Discussion in 'Hangar Talk' started by cwilliamrose, Aug 31, 2018.
I happened onto to this today. Some interesting tools and techniques, enjoy.
Was that casein glue they were using? The 15 minute assembly process time limit makes me question that guess...
wow....when anything was possible....
A lot of glues made in that era were made from animal hides and I have an old, turn of the century violin that was made using hide glue but I have no idea what they may have been using.
Fwiw, modern instruments are still made with hide glue, because it can be steamed apart to make repairs. "Better" glues just mean you destroy the instrument if you need to open it up for repair.
I can't imagine they'd use a hide glue on a propeller like that, it wouldn't be strong enough. They probably used whatever was the state of the art. I didn't see a date on the film, but I was thinking resorcinol, though it came out in 1946, so possibly it didn't exist at the time that film was made.
The date is 1941. The glue seems to be light colored and about the viscosity of cheese sauce including being a bit stringy.
I wonder how long that prop was in service?
Could be a urea formaldehyde glue like Aerolite, it's been around for a long time.
That was awesome! Maybe she’s still spinning!
This came up next for me. Building a Cub start to finish.
Maybe. The first year I worked for the army in the super sonic wind tunnel branch of the BRL at APG, Md. No wooden props there but I did TDY at both Langley and Moffett where they had large sub sonic tunnels. During the visit I recall a giant propeller like this one but I forget where. The BRL tunnels were scrapped long ago made obsolete by computers, I don't know about the others?
I built my cub bungee tool from this movie 25 years ago, still the best as it stretches the bungee and wraps it around.
The prop building video was awesome. Look at all the hand laboor involved! Sort of like building the pyramids. Loved it.
I wonder if the tips were painted red? Or yellow?
That would be neat if its still in 1 piece somewhere....
Five or six years ago, when they were building my prop (for an as of yet unfinished project), I hung around the shop while they were gluing up my blank... most of the standard sized props were built off of templates of course, but they were hand-working an over-sized order for a 108" (or maybe 112", can't recall) prop for a WWI restoration project -- they used power tools for the macro cuts, but the fine stuff was still all by hand... hand/eye skills I can only dream about...
After graduating from college in the late 80's my first professional job as a newly degreed aerospace engineer was at the CALspan transonic wind tunnel outside Buffalo NY. The primary drive blades were aluminum, Hartzells about 5 or 6 ft. long with a about a 18 in. chord at the base as I recall. They were attached to angle adjusting mechanism in a large diameter (30 ft.??) hub. Three (?) rows of a long forgotten number of blades (36?) per row. Clearance to the ID of the tunnel was minimal (.5 in?). It was an amazing feat of engineering and is still in operation today. Short of a Navy ship I have never seen so much heavy steel in one dynamically operating structure.
One day one of the lead row blades failed. The debris took out more blades. The imbalance shook the entire tunnel and building as the operating crew rapidly shut down the drive. The analysis, repairs, and re-start up took many weeks. The staff did an amazing job in a relatively short time and even used the downtime to calibrate, upgrade and/or improve other systems within the tunnel.Somewhere I have a chunk that was band sawed out of one of the failed blades as a memento.
I should contact some of my old colleagues (some have passed unfortunately, some have moved on as I did, but some still work there) and we should make a short memoir about that incident. Their familiarity and memories would likely be better than mine at this point. It was nearly thirty years and, at least for me, several different lifetimes ago. This post brings back some of the memories and appreciation for what the first two or three generations of people in the aerospace industry did with only rudimentary equipment but astounding skills, insight, and perseverance.
One older crew chief told me how when he was a young post WWII technician they didn't have electrical testers. They would literally lick their fingers and judge the voltage by the amount of tingle they felt when they touched the contacts. Others who never went to college but had more technical and engineering knowledge and skills gained from working from the bottom up and building the systems from scratch than any body I have met since. And when something went wrong they always had an instinctive "feel" for where to find the root cause that us younger types couldn't locate after hours of troubleshooting. And engineers that could sit down with a pencil and paper (pre-computers!!) and analytically reason out solutions and results that were elegant in their simplicity but profound in their applicability.
Amazing people from a different (better?!) era.
Some the workers look like they are still in high school. A very young work force learning some life long skills in a demanding situation that only gets worse after 1941.
Amazing...teams of workers.
People climbing more than a few feet up without a safety harness or even a ladder.
Using white lead
Yes they do look young. Probably glad to have a job and support the family coming out of the depression. After 1941 most probably went in the service and were replaced by women. And today most of them are gone. They were America's greatest generation!
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