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Post by Ferox on Aug 13, 2008 14:07:03 GMT 8
Okay so this is a noob electrician question but I never really paid much attention in my GCSE physics. Something to do with setting myself on fire or licking live wires.
Anyway I've had this on my mind for a while, but with the new guarder motor I've hit a wall and need to ask wtf is going on?
Firstly you look at something like the JG HK416. That sucker is 1.6/1.9 out of the box and yet it only needs a 8.4v battery to run fine.
Then you look at my M4. 1.3 but it needs a lipo to run. Conversely you look at my G36C which is 1.3 as well but only needs a 8.4v mini battery to run.
And then finally the guarder motor, which I just plugged in and I can hear it's working, but it can't pull back the 1j spring? And this is off a mini 8.4 volt.
So overall, this is sort of confusing to me. Are there different standards of motors and how much power they need? Apparently my new motor has no torque...but it doesn't even have enough to pull back a 1j spring?
I'm going to try get a 9.6 and see if that does it, I refuse to put a lipo in though, since even on semi I can hear the unused power in the piston! It would be nice to run the thing on an 8.4 but that doesn't seem possible!?
Someone please break it down for me, how is it some motors can get away with it and some can't and how do I tell the difference so I don't end up with weird mechanical failures when I start building new AEGs.
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Post by Noa on Aug 13, 2008 17:45:18 GMT 8
Regarding power of the gun:
It is how good the combined cylinder air seal and the spring strength is. Example: Using a half cylinder gives me 1.1J but when I use a full seal cylinder I get 1.6J with the same spring. But the power of the gun mainly comes from the spring.
The guarder motor:
may be burnt out ie lost it's torque power. Or it needs a higher voltage to induce enough magnetic strength to turn. Also is there something inside the motor that has jammed it? This is quite likely and it has happened once to my systema high torque motor -_-...
Regarding why some guns need lipo and others don't:
1) The circuit may be using up the battery via heating. The common red/black wires are known to heat up alot and lose power when it is long. So the longer the wire is in your gun, you will need more voltage to get the gun to fire right. Shorter the wire is best.
2) The 2nd major factor is the gearbox and the spring. A smooth gearbox and spring requires less torque to cycle while a not so smooth gearbox needs more torque (more voltage) to cycle and output the same power.
I know this for sure because my AK47 had a problem with it's circuit and gearbox.
---
In your case:
Test the motor on your M4. If it cannot work there, then the motor is burnt out.
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Post by Ferox on Aug 14, 2008 1:19:44 GMT 8
Test the motor on your M4. If it cannot work there, then the motor is burnt out. That's the thing though. I was told that this motor has no torque, it's all about speed?? I don't see how the two can be seperated over 1 gear head... So if I put it in my M4, it might not move anyway?
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Post by Noa on Aug 14, 2008 7:50:36 GMT 8
Well sounds like it's burned out xD
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Post by milkkart on Aug 14, 2008 9:17:31 GMT 8
well i could give you a long complex technical explanation but if you've only done gcse physics and weren't much interested then, then you're probably not gonna understand it and it'll be hellish boring anyway.
basically what it comes down to is the electrical and physical properties of the motor (resistance, backEMF, friction) can be designed so that for a given voltage a motor either produces a high speed with with a low maximum torque or vice versa.
edit: does he not mean that its meant to be a high-speed low-torque motor noa?
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Post by Noa on Aug 14, 2008 10:37:02 GMT 8
He means that it's a high-speed motor and not a high-torque motor.
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Goliath
Gunnery Segeant
Argh.
Posts: 571
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Post by Goliath on Aug 20, 2008 4:45:04 GMT 8
Right, batteries are given two ratings: Voltage and Capacity.
IE: 8.4v 2000mAh.
What does this mean? It means:
This battery will:
1) Output at around 8.4v 2) Sustain a discharge of 2A for an hour.
This is an enormous simplification, but in general:
Imagine the battery is a bucket full of water with a hole in the bottom.
The VOLTAGE is the size of the hole. More voltage means more water (energy) is given out every second.
The CAPACITY is the amount of water. More water means more pressure, so the water will come out a little quicker. (A 8.4v 2000mAh will give a higher RoF than a 8.4v 600mAh).
Of course, the quality of the battery helps - as better quality cells will have higher discharge rates - which give more RoF.
So:
HIGHER VOLTAGE = HIGHER RoF.
HIGHER CAPACITY = HIGHER RoF.
HIGHER DISCHARGE RATE = HIGHER RoF.
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Post by Ferox on Aug 20, 2008 22:46:10 GMT 8
Thank you, that explains the mechanics of motors and batteries. I appreciate it.
My other question is still unanswered though...besides burnout, which is highly unlikely on my end since it's brand new, right?
What other reasons are there for motors working on some guns but not others, even though they have totally different spring powers i.e. the HK416 uses a 8.4 battery but can move a 1.6-1.9? Is there anyway to tell what power a motor can run at, what it's torque is?
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Post by woozie on Aug 21, 2008 0:14:48 GMT 8
gears, probably
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Post by milkkart on Aug 21, 2008 1:47:28 GMT 8
its more likely due to it being a higher torque motor, the one you've got is a high speed motor and so won't be able to produce much torque.
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Goliath
Gunnery Segeant
Argh.
Posts: 571
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Post by Goliath on Aug 21, 2008 6:20:50 GMT 8
Thank you, that explains the mechanics of motors and batteries. I appreciate it. My other question is still unanswered though...besides burnout, which is highly unlikely on my end since it's brand new, right? What other reasons are there for motors working on some guns but not others, even though they have totally different spring powers i.e. the HK416 uses a 8.4 battery but can move a 1.6-1.9? Is there anyway to tell what power a motor can run at, what it's torque is? Ok. Motors usually have two properties that we concern ourselves with: Speed and Torque. Now, Speed is measured in RPM - Revolutions Per Minute. Torque is measured in Moments, or Newton-Meters. Speed obviously relates to the RoF, Torque to the amount of power that the motor can handle. Without getting too complex: SPEED AND TORQUE ARE EXCLUSIVE ON MOTORS. So a high-speed motor will not have much torque. A high-torque motor will not have much speed. Now, if you gave two AEGs that were identical - but one has a high-torque motor and the other a high-speed motor - the same battery, to an extent they'd be the same. This extent depends on the quality of the motors in question. For example, most chinese AEGs ship with high-torque motors. However most TM AEGs ship with high-speed motors. There's no set "This will do this" in this case, there are far too many variables to consider. However, damage wise, it's excessive voltage that will damage a motor.
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Post by milkkart on Aug 21, 2008 22:33:50 GMT 8
thats what i was trying to explain in my first post, but failed. lol
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Post by malavern on Aug 21, 2008 23:41:07 GMT 8
thats what i was trying to explain in my first post, but failed. lol nice try though. I know jack all about electrical systems, I'll take my gas/spring actions anyday!
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Post by Arclight on Aug 24, 2008 11:52:47 GMT 8
And don't forget gear sets as well.
High speed gears are harder work for a motor to turn but for every single motor turn, the output has more turns; heance higher rate of fire. High torque gears are relativley easier to pull (sort of) with less turns in then output but the output is higher torque now then input.
If you have a 1.3j spring sitting with a high-speed gearset and a high speed motor and attach a 8.4v battery, there's a very good chance it won't pull at all as the motor generates insufficiant torque to over come the hi-gears and strong spring. The result is that your 8.4v won't cut it.
If you have a 1.6-1.9j spring sitting with a high torque gearset and a high torque motor and attach an 8.4v, the high torque motor has it's torque increased again through the high torque gearset. The result is that your tiny 8.4v will shoot slow but all that assistance will in all likleyhood let your tiny battery pull that strong spring.
Okay, so there's more to it then that, but the jist is whats important here. A high joule gun and low joule gun on the same small battery may not always work the way-round you expect due to variance in internal composition.
Chinese guns normaly come with nice heavy duty metal gears and a high torque motor, your typical overall high torque setup. This is how tiny batterys allow them to shoot and why china guns generaly shoot quite slow. It is also why they're perfect for LiPos, 'cos that all-torque setup is ideal for harnessing the raw power of the LiPo.
Japanese guns come with plastic gears I think (unless they switched to metal, I don't know, haven't bought/used a Jap gun in years) and a high-speed motor. This setup is designed for a small battery to shoot very fast on a low powered spring, ideal for Japan with their low-powered gun power laws. But if you mod, and plug in a higher power spring, even if it's only a step up from 1j to 1.3j, the relative torque required for the motor is amplified by the time it gets from the spring to the motor input power.
In HKs sea of modified guns, gearsets, motors and springs are swapped out like bowling pins; so if you're running modded guns, its quite important to remember whats going on inside yours in particular.
Of course, then, when you throw in a broken gear, it screws up, but the nasty grinding noise is a give away. A burnt out motor, on the other hand, just doesn't work and sounds no different. Somtimes if you get real close, you can smell a faint trace (or not-so faint if it's bad) of burning metal but thats no gurantee.
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Post by Ferox on Aug 24, 2008 12:50:00 GMT 8
Thanks guys, good stuff. So in order to get my MP5 working, I will put some high speed gears in it, and then if it's still crap I'll throw a 9.6 in there as well, that should cut it right?
I remember Chris fixed my MP5 last time, and may have used Chinese/high torque gears in the process. I'll have to run it by him but something to do!
Thanks again!
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play150
Staff Segeant
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Posts: 460
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Post by play150 on Aug 24, 2008 18:58:33 GMT 8
Ohh! It all makes sense now!
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