Fastener Question

[Anthony_V]

Hello Everyone,

Our team is looking for an alternative to the Dzus self-ejecting type fasteners. Basically, we're having some issues with regards to durability. I've been looking over pictures from past competitions, and I've noticed some teams such as the University of Western Australia are using what appears to be press-in fastener. It looks a bit more flush with the nonstructural panels. Anyhow, is that what they are, press-ins? I appreciate any feedback.

Thanks,

Anthony

[Jersey Tom]

In aerospace, for sheet metal joining a lot of places use PEM fasteners. They are essentially press-in nuts. There also exist some sort of nut tabs that Boeing uses.. but the real name of them escapes me.

Formula Atlantics and other large, professional formula cars have thick body work and use flat head, countersunk, allen-drive bolts to fasten everything.

And yea. I hate dzus's.

[Schwanger]

I think nut plates is what you're looking for. They are riveted on using two blind rivets. You can also use a nut clip that just slides on from the edge.

[Anthony_V]

Hey Guys,

Thanks for the timely reply. Anyhow, is this what your referring too?

http://www.pemnet.com/fastening_products/prod_desc.php3...anel+Access+Hardware

Thanks,

Anthony

[Jersey Tom]

I've only used it for sheetmetal, where we use this series

http://www.pemnet.com/fastening_products/prod_desc.php3...eners+for+Sheetmetal

The self-clinching nuts. That panel access stuff might be promising though

[BrunoC]

You can try camloc. We use that and they work fine. Also, they are very cheap and use in aerospace for access panel
http://www.milspecproducts.com/26002700c-lock.htm

[Kevin Hayward]

Anthony,

Not sure what pic you are looking at, but in 2003 UWA started using velcro to attach its nose cover, which was the only removeable non-structural panel on both the 2003 and 2004 vehicles (2004 and 2005 US). The seat panel was semi-stressed and was bolted in. I am not sure what the team did with the latest car.

The velcro is quite impressive. We did a couple of unnecessary instron tests late at night and found that it could hold quite a lot of load. Invariably we used far too much of it when we were attaching the nose covers, which made the nose annoying to remove at times. Although it was still a lot less annoying than Dzus fasteners in 2001, and countersunk bolts in 2002.

The monocoque allows for easy use of velco because it is a flat panel mounting to a flat panel, quite easy to get a fairly flush fit. Very easy to apply. Unfortunately it is not as expensive as special motorsport fasteners

Kev

[Anthony_V]

Hey Kevin,

I believe the pictures I have looked at are from 2006 FSAE competition, but it could have been from the '05 competition. I'm not entirely sure at the moment. Anyhow, I'm not very experienced with assessing other cars, but it looked liked you guys had press-in fasteners...

Our team is really considering going with Velcro throughout. I don't know what the drawbacks are as of yet. I actually e-mailed Western Australia, so maybe they can shed some insight on the subject. By the way, fantastic car!

[Tommo]

Anthony,

Not exactly sure what your referring to as press-in fasteners

you're probably talking about the magnets we're using to attach the footwell/pedal box cover?
a few magnets glued into the chassis/thin sheet laid into the carbon cover
there's some velcro there as well

if that's not what you're seeing, some specifics may help

anywho, velcro rocks if you can get things flush
the adhesive is usually the weakess link

tom

[Anthony_V]

Hello Everyone,

Hey guys, thanks for all the insight. Tommo, I could send you a few pictures, and I can somewhat point out what I'm looking at.

As far as the Velcro, I contacted Velcro USA. I wanted to see if a technical representative would stop by and recommend something, but I was told that my possible purchase isn't big enough to justify one. Then I was told if I want Velcro, I should go to a nearby distributor and pick out what she referred to as a 'hook-loop' application...whatever that is. How the heck do you guys go about doing this? Anyone? I want to this to be a tidy application....