Edge FB nose job

[ghickman]

Hi All
Hasn't been much to look at lately on the FB forum so I thought I'd give everyone a look at some rework we've been doing to our car.

When we built the body we thought that removing the nose wouldn't be that big a deal if we needed to check the fluid levels in the clutch and brake master cylinders...boy were we wrong. We were also rushing to make the 2008 ARRC and decided to not make this change. So after the first race a few weeks back we decided to bite the bullet and redo the nose and shock cover molds. Now when you remove the shock cover it exposes the ARB and Master Cylinders.

Thought that some of you neophyte fiberglassers out there would like to see how a parting line flange is done. It's not really that complex it just takes some patience. Typically we use .035 aluminum or hard board. Make a pattern with posterboard and cut the flange out. Liberal use of masking tape and hot melt glue. Those triangular pcs. in the pics. are hardboard gussets to support the flange.

The nose mold could be made 1 pc. but it's tough to get down inside the mold to do the layup. Tony and I are old school, we still use polyester resin wet layup. We've been doing this for so long that we can get as light and strong a part as vac. bag and it's cheaper to build.

Enjoy the pics....if anyone has questions feel free to pm me. Oh, and that old guy in the pics. is Tony...and he's younger than me...LOL

Gary

[Stan Clayton]

Tony and I are old school, we still use polyester resin wet layup. We've been doing this for so long that we can get as light and strong a part as vac. bag...

With all due respect, no you can't.

Good looking piece, btw.

[S Lathrop]

Gary;

Is this nose cone structural?

[ghickman]

Gary;

Is this nose cone structural?

Hi Steve
If you mean does it have the required SCCA crush structure internal then yes. We use Aluminum Honeycomb.

Oh, and Stan....I do vac. bagging...just not all the time. We also manufacture tappered carbon fiber tubing using expanding Silicon mandrels and single cavity metal molds. These tubes are used in our BMX (Bike) Racing forks, our rider Marris Stromberg won the Olympic Gold this past Olympics using this fork.

Gary

[Stan Clayton]

Oh, and Stan....I do vac. bagging...just not all the time. We also manufacture tappered carbon fiber tubing using expanding Silicon mandrels and single cavity metal molds. These tubes are used in our BMX (Bike) Racing forks, our rider Marris Stromberg won the Olympic Gold this past Olympics using this fork.

Gary

Congratulations on the Olympic Gold, Gary, but given your experience and accomplishments in the field, and the credibility you derive from that, it is all the more important that you not make such sweeping and demonstrably false claims.

That is not to say that one cannot make perfectly adequate parts, even structural parts, using polyester resin wet layup w/out bagging, but it is a violation of the laws of physics to claim that such parts are simultaneously as light as, and as strong as, equivalent vacuum bagged parts. You can make them as light as, or as strong as, vacuumed parts, but not simultaneously. And you know it.

Stan

[ghickman]

Stan
Wow, talk about getting thrown under the bus....maybe this is a matter of symantics. Maybe what I should have said was nearly?

[formulasuper]

Congratulations on the Olympic Gold, Gary, but given your experience and accomplishments in the field, and the credibility you derive from that, it is all the more important that you not make such sweeping and demonstrably false claims.

That is not to say that one cannot make perfectly adequate parts, even structural parts, using polyester resin wet layup w/out bagging, but it is a violation of the laws of physics to claim that such parts are simultaneously as light as, and as strong as, equivalent vacuum bagged parts. You can make them as light as, or as strong as, vacuumed parts, but not simultaneously. And you know it.

Stan

Stan, Just for my curiosity sake, not that a pound or two is going to make any difference on my car until I have become a "perfect" driver, IYO how much heavier would a part such as this nose cone have to be w/o vac bagging to make it as strong as a bagged one? I have never done vac bagging & am wondering if it would be worth my time & expense when fabbing parts, such as an engine cover.

[S Lathrop]

Gary;

From the pictures, I can't tell what the attachment and side walls of the nose box are. My experience is that I would have solved the problem of getting the "full" nose cone off easily. I have spent years evolving nose boxes that fail progressively from the front.

The IPS Dallara chassis use 6 bolts that take seconds to remove with a battery powered driver. I use the same idea with 4 bolts for my Zetec FC.

A couple of my cars have up root guard rail posts with insignificant damage to the front bulkhead. But all the nose boxes have failed at the junction with the front bulkhead. I had a scary situation once where the front wing and the nose box were intact but the nose box had separated from the mounting brackets.

Remember that the master cylinders are lethal to the front bulkhead if, in a crash, they are driven through the bulkhead. This is why many modern cars have double front bulkheads.

[ghickman]

Steve
Originally the nose cone bolted thru the front bulkhead. We found that it held real well but was a pain to remove.

This iteration has 4 bolts coming in from the sides now, 2 on each side. I still like the idea of being able to get at the master cylinders quickly by simply removing the shock cover. We got so rushed trying to make the 2008 ARRC we just wanted to get the nose secured (it was the last item on the list ) and get on the track, now we're redoing it for the long haul.

We have a steel doubler plate on the front bulkhead to help keep the master cylinders from being driven inward in a head on impact. Similar what you are describing.

Thanks for the input
Gary

[R. Pare]

Gary:

A doubler plate is not the same thing - what Steve is referring to is an extension of the whole frame past the master cylinders so that they reside inside a tube "box". I believe that this may now be mandatory on British FFs. In the study done to come up with the new mandatory crush structure, the crush box sits against the face created by this additional bulkhead, and the crash loads against it are directly transferred to the main frame at the corners - it is only if this additional section of frame collapses that the master cylinders get hit.

