Brake duct fabric layout?

Talk Composites - The Forum for Advanced Composites

Back

Brake duct fabric layout?

Author	Message
AlpineCoupe	A AlpineCoupe posted 5 Years Ago HOT Topic Details
A Group: Forum Members Posts: 44, Visits: 2.1K	Hi all - I'm new to the composite world. I have made a couple of small parts but am still learning a lot. The question I have is how to lay out the fabric on a brake duct I am going to be making. I am struggling to determine if I should lay out the carbon fiber as shown in the picture below - essentially 5 separate pieces, as indicated by the different colored outlines. Or attempt to find a way to wrap the shape in fewer separate pieces. The piece will just be directing airflow so it will not see large loads so strength is not the utmost concern, I just want to make a solid part. Thanks in advance for the help!
	Reply Like 3
Fasta	Fasta posted 5 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	I would consider just two pieces for this shape. One piece large enough to lay over the longer tapered end, down the sides onto the flange and also including up the tube on that side only. The second piece can lay up the vertical side inc up the tube end and wrap to overlap first layer on the sides, plus the flange at the bottom. Assuming you are using 200g 3k materials then it would be best cut to be +- 45 degrees to help it contour the shapes. If you have a nice material like 90g or 120g carbon then that would be even nicer/easier if the part is very small. It's hard to tell the scale from the picture? Then a second layer of the same carbon or fibreglass which is often easier as it is usually lighter weight/softer and easier to apply, in turn makes a cleaner finish part on the back side. You could also wrap the surface with peel ply very carefully with a smaller pieces. Fastacraft Facebook page Edited 5 Years Ago by Fasta
	Reply Like 3
AlpineCoupe	A AlpineCoupe posted 5 Years Ago HOT Post Details
A Group: Forum Members Posts: 44, Visits: 2.1K	+x Fasta - 11/12/2019 5:59:37 AM I would consider just two pieces for this shape. One piece large enough to lay over the longer tapered end, down the sides onto the flange and also including up the tube on that side only. The second piece can lay up the vertical side inc up the tube end and wrap to overlap first layer on the sides, plus the flange at the bottom. Assuming you are using 200g 3k materials then it would be best cut to be +- 45 degrees to help it contour the shapes. If you have a nice material like 90g or 120g carbon then that would be even nicer/easier if the part is very small. It's hard to tell the scale from the picture? Then a second layer of the same carbon or fibreglass which is often easier as it is usually lighter weight/softer and easier to apply, in turn makes a cleaner finish part on the back side. You could also wrap the surface with peel ply very carefully with a smaller pieces. Thanks, Im using some ~ 200g 3k 2x2 twill, Ill cut some tonight and see if I can make the 2 piece wrap work. Im still learning so it's hard for me to visualize how it can all wrap and work. Thanks for the help!
	Reply Like 3
Fasta	Fasta posted 5 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	+x AlpineCoupe - 11/12/2019 8:13:48 PM +x Fasta - 11/12/2019 5:59:37 AM I would consider just two pieces for this shape. One piece large enough to lay over the longer tapered end, down the sides onto the flange and also including up the tube on that side only. The second piece can lay up the vertical side inc up the tube end and wrap to overlap first layer on the sides, plus the flange at the bottom. Assuming you are using 200g 3k materials then it would be best cut to be +- 45 degrees to help it contour the shapes. If you have a nice material like 90g or 120g carbon then that would be even nicer/easier if the part is very small. It's hard to tell the scale from the picture? Then a second layer of the same carbon or fibreglass which is often easier as it is usually lighter weight/softer and easier to apply, in turn makes a cleaner finish part on the back side. You could also wrap the surface with peel ply very carefully with a smaller pieces. Thanks, Im using some ~ 200g 3k 2x2 twill, Ill cut some tonight and see if I can make the 2 piece wrap work. Im still learning so it's hard for me to visualize how it can all wrap and work. Thanks for the help! The 3k material is not so flexible as other materials but it all depends on the shapes and corners you have to deal with, cutting pieces to fit where the edges are on the corners will just make things worse for getting it stay down in place. Also since twill material is a loose weave if you cut it into small pieces then it also falls apart much more too so the bigger the piece the better for twill weave. Looks like a nice shape part for vacuum infusion, if the mould has some good size flanges there? Fastacraft Facebook page
