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There have been 137 items by Lunas (Search limited from 15-November 92)
You will need to buy a charger that supports li ion 9v they are around 25-50 as well and from the reviews they don't last very long
The shots per charge was not calculated in a very accurate way it doesn't take into account that as the battery drops it drops quicker the lower it gets. Also the 35C constant 75C burst is 300mA * 35 and 300*75 for 10.5 amp constant and 22.5 amp burst this kinda puts it down to imr range.
I call bullshit on those shots-per-charge calculations. 300mAh is a tiny battery. Stock motors have winding impedances of something like 12-15 ohms, right? Even if we give them a relatively conservative number like 20 ohms, they'll still be pulling about 300-350mA at 7.4V. That gives them less than an hour of operation under ideal conditions. So I don't buy it.
For those that did not know C rating is a measure of how much current can be discharged it represents the capacity of the battery array * rating C = amps possible. So if you have a battery that is 300mA with 25c constant it can deliver 10.5 amps constantly.
I think unless your running non stock motors that pull 20 or more amps you dont really need to run these lipo packs you can do IMR. Are they ideal? No, but the good chargers for them can do other chemistry too. I use a nitecore d4 to charge mine it does NiMH, Li-ion, Li-Mn, Li-Fepo4 and Nicd and it has a 12v input so i could use my car accessory plug to charge them.
my stryfe is running on a pair of these they are ~14c
efest v2 IMR 14500 3.7v High Discharge
Maximum Continuous Discharge Rate: 9.75A
Maximum Continuous Charging Rate: 1.3A
Rated Capacity: 700mAh
Good tips, thank you. I like these ideas.
I have not formally monitored the battery life. However, I have fired about 200 darts through my Stryfe with the Turnigy Lipo and it's dropped from 4.16v/cell to 3.96v/cell, which linearly extrapolates to 860 darts before the Turnigy Lipo needs to be swapped out (low voltage alarm is set to go off at 3.3v/cell.
Start/End Voltage: 4.16/3.96 = 0.2v used
Darts Fired: 200
4.16v-3.3v = .86v/.001 = 860 dart battery life (SD +/-80)
Dang, I like the idea of a digital voltage meter. I could probably trim out a window on starboard side and rig my digital voltage meter/alarm for viewing. I like your top side idea better though, more functional.
Those are the ones i got. Like i said no cutting needed the plastic of the nerf gun lets enough light through that you can just glue it to the inside and it shows through. In the stryfe on either side of the magazine area the meter is thin enough that it doesn't interfere. I'm also thinking near the back on the left half of the shell it should not interfere with the trigger but ill have to decide when i get around to putting it in where exactly it will end up.
If that is the one thing you remove from the internals i highly suggest it. It is just a mechanical lock that gets in the way more than it helps honestly i would pull all the mechanical locks and trim the top of the rev trigger so the dart trigger does not hit it rather than trimming the dart trigger like most guides suggest.
Yes, you are correct.
Also what are the run times like for that battery pack?
My next mod is going to be the addition of a volt meter inside my stryfe when i do ill get pictures of my rewire with solid core 18 gauge it was interesting to work with. I may or may not swap the stock rev switch to a 10A switch. and i may or may not use the jam door switch to turn off and on the volt meter i also thought about placing the volt meter where you have your battery so when i check the voltage i flip it up get the reading close it turns off the meter. I tested it and when placed against the plastic you can read the numbers through the plastic so it can be super stealth.
Normal NiMH can only push at best 1500mA Normal AA can only do .5A or 500mA. If you use a microswitch rated to .5A only .5A can pass through it without generating heat over that can go through it but it will heat and can fail. Example of what can happen you have a stryfe you have blades in it low resistance wire and use a 25-50c battery pack then you use the switch that came with the stryfe the motors will attempt to draw up to 10A when a jam or dart hits the flywheels the only thing your gun has that cant handle that type of load is the switch. When the motors start pulling the amperage the switch passes it as best it can as it exceeds the switch it gets hotter and hotter until thermal failure occurs something burns or melts.
Also, If i use a microswitch rated for .5 amps, will some nimH cells or a 2 amp lipo burn it out when i get some crazy stall motors?
and i dont get why lighter flywheels can be dangerous
Stock motors with better wires and cleaned up circuits will have little issue with the stock switches and amperage under 3A if you upgrade the brushes/motor and raise the voltage a better switch might be in order.
