Dzus fasteners long grip length

[EGLITOM]

Hi

I mounted my front hatch last week, using 3/4" head dzus fasteners. I bought the ones with the maximun grip length of 0,650". Couldn´t find anly longer ones.
The issue is this length is to short. I have to mount the spring receptable flat on top of the front clip and adjust the height with shims.

There are three reasons , why i don´t like this solution.:

1. It is not as save as it would be if you mount the spring on the back side of the clip
2. the spring can not be preloaded, because it need to be mounted flat in order to give enough clearance for the hatch inner side
3. it looks shit if you pop of the hatch

I would need 3/4" head Dzus fasteners ( without a handle) with a grip length of 1,15 ". this would be working fine with spring receptables of 0,300" height ( giving me adjustability up and down with other springs)

Anyone an idea if they are available and where. ( i wonder how the originals have done it, becuase on the pics you can see holes, meaning the spring need to be on the other side, dimensionwise itshould be th same)

Thanks for your help

TOM

Nice infos on this site:

QUICK RELEASE DZUS® TYPE RACING FASTENER | CAMLOC® DZUS® AIRLOC® MILSPEC® MILITARY AVIATION 1/4 QUARTER TURN DRAGSTER CHASSIS PANEL QUICK LOCK MIL-SPEC FASTENERS

 

[Randy V]

Here's a place where you can buy the .750" long Dzus buttons;

McKinney Corp. Race Cars - Dzus Fasteners and Tabs

McKinney Corp. Race Cars - Pan 6750 - Dzus Button .750 Long - Dome Steel

Another place is through Aircraft Spruce but I think the longest stud is .700;
DZUS Studs from Aircraft Spruce

 

[Dave Deerson]

Are you using the Dzus buttons that have the integral flange and stay on the panel after release(captured)?How many panels are you going through and how thick are they?How thick is the spring plate?Unless the 'glass is unusually thick,I find that I can get the right grip length pairing between button and spring by mixing and matching most of the time.

 

[Scott McDill]

.80 are the longest I was able to find. Pegasus - Dzus 1/4 Turn Stud Assembly - EHF5-80

 

[andy loveday]

Hi Tom

Europa do 15 and 20mm shafts, or try Merlin motorsport, Andy

 

[Bill Musarra]

Tom,
Rather than send you an email to my solution to mounting the hatch, I thought I would post it here for the benefit of the others with the same problem. When my car came it had some wierd latch mechanism I had never seen before. They were O K, but not what I wanted. When the car went to the painter I expressed my concerns to the owner who was a renound fiberglass guy. He suggested the Dzus fasteners. Upon looking, I couldn't find the ones long enough as well. When I told him that he put his thinking cap on and came up with an out of the box idea that was so simple that none of us had thought of it. What he did was cut out the corner, flip it over and reglass it in. This moved the mating surface up to the hatch surface and the regular lenght fasteners worked beautifully. Problem solved. You can see how he did it by the pics. Tom, I am sure this won't be a problem for you with your glass skills. I plan to replace the pop rivits with small button head screws and locking nuts. The underside expansion of the rivits doesn't loook real encouraging. They have held for about 4 1/2 years, with a lot of on and offs, but the car is still in the build stage and hasn't been stressed by the wind YET.

Bill

 

[denny dera]

Hi Tom,
Try a place called full bore race products ,They are a company like Hartwell Dzus.Also if they do not have them, here is the number for Hartwell- Dzus 1 800 441 0327. I am looking at their catalog now and they say there is no max length on the grip length. They have made me custom fasteners before for a military project. Let me know how things go! Good luck!

 

[Randy V]

Hi Tom,
Try a place called full bore race products ,They are a company like Hartwell Dzus.Also if they do not have them, here is the number for Hartwell- Dzus 1 800 441 0327. I am looking at their catalog now and they say there is no max length on the grip length. They have made me custom fasteners before for a military project. Let me know how things go! Good luck!

Thanks Denny -

Link: Home Page

 

[EGLITOM]

Thanks for all your answers, Very good ideas indeed ( thanks Bill).
But yesterday i had my cousin visiting me and he has a small company with app 20 CNC lathes. Some of them have driven tools. I showed the DZUS Fasteners to him and explained the issue to him. He agreed to fabricate them with a grip lenth of 1,15".
So i will by standard lenghts one cut them out, open up a little the flange, mount the longer ones and rebend the flange. He will make them first in mild stell and they will be silver galvanised. If the first batch wents good we may try them in stainless as well.
As we are about to make them on a self feeding CNC from bars, we could make more if anyone is interested.

