Marble Drop Timing Test - mmxt-droptest


1.0 Test Design


1.1 Research Questions

- How Consistent can we make the timing of a marble drop, from release to hit?
- What is the difference in accuracy between free fall and marble guide rails?
- How do different types of guide rails affect the timing accuracy?
- What is the most accurate dropper design?

1.2 Vocabulary
Release - The moment the dropper is opened
Dropper - The moving part in contact with the marble
Guiderails - Rails to alter the marble path after release
Fall Duration - Duration of time between Release to Hit
Hit - The moment the marble hits the hit point


1.3 The Basic Test
Release a marble onto a hit point.
Record the timing of the Release and Hit with good enough resolution so that the Fall Duration time can be calculated in milliseconds with one decimal accuracy.

Drop 30 marbles for each test variant and record the fall duration time for each drop.

The data we need is the deviation in fall duration from one drop to another within the same test Variant. The test rig do not need to be accurate with other test variants or rigs. Latency for example is a non-issue as long as it is constant.

1.4 Sensoring Methods
You can use any sensoring method that can record the fall duration time in milliseconds with one decimals accuracy.

Current ideas includes Solenoids, Limit Switches, Break Beam Lasers, Slow-Motion Footage, and Audio Recording.

1.5 Release Signal Clarification
Use the dropper movement as input signal to capture the release data.
Do not use movement in the marble as release data. We want to capture the delay between when the dropper opens and the marble starts moving to get correct data.


Example: Using solenoid and a hit pad
Example: Break beam Lasers instead of solenoids


Example using sound only as measurement data



2.0 Test Variants and Variables

2.1 Definition of "Test Variant"
Perform the test in different Test Variants, Example:

The test rig is completed and ready to go
Drop the first 30 marbles in a row without making any changes to the rig.
The data from these 30 marble drop will be registered under "Test Variant #1"

Change one of the test variables on the test rig, and record 30 new marble drops. The data from these 30 marble drop will be registered under "Test Variant #2" etc.

Try to change only one variable at the time, so we know better what causes any differences.

2.2 Test Variables - Guide rails
- Free Fall (no guide rails)
- Short Guide Rails
- Long Guide Rails
- Curved Guide Rails
- Straight Guide rails
- Guide rails materials/friction
- Guide rails angle

2.3 Test Variables - Dropper
- Dropper Design three contact points (Rail+Rail+Dropper)
- Dropper Design four contact points (Rail+Rail+Dropper+Dropper)
- Dropper Design circular contact point (all around the circumference)

Test different geometries/designs for holding and releasing the marble, strive for a stable constant resting position and a constant accurate timing of the drop.

The thesis is that three contact points, two from the rails, one from the dropper, will give the best result while allowing for highest build tolerances, three points is probably a good place to start.

Another aspect of the dropper design is to search for a design that requires least amount of force to keep closed, but stills holds and stops the marble at a very constant position/height. On the Marble Machine the marbles are loaded onto the dropper by falling down onto the dropper from 5 cm. Replicating that in the test rig by manually dropping them down on the dropper would be an interesting test variant.

2.4 Test Variables - Drop Height
- 25 cm
- 50 cm
- 100 cm

2.5 Test Variables - Marble Diameter
- 15,875-20mm diameter
- Around 30mm
- Around 11mm


3.0 - Data Collection

3.1 - Register your Discord Username as a Data Contributor
- Join The Wintergatan Discord Server
- Assign yourself the "Tester" Role by Clicking the test-tube emoji here

3.2 - Data Collection Form
For every unique test variant fill out the Data Collection form here.
Under "What test are you submitting data for" Choose: MMXt-Drop Test
If you have performed 8 unique test variants, fill out the form eight times.

3.3 - Video documentation
Phone camera is OK
Submit two video clips for each variant:

Clip 1: Handheld camera, showing the setup up close with clear details, keep it short, under 1 minute.
Clip 2: Camera on stand, showing one or more marble drops from a side angle, so release, fall and hit are all clearly visible within the frame, keep it short, under 1 minute

NOTE: The videos you are submitting will be publicly available, do not share personal info or include people in the footage who do not want to be seen.

4.0 General Info

4.1 - Volunteering Collaborator agreement
Read the Volunteering Collaborator Agreement here

4.2 - Reimbursements
We are thankful if you manage to build this test setup from free scraps and materials you already possess. But if you want to perform the test and are missing some vital parts, please reach out to joanna@wintergatan.net to discuss reimbursements for expenses. To be sure of reimbursement you must obtain written approval from Joanna before making any purchases.


4.3 - Discord discussion Channel
Discuss and collaborate with the Community in the dedicated mmxt-droptiming-test channel

4.4 - Youtube Videos & Social Media
Feel free to share any part of your process publicly in any way you like
Use Hashtag #mmxtdroptest for all your online posts regarding these tests to make them searchable

4.5 - Project Summarization
Once you have submitted your test data - you are done!
A data summarization team on discord will compile the meta-analysis
The final Results will be published here on wintergatan.net, on discord and on Wintergatans Youtube Channel

4.6 - Credits
We will publish an official database with credits and promotion links to anyone submitting valuable test data and have been involved in making Marble Machine Xt happen.

4.7 - VIP World Tour Concert Ticket Reward
As a symbolic gesture we will offer Two Free VIP World Tour Tickets to anyone submitting accepted valuable data. The VIP Part includes visiting the Marble Machine Xt up close, meet Martin and receive a personal thanks. This would happen before or after the concert, so that you and a friend can enjoy the resulting Machine you have been part of creating.

But - there are some serious caviats that needs to be made here:

- The World Tour might never happen, we will try but we can not know for sure.
- The Definition of "accepted valuable data" to be eligible for the ticket reward will be a subjective decision taken by Team Wintergatan. We are sure that any serious test will be eligible but we need a limit to filter non-serious data entries.
- There might be logistic or security hindrances on some concerts or festivals that makes arranging the meetup impossible, we will try to plan the tour so that the meetups are possible or arrange alternate meetups or acces to other concerts when necessary.
- we are currently in the beginning phases of designing a database to track these rewards, its not built yet, it might take a while before you can check your eligibility status.

- It feels kind of silly to give out a reward that might never exist, but when i think about it more it does make sense. We are all believing in this Machine and we are all invested in one way or another. If we can pull this off i would like everyone who has been involved in the Marble Machine X to visit the World Tour as part of the team who made it happen.

Thank you to everyone who will be involved in this, Lets make it happen!
Martin