even a fraction of a MM you'll end up with a massive failure -- which is kinda where you're at now)

And no you can't replace the motor with an EG700 equiv. You need an EG560. (good luck)

There is a mod to fit a short motor into a FAMAS gearbox....but I'm not sure where it is on the internets.

With all this...

What is my next step?

Battery?
Motor?
Shims?

I will take a look to see what I can find

Thanks

When I put a polycarb piston in my V1 mechbox, we actually had to cut part of the piston down as a lip of it prevented the piston from sliding along the mounted guide rails inside of the mechbox. This may be part of the original problem.

Do you remember which brand?

I used a System polycarb and didn't encounter that.


@moogy:

Start by checking the shimming. That's always the place to start.

Actually I did this.

I figured this one by trying to turn the gears with the piston but no spring just to see if any thing was blocking it.

i use a guarder infinite torqu motor on my M14. seems to run fine. no complaints (knock on wood)

The issue isnt the brand of motor. Its the physical size. The FAMAS uses a different size motor then any other AEG, see the pictures

I think it was a systema polycarb

Is that the name of the motor????

No, he is referring to a polycarbonate piston.