Stampede Problem
#1
Posted 19 February 2012 - 11:18 AM
I'm not sure what i'm doing wrong. In this thread (http://nerfhaven.com...=1)SpectreX said connecting it in reverse bias solved his problem but that hasn't worked for me.
Thanks in advance.
Any Blaster mod or homemade that I post I can commission. Send me a PM on NerfHaven or BritNerf or email me by sam@lusher.org.uk
#3
Posted 19 February 2012 - 03:35 PM
I forgot to mention, i did a continuity test on the 4 AA pack with the trustfires and they run fine.
I'm confused because SgNerf has put over 20 Volts through the stampede's motors without any problems.
Any Blaster mod or homemade that I post I can commission. Send me a PM on NerfHaven or BritNerf or email me by sam@lusher.org.uk
#4
Posted 19 February 2012 - 03:39 PM
#5
Posted 19 February 2012 - 04:07 PM
~Talio
#6
Posted 19 February 2012 - 07:19 PM
In your case, the trustfires only have enough strength to advance the bolt/plunger assembly partway forward. The switch to the motor is still depressed by this assembly, and will fire once adequate power is supplied, (in this case from the original batteries.) That's what's happening mechanically.
I don't have a terrible amount of experience with rechargeables, but on a more general level, compare the voltages and curent output of the two battery types, and some simple calculations can get you an approximate value for the power output from the trustfires vs the original batteries. Check that you have wired them correctly, and remember that "voltage" is only part of the equation.
Edited by Aeromech, 19 February 2012 - 07:20 PM.
#7
Posted 20 February 2012 - 02:36 AM
Are you using protected or unprotected TrustFire Li-Ion batteries? Some sellers may not indicate the characteristics clearly on their product info, so you have to check with them directly to make sure.
Protected batteries have limited discharge rates so once the motor is under load and the amp draw increases above the discharge limits, the battery's protection circuit will cut off the power... hence resulting in a similar effect you encountered with the plunger only moving abit then stalling.
Thats why we use unprotected versions instead, as they can supply the motor with enough amp current to pull the spring load properly.
Edited by SgNerf, 20 February 2012 - 02:37 AM.
Nerf Mod Guides! >> http://www.modworks.blogspot.com
#8
Posted 20 February 2012 - 12:17 PM
ThatBritishGuy,
Are you using protected or unprotected TrustFire Li-Ion batteries? Some sellers may not indicate the characteristics clearly on their product info, so you have to check with them directly to make sure.
I'm not sure, but from your description of grey batteries and the problem i am guessing mine are protected (they are black with flames on the sides).
Do you know of any way to unprotect the batteries? If circuitry is required thats fine, i have PCB production facilities at school.
Any Blaster mod or homemade that I post I can commission. Send me a PM on NerfHaven or BritNerf or email me by sam@lusher.org.uk
#9
Posted 20 February 2012 - 05:15 PM
These batteries are capable of outputting high currents and can get hot in the process and maybe explode.
So if you try and open up one of these guys, And short circuit it in the process, you could have bits of batteries implanted in your face.
You say you have PCB equipment at your school, so that means there should also be bench power supplies.
You could definitely use a bench power supply to test that your mod worked, whilst waiting for your next unprotected trust fires to arrive.
A 12 V car battery, then if this works, proceed to Maplin or RS and buy a compact 12V lead acid battery. these devices are also sealed,
Lead acid batteries are capable of delivering high currents, this is why they are used in vehicles to turn the starter motor.
Edited by Hammy, 21 February 2012 - 03:41 AM.
#10
Posted 21 February 2012 - 02:52 AM
Don't worry so much about what other people will allow. Throw your own wars and kick your friends' asses until they all want one.
#11
Posted 21 February 2012 - 03:38 AM
Please forget the lead acid battery concept.
Just use the bench power supply to make sure the mod works, and await delivery of your unprotected Trustfire's.
#12
Posted 21 February 2012 - 01:04 PM
Thanks for all the help in this thread feel free to close it now.
Any Blaster mod or homemade that I post I can commission. Send me a PM on NerfHaven or BritNerf or email me by sam@lusher.org.uk
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