Motor Adjustment - AEG Not Firing Correctly?

[Cardinal]

Alright, so, I have taken the liberty to install a new motor. I know how it works, and the first time installed the motor it would give a "click," indicating that the motor was sitting too high. I then recharged the battery, readjusted, and it worked. Now, I am out doing what I *think* will be firing it and sighting in the red dot, when the same issue occurs. Adjustments were made, and it fired fine. I however set it down for a few minutes, returned, and it wouldn't fire. For the past hour the same issue is occurring and I'm recharging the battery just in case.

Any possible ideas/fixes?

[dizzyshot (Bad Company)]

Did you check to see if your connections to the motor are to loose? That's happened to my AEG before.

[Cardinal]

Care to elaborate? If you're saying what I think, the connections seem fine.

My stock motor was high-torque while this is a high-speed motor so I'm unsure as to if I just need a more powerful battery. Currently running a 9.6v 1600mAH.

[dizzyshot (Bad Company)]

Well I'm not that experienced of a tech to elaborate, but I can tell you changing motors from high-torque to high speed shouldn't do anything to the gun. Deacon could likely help you more in depth than I.

[Cardinal]

Just as a precaution I'm currently charging my battery to see if it influences anything. I'm thinking so, since the new motor probably uses more power.

[Cardinal]

Can a mod please close the thread?

Problem's determined: need more mAH. Seems like 1600 won't cut it in the long run.

[zephurah]

What is going through my head is that a connection somewhere not near the motor is being jarred when you set it down, then is being moved and allowing flow. I would try taking your gun apart and inspecting the wire. Because that's the only explanation I can think of, because the battery should be able to handle the motor.

[Cardinal]

Already diagnosed the problem. The problem being that it seems like the motor isn't powerful enough to move the spring because the stock motor works perfectly fine. Stock motor is high torque for a good reason.

[zephurah]

What kind of stock spring are you running? Because that is really weird.

[MayhemXXXFrosty (AndrewMp5k)]

High-speed motors need to wind up, where as High-torques don't. There really isn't much of an advantage to High-speeds anymore since they've made low-ratio gears to compensate. High speeds were great in TM builds because the gears were high ratio and the springs were usually pretty weak in comparison to what people run now-a-days.

1600 mAh is plenty, but if it's not a LiPo than more mAh will "help" in a NiCad or NiMh as their power doesn't ramp down before they are almost dead unlike LiPos. My question would be the battery quality because if it's an old, not well maintained, or junk quality battery then it doesn't matter the mAh. I've pulled 500+ fps setups with Intellect 9.6v 1600mAh AUG brick batteries fine. They usually lasted a hi-cap or two and for a DMR that was pretty substantial back then. The more "buttery" your setup is, meaning how well tuned your gearbox and everything meshes then the less resistance you will create which in turn won't ask your battery for more juice.

[TheEnd]

When you change your motor, you need to adjust your shimming. Motor height adjustment is intended only to get the pinion gear and bevel gear on the same vertical axis. Once they are properly adjusted vertically you need to shim the bevel side to side to properly mesh with the pinion gear. If you don't shim your gear box with that method you can potentially force your motor against the bevel gear which will cause a tremendous amount of stress on the motor shaft. This can lead to the motor becoming very hot along with the wiring and the battery.

A while back I began modeling a V2 gear box to help explain concepts like AOE correction, motor height adjustments, and disprove myths like barrel suck and gear timing. I suppose I can try out my teaching aid here.

This rendering shows the bevel gear at the same height across the board. First render on the left shows a proper mesh. The pinion gear is aligned with the bevel gear both vertically and horizontally. In the center render you can see that the motor is too low. The important concept to walk away with here is not the vertical distance, but the horizontal distance. If you can visualize moving the bevel gear over to the left it would allow the gears to mesh. They would be meshing, but not correctly. This is by far the number one issue when it comes to motor height problems. If you cram the motor on up in there you have no clue at what angle those gears are meshing at. The third render on the right displays a bevel gear that is shimmed too far to the right. The important concept here is that if you crank that motor on up in there, the gears will eventually mesh. Once again we run into the problem that the gears will mesh but the angle is all wrong.

This is one of the most misunderstood concepts when it comes to building a gear box. You shouldn't just stick a new motor in and go. Of course there are tolerances in there that will allow a little play here and there. The thing about tolerances though is the more out they are, the less efficiency you have.

If this type of render helps anyone, or anyone would like more clarification, let me know. It has been my little side project and it would be nice to use it for something. It's what I do all day at work, except with airsoft components instead of fuel measurement and conditioning equipment.