carbon fiber aircraft flap
Performance applications that require high-strength and lightweight components.
At first, it seems daunting to make something out of carbon fiber, so the goal of this manual is to present composite manufacturing technology and provide a list of materials and suppliers.
This aircraft flap contains four components that are bonded together using adhesive and fasteners.
The leading edge, lower panel and upper panel contain the honeycomb core.
The spar in the middle does not contain the honeycomb core, but only the carbon fiber layer.
5 MilestonesMold care products FillerMold core film fiber carbon fiber orsshop equipment vacuum loose bag processing composite surface preparation fastenerstooling)
This will make our part.
They are made of fiberglass.
Making the mold itself is a topic, so look at the details of each mold and ask yourself why.
The mold must have a smooth surface that is not sticky (Chemical bond)
The final carbon fiber part
To do this, clean the mold, seal the mold and apply the mold release.
Clean the mold every 2-
10 parts or until overbuilt
Rise of mold release.
Remove the remaining resin using a huge Popsicle (
Tongue pressing board)
Their ends are polished to wedge tip.
To avoid damage to the mold, use the appropriate tools and a lot of care.
The soft tongue tip tongue pressing plate can remove the resin but does not damage the mold.
Remove the residual resin using an improved tongue pressing board.
Be sure to be very careful if you have to use the blade!
Mold is very important, proper care is essential.
Here is how you can remove the resin using the blade: 1.
Blunt the blade by dragging it over the table.
This will slightly bend the sharp edges of the blade and prevent inadvertent planing of the parts. 2.
Remove the resin very carