500s motors on relays?
 

I know that FP motors aren't allowed to be run on a spike. My question is can any other 500 series like a BaneBot or AM, allowed to run on a spike? I'm assuming they can because I haven't read anything saying the can't in the manual. Plus, I have never done this since joining FIRST. All answer would be helpful thanks!

Re: 500s motors on relays?
 

According to the rules they can, but be aware that you cannot replace the 20A fuse of the Spike for these circuits and these motors draw much more than 20A at stall.

Re: 500s motors on relays?
 

I forgot about the fuse part. But if the motor stalled in our application, then we have some serious problem. I guess well have to try it out on the practice robot.

Re: 500s motors on relays?
 

A 20A fuse wont usually won't "pop" unless the motor draws 40A for about 1 second. If i remember correctly they can handle the motors 80A stall current but only for a fraction of a second.

Re: 500s motors on relays?
 

Trip characteristics are on the specification sheets for the circuit breakers.

20 A and 30 A: Snap Action VB3
40 A: Snap Action MX5

Re: 500s motors on relays?
 

He was talking about the fuses on the spike itself. Which you cant replace.

Re: 500s motors on relays?
 

Fair point, I forgot that the Spike fuse could trip too. It's been a while since I've driven a motor with one, as you might imagine. (And you may replace the fuse on the Spike powering the compressor.)

Re: 500s motors on relays?
 

I knew the fuse for the compressor can be changed, heck its the only spike we use. But this year for our ball pick up we wanted to power the three motors (2 PG71, 1 AM500s) with spikes because there is no need to control the speed because they are in custom gear boxes. So basically it should work. Like I said before if the motor stalls then there is a huge problem.

Re: 500s motors on relays?
 

ATM fuses are rated to open in 500 ms with 135% overload. That's 27 amps for those without a calculator. Every overload over 20 amps weakens the fuse so that even repeated surges of 22-25 amps will likely open the fuse at some point in time.

Re: 500s motors on relays?
 

We ran the two 550's on our roller claw last year through Spikes and never had an issue. With proper gearing you SHOULD be alright as far as current draw goes. We plan on running a 500-series sized motor through a spike again this year but are prepared to swap it out to a Victor if needed.

Re: 500s motors on relays?
 

I never like putting a motor which can draw (vastly) more than 20A in line with a 20A fuse under any circumstances. Even if the motor *shouldn't* stall in its application, I would not feel comfortable.

Re: 500s motors on relays?
 

The fuse / breakers are there to protect the motor and wring. So depending on the mechanism, I can see an advantage. If it is designed to never need more than 10 amps, at a constant speed, the fuse will (should) prevent a smoked motor in case of stall.

Re: 500s motors on relays?
 

Dad,
While that is generally the case, the fuse on the Spike is meant to protect the contacts of the relays inside. The rule about using a breaker came from a manufacturer's recommendation for the Spike driving a compressor.