sr25 wiring/mosfet issue

[neverseemecoming]

ive spent the lastt couple of days upgrading my sr25 to 425 ish fps and adding a mosfet. went to test it and the fuse that i had put between the mosfet and the battery has blown. the wiring diagram i was given with the mosfet didnt show the need for a fuse but i thought i might as well protect the mosfet if i can. before it went it started winding the gearbox along but blew before it let the first shot off. so i know ive got it wired correctly i think. do i remove the fuse? or has the fuse protected what could otherwise be an expensive mistake????

cheers.

two tone

[paulyboy]

Re: sr25 wiring/mosfet issue

u using a lipo ?? if ur using a lipo u need a stronger fuse is it a standard 15 amp fuse if so try using a 17 and only fire 1 shot to be on safe side if fuse blows again check wireing making absolute sure its all corect if it is either try without fuse or try using a stronger fuse each time

[Caveira]

Re: sr25 wiring/mosfet issue

Did you change the motor?

It sounds to me like the gearbox tried to cycle, but there wasn't enough power with the bigger spring, leading to strain on the motor and a blown fuse.

[neverseemecoming]

Re: sr25 wiring/mosfet issue

im using a 9.6v battery. i do think there was too much strain but only as the spring guide buckled down towards the gears therefore jamming them and stopping the spring going back further. just realised this as i went to screw the stock in and it wouldnt. so ive straitened it back into position and put the stock on. do you think its best to keep the fuse on then? and then try again?

[Caveira]

Re: sr25 wiring/mosfet issue

I'd keep the fuse, at least until you know what the problem is.

If the spring guide is damaged, be careful that you don't have a major failure in the GB.

[neverseemecoming]

Re: sr25 wiring/mosfet issue

its not damaged. just the spring pushed it out to one side. only took a small screwdriver t and a tiny amount of pressure for it to pop back up strait and into place. with the stock on it sits perfectly strait. ill get another fuse and give it a go. cheers guys. will post in a bit as to my success/failure

[Fossilfuel]

Re: sr25 wiring/mosfet issue

Running such a powerful spring will draw maojr ampage from the battery (not volts)
What motor are you running? and what MAh battery?

The mosfets I use have a built in electrical self resetting thermal fuse so an inline fuse is not needed.

[neverseemecoming]

Re: sr25 wiring/mosfet issue

i have absolutely kained it on my bicycle to the local hardware store before it closed and bought 6 more. put one in and its running well :-)

i will email the supplier of my mosfet to see if it does have its own fuse. if so i can remove it. otherwise i can leave it in knowing its working. :-)
cheers for all the advice guys. panic averted :-)

[paulyboy]

Re: sr25 wiring/mosfet issue

good to hear