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Unread 07-02-2012, 12:06
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Re: Blowing spike fuses

Quote:
Originally Posted by rsegrest View Post
256:1 Banebot on a conveyor system -> VexSpike -> PDBoard (20AMP fuse)
64:1 Banebot on a loader wheel -> VexSpike (@ 2.5 in compression on ball) -> PDBoard (20AMP fuse)
4:1 Banebot on launcher wheel -> Jag -> PDBoard (20AMP fuse)
Even though you're using the same motor, the fact that you're using different gear boxes and using them in different applications is comparing apples to oranges to bananas.

The stall current of the RS550 is 85 amps. Thus you can use less then 1/4 of the stall torque before blowing the fuse. Your gearboxes also play a role. With the 256:1 gearbox, you can get 4 times as much torque before blowing the fuse as the 64:1.

Fuses don't blow immediately when the fuse current is exceeded. It takes a little time for the metal inside the fuse to heat up and blow. The higher the current, the faster this happens. Most likely, your intake is drawing a little more then 20 amps, and after a few activations, it's finally enough to blow your fuse.

Besides changing to a speed controller, other options would be to change the gearbox to a larger reduction, or decrease the compression on the ball (this should require less torque and thus draw less current).

Last edited by Joe Ross : 07-02-2012 at 12:10.