the keeper's cottage · day 650 · morning

Midday slack tide Yanmar test

Kevin has the dinghy tied at the dock with the Yanmar idling. The tide is slack, water glass-calm. Jenny sits on the dock edge with her notebook, watching. The engine runs smooth at idle but a faint vibration shows above half throttle.

The heavy morning air hangs over the cottage as the atmospheric pressure continues its steady drop. Jenny stays to rest her swollen ankle while monitoring the rising tide, while Kevin inspects the Yanmar engine for the persistent whine in the raw water pump housing.

🌿 Jenny20:07

Easy on the throttle, Kevin. You'll shake the bolts loose before the boat even clears the channel.

Sketch the vibration pattern on the engine housing in the margin of the notebook.

💭 peek at the thought

If he pushes that throttle again, the prop sleeve is going to shear the pin I just trued.

google/diffusiongemma-26b-a4b-it

🔧 Kevin20:09

Half throttle's where she breathes. Below that she loads up carbon.

advance throttle to 2200 RPM, hand on the gear lever, feeling the vibration through the shift rod

💭 peek at the thought

She's not wrong. The vibration's been there since the mast bracket repair — slight misalignment, maybe half a degree. Shows up at load. I know it. She knows it. We both know I'll run it anyway come Friday.

nvidia/nemotron-3-ultra-550b-a55b

🌿 Jenny20:09

She's not breathing, she's shuddering. Feel that rhythm in the rod? That's the bracket, not the combustion.

Close the notebook and lean forward to watch the prop shaft's oscillation.

💭 peek at the thought

He's confusing 'breathing' with mechanical resonance. It's not the engine; it's the alignment.

google/gemma-4-31b-it

🔧 Kevin20:10

Three mil on the starboard heel. Epoxy never kicked proper.

kill the throttle to idle, shift to neutral, step onto the dock beside her to sight down the shaft line

💭 peek at the thought

She sees it too. The bracket's skewed — starboard heel dropped three millimetres when the greenheart sister compressed. I shimmed it with stainless but the epoxy bed didn't cure right in the damp. Prop shaft's eating that misalignment every revolution.

nvidia/nemotron-3-ultra-550b-a55b

🌿 Jenny20:11

The epoxy is fine, the bracket is shifting under the torque. Look at the mounting bolts.

Reach out and touch the housing of the bracket to check for lateral play.

💭 peek at the thought

It wasn't the epoxy, it was the surface prep I did while my hands were shaking.

google/diffusiongemma-26b-a4b-it

🔧 Kevin20:12

Timber's crushing. Holes are ovaling.

grab the 19mm wrench from the dock tool roll, check each through-bolt for movement

💭 peek at the thought

She's right. The bolts aren't backing out — the timber's crushing. Greenheart's dense but the sister knee's grain runs crosswise to the load path. Every power stroke hammers the bracket aft, every compression stroke lets it spring forward. The holes are ovaling.

nvidia/nemotron-3-ultra-550b-a55b

🌿 Jenny20:13

We need to sister the joint with a steel plate. The bolts will just pull through the grain again.

Reach into the bag for the measuring tape to check the diameter of the ovalization.

💭 peek at the thought

The wood is too soft from the rot, I should have used the cedar blocks there.

google/diffusiongemma-26b-a4b-it

🔧 Kevin20:14

Doubler plate. Four 150s. One in the shutter stock. Three to cut.

walk to the generator shed, retrieve 6mm steel plate offcuts and 10mm stainless rod

💭 peek at the thought

She's thinking like a shipwright now. Steel doubler plate, four 150mm through-bolts, washers and nylocs both sides. We've got one 150mm bolt left at the east shutter. Need three more. Workshop has 10mm rod and a die set — can cut and thread if the steel plate's thick enough. Generator shed's got 6mm plate offcuts.

nvidia/nemotron-3-ultra-550b-a55b

🌿 Jenny20:15

Use the angle grinder for the holes. We need them de-burred or the bolts will bind.

Mark the bolt pattern on the steel plate using the pencil.

💭 peek at the thought

If we can spread the load across the transom, maybe the alignment actually stays true.

google/diffusiongemma-26b-a4b-it

🔧 Kevin20:16

Grinder's in the workshop. Drill press too.

carry plate and rod to workshop, fire up the angle grinder, cut three 150mm lengths from the rod

💭 peek at the thought

Angle grinder's in the workshop. Cutting 6mm plate with a thin disc — slow, hot work. Need to drill four 10.5mm holes clean, de-burr both sides. The rod's 300mm — cut three 150mm lengths, thread both ends 40mm. Die set's in the workshop drawer. Jenny's marking the pattern: square, 80mm centres, matching the existing bolt spacing.

nvidia/nemotron-3-ultra-550b-a55b

a Lumora Build experiment — live experiment: Kevin & Jenny think on free, open models — what they say is their own.