'75 CB550K1 Gulf - Round...3, the fun stuff
- Thread starter Ringo
- Start date
Swagger
Putting boot to ass since 1967!
Re: '75 CB550K1 Gulf - last of the carbon
Just for general information...
The front fender and hugged on my Triumph are cf pieces made by Cosworth in Merry Ol' have a wee buy of 'wiggle' to the weave. It's all part of the experience. I had a cf extractor hood for my 'toy' and it had just a bit as well. Trust me Chris, your stuff looks fantastic!
Just for general information...
The front fender and hugged on my Triumph are cf pieces made by Cosworth in Merry Ol' have a wee buy of 'wiggle' to the weave. It's all part of the experience. I had a cf extractor hood for my 'toy' and it had just a bit as well. Trust me Chris, your stuff looks fantastic!
Re: '75 CB550K1 Gulf - last of the carbon
Thanks Lee!
Goings, let me see if I'm following you correctly. You're talking about how easy it is to actually lay the stuff if you position it so the weave flows over the bends at a 45* angle? I've definitely noticed that, and you can make it contour even easier if you stretch the fabric along the bend. Maybe not something I'd want to do with exposed carbon, but with fiberglass it works a treat.
I thought at first you were talking about the cured strength of the piece, depending on how you laid the fabric. I have found that warpage tends to follow the weave at a 45* angle. My front fender wants to warp diagonally if I heat it too much.
But yeah, much more of a bear to contour if the weave is perpendicular to the bend.
Just wanted to clarify; I know you're the guy for composite questions.
Thanks Lee!
Goings, let me see if I'm following you correctly. You're talking about how easy it is to actually lay the stuff if you position it so the weave flows over the bends at a 45* angle? I've definitely noticed that, and you can make it contour even easier if you stretch the fabric along the bend. Maybe not something I'd want to do with exposed carbon, but with fiberglass it works a treat.
I thought at first you were talking about the cured strength of the piece, depending on how you laid the fabric. I have found that warpage tends to follow the weave at a 45* angle. My front fender wants to warp diagonally if I heat it too much.
But yeah, much more of a bear to contour if the weave is perpendicular to the bend.
Just wanted to clarify; I know you're the guy for composite questions.
cyclefreak
Over 1,000 Posts
Re: '75 CB550K1 Gulf - last of the carbon
Just keeps getting better and better!
Just keeps getting better and better!
stroker crazy
crazy as a fox
Re: '75 CB550K1 Gulf - last of the carbon
The twill weave on the bias is the easiest way to lay-up compound curves by far. Plain weave at right angle is best for flat or curves in one direction.
That said, Ringo keeps raising the standard for the rest of us!
Crazy
The twill weave on the bias is the easiest way to lay-up compound curves by far. Plain weave at right angle is best for flat or curves in one direction.
That said, Ringo keeps raising the standard for the rest of us!
Crazy
Re: '75 CB550K1 Gulf - last of the carbon
The hugger has a skim coat of resin to fill some unsightly pinholes/pockets. It's not that glossy direct from the mold, but close. If you go a couple pages back you'll see the front fender fresh from the mold, but it's still covered in PVA mold release, so picture half way between the two is how glossy they are. I chose the twill weave for it's sex appeal. ;D Plus it's a bit heavier, requiring less layers.
The hugger has a skim coat of resin to fill some unsightly pinholes/pockets. It's not that glossy direct from the mold, but close. If you go a couple pages back you'll see the front fender fresh from the mold, but it's still covered in PVA mold release, so picture half way between the two is how glossy they are. I chose the twill weave for it's sex appeal. ;D Plus it's a bit heavier, requiring less layers.
JustinLonghorn
No Purple Hearts, No Blue Ribbons
Re: '75 CB550K1 Gulf - last of the carbon
Beats, Bears, BattleStar Galaxica.
Fantastic work, sir.
Beats, Bears, BattleStar Galaxica.
Fantastic work, sir.
Re: '75 CB550K1 Gulf - last of the carbon
Hey Chris,
Yea we are on the same page, with the 45's. It is warping because it is probably not balanced and symmetrical.
if you do a lay up you always want a balanced and symmetrical laminate, example.
90
0
-45
+45
+45
-45
0
90
if you are only using 3 plys do something along these lines
0
90
0
does that make since
twill also acts differently because of nesting, the outer layers are the most important too.
Hey Chris,
Yea we are on the same page, with the 45's. It is warping because it is probably not balanced and symmetrical.
if you do a lay up you always want a balanced and symmetrical laminate, example.
