High Speed Gears Stripping Pistons

[MADDOG]

The reason the lipo works and not the others is it has more voltage going to the motor ( a moderate torque motor) trying to pull non-torque up gears with a 400 fps spring. The motors you are using do not have enough torque with a lower voltage to power the 13.1 ratio gears through the spring cycle. This is why you need a high c /high mah discharge battery and good fast and torque motor with higher fps springs. These gears are meant to be fast not easy to pull hence the need for the other upgrade parts.

[ScooterVauto]

I love G&P 120 motors, with an 9.6 nimh and a reasonable shim they should be able to
cycle with the 120 spring with the right gears.

[iKliiu]

Definitely get a new motor, perhaps a JG Blue or Lonex A2. Those have insane torque. Another option is to get a AK stick lipo, which should have similar dimensions to a 9.6v stick battery.

[Bar1975]

Originally Posted by iKliiu

Definitely get a new motor, perhaps a JG Blue or Lonex A2. Those have insane torque. Another option is to get a AK stick lipo, which should have similar dimensions to a 9.6v stick battery.

Where would i order one of these "AK Lipos"? This is exactly what i need..

I don't want to pay a crap load for shipping so are there any stores in Ontario that sell these?

[iKliiu]

Originally Posted by Bar1975

Where would i order one of these "AK Lipos"? This is exactly what i need..

I don't want to pay a crap load for shipping so are there any stores in Ontario that sell these?

TorontoAirsoft's MP5k/AK LiPo's are out of stock. Airsoft parts might have some. If you want another place in Canada, check this out http://www.milsig.ca/airsoft-batteri...ery-20c-p-2088

However, buying from Hong Kong is cheaper, if you can wait. http://www.airsoftpark.com/firefox-1...ry-p-1715.html

[Stealth]

Originally Posted by Bar1975

Where would i order one of these "AK Lipos"? This is exactly what i need..

I don't want to pay a crap load for shipping so are there any stores in Ontario that sell these?

Either of these batteries will go into an AK.
http://www.airsoftstore.ca/index.php...roducts_id=193

http://www.airsoftstore.ca/index.php...roducts_id=194

[lurkingknight]

if you are shimmed properly and not too tight, a new motor may be in order. I have not used them myself but the reputation of g&p 120s among more technical tuners is not terribly great. It just doesn't have the torque to compare to a neo maget motor.

cheapest one you can find would be SHS motor, but they're a bit more power hungry, and since you have an AK and battery space is limited, maybe a more power efficient motor would work, jg blue or lonex a1 to a3.

Originally Posted by Bar1975

So i just slapped the G&P M120 motor back in this thing and the same thing is happening. Only the 11.1 Lipo will turn it over and shoot anything.

I have a decent quality crane stock 9.6V 2000Mah and even that wont get this thing to fire.

So with the new M120 Spring it appears the only battery that will turn over any kind of motor i currently own is a lipo.. that's insane though...how is everybody else running M120's and NiMh batteries? Not everybody swears by Lipos..

Is it possible i'm not seeing the real issue here? Could it be shimming that is too tight maybe? Should i crack this thing open again and start looking for tightness/friction in other areas? (damm though.. i've polished the GB piston rails.. lightened the piston.. shimmed the gears to what i guess is an ok job )

what else do i have to do!! LOL!!!

This little gun is quickly working itself into a spare parts only gun..

[Bar1975]

The battery is not for an AK guys.. its for a super tight fitting MP5K..

someone recommended an "AK" battery...

STEALTH i will more than likely end up picking up one of those 7.4V Lipos for my actual AK... awesome price and exactly what im looking for.

I can't pick up a better motor until i have this MP5K Battery issue figured out...

[iKliiu]

What is the diameter of the battery that fits in your MP5k? Just find a LiPo with similar dimensions and it should fit.

[Bar1975]

so i picked up a 7.4V 20C lipo and the gun shot a few rounds no problem.... started firing a few full auto bursts and it worked for a while no problem.. but after about 5 mins of shooting it started to seize up again and the only way to get it to fire again was swapping out the 7.4 with my 11.1V 15C lipo.

so am i crazy or is the only thing that can turn this gun over is an 11.1 lipo battery? I thought the 7.4 would do the trick but it doesn't appear to.

I think im going to downgrade to the Sp110 again because this m120 business is not working out for this particular set up... unless i hook it up to a car battery or something

I want to grab the SHS Ultra High Torque motor.. will the 7.4 lipo pull that or is that in need of the 11.1 ?

[Stealth]

Check your shimming?....

[MaciekA]

Most LiPos deliver a very high peak of voltage for the first bit of their discharge curve before settling into a flat plateau for the rest of the charge, so it's not unusual that the initial burst of juice would overcome whatever friction or binding you have in your system.

That said, you probably *do* have some source of friction or binding that you need to identify. Sure, you could throw a 14.8V 10000mAh monster at this, but you'd only be avoiding the true source of the problem, and you'd have the personal shame of knowing that your gun wasn't as efficient as it could be

Strip your gearbox to the bone and add parts one at a time. Test to see if your piston and sector gear bind, or if your piston and cylinder are binding, etc. Test your gears without any compression parts and watch everything as it moves.. You will eventually spot the source of friction or binding. These problems are hard to spot because you typically have to partially assemble the inside of your gearbox while fully assembling the exterior (shell) of your gearbox (screws, and often motor + grip) to spot the problem or narrow it down to 1) before the sector or 2) after the sector (etc... you can choose many halfway points in this search).

On the flipside it's worth it because you will probably find a bad bearing or too-low sector or immobile tappet plate -- or whatever -- was the issue, after which you fix it and the gun is smooth as silk.

[Spike]

See if your piston moves freely in the gearbox with nothing else in it. I was running into that problem with modify white pistons + G&P mechboxes.

[MaciekA]

Originally Posted by Spike

See if your piston moves freely in the gearbox with nothing else in it. I was running into that problem with modify white pistons + G&P mechboxes.

Correction: See if your piston moves freely with the cylinder + cylinder head still in it but nothing else. You can mask a problem with piston-to-cylinder binding by not including the cylinder, even if it involves the rails.

[Bar1975]

when i recently installed the new Lonex burgundy piston i spent a good hour or more polishing the rails and making sure that everything moved freely in regards to the piston at least. When the gearbox is closed up and inverted the piston would slide out of the cylinder and down the length of the gearbox freely with no assistance from me whatsoever.. purely on gravity alone.

I don't expect it can get any more free moving than that?

I'll check the shimming but the problem is... way back when this thread started out as a 'pre-engagement' issue i had no binding or motor/battery power issues whatsoever. It was actually the complete opposite.. everything was moving to fast and caused the pre-engagement. This binding only started with the new m120 spring upgrade and lonex piston (although im sure it's not the piston)

I am guessing that despite having a new 7.4Lipo it's the lack of torque motor (still running the G&P M120) not the lipo. The 11.1 lipo will turn over the G&P motor but as noted before.. probably not good for the motor.

I have heard that the SHS Ultra High Torque motor is great but power hungry.. will a 7.4V 20C battery pull the SHS motor ok? The other option is the Lonex A2 but that is over $20 more than the SHS.