15 replies to this topic

[pit viper]

Hello everyone that may or may not be able to help me,

I am planning on doing motor swap on my Stryfe using these(image doesn't seem to work when posted on here).

I do know that one of the ends of the shaft will have to be cut off to work. All electrical and physical locks will be removed as well.

I do not however, know what battery set up to run these motors on and whether or not I will need to replace the on/off trigger for a higher rated one. I will also be running a simple 2 wire voltmeter in the wiring to keep tabs on the battery.

-Thanks

Edited by pit viper, 03 September 2014 - 06:27 PM.

[pit viper]

So the discharge rate of the battery or the current of the motors has nothing to do with it?

[pit viper]

Thanks for the help, I found one on Amazon with a charger for about $25.

[Lunas]

Be careful about amazon batteries particularly ones with fire in the name a lot of fakes.

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.

Edited by Lunas, 06 September 2014 - 07:49 PM.

[pit viper]

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.

[Lunas]

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.

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

[Number 1 nerf nut]

If you want to go really cheap, you can use thisHobbyKing 1S 950mAh battery it's $3.80

Keep nerfing

Edited by Number 1 nerf nut, 24 September 2014 - 08:15 PM.

[bex]

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.

Edited by bex, 27 September 2014 - 06:59 PM.

[Number 1 nerf nut]

I guess you could use some 1.2v nimh cells. (nimh cells are really rated at 1.4v each)

Anyways this should get you to 2.8v which should be close enough to 3v

P.S. here is a list of rechargeable batteries a know of.
lipo 3.7v per cell
lion 3.7v per cell
life 3.3v per cell
nihm and nicd 1.2v per cell(really 1.4v per cell)

This is all I remember right now
I hope I helps and keep nerfing

[Lunas]

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.

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.

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.

[Number 1 nerf nut]

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

[Lunas]

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

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.

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.

Edited by Lunas, 30 September 2014 - 10:15 PM.