Surface finish standards (Ra) in CNC Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the surface roughness value to 1.6 micrometers.

CNC Programming

surface_roughness = [1]  # Ra value in micrometers

Drag options to blanks, or click blank then click option'

A6

B16

C0.16

D1.6

Attempts:

3 left

💡 Hint

Common Mistakes

Using a value too large like 16 which is not typical for Ra.

Using a value too small like 0.16 without context.

The standard Ra value for a smooth finish is often 1.6 micrometers.

2fill in blank

medium

Complete the code to calculate the average surface roughness from a list of Ra measurements.

CNC Programming

average_ra = sum(ra_values) / [1]

Drag options to blanks, or click blank then click option'

Alen(ra_values)

Bmax(ra_values)

Cmin(ra_values)

Dra_values[0]

Attempts:

3 left

💡 Hint

Common Mistakes

Dividing by max or min values instead of count.

Using an element instead of the length of the list.

To find the average, divide the sum by the number of measurements using len().

3fill in blank

hard

Fix the error in the code to compare if the Ra value is less than the maximum allowed roughness.

CNC Programming

if ra_value [1] max_roughness:
    print('Surface finish is acceptable')

Drag options to blanks, or click blank then click option'

A>

B<

C==

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' which checks if roughness is greater, meaning worse finish.

Using '==' which only checks equality.

We check if the Ra value is less than the maximum allowed roughness to accept the surface.

4fill in blank

hard

Fill both blanks to create a dictionary of parts with their Ra values filtered by a maximum roughness.

CNC Programming

filtered_parts = {part: ra for part, ra in parts_ra.items() if ra [1] [2]

Drag options to blanks, or click blank then click option'

A<

B>

Cmax_roughness

Dmin_roughness

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' instead of '<' which would filter the wrong parts.

Using min_roughness instead of max_roughness.

We filter parts where Ra is less than the maximum roughness allowed.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that converts Ra values from micrometers to nanometers for parts with Ra less than max_roughness.

CNC Programming

converted_ra = { [1]: ra * [2] for [3], ra in parts_ra.items() if ra < max_roughness }

Drag options to blanks, or click blank then click option'

Apart

B1000

Dra

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'ra' as key instead of 'part'.

Multiplying by wrong factor or variable.

Swapping variable names in the loop.

We use 'part' as key, multiply Ra by 1000 to convert micrometers to nanometers, and iterate with 'part, ra'.