regulated power for potentiometer

[Ether]

Originally Posted by cgmv123

You also aren't allowed to power anything but the wireless bridge from the regulated 12v slot. [R43]

So they're calling a 10K pot an "electrical load"?

It's more like a reference voltage.

Oh, well.

[cgmv123]

Originally Posted by Ether

So they're calling a 10K pot an "electrical load"?

It's more like a reference voltage.

Oh, well.

I don't make the rules.

[excel2474]

Originally Posted by Ether

It may just be old batteries.

Aaron, when's the last time you guys capacity-tested your batteries?

All brand new batteries. I'm not the programmer, so I'm just told that we are having this issue with the potentiometer.

-Aaron

[cgmv123]

Originally Posted by excel2474

All brand new batteries. I'm not the programmer, so I'm just told that we are having this issue with the potentiometer.

-Aaron

Can I see a driver station log where you drop below 6 volts?

[excel2474]

Originally Posted by cgmv123

Can I see a driver station log where you drop below 6 volts?

I'll email our programmer and ask him to post it or send it to you. Due to work schedules, it likely won't be available right away. Thanks for following up with this.

[JamesCH95]

Originally Posted by Joe Ross

If you're having trouble with the Analog Breakout, the Digital Sidecar isn't far behind, with much worse symptoms. It might be helpful to make a new thread about how you're killing batteries over the course of a match, and describe your robot and power systems so that people can provide suggestions on how to reduce power draw.

This.

A serious mechanical issue can cause a severe battery drain too.

2474,

Without knowing more about your robot, assembly techniques (how did you crimp your 6awg terminals?), its mechanisms, etc. I fear that you are trying to band-aid the symptom of a much more significant problem.

[excel2474]

Originally Posted by JamesCH95

This.

A serious mechanical issue can cause a severe battery drain too.

2474,

Without knowing more about your robot, assembly techniques (how did you crimp your 6awg terminals?), its mechanisms, etc. I fear that you are trying to band-aid the symptom of a much more significant problem.

I cannot answer your question about the 6awg terminals right now, but as for the Mechanisms:
Drivetrain- 2 CIMs on this Sonic shifter (am-2509_37) for a total of 4 regular CIMS

Collector- 2 banebot RS-550 motors each on P60 PGBs with 5.09 ratio

Pneumatics- We use pneumatics for shifting and lifting our collector up and down. The compressor only runs when motors (other than the drive motors) are not spinning.

Arm/Shooter- 2 am-0912 with that are reduced by 630:1 ratio. The shooter uses 2 more CIMs for spinning up our wheels.

Summary:
- 6 CIMs total
- 2 banebot RS-550
- 2 am-0912
- 1 Compressor

-Aaron

[cgmv123]

Originally Posted by excel2474

Summary:
- 6 CIMs total
- 2 banebot RS-550
- 2 am-0912
- 1 Compressor

Assuming an 11 milliohm battery internal resistance and 4 total feet of 6 gauge wire on your electrical system, you only need about 400 amps to lose 5 volts. 4 CIMs alone can use over 400 amps at stall. If you run most of/all your motors at once, you could be looking at significantly more than 5 volts of loss.

[Tom Line]

I'm curious about your drivetrain. I wager a guess you're seeing this in high gear when accelerating your cims near stall from a stand still.

The sonic shifters in their default ratio, direct driven to four inch wheels with 4 cims are at the very extreme end of gear ratios - a full battery easily drops to 8 volts under acceleration from a stand still in high gear.

[cgmv123]

Originally Posted by Tom Line

I'm curious about your drivetrain. I wager a guess you're seeing this in high gear when accelerating your cims near stall from a stand still.

The sonic shifters in their default ratio, direct driven to four inch wheels with 4 cims are at the very extreme end of gear ratios - a full battery easily drops to 8 volts under acceleration from a stand still in high gear.

This can be fixed by having your shifter shift to low gear when the robot's not moving. Shouldn't take more than a few lines of code.

[excel2474]

Originally Posted by Tom Line

I'm curious about your drivetrain. I wager a guess you're seeing this in high gear when accelerating your cims near stall from a stand still.

The sonic shifters in their default ratio, direct driven to four inch wheels with 4 cims are at the very extreme end of gear ratios - a full battery easily drops to 8 volts under acceleration from a stand still in high gear.

I forgot to mention that we are using 4" wheels. Voltage is not as much of a problem accelerating as it is turning. We are going to switch our outer wheels on our 6 wheel drive to omni wheels.

[JamesCH95]

You're using a flat 6wd? (As opposed to a drop-center 6wd.)

Do you know what your drivetrain is geared for?

[excel2474]

Originally Posted by JamesCH95

You're using a flat 6wd? (As opposed to a drop-center 6wd.

Correct. We have a wide base.

The ratio in high gear is 3.7 : 1.

[excel2474]

Originally Posted by cgmv123

If you run most of/all your motors at once, you could be looking at significantly more than 5 volts of loss.

We never run all of our motors at once. The AM-0912 motors power the arm which has very high torque and holds it's own weight un-powered. The collector wheels spin only when we pick up a ball, so it's not the often. The shooter CIMs spin only when we are shooting a ball. The 4 Drive motors are the ones that spin most often.

[JamesCH95]

Originally Posted by excel2474

Correct. We have a wide base.

The ratio in high gear is 3.7 : 1.

Wow.

I used the JVN calculator (which I think everyone should have in the Excel 'recent docs') and it seems that in high gear you're set for 20+ft/s. Which is insanely fast. It predicts a maximum drive-train draw of 680A, which will definitely cause the voltage sag issues you've been seeing.

This issue is probably compounded by the fact that you've so deeply discharged most, or all, of your batteries by now and damaged them.

Omni wheels will definitely help turning. I would strongly encourage some sort of software feature that uses low gear as much as possible.