DAMMERR.COM

08/09/2026

Some notes on proof loading and bounce testing.

06/17/2026

The recent news about Snake D**e caused me to revisit a removal method for 3/8" drive anchors. If you don't know, Snake D**e on Half Dome was retro bolted. The retro bolts appear to be carbon steel 3/8" drive anchors with (stainless?) steel hangers. This is just a proof of concept and there needs to be more trials and refinement of the methods and tools. The device to hold the stud in place especially needs to be redesigned.

Somebody has begun removing the bolts but I am not sure how they are doing it, possibly by grinding off the heads.

Pre-tinning the stud might help, especially if you could get enough silver in place to make the joint.

I think BAg-5 solder would be best.

06/10/2026

Sent out some rebolting tools.

03/13/2026

Inventory

01/30/2026

I don't know if you know my buddy Bruce Hildenbrand, climber, former professional cyclist and journalist writing for Outside, Cycling and Climbing. He called me last night from Stanford Hospital. On Wednesday afternoon he was riding his bike near his home while testing my cycling gradient meter and got hit by a dump truck! Broken wrist, broken clavicle, cracked vertebrae and a badly broken femur. He's had some nasty bike crashes over the years, he got hit by a car in France about 10 years ago and had to charter an AirMed flight to get to better surgeons in California.

Send a message to learn more

01/15/2026

This is totally unrelated to hammers, but here's a nerdy rabbit hole I've gone down...

I love to ride my bike, and I also love playing with data. My Garmin bike computer displays gradient, but it's frustratingly inaccurate. The problem? It relies on GPS (slow, only accurate to maybe 10 meters) and a barometric altimeter (imprecise and unstable).

So I thought: why not measure the tilt of the bicycle frame directly?
I spent a significant part of my career doing instrumentation and measurement, so I started experimenting with tilt meters. A simple bubble level won't work—any acceleration when you speed up or brake throws it off completely.

First, I tried a tiny Bluetooth tilt meter taped to my top tube (WIT Motion WT9011DCL—under $20 from China). Super accurate and stable, but I couldn't keep my phone awake on long rides to watch the data in real time.

So I built my own standalone display and logger with a touchscreen, using a Waveshare ESP32-S3 development board (about $30). Here's the thing: I don't write code. The only programming class I ever took was 50 years ago using punch cards. But with AI help, I wrote and compiled 1,000 lines of code to make this work.

The device measures slope using gyroscopes with corrections from accelerometers. The gyros measure rotation rate, which you integrate over time—but integration amplifies errors. That's where Kalman filtering comes in, a probability-based method for correcting telemetry that's completely new to me and absolutely fascinating.

I've got it working and logging data to a micro SD card. There's still snow and black ice everywhere, so no road test yet, but bench testing looks great.

The hardware cost: $30-50. The software, based on my invested time: roughly a million dollars. Software always costs more than hardware.

01/08/2026

"Give a small boy a hammer and everything he meets has to be pounded."

Hammers with stainless steel tube on the handles. A mix of hickory and black locust handles. A few thin picks, some thicker.

12/07/2025

8/4 black locust slabs for handles.