90
0
-45
+45
+45
-45
0
90
if you are only using 3 plys do something along these lines
0
90
0
does that make since
twill also acts differently because of nesting, the outer layers are the most important too.
Flugtechnik
My bike is not transportation, it is a respite
Re: '75 CB550K1 Gulf - last of the carbon
Here are the guidelines we typically stick to when designing composite parts for aircraft.
Laminates Are to Be Symmetric About Their Middle Surfaces.
There are two reasons why this guideline is representative of good practice: (1) to uncouple
bending and membrane response, and (2) to prevent warping under thermal loading.
Laminates Are Required to Be Balanced. In this context, balanced means that angle plies (those at any angle other than 0° or 90°) should occur only in balanced pairs. (This is satisfied by using fabric)
Laminates Will Be Fiber Dominated, Having at Least 10% of their plies in Each of the 0°, ±45°, and 90° Directions.
Laminates at Mechanically-Fastened Joints Should Be Fiber-Dominated, Contain No More Than 60% Plies at Any Single Orientation, and Contain No Less Than 35% ±45 Plies.
....there are a bunch more, but they don't really apply here. Also, the guidelines tend to be geared towards using unidirectional tape plies instead of fabric. When using non-biased fabrics (like plain weave or satin weave), I usually don't worry about whether it is 0° or 90°.....or +45° or -45° because the difference in properties between the warp and fill directions are pretty small. I would typically use laminates like the following:
[45,0,45]
[45,0,0,45]
[45,0,45,0,45]
[45,0,45,45,0,45]
[45,0,45,0,45,0,45]
[45,0,0,45,45,0,0,45]
etc.
We typically put 45° plies on the outside to prevent cracking around fastener holes, but with nonstructural parts like the ones you are making, it really doesn't matter so you could swap the 0s and 45s if you are going for a particular pattern on the surface.
I don't remember you discussing how you cure the parts. If they are cured at room temp, then warping shouldn't be that big of a deal because the temperature changes will be small. However, with the unbalanced layups, you will see them warp a bit as they heat up or cool down depending on the weather. Additionally, they may slowly warp as they soak up moisture during their lifetime....hence the guideline to use symmetric laminates.
I am a fan of the original Gulf and it looks like you are making it even better. Keep it up sir!
Here are the guidelines we typically stick to when designing composite parts for aircraft.
Laminates Are to Be Symmetric About Their Middle Surfaces.
There are two reasons why this guideline is representative of good practice: (1) to uncouple
bending and membrane response, and (2) to prevent warping under thermal loading.
Laminates Are Required to Be Balanced. In this context, balanced means that angle plies (those at any angle other than 0° or 90°) should occur only in balanced pairs. (This is satisfied by using fabric)
Laminates Will Be Fiber Dominated, Having at Least 10% of their plies in Each of the 0°, ±45°, and 90° Directions.
Laminates at Mechanically-Fastened Joints Should Be Fiber-Dominated, Contain No More Than 60% Plies at Any Single Orientation, and Contain No Less Than 35% ±45 Plies.
....there are a bunch more, but they don't really apply here. Also, the guidelines tend to be geared towards using unidirectional tape plies instead of fabric. When using non-biased fabrics (like plain weave or satin weave), I usually don't worry about whether it is 0° or 90°.....or +45° or -45° because the difference in properties between the warp and fill directions are pretty small. I would typically use laminates like the following:
[45,0,45]
[45,0,0,45]
[45,0,45,0,45]
[45,0,45,45,0,45]
[45,0,45,0,45,0,45]
[45,0,0,45,45,0,0,45]
etc.
We typically put 45° plies on the outside to prevent cracking around fastener holes, but with nonstructural parts like the ones you are making, it really doesn't matter so you could swap the 0s and 45s if you are going for a particular pattern on the surface.
I don't remember you discussing how you cure the parts. If they are cured at room temp, then warping shouldn't be that big of a deal because the temperature changes will be small. However, with the unbalanced layups, you will see them warp a bit as they heat up or cool down depending on the weather. Additionally, they may slowly warp as they soak up moisture during their lifetime....hence the guideline to use symmetric laminates.
I am a fan of the original Gulf and it looks like you are making it even better. Keep it up sir!
JustinLonghorn
No Purple Hearts, No Blue Ribbons
Re: '75 CB550K1 Gulf - last of the carbon
This is a very good write-up, Flug.
This same practice applies to the construction of Printed Circuit Boards as well.
This is a very good write-up, Flug.
This same practice applies to the construction of Printed Circuit Boards as well.
