Thread: Dzus Forming Tool

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Here's an easy to make Dzus Button forming tool.

This one turned out on a lathe, but it can be made on a drill press as well. All that's needed is a little care in finding center and drilling the hole square with the aluminum body.

The body is made of 1" OD 6061 T6 aluminum.
(6061 T6 is what you usually get when you buy aluminum. 7075 T6 works ok as well, but stay away from alloys with a softer temper such as 5054 T4. Aside from not lasting long, it doesn't machine real well.)

Cut the aluminum body to length making sure it's square on both ends.

Drill the body with a 3/8" drill on center.

Countersink the body with the usual 82 degree countersink.
A 3/4" OD countersink works well, but a larger one can be used if you're careful.

The pictures show a Phillips head F.H. 3/8-16 machine screw, but what you really want is an F.H. Allen machine screw (F.H. = Flat Head). A standard/non-stainless one. Most times black in color.

The Phillips will work, but life is a lot easier with an allen.

Shown in the pic as well is a stainless washer and nut.
You're better off to use a standard nut as the stainless nut galls and drags on the regular alloy Allen head.

To form the Dzus countersink in body sheet metal drill a 3/8" hole where the Dzus goes.
Assemble to the tool with the anvil (aluminum body) on the inside with the flat washer between anvil and nut.
Draw together until the Allen head is firmly bottomed out.
That forms the Dzus sheet metal countersink.
Remove tool and install the desired style Dzus.

Incidentally, DeWalt has a neat little drill set that incorporates a small pilot drill into the drills.
These work great for drilling sheet metal.
No center punch needed in most cases.

Note the formed hole in the sheet metal.
This was done in a piece of 18 gage sheet metal and it pulled the Dzus countersink in with no problems.
Most body metal is 20 gage so pulling in the countersink is easy.

One of the advantages with this tool is that no striking with a hammer is necessary.
Another is that the tool can be operated in very tight places.

Best of all, the price is right.
There's less than $2.00 invested in the one shown and the price is more than likely right around a dollar.

In my view this simple little tool beats the $35. + commercial tools that are on the market today.

This pic shows the backside of the formed Dzus countersink as well as the assembled tool.

This pic shows the captured style Dzus buttons I like.

These are pop-riveted in - easy to remove by drilling out the pop rivets if required, but the only time that was needed was when the car was painted.

I've since found a supply of #6 button head allens and nylocks.

Small nylocks can be found at hobby shops that carry R/C model aircraft.

I hate to sound like a dummy but I have seen numerous discussions on Dzus fasteners and I have no idea what they are and why you would use them. Can someone enlighten me. Maybe a picture of one of these.
Thanks

Here's some catalog shots of various dzus pieces. The are a quarter turn, quick attach/release fasteners favored in aircraft and race car use. The screw looking device (Usually panel mounted) engages the wire piece (usually frame or other support structure mounted).
http://www.speedwaymotors.com/search...J4NF34QDHS7PWF

Here's a pic of a mockup done for the hood sides of my 31 on 32 rails roadster.
Photo shot from inside the hood - as you can see - and shows the wire spring mounted backwards from most Dzus installations.

The aluminum piece is a stand that bolts to drilled and tapped holes in the top of the frame.
I like to do it this way instead of welding a piece onto the frame.

The rectangular tubing you see was used as standoffs to get things spaced out properly.
Nice thing about the Dzus captured fasteners - as well as the loose ones - is there are a couple of lengths available in either style.
The long ones are .050 longer than the short ones.
Makes life easy if you want a tighter or looser fit depending on the cowl welting and other factors.

There are commercially available sheet metal formed tabs for the springs and a lot of guys weld these to the cowl lip sheetmetal.
That works well too, but the first time I used the aluminum stand was on my glass 32 roadster.
It worked so well that I'm doing it again on the 31.

Front Dzus mounts are a little different as well.
I'll post a pic of those next.

Here's a pic that shows the front Dzus stand on my 32.
Yeah . . . it's dirty.
Seems to get that way when I drive it.

Anyway, I did start out here with a tacked on steel tab for the Dzus spring, but found that getting the welder in the small corner between stand, frame side and front crossmember wasn't going to work.

A couple of threaded weld bungs were made up (1/4-20), and TIG'd in.
A couple of aluminum stand off spacers (7/8" OD) go between the aluminum (1/8") stand and frame.

Like the above aluminum stand, the Dzus springs are mounted backwards.

I thought perhaps the 1/8" aluminum stand would fatigue and break off, but it's never been a problem.
Even if it did break, the hood side is not going anywhere because it's narrower in front than at the rear where it sits on the cowl lip and aerodynamic forces tend to hold it in place.

There's a small jog in the left side aluminum stand, that cuz I missed in the measuring/matching dept.
On this car I had the hood sides set up for the original tacked in steel tabs and was working in the blind to an extent.
The right side stand is straight fwiw.

What makes the Dzus buttons nice for hood retainment is that once the hood top is up, spin the two hood side Dzus buttons a quarter turn and the bottom of the hood side is free.
The left side simply lifts off.
It's located on top by a couple of dull point stainless pins.
The right side is located/retained by three 10-32 F.H. stainless allens into small threaded weld bungs in the 1/2 x 1" rectangular tubing radiator/grille shell braces.

All this Dzus stuff and minimal hold-down devices make the front of the car easy to work on.
Most engine work can be done with the hood sides removed and the hood top up on it's prop.
Or the hood top can be pulled by removing a couple of pins, one small bolt, two wires (horn) and lifting it off.
Taking your time it takes about ten minutes to get all the hood components off.

Another 10-15 minutes has the grille shell and radiator off, all hood braces off and the front of the engine is easily accessed for cam changes - or whatever....