HP-24 Project

Update 29 May 2007: Long distance runaround

For the Memorial Day weekend my company is shut down Friday through Monday, making it a full four-day weekend. That's great, it gives me lots of time to get stuff done at the shop and also do stuff with the family.

On Friday I mostly just lazed around. I also cleaned up our cache of camping gear somewhat, testing the Coleman stoves and figuring which we'd take on what sort of trips. The bigger and older of the two is nice for car camping, but the shutoff isn't very secure, so it's prone to orange-fire startups and slow shutdowns. We also cruised the local yard sales and scored a new bicycle for the daughters.

Saturday I spent about half the day at the shop. I worked a bit on the ASK21 tools, prepared for some tension tests on commercial-grade quicklinks, and prepared to cut the flaperon plug hinge radii on Radius Maximus.

In order to cut the radii, I finished off a bunch of the hinging features and also made an extended-length hingeline support tube. When I originally made Radius Maximus, I made the hingeline support tube just as long as the machine, which worked great for the 40" elevator halves. However, for the 136" flaperon sections I needed the hingeline support tube to be at least 100" long. It's OK to have some unsupported surface out beyond the machine envelope, but if there's too much I risk having the workpiece break or having its flexure distort the part and affect the cutting path.

Anyhow, I didn't have a 100" length of 2" square steel tubing handy, but I hunted around the shop and did manage to come up with a 40" piece. So I splinted the 60" and 40" pieces together with a couple chunks of angle iron and eight C clamps and welded them together. It didn't come out perfectly straight at first, so I cut one side back open and re-welded it, and the weld shrinkage pulled it about as straight as can be seen with the naked eye.

On Sunday we drove down to Tioga Pass Highway (Hwy 120) and did the 4.4 mile hike from the Porcupine Creek trailhead down to the top of North Dome. This hike is one of my favorites. It offers one of the best views there are of Half Dome and the Yosemite Valley. It descends on the way out and ascends on the way back. And, it's not as well known as some of the other Yosemite hikes, so you can do it on a holiday weekend and not be tripping over a dozen other parties like if you were hiking in the valley. It was pretty gratifying to look down into the valley and see bumper-to-bumper traffic on Northside and Southside drives and know that I wouldn't have to be part of it. On the way back we cached a liter of water at one of the trail signs, figuring that some thirsty hiker (or Crest Jewel climber) would appreciate a bit of hydration going back to the highway.

Monday saw me back at the shop, chucking the flaperon plug up on Radius Maximus and cutting the entire 136" upper hinge radius. It was pretty nice to get that piece of work done so accurately and quickly, I am really glad I went to the trouble of making that machine. However, I didn't bring the camera, so no photos of that.

When I shmoo'd on the hing radius blanks, I wasn't careful enough around the hinge pivots, and got some of the shmoo in the pivot bores. I welded together a drill bit and a piece of steel rod to make this pivot bore cleaner to scrape out the shmoo.

Welding together the extended-length hingeline support tube for Radius Maximus.

Assembling the hinge features for the right outboard flaperon plug. The Y-shaped parts attach to the support tube (note the shiny welded splice) with 8-32 screws in tapped holes. Then the support tube drops into cradles on Radius Maximus, gets adjusted and clamped into place, and the cutting operation begins.

Atop North Dome on Sunday after hiking 4.4 miles. View? What view?

The obligatory family portrait with famous landmark.

"We hiked to North Dome with Mom and Dad, and all we got was this stupid photograph."

Homebuilt aviation is not for folks who don't try things at home.

Return to HP-24 page

page updated 29 May 2007 all text and graphics copyright (c) 2007 HP Aircraft, LLC