	Reply Like 2
AlpineCoupe	A AlpineCoupe posted 5 Years Ago HOT Post Details
A Group: Forum Members Posts: 44, Visits: 2.1K	+x Fasta - 11/13/2019 3:37:01 AM +x AlpineCoupe - 11/12/2019 8:13:48 PM +x Fasta - 11/12/2019 5:59:37 AM I would consider just two pieces for this shape. One piece large enough to lay over the longer tapered end, down the sides onto the flange and also including up the tube on that side only. The second piece can lay up the vertical side inc up the tube end and wrap to overlap first layer on the sides, plus the flange at the bottom. Assuming you are using 200g 3k materials then it would be best cut to be +- 45 degrees to help it contour the shapes. If you have a nice material like 90g or 120g carbon then that would be even nicer/easier if the part is very small. It's hard to tell the scale from the picture? Then a second layer of the same carbon or fibreglass which is often easier as it is usually lighter weight/softer and easier to apply, in turn makes a cleaner finish part on the back side. You could also wrap the surface with peel ply very carefully with a smaller pieces. Thanks, Im using some ~ 200g 3k 2x2 twill, Ill cut some tonight and see if I can make the 2 piece wrap work. Im still learning so it's hard for me to visualize how it can all wrap and work. Thanks for the help! The 3k material is not so flexible as other materials but it all depends on the shapes and corners you have to deal with, cutting pieces to fit where the edges are on the corners will just make things worse for getting it stay down in place. Also since twill material is a loose weave if you cut it into small pieces then it also falls apart much more too so the bigger the piece the better for twill weave. Looks like a nice shape part for vacuum infusion, if the mould has some good size flanges there? I was actually going to start trying vacuum infusion using this piece. The flanges seem to be plenty big for it to work. Im glad you think it will work to infuse it!
	Reply Like 3
AlpineCoupe	A AlpineCoupe posted 3 Years Ago HOT Post Details
A Group: Forum Members Posts: 44, Visits: 2.1K	So it was mentioned that this would be a good mold/ part for vacuum infusion. If I were to vacuum infuse this would I run the vacuum line to the top of the part and the feed wrap the spiral around the base. So the epoxy is running up the part essentially? Sorry that this isn't in the infusion forum but it seemed silly to repost over there if infusion was already mentioned here.
	Reply Like 3
Hanaldo	Hanaldo posted 3 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	I would do that layout, but I would feed from the top of the duct. So still run your spiral around the base, but make that your vacuum manifold, and still place a port on the top of the duct but feed your resin in there. This will feed much more evenly, as well as waste less resin. On such a small part it is unlikely to make much difference, but that's my advice. Just be sure to give yourself a good brake zone around the base so that the resin doesn't just race through the part and out the vacuum port before the part is fully infused. It will be a very quick infusion, 30 seconds to a minute sort of thing. No time to fix anything, so just be well prepared.
	Reply Like 3
Warren (Staff)	Warren (Staff) posted 3 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	If you use a loose fabric you may be able to use one piece. Many a year ago when I first started here, one of my initial tasks was to make a similar shaped NACA duct in pre-preg. Our expert laminators would do it in a single piece of pre-preg with the join on the back edge. Took a bit of practice to achieve a good result. Obviously you have the tack of pre-preg to help hold it, but a raw fabric has a lot more flex than a pre-preg. If you struggled you could use the lightest of dusting of a spray tack but the more you use the more the surface will need finishing. Certainly in more than one piece you should be fine. As Hanaldo says, top down would be easiest. From your picture you have a big flange so plenty of room to make a decent resin break. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
	Reply Like 2