13:1 Gears killing my power

[Ugly American]

Hi all. I specifically signed up for this site for help. Out of all the forums I've read, this one seems to be the most chilled with some of the smarter members.

My problem is that I installed some Echo 1 13:1 gears in my G&P Ver. 2 gearbox.I properly shimmed them and it is exactly what I want, I mean it's fantastic sounding. However when I select semi-auto It dies. No power until I take the thing apart and put it back together. I don't know what info you guys will need or pictures, however I'm willing to put up whatever necessary to get this working. I've essentially just built my dream gun, but it's turning into a nightmare.

Here's the info I can think of:

G&P ver. 2 gearbox 8mm bearings
m120 G&P motor
7v lipo (I wired and soldered everything, it's solid)
Echo 1 13:1 gears
Speed Trigger (had to dremmel it in order to make it fit proper, no issues before swap)
Stock G&P 14 tooth piston and head

I'm clueless as to what's going on! I've got 2 weeks to get this working properly as I'm going on my 1st vacation and 1st big op (Irene Lion Claws)

Help guys!

Thanks in advance, I hope all the information is helpful. I'm stuck and have no clue as what I need to do at this point.

[GBBR]

try out a different motor, G&P120 is really poor, also you can PM me to get in touch, I'm sure you have skype video calling.

because you are somewhere in the states its difficult for me to actaully see the gun, video may be the closest I get

[Sequential]

Originally Posted by GBBR

try out a different motor, G&P120 is really poor, also you can PM me to get in touch, I'm sure you have skype video calling.

because you are somewhere in the states its difficult for me to actaully see the gun, video may be the closest I get

Wow Mr.Yan so nice..

[GBBR]

Originally Posted by Sequential

Wow Mr.Yan so nice..

stop stalking my posts and help this man out.

[Ugly American]

Thanks GBBR. What.motor do you suggest? I've got a few lying around. Also I've never skyped however I know it can't be hard. It's driving me crazy! I should add I've got a echo 1 and king arms gearbox lying around, however they're not 8mm bearing. Are the 8mm's better? I mainly work on cars, I'm still a skrub.

[GBBR]

I'm also a mechanic. I'm sure there are automotive examples I can use to help relate

[lurkingknight]

bearings aren't that much better than bushings.. in fact I prefer bushings.

what was your method of shimming? did you start from the pinion to bevel mating or did you just start throwing shims into one gear and start from that?

The reason I ask that if you did not start from the pinion to bevel mate, you could have shimmed the bevel too high and you're causing the pinion to bind on the bevel with too much resistance.

The other possibility is that it's shimmed too tight. there should be just a bit of side to side movement in the gears, about 1-2 sheets of paper width movement in all the gears with the 2 halves of the gearbox screwed together.

To shim it from the pinion to bevel, take the bottom half of the gearbox and put your bevel in, take your motor grip and screw it into the half of the gearbox and install the motor into the grip with the baseplate. The pinion should meet the bevel and mesh nicely, but not tightly with the bevel but not be too far towards the center. If the pinion is resting on the bevel then the bevel has too many shims under it. It's too high. Adjust it until it has a bit of play.

From there, take the grip and motor off, and shim the bevel from the top with the other half of the gearbox so that it has 1-2 sheets of paper of side to side play. From there work up the gear train.

It also helps to superglue your bushings or bearings into the gearbox shell so they don't move. if they slide around they can throw your shimming attempts off... and if there's slop they can actually rotate in the shell (bushings moreso than bearings) and end up enlarging the bushing holes in the gearbox further causing misalignment in the gears.


furthermore... I agree the g&p 120 is a shit motor.

[RaisinBran]

a great motor for the price would be the newer SHS high torque's I think mine was ~$30+ shipping currently pulling a m120 and using 13:1 gears.

[ThunderCactus]

Originally Posted by GBBR

I'm also a mechanic. I'm sure there are automotive examples I can use to help relate

He just replaces his 3.93 rear axle with a 3.21 on a half ton truck that he uses to tow 10,000 lbs.
It'll move when you give it shit, but takes forever to get rolling lol

Short term fix is to use a 3s lipo. Actual solution is to use a high torque motor.
Gone are the days when you had to sacrifice speed for torque, these days some of the high torque motors spin even faster than the stock motors.

[GBBR]

Originally Posted by ThunderCactus

He just replaces his 3.93 rear axle with a 3.21 on a half ton truck that he uses to tow 10,000 lbs.
It'll move when you give it shit, but takes forever to get rolling lol

Short term fix is to use a 3s lipo. Actual solution is to use a high torque motor.
Gone are the days when you had to sacrifice speed for torque, these days some of the high torque motors spin even faster than the stock motors.

couldn't be more correct, I just had this gut feeling that he shimmed it properly. G&P120 motors... don't even get me started at the store I work on, we LITERALLY have a bucket of cookie tin, ( yknow the butter biscuit things ) FILLED with G&P 120, almost EVERY G&P M4 we've ever sold we've replaced a lonex durable long motor.

sad fact, the m120 motors just barely pull their stock springs...

[Ugly American]

I forgot to say, I'm using a m110 spring. I can't be over 370fps. Would I still get the high torque? I understand the car metaphor better. I lurked and read and researched...I'm just wondering what tge heck is going on! I had the bright idea to put the 13:1's in my other mechbox's and see if they crap out. I'm just stuck! Hours have been spent tinkering and reading....So you guys think it's the motor? I've got a jg, echo 1 and an unlabled generic one. It's getting old. I've got the accuracy down. I just like a high rof because I spray...

[GBBR]

I gave you my skype information. a quick skype call and I'd be walking you thru what to do.
I skype becuase yknow, typing is tough.

[pestobanana]

Labels like "high torque" and "high speed" generally don't mean anything.
G&P M140 is supposed to be a "high torque" motor but it's still faster than the M120, and considering how long it takes the damn thing to reach full speed, it's wound more as a speed motor than a torque motor.

It may be a good idea to check your setup with a multimeter, check how many amps you're drawing. It's probably a good indicator of how good your shimming is. Last time I checked my setup doing 455 fps at 15 RPS was drawing about 16 amps.

As for a motor just get any neodymium magnet motor, and since you have 13:1 gears you'll want one wound for torque. Cheaper motors seem to work, but they're rather inefficient and get excessively hot. I have a VS high torque motor in one of my guns pulling a M110 with a 16:1 gearset. It's not too bad, I'm getting a decent 32 RPS. Kills the battery pretty fast and the motor also gets hot pretty fast though.

[ThunderCactus]

Comparing amperage isnt a viable diagnostic. Guns draw across such a large range it would be impossible to tell trouble pulling a spring from having a bent armature. There isnt enough consistency in setups to derive any conclusion from amp draw.
But we know the M120s are bad and we know you need a high torque motor to pull a 370fps spring on high speed gears. Solution is simple.

[GBBR]

Lets all to agree disagree on how to further diagnose this aeg and all of us can basically agree that g&p m120 is terribad and he should try a torque + motor.