day 5. translation

The question for today is not how do I build my sketch but how do I get close to my sketch with what I have. The found parts set the constraints.

We will look at the mechanical parts present and at the sketch and ask: which part covers which role? What plays the transmission? What becomes the point of action? 

Mechanical problem-solving session (10:00 – 11:15)

This is a hands-on problem-solving block. The goal is to produce the a mechanism that runs and produces the intended motion. Key mechanical challenges that will come up, and how to address them:

Making a crank from scratch 

Getting the right speed reduction 

Making a pivot point 

Stroke length and geometry 

Assembly

Move from temporary to permanent fixings where the geometry is confirmed. The morning’s problem-solving should have established where things go; the afternoon is execution.

A few principles worth stating at the start of this block:

Fix the motor mount first. Everything else is relative to it. A motor that shifts position under load makes all subsequent geometry unpredictable.

Build one stage at a time and test it before adding the next. Motor running freely → transmission connected and running → point of action attached and moving. Each stage confirmed before the next is added. This is the single most effective way to avoid spending an hour debugging a three-stage mechanism with the problem somewhere in the middle.

Use adjustable fixings wherever possible. A bolt in a slot rather than a bolt in a fixed hole means geometry can be tweaked after assembly. An extra 10 minutes making a slot instead of a hole saves an hour of remounting later.

15:00 – 15:15 — Short break

15:15 – 16:00 — First full run and observation

Connect to the 12V supply with the speed control. Run it across the full speed range. Step back and watch for at least five minutes without touching anything.

The questions to hold while watching:

• Is the failure in the right place — the place named in the sketch and on the task card?
• Is it attempting, reaching a threshold, failing, resetting? Even roughly?
• What’s unexpected? What did the mechanism produce that the sketch didn’t anticipate?

Make notes. Don’t fix yet.

Then adjust speed deliberately: very slow, medium, fast. Does the character of the failure change? Is there a speed where it’s most itself?

16:00 – 16:45 — Adjusting

One or two targeted adjustments based on the observation. Not a full rebuild — one thing at a time. Change the crank eccentricity to adjust stroke. Move the load position to change the threshold point. Loosen a connection deliberately to introduce irregularity. Swap a pulley to change speed.

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Day 6 then becomes the character and interaction work, with participants arriving having genuinely lived with their mechanisms for two full days. Want me to revise Day 6 with that in mind?