12-02-2010 13:37

Cory

Re: pic: Part of the control board along with the bump

It's hard to tell from the picture, but those wires on your jaguars look awfully small (assuming they're for 40A fuses). Make sure you're following the wiring size rules.

12-02-2010 14:33

Trent B

Re: pic: Part of the control board along with the bump

Agreed, though our wires look pretty thin as well because they have a thin very hard jacket as opposed to the thick silicone jackets from the KOP

Also, when you transfer it to your competition robot, keep the wires well labeled and strapped down well so you can more easily diagnose problems.

12-02-2010 14:35

Al Skierkiewicz

Re: pic: Part of the control board along with the bump

Bryan,
This picture is a classic example that I would use when demonstrating a different approach to robot wiring. Long, small wires will not give you the power you might expect from CIM and FP motors. The wire produces series resistance that lower the available power from this high current motors. However, a few minor changes can make huge improvements. By placing the PD in the center of your board, you shorten the path length between the PD and speed controllers. By then placing speed controllers near the motors they will control, you shorten the path again. I would guess that your robot like most, will be running four motors. If they are close to each other, then place the controllers close enough to the motors that you won't have to add any wire to the motor. If you have two motors on the front and two motors on the back of your robot then place the speed controllers in a like manner, two in front and two in back. This simple rearrangement of parts will cut 6-8 feet of wire out of your design, make things much neater and give you maximum power from your drive motors. If you use #10 wire instead of #12, you will cut the series resistance in half.
The Crio and the sidecars can be placed anywhere that might convenient (or for COG weight distribution) as they do not draw significant currents nor do they produce signals that are affected by long runs.

12-02-2010 14:40

MPG

Re: pic: Part of the control board along with the bump

It looks to me as if your board is made out of aluminum, if this is the case you are probably going to want to rethink this. You will want to mount you electronics, most important the cRIO on a nonconductive surface. This will minimize the possibility of a static shock that would kill your electronics.

12-02-2010 20:16

Phreadumb

Re: pic: Part of the control board along with the bump

Actually, a metallic surface reduces Electromagnetic Interference.

12-02-2010 20:25

Al Skierkiewicz

Re: pic: Part of the control board along with the bump

Actually, aluminum isn't as good as materials containing iron, nickel and a few others. However, it is as good as any metal at conducting static charge/discharge. Sometimes the offending signal passes through a device, reflects off the metal and returns through the device. Sometimes the whole shooting match acts as an antenna and that could be good or bad depending on if you wanted an antenna.

Let me reiterate, the Crio and the camera both have their chassis connected to the negative terminal of the battery through the power cable. Both need to be insulated from the robot frame.

<R43> All wiring and electrical devices, including all control system components, shall be electrically isolated from the ROBOT frame. The ROBOT frame must not be used to carry electrical current (e.g. this is necessary due to polarity reversals that occur under certain operating conditions such as during motor direction reversals).

12-02-2010 21:23

longrange

Re: pic: Part of the control board along with the bump

Solomon90 it looks like you are only using 1 40amp breaker. The CIM and Fisher Price motors can draw a lot of current when starting up, climbing a burm or pushing another robot. You're probably using 4 of these high current draw motors which should be protected by 40 amp breakers. As mentioned earlier check out rule R47A for the appropriate wire size. Good luck and have fun!!!

12-02-2010 22:26

Al Skierkiewicz

Re: pic: Part of the control board along with the bump

Uh, looks like 5 40 amp plus one 20 feeding the sidecar and one not connected.