15 replies to this topic

[mike.]

I'm getting a new bonnet soon - A single skin fibreglass one with hinge mounts.

I was thinking of using straps to hold the front down but now want something abit smother looking and secure.

I reckon if i have straps people will know the engine bay is easy access - I want something more secure like a dzus fastener. Would they work with a bonnet if i mounted them on little triangle plates like bonnet pins? How do they work? What do you open them with?

Also i've seen these: Link

I was thinking of using them but with a smaller washer (like 15mm) rather than the big one. Would that be secure enough to hold a bonnet down?

[Southy]

I use the Dzus fastners on the front end of the clubby and they do a really good job, only used one on either side was originally gonna use 2 but saw how well the hold is, they just pull the side in nice and tight and sit well.

They use an S shaped cam and you use a flat blade screw driver to twist the fastner and as it turns it pulls the body panel inwards and locks in place, you mount the actuall cam fastner on the outside body panel and rivet a s shaped metal piece onto the inside panel and this is what it attaches to.

[mike.]

Yeah i just worked out how they work from looking at pics. The only thing putting me off is how easily it is to get them back in. They look like they might be pretty tricky to line up with the spring. I want something i can do really quick but that are also secure

[mr_s_leeming]

Yeah i just worked out how they work from looking at pics. The only thing putting me off is how easily it is to get them back in. They look like they might be pretty tricky to line up with the spring. I want something i can do really quick but that are also secure

these are very quick and easy to remove/ refit. they are used on the fairings of race bikes to aid speedy removal of fairing panels so should work fine on your bonnet.

[Southy]

I dont have any problems getting mine to line back up and its a lot harder with a front end because its more flexible and can line up in a lot of positions, just when you come to fit them line all your panel gaps up the same and drop it on in that position you cant go wrong. They look a lot neater than usuing catches, ive painted mine the same colour as the car so they blend in.

[mike.]

So how are the sizes measured? Demon tweeks has like 15 different options.

Also whats with those ones on demon tweeks? They don't have the flat head screwdriver type thing i've seen on the others?

Anyway how do i know whih size to get. When it says 4.4-5.2mm whats that referring to? The width of the dzus head or the depth it reaches under the panel?

http://www.rallydesi...hp?cPath=74_703

[Southy]

The size refers to the depth of which the fastner would handle for the body panels, if you are doing it on a bonnet with a single skin and i take it the triangle plates in the corners i would use 4.4-5.2 mm fastners.

About the ones on demontweeks i dunno what they are but i got mine from that rally design and they are good.

[mike.]

So to measure the depth i need accuratly i'd have to fit the bonnet and measure how far it is from the bonnet outer to the triangle plate?

[Ethel]

Yes,

It would help if the bonnet and bracket butt up against each other..

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first thing to do is to make a hole in both parts to be joined large enough for the male half of the fastener to fit flush on the outer panel, this means the tapered sides of the fastener will centralise both parts. You then drill both parts through the fixing holes in the male half, the spring's mounting holes are on the same centres. Note that this means the rivets or whatever you use will be on top of one another so use countersunk fasteners and some packing so they don't interfere with each other.

[dklawson]

We have them on every panel of our family's Formula-Vee race car. The more you use, the more effort it takes to line them up but it's never too hard. They are costly for what they are. And as far as a screwdriver is concerned... everyone uses screwdrivers... but they actually have a special tool for tightening them.

Warning: History Content
Dzus fasteners were originally designed to attach sheet metal fairings to aircraft engine cowls. They needed a fastener that was secure but would also allow some motion of the panels.

[mike.]

Well i'm planning on just using 2 at the front of the bonnet. Is that enough to hold it down?

The only other question i'v got is about making the triangle plates. I've got some 2-3mm thick sheet metal and the tools i neec its just the shape i need to get right. Obviously i know what a triangle is but its the curvature of the plate. How can i bend it so it'll hold the spring at the same angle as the fastener?

[Ethel]

2 should be easily strong enough. You won't need to match the curve of the bonnet, just have the clips lined up across the curve so they sit as flat as possible - the spring only touches where it fixes.

2-3mm is thick enough to hang your suspension off!

It's also worth sorting out a decent tool to open them with, screwdrivers will chew them up in time, as Derek says. you could get a little bit of plate and fashion it in to a tool and keyfob.

Edited by Ethel, 17 May 2008 - 03:57 PM.

[mike.]

haha you stole my idea! i was going to get a screwdriver, pull the plastic handle off, drill a hole through it and put it on my my keys

Yeah the metal is pretty thick, infact maybe too thick? Aslong as pop revets go through ok then it'll do.

[Ethel]

The size stated is usually the combined thickness of the panels you are joining together. Remember, you need to allow for the heads on the rivets or screws as well - better to go a bit bigger and put some packing in between.

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Screwdriver blade isn't big enough, you'll see when you get them - a penny washer would be pretty good.

Edited by Ethel, 17 May 2008 - 04:28 PM.

[mike.]

Without curving the triangle plate i can't see how i'll get the bonnet and plate to mount flush against eash other though...