HH - Toolshed
← All tools

Intake Designer

Roller speed, compression and throughput together. The first thing this checks is whether your intake pulls objects in at all, which is not a given.

Inputs

in

Flex wheel or roller, measured uncompressed.

in
in

Roller surface to the opposite surface, whether that is another roller or a fixed plate.

ft/s

How fast you drive at objects. This is what the rollers have to beat.

in

Used for the throughput figure. Roughly how far apart they arrive.

Results

Will it pull objects in?

—

Roller surface speed

—ft/s

Faster than the robot by

—×

Must be above 1.

Roller speed

—RPM

Compression

—%

Squeeze on the object

—in

Objects per second

—

At full speed, if they keep arriving.

Likely failure mode

—

Roller speed, against how fast you drive in—

The roller surface has to outrun the robot or it pushes objects away instead of pulling them in. Half the bar is break-even; a full bar is roughly twice the approach speed, which is comfortable.

How this is calculated

An intake has two jobs that pull against each other. It has to grip the object hard enough to move it, and it has to let the object through without wedging. Almost every intake problem is one of those two winning.

The check most designs skip

roller surface speed = roller RPM × π × roller diameter ÷ 720 (ft/s)

That surface speed has to be faster than the robot is driving forward. If the robot approaches at 3 ft/s and the roller surface moves at 2 ft/s, the roller is moving backwards relative to the object and pushes it away. The intake spins, looks like it is working, and shoves game objects across the field.

This is why intakes usually run on the fast cartridge geared up rather than down, which is the opposite instinct to a drivetrain. A comfortable margin is roughly double the approach speed, so the roller keeps drawing the object in even when the driver is charging a stack.

Compression is the other half

compression = (object diameter − gap) ÷ object diameter

Too little and the roller skids across the surface without carrying it, or lets a second object slip in behind the first. Too much and the object wedges, the motor stalls, and something gives. The failure modes point in opposite directions, which is exactly what theIntake Jam Reliability Analyzerexists to separate once you have a prototype to test.

No published figure says what compression a VEX game object wants, because it depends on the object, the wheel durometer and the surface. The bands this page shows are a starting point from common practice, not a specification, and the right answer comes from testing.

Throughput rarely limits you

objects per second = surface speed ÷ spacing between objects

Almost every intake can swallow objects faster than a driver can present them. If the throughput number looks high, that is normal, and it means the constraint is driving and alignment rather than the intake itself. Chasing more roller speed past that point buys nothing and costs grip.

Sources & assumptions

Cartridge speeds and gear tooth counts are VEX published figures. Surface speed and compression are geometry from your own measurements.

Compression bands are estimated from common practice. VEX publishes nothing about how much squeeze a game object tolerates, and it varies with the object, the wheel and the surface. Use them to start, then measure your own with repeated trials.

Assumes the roller grips without slipping and that the object is round and compliant. A rigid object behaves quite differently: it does not compress, so the gap has to exceed it and grip comes from friction alone.

Save this run, and compare

Keeps what is on screen so you can change something and see both sides of the change. Saved in this browser only, never uploaded.

Save this as evidence

Collects what you entered, what came out, how it was worked out, and anything the tool flagged, with a timestamp and a version so someone else can reproduce it.

This is evidence, not a notebook entry. It deliberately does not write your problem statement, your reasoning, or your conclusion, because under RECF rules an Engineering Notebook has to be the students' own work and no tool may generate or organise its content. Take the numbers, decide what matters, and write it yourself.