THanks
TOM

 

[EGLITOM]

Instead of doing them on our own i found out that i can order them to any lenght ( as long as you order at least a minimum volume).
So i placed a order for 1,15" grip length fasteners at MILLSPEC. They will be delivered in 6 weeks.
I ordered 100 pieces ,of which i will take 50 to europe and give 50 to one of the members or Fran in US to have it available there.


TOM

 

[Chris Headon]

Tom
I am increasingly fed up with the standard steel dzus fasteners holding down my front clip removable section (twin nostril panel) mainly because I have had them come loose (become undone) during driving, causing the panel to lift. Before I take the car to a track day I need to be sure that the fixings are not going to come loose and let the panel fly off. Stainless replacements might be better and if you get get these made I would be interested. I have not measured the length yet but if you have any left perhaps you could let me know what dimension to confirm and see if the ones you had made are suitable, alternatively can your source make any more of a different length?

 

[EGLITOM]

Chris

The material spec doesn´t influence the lock grip.
The usual max grip length available (0,650") is not long enough for most to locate the receptable spring on the back side of the front clip opening. Most have mounted the spring on top. By doing so it is not possible or very difficult to achieve the pretension on order to have a save and secure function of the DZUS.
By mounting them below, using rubber distances to adjust your nostril panel height fit, and in combination with the long grip DZUS you are enabled to put a preload on the DZUS fasteners. They realy snap in when they are closed and the pretension of the spring should keep them from opening themselves.

THe grip length of my DZUS is 1,15" and they have a#6 stem. (w=3/4" head)
check this to see the exact definition of the measurement ( the are of the right hand side type)

You should be able to use your springs. Preload can be adjusted with washers underneath the mounting point of the spring.

Price is 7€ each plus shipping ( app 15 € to UK). plus 4,5% paypal fee.

If you are interessted send me your adress and how many you need

Of course it would be possible to make any length (minimum order 100 Pieces)

TOM

 

[Bill Musarra]

Chris,
I think you suffer from the Dzus fasteners not engaging enough when you tighten them down. There is a small what I call a detent at the end of the twist that the wire lock seats into. If the distance of the lock is not deep enough, the wire will not engage the lock and will be left to unwind from vibration. Mine were put in by my body guy and done with Pop rivets. I find that to be insufficient. Some one on the forum posted the wires held in place with small bolts, washers and nylocks.

I think this is a better idea in that if the distance is off by a fraction and not allowing the wire to lock, it can be removed easily and adjusted to the correct length. If it is too far away, a little grinding of the fiberglass can be done, or if you use a flat washer between the wire and the fiberglass, it can ge ground down or removed if you have enough fiberglass to hold it without cracking. If that doesn't seem to be a good option then a little longer length rod would be in order. I think the fasteners are designed to HOLD the panels together, not be a bridge between them.
On the matter of them being used on the nostril panel, I don't see why you guys want to get longer fasteners. To me, any distance between the two panels gives less surface area to hold the panel rigidly in place and is prone to amplify the vibration . If the two panels are locked tight to each other, without any space between them, the lock will hold them better. I am no engineer, but my common sense tells me there would be less movement of the panel and fastener if there is no space between the two surfaces. I am sure some engineer out there will set me straight.
To that end, I still think my fiberglass guy did the right thing by inverting the corners under the panel and bringing the two surfaces together.

Bill

 

[EGLITOM]

Bill,

i agree contact between both part is important to enable the DZUS to put the preload on both of them to clamp them together. If one don´t wnat to redo and reglass all for corners of his front clip, a correct size solid rubber, sandwhiched between the two parts in combination with the long grip DZUS should do the same without the need for reglassing and without to glassfiberparts touching each other.

TOM

 

[Bill Musarra]

I agree with you on that one. It would be much simpler. I assume the rubber spacer would be attached to the clip or the hole for the spacer would be small enough to hold it onto the fastener.

Bill

 

[EGLITOM]

I more thought about a flat rubber plate in triangular shape taking up most of the space of the corners( giving lots of contact surface ) with the hole in it. COuld be eather attached to the clip or to the nostril panel. Add 2 equally spaced small rubber contact patches on each of the 4 sides and one should have a nice low vibration, low stress mount of the nostril panel.

TOM

 

[Darrin]

This is a very old thread but wanted to say that I was able to locate long (0.92") Dzus fasteners from Pegasus Racing. Fair price too.