You'd be surprised at just how little a hit the masters can take before the typical mounting rails collapse.

[jerry freeman]

A curiosity question. I have a 1/4 inch 6061 plate attached to my front bulkhead and was wondering if the master cylinders would break before they got shoved through the plate? Or, do you still recomend a box around them?

Jerry

[ghickman]

A curiosity question. I have a 1/4 inch 6061 plate attached to my front bulkhead and was wondering if the master cylinders would break before they got shoved through the plate? Or, do you still recomend a box around them?

Jerry

Jerry
This question was probably for Richard but I'll tell you what we did. We have something very close to yours except we went as far as to on the drivers side we have an additional steel bulkhead plate to stop further ingress. In my opinion they would (the cylinders) crush before they went past that point. Of course we haven't done crash testing.....

Having an additional sheetmetal or tubular structure ahead of the master cylinders would be good. We're trying to save weight every place we can.

Gary

[R. Pare]

Jerry:

The plate will definetely help increase the load at which the front bulkhead will start collapsing, but whether or not the bending will start first or the master cylinders fail first is anyones guess - it will depend a lot on the angle of the hit.

For a "typical" front bulkhead master cylinder mounting tubes - a 1x1x.062 x 10" long lower tube, and a .75x.75x.062 x 10" long upper master cylinder mounting tube - it will take only about 2700 - 2800 lbs for the tubes to start to buckle - around only 2.5 g's decelleration. It can obvioulsly go up from there, depending on floorpan attachment integrity, etc.

[Mike Devins]

One more solution - this was from the Vestal FF using a CF brace with aluminum honeycomb crush material.

[S Lathrop]

The Vestal piece is a great solution. But!

You still have the problem of attaching the cone to the frame so that the attachment and the open area are the last part to fail in a crash. The picture does not show how this fastens to the frame.

My experience has convinced me that almost any type of crushable nose box is valuable in minimizing damage to the frame and possible injury to the driver. In SCCA racing there have been 2 recent incidents that I know of where sever injury resulted from not having any nose box.

I have had one driver severely injured in a FA when the nose cone was knocked off at the initial impact and the steering rack was then driven through the front bulkhead of the carbon tub and into the driver's foot. This is why I am anal about the strength of the nose box where it fastens to the frame.

[Mike Devins]

Steve,

The vestal bolts from the side similar the VanDiemen FC or the Swift 014 FA. The customer put those in when he installed it to his chassis.

[KevinFirlein]

when wondering about when a master cylinder itself would break take this as a point of information. At the 2006 sebring Nat our Ralt RT-41 was invloved in a heavy front end impact. Car spun in front in T17 and Jim hit it head on just behind its front wheel and in front of the side pod. Impact punched a hole into the FM tub that he hit. It also crushed the ralts nose and the masters took a big enough hit to rip the carbon bulkhead they were attached to clean off the chassis , pull the pedal box and its attachment bolts up thru the floor and shove the entire assy back towards the driver. Luckily the driver was well under 6' tall and had plenty of room for his feet and legs to fold backwards so he wasnt hurt. Point of the story is that a master cylinders can take a massive load before they break.

[S Lathrop]

Mike;

What I am questioning is the strength of the nose cone in the area where it is secured to the frame. Cutting out the top of the nose cone to get access to the reservoirs could make that the failure point. A better approach might be an access panel through the nose cone.

The down side of composite nose cones/boxes is that when you have a failure, you have a complete failure. In the case of the nose cone, you want the thing flat against the front bulkhead when the mounting point finally fails. In the case of my Atlantic car, the nose cone failed at the mounting point to the front bulkhead. Except for the mounting area, the cone was hardly damaged. Given the speed of the impact, the front wing and the front of the nose cone should have been destroyed well before the thing failed at the mounting.

I have kept several of my nose boxes that have been involved in crashes in order to better design the next version. All the failures have occurred in the area of the cut out for the reservoirs. But because they were aluminum, the cone stayed attached to the frame. Two thing I am doing now with my nose boxes: 1 - I am building them with more taper front to back, and 2 - I no longer have the tops opened.

I am about to do my first composite nose box. This is why I am so interested in what others are doing.

The Vestal cone will be great in a straight frontal impact. But what will happen in a 45 degree angle, 30 mph impact on the tip of the cone? Will the outer cone and the honey comb block flatten against the carbon part or will the whole thing separate at the front bulkhead? If the carbon is 1/4 inch or thicker at the bulkhead and thins to say 1/8 at the front edge, that I think might be excellent. But I don't have any idea.

The factory RT 41 nose cone was 2 pieces. The front third was a carbon cone that glued and bolted to the main box which was carbon and aluminum honey comb. The honey comb panels tapered toward the front. The wings attached to the front cone. Most crashes would damage the front cone which could be replaced. That was not what was on the FA when my driver was injured.

[VehDyn]

Great job, Gary. Thanks for the update.

[ghickman]

Great job, Gary. Thanks for the update.

Thanks Ken.....I really didn't intend for this thread to go the direction it went (but it went in a good direction). However I'm always honored to have the great Steve Lathrop chime in. He's like a legend for me since my SCCA roots go back to late 70's. Steve's comments got me thinking for sure.

Gary

[Tony Moore]

Hi All
Hasn't been much to look at lately on the FB forum so I thought I'd give everyone a look at some rework we've been doing to our car.

Enjoy the pics....if anyone has questions feel free to pm me. Oh, and that old guy in the pics. is Tony...and he's younger than me...LOL

Gary

What, did I forget my grecian formula for men that day?