help with costum made shinguards

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#1

Hi

I’m new to this forum, and have some questions, i hope you can help me with.

The project is to make a costum made shinpads for soccer. (kind of like these http://c6agility.com/), other posts about this on the forum, did not answer my questions.
On the inside of the “shell”, there is going to be a layer of soft poron-material/foam (2-3mm thick).

First question is about the mold.
Do you have any suggestions about which material is best used to create a mold? My first thought was to make a mold directly on the leg, with plaster bandage. And then make a mold of the inside of the plaster mold. But then the finished product, woould be to small, because of the layers of fiber and the foam inside.
Any good advice here, on technique and material?

My second question is: Which material should i use?
-Carbon Fibre 2/2 Twill
-Carbon Fibre Plain Weave
-Carbon Armid 2/2 Twill
-Black Diolen 2/2 Twill
-A combination, or a different materiale?

I’ve read that Carbon fibre could shatter in case of a hard direct impact, so this made me think if there is any another combination of materials, best suided for shin guards.

Thanks in advance :slight_smile:

#2

Welcome to the forum.

I’m by not means an expert, but here is my 2cents worth of info.

If it was me making the mold, I would probably use something around 5mm thick to act as a spacer for the mold. That way you will have a little bit of spare space after your 2/3mm of foam.
Regarding mold material, I suppose it would depend on how many shinguards you plan on making. If its hundreds of them, then maybe machined metal, otherwise fibreglass molds may serve you ok.

In terms of which material to use - I would personally use 2x2 twill and a couple of layers of carbon/kevlar hybrid for impact resistance.

That’s just my opinion. Feel free go ignore it! Lol.

Regards,

Kyle.

#3

Hi Kyle

Thanks for your 2cents :wink:

I’ve also thought about using something thick to act as a spacer, but im not sure which material i could use to make a mold, which i then can make a fibreglass mold out of.

Does the order of the layers have any difference? Say carbon in the first layer and then some carbon/kevlar or should the carbon/kevlar be the first layer for impact resistance?

Regards
Michael

#4

Maybe quick and simple way could be to bend a thin 1mm thick aluminium around your shin. Then use this as your mould and layup over the outside of it.

Refinish the outside of the new part and maybe add some thin foam to the inside??

#5

That was a pretty good idea fasta, thanks :slight_smile:

I think i will go for a combination, of putting something 4-5mm thick arround the shin and then bend a thin 1mm aluminium plate around that. Then i can use it as a mold on the inside to place the carbon sheets, and get a perfect finish on the finish product.

Any ideas on a cheap material to hold the shape of the aluminium mold? or would it be easier to put fiberglass on the outside?

Would the shin guard hold up, just as god, or god enough, if i don’t do a vacuum resin infusion? but just use a brush and apply pressure.

Thanks so far for the good input :slight_smile:

#6

That’s even better moulding off the inside to get a nice finish on the outside of the new part.

The mould should not need any reinforcing to hold the shape if the thickness of it is sufficient? you may need to be careful when releasing the part as too much force could bend your mould from the original shape.

No need for any pressure or infusion process, just put some layers down, wet and roll or hand smooth the air out.

I would consider 4 or 5 layers of 200g carbon fabric which will make the part about 1mm thick. Use a peel ply on the last layer to make nice finish on the part.

#7

Thanks for the tip about peel ply :wink:

Regarding the mold (aluminium sheet) if it’s only 1mm thick, then it would easily be bended when i apply the carbon fabric? Don’t you think i need to reinforce it?

A question regarding the fabric again. Does it make any difference in durability(or a direct impact) which order i use carbon and carbon/kevlar?

#8

How you arrange the layers of fabric is up to you really (as long as they are equal in direction terms of 0, +/- 45, 90).
I would personally use 2x2 twill for the outer layer as this is what you will see. But to be a bit different, you may want to have the hybrid carbon/kevlar fabric as the outer layer.

You will want to make sure that the layers of fabric that have kevlar are cut slightly smaller than the layers of carbon. This is because when kevlar is sanded down, you tend to get tiny fibres that fray and doesn’t leave a clean edge.

#9

There is no reason the metal mould would bend when you do your layup. The thicker the better but you need it thin enough to bend your shape to begin with.

As for materials I would avoid Kevlar in general unless there really is some specific requirement that you need it. It’s hard to cut when dry, it’s hard to cut when cured and you would get furry edges unless the Kevlar layer is made smaller than your trim line.

You can start and finish with a layer of carbon and the inner layers could simply be fibreglass to make up thickness which will save some cost too.

As far as general durability the carbon could crack with big hit (like a hockey stick) but I think your general thickness is what will make this part better or worse.

You may want to consider something flexible so that it might flex and be more comfortable to wear? Look at Innegra or Diolen fabrics.

#10

Once again thank you very much for some great answers fasta and kyle, you have given me some good inputs :slight_smile:

As for the edge on the shinguard, any idea’s on how to make them smooth?

I’ve thought about 3-4 layers of Carbon Aramid 2/2 Twill 3k 210g, would that be okay? or do i need a layer of pure carbon fibre 2/2 Twill?

fasta wouldn’t diolen be too soft?

#11

I would personally just use 1 (2 at most) layers of carbon aramid, with the rest made up of 2x2 twill. You could always try and find some ‘downgraded’ carbon fabric for the middle layers, as this would save you money and nobody would know. Or, you could get some heavier fabric (eg. 400gsm) so you don’t need to use lots of your 210g 2x2 twill.

I have read that diolen is not great at sticking to layers of carbon - i.e it can cause delamination. That was why I suggested carbon/kevlar hybrid.

#12

I have not ever used Diolin and only recently read about it. I have though just built a carbon part that was two layers of Innegra sandwiched in-between single layers of 200g carbon. These were all pre preg and the part has quite some curvature to it so this helped add strength too. My theory was that the Innegra is very light and twice as thick as a layer of carbon so my laminate would be thicker yet weigh no more than all carbon whilst also saving the cost of an all carbon laminate especially since I would have needed two carbons for every one layer of innegra.

For your small part weight the weight difference is probably not worth pursuing so substituting fglass for the inner layers would be fine. And then again your part is so small making it all carbon would not be so expensive even if it doubles your carbon costs? It’s up to you.

#13

Use the stuff noted in this article.I have used it before for making elbow protectors.

http://www.instructables.com/id/Fiberglass-costume-face-mask/