This is why i feel unless your going for the full rebuild you dont need a lipo pack if your doing wires, motors and a lipo pack why keep the old switches might as well change them too.
no they have a discharge of 3-5A but it is a cheaper reliable source of quality cells vs spinning the wheel on a *fire brand battery if you're after 18650 size. 14500 you need to spin the wheel and you should not run any cell other than imr or li-fe. Normal unprotected Li-ion are asking for bad things.
Lithium batteries from a laptop are not high discharge, though. Just FYI.
It is a known fact that "fire" batteries can vary from 500mA up to 4A discharge current and most fall in the 2-3A range unless they are cheap low quality cells. The stock motors are made to do with 500mA at best with 4 AA batteries. By giving them a proper power source they can scream to their hearts content. IMR or LI-MN cells discharge 10A-35A burst and should be the only drop in choice anyone considers. Lipo packs like most suggest are expensive but they are far better than any others you can pickup ones that can do 50-100A burst discharge.
It's not opinion. Battery ratings aren't user based. Google 'Trustfire explosion,' or similar.
Also trust fire and ultra fire are very commonly counterfeited look up counterfeit ultrafire dissection. There are 3 ways they are faked the worst is when they put a 30 mAh foil pack inside an 18650 can and fill the rest with sand or flour or plaster dust so the weight is close enough. There are just cheap cells not made very well these are the fire balls waiting to happen. Then there are 900mA cells labeled 3800mAh.
I would pull cells from laptop batteries before i bought a fire brand. For 14500 cells aw or efest imr are better than any fire and they can do decent amps.
Pc fans are true brushless but they dont have to have 3 wires. They use hall effect sensors to determine direction rather than comutators. Generally it is positive (red) ground (black) and rpm sensing (yellow) Now 4 wire pwm setups are getting more common the 3 wires remain the same. Though red 12v input black ground and yellow blue or green rpm sensing the 4th is used to adjust speed. Previous to this they were slowed by a pot dropping the voltage to the stall level around 5v-7v. An 80mm or 92mm or 120mm fan would have a similar sized hub to a flywheel dropping the other wires and keeping the red and black tossing them into a blaster would require modification of the flywheel cage cutting out the 130 size sleeve since without modding the speed controller you cant reverse the direction and to get access to the controller you must remove the hub.
do those brushless fan motors have 2-wires or 3-wires, if they have three then there true brushless motors and requires a brushless specific speed controller
I have been thinking about how to do it and i am almost positive ill be making my own nerf gun when i get around to making the one based off pc fans i will need to see how slow they speed up and how the motor behaves without the fins on it though. It has been brought up to me that the torque and spin up time might not be good.
The stock motors are rated to 6v and do fine on 7.4v-8.4v i have a pair of IMR running mine the IMR say they can do 20A continuous the stock motors should not have anywhere near that stall current.
Why would you put a 3.7V battery in a gun designed for 6V? I don't think that motor will work. Does this gun need a double shaft like that? I am putting a 7.4V Lipo in mine today. We will see if I fry anything.
If you do like the op is doing with his he is putting a pair of 130 size race motors in his that are rated to 3v so 3.7v battery pack or even a pair of IMR in parallel would do. Putting double the voltage on those race motors would likely burn them out very quickly.
I want to do a brushless motor mod and i have an idea for cheap durable brushless motors. Computer fans they are 7-12v brushless ball bearing sleeve and several others are available and spin 600-4800 rpm all i would need to do is free them from the frame and cut off the fins and smooth out the hub would take 20 min with a belt sander or dremel. If i end up doing it ill post a write up on it my main concern is there is not an easy way of reversing the rotation on pc fans so i would have to mount them with one flipped over.
Remove the electrical tape therfore is a number of things you can use:
Duplicolor Truck Bed Coating
plasti dip<- most people use this it is cheap but eventually wears off.
I also wonder if just lightly sanding them with 1000-2000 grit sandpaper to get the smooth sheen off the flywheels would be enough.
IF you absolutely need to use AA shaped sized batteries that you can get in a place like wal-mart your stuck using NiMh or lithium primaries.
