Carbon GT mono - Page 5

BruceLambo · 01-29-09, 04:12 PM

Urs. Great project. Just a question about making the a-arms.

Are they made in 2 halves first and then joined or somehow made in one peice? If they are made in 2 halves, how did you join them?

Urs · 01-29-09, 04:42 PM

It would be not good to build them in 2 halfs .You have a to great delaminating chance.

Chris P. · 01-29-09, 08:53 PM

Urs - you are using a core (like a foam) inside the layers of CF right? Or are the arms solid CF? You must be getting a great price on all that carbon....

Urs · 01-30-09, 02:36 AM

yes they are fully filled with CF.

BruceLambo · 01-30-09, 05:33 PM

Ahh I see how you are making the arms now. They are not a 2-peice moulding, just a single mould and the arms are totally flat on the bottom.
If they are filled with CF and resin, what is the weight of the arms then?
I would have thought with the amount of resin in the arms the weight would be very close to that of either a large diameter/thin wall tube or perhaps even a machined billet aluminium unit. Do you feel the small amount of weight versus layup time/overall strength is worth the effort?

Urs · 02-01-09, 08:27 AM

hello rambo
you have also to think about ,what you have to pay for a carbon brake disk!! and you throw them away after some races or in bad case after one race.
the weight of one piece is 1,4kg and it s till oversized .It s no problem to build them in cro mo or alu,But we wanna try to build as much as we can in CF.

Tiago B. · 02-05-09, 02:45 PM

Looks great. Keep up the good work

Urs · 03-30-09, 06:10 AM

Hello !
after a lot of work in our company,a nice ski holiday and correcting a stupid failure!!

i took a new builded set of lower and upper a arms out of the molds

I have the bad feeling, that it will be not the only part that i build two or more times!!

here some pictures from the new arms.
this week i will laminate the arms of the right side and after it goes to fit them on the chassis.

Dom · 04-03-09, 07:19 AM

Just found this thread now - Awesome build!

Keep up the good work and keep us updated!

Urs · 04-10-09, 09:54 AM

now i drilled the holes in the chassis tu glue in the bearings for the suspension axles.
I mounted a wheel to see how it looks and it doesnt look bad.

here some pictures.

EGLITOM · 04-10-09, 10:11 AM

Hi Urs,

nice to see your progress. Is there any specific reason for mounting the Caliper in the front position. If not i would say you have the uprights of left and rights side interchanged.

Thanks
TOM

Urs · 04-10-09, 11:12 AM

Hello Tom

You are right its not the right way ,they are mounted but was only fun to look how it would look ,in this case with the caliper on the other side.

My hands were faster than the brain!!

Dom · 04-15-09, 10:50 AM

Urs, without reading the thread again... Were there any hard points built into the chassis during construction? Liek any aluminium spigot things where the suspension will load the chassis, or are you putting them in after, as per the photo above, to spread the load? i assume if you just mounted the wishbones direct to the carbon pick up points on the chassis, the carbon would just crack?

Lynn Erickson · 04-15-09, 01:56 PM

Quote:

Originally Posted by Dom9

Urs, without reading the thread again... Were there any hard points built into the chassis during construction? Liek any aluminium spigot things where the suspension will load the chassis, or are you putting them in after, as per the photo above, to spread the load? i assume if you just mounted the wishbones direct to the carbon pick up points on the chassis, the carbon would just crack?

My entire aircraft is made of glass and carbon, no metal except the engine and bolts. the hard points are many layers of carbon the taper out into the structure. adding metal into a carbon structure is a bad idea and just aids in cracking. The metal and carbon do not flex the same and do not stay bonded well. The carbon will cause the metal to corrode through electrolysis. aluminum is the worst.

Urs · 04-16-09, 03:00 AM

Quote:

Originally Posted by Dom9

Urs, without reading the thread again... Were there any hard points built into the chassis during construction? Liek any aluminium spigot things where the suspension will load the chassis, or are you putting them in after, as per the photo above, to spread the load? i assume if you just mounted the wishbones direct to the carbon pick up points on the chassis, the carbon would just crack?

We have glued in steel bearings(no problems with corrosion) which you see on the pictures.
To resist the cracking you have to arrange the layers in the right way ,and one of the most important things is ,that they not all end at the same place .It s difficult to discribe all the things.
For hard points where you bolt on some metal parts on the chassis,you have to cut out the foam ,and strengthen it with some cfk layers.
greetings from switzerland

Jim Rosenthal · 04-16-09, 10:45 AM

Very cool. Are those the brakes you are using? What make are they?

Leon · 05-04-09, 11:59 AM

Hi Urs........ I have been watching your build and its great stuff, I have a question. I see you have used alloy front uprights, Did you consider CF units or is it not practical or strong enough or did you just not consider it. I'm sought of thinking about it for the rear up rights??? what are your thoughts.
Cheers leon

Urs · 05-05-09, 02:45 AM

@Jimbo
in front we have 6 pot wilwood and rear 4 pot wilwood.

@Leon
We have the front and rear uprights from RCR,It would be also possible,to build uprights also in carbon ,but we dont want to overdo things

maybe for ultra ultra light gt40.
greetings from switzerland