Problem with most Dzus style fasteners these days is cheap springs. The fasteners are still fine, just buy the best springs you can fine. They collapse almost instantly. We used a lot of them on dirt late models and mods. Would occasionally have to move the spring away from the hole with a sharp wrap of a hammer on a 1/4" extension to get them tight again in the pits. DoNOT use Speedway springs, get original Dzus springs. SPark
Danny, I'm sure you're aware of this but there are many variations. Small and large shank, different lengths, different springs all that accommidate different material thicknesses. I use flat heads most often. I made a simple tool to dimple the panels that uses a fastener to pull the 2 haves together. They may not be for everyone but if properly installed are very useful.
@HOTRODPRIMER they are a fantastic fastener...huge in aviation and its not surprising they were used in race as well with the combined fields of use spreading over to the hobby we hold close to the heart. A recent thread in memory of the late Roy Fjastad had a related angle on this type of fastener... Quoted from @HEMI32's post "Later, he reinvented the humble Dzus fastener, the ubiquitous quick-release device that holds body panels in place. Roy replaced the slot with a more secure Allen wrench receptor." Quite an accomplishment in a highly evolved seasoned rock solid established attachment as the Dzus. https://www.jalopyjournal.com/forum/threads/rip-roy-fjastad.1098641/#post-12459123
I have been using them on race cars and hotrods for over 40 years. It was always a struggle to punch and dimple the 3 holes to install the wires in panels, or making specialized plates for mounting. About 10 years ago, I acquired a Pexto kick punch with the die punching and dimpling all 3 holes with one hit. Now it's a breeze.
There is no "clip" on the back side. The spring plate is attached to the cowl and the radiator shell.
This is a very interesting thread. I have to say I am in love with this kind of old patent application drawing. No computer generated crap, even if in 3-D, is ever going to match the artistry of these drawings.
I made this tool for the race car. We had many places that had mismatched panels and the springs for retaining the fasteners needed adjustment. You place the end of the tool through the hole and twist it to attach to the spring. Then you can pull out or push in to bend the spring for the right amount of tension on the fastener. John
Speedway now sells their copy of the full bore design https://www.speedwaymotors.com/Steel-Dome-Head-Quarter-Turn-Fasteners,63577.html
The current mfg's of Dzus fasteners are more commercially based. The bulk of their product line looks nothing like what we are familiar with. https://www.southco.com/en-us/product/hierarchy.html?hid=7345
Both these race cars are held together with Dzus fasteners. One HAMB friendly and one not. The dirt Super Stock at Perris Auto Speedway can have the entire front end and sides off in less than 2 minutes; and the Bonneville/Dry Lakes roadster in about 5 minutes..It's amazing how much that helps. On the Dirt car you can see the large head aluminum fasteners on the front fenders to the body side panel... There are a lot of companies making ez parts for racers and street/hot rod cars...you just need to look.
Morgan uses them on the bonnet of the 3 Wheeler and sometimes I find it a challenge to get all four lined up correctly. They do provide a clean look and once fastened it stays put! My blog: https://ontheroadtonowhereville.wordpress.com/ High Noon
Spent a year looking at those kinds of drawings while I modeled them in 3-D and generated very sanitary generic prints. Progress??? Nah.
Living near an air force base AND an army base ...one finds all sorts of useful "stuff" surplus that originates from those places.Usually pretty cheap. I went to a garage sale where I bought boxes of cad plated nuts and bolts along with Dzus fasteners.
I got a lot of cool tools out of different aircraft plant tool cribs. Still got some of the brass needed to trade for the tools. Amazing how well they work in our hobby, huh?
I pass their OG factory almost every day. Which is now a Super Fund site. They had it cleaned up maybe 15 years ago, removed all the test wells, etc. Then nasty things were found in the ground water.. again. Very much a hot topic in my home town, also where I live now. I am upstream of the contaminants. http://www.dec.ny.gov/data/der/factsheet/152033ou3cuprop.pdf
We used Skybolt quarter turn fasteners on an airplane cowl. They are nice & do not have the spring like the Dzus fasteners. The Skybolts are adjustable for thicknesses. We did a mock up to set all the depths before they were installed. Skybolts are a nice looking fastener.
I think the Dzus look really clean on a Streetrod but would like to see a pic of patterg2003 skybolt, by the way like your new (old) 32
I have the spring loaded style holding on the hood sides on my roadster. Speedway sells them and I just used small machine screws to hold them on the hood sides, instead of riveting them on.
We switched to a variation called Mote fasteners comparable in weight but made out of Chromoly and can use a flat screwdriver or torx and won’t slip or strip the heads.
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