With rm2 you cant go much above stock 6 volts with proper current or you will fry them unless you c-mod them.
Best:Highest discharge Reasonably safe. Most expensive you will be looking at 10-40$ for the battery and 20-300$ for a charger.
4.2v rc lipo pack look for tenergy or a well made pack
7.2-11.1v rc race pack tenergy is a good brand you need a balance charger
Acceptable: less expensive than rc pack more expensive than nimh 10-15 for a pair of imr and 15-20 for a nitecore d4 charger. Use 1 or 2 in parallel unless you c-mod the rm2 using 2 in series is the most you should try 2 in series is 8.4v fresh off the charger 7.4v is what they will drop to then when dead 6.2v If you continue to run them down you will damage the cells and end up with batteries that wont take a charge.
14500 size lithium batteries li-Mn or Li-Fe-po4 High current they are available up to 20A discharge rates these chemistry are much much safer than Li-ion Li-Fe being the safest of the 2...
14500 Efest IMR Li-Mn 3.7v
14500 AW imr Li-Mn 3.7v
14500 Tenergy Li-Fe-Po4 3.3v
Bad: the cheapest about 10$ gets you 4 batteries and a charger. Nimh deliver about 1-2A in bursts but don't have the capacity to sustain much more than that. Lithium primaries can do 3 A continuous or 5A burst.
AA NiMH batteries 1.2v batteries
Lithium primary energizer or photo cells AA
worst:4-6 dollars a pop for 4 low current discharge
AA duracell rayovac energizer doesn't matter what they add to the end of it they all suck 500mA draw is the best they can muster.
*****Fire Li-ion unprotected cells (your asking for a fire or a face full of lithium hydroxide)
goes by many names: Trustfire and ultrafire are most common these are the typical cell most modders used at first they are good for about 2-5A draw and they are the most volatile they have been known to propel flashlights around the room like a rocket propelled on highly toxic gas that even a little bit can damage your lungs permanently.
Fix those 2 issues you should see about 110 FPS and around 70-90ft ranges. Some sort of voltage monitor would be advised to add to the setup with anything rechargeable draining them past a point will damage them.
If you are handy and know your way around a soldering iron then you could just mod it.
I used a pair of laptop batteries in mine I had already reclaimed the 6 18650 they held a charge at 4.1v for 3 months before I did anything with them I put them in a pair of protected battery holders
I never go near any batteries with the word fire in the name. I ended up ordering this one. Since its only 3.7V I will try running the motors without limiting the voltage, if hear, smell, see anything wrong then I'll install something to limit it down to a lower point.
On the cheap end i would do a single imr 18650 or 14500 if you want to fit a pair of them in the original battery compartment with some rewiring to put them in parallel or a li-po pack for a rc rated at 4.2v. The imr is good for 25-35 amps depending on the brand i would recommend efest or aw.
I would also look at PWM regulation since the motors are only rated for 2.4v going too much higher than that will burn them quicker the circuit is relatively simple and can be made small enough to fit in the gun or even the battery compartment depending what battery and where you put it.
If you dont want to put that much work into figuring out the power situation. 4 eneloops in the stock bay would power the motors with a slight over-volt would not provide the amps for stall though.
The main thing I am curious about is that the black things connected to the motors are not resistors they are inductors designed to drop voltage and increase current I don't pretend to know everything but would not having them in place help with current draw as the AA it is meant to run on would not provide the current to drive the stock motors well enough on their own.
For Ni-MH energizer claims 4c eneloops say 1c duracell claims 2c.
Other options involve much more complicated methods involving making a new control board with an arduino. It would not be overly complicated to control a 3 position servo a variable speed motor and the launch solenoid. It is beyond my skill but it would be possible.
A easier method might be to buy a second one with a remote they are 65-130 on ebay or find someone with the remote willing to let you record the pulses from it you could then program a select few remotes perhaps even a tv be gone diy type unit you would just need to use the 2 codes from the actual remote instead of the on/off db they flash on the diy chips.
What i would do is grease it up to see if it helps if it solves the issue great if not i would say that you removed too much dead space you could trim down the hot glue slowly until the issue gets fixed.
Just remember that without the AR dry fires are not recommended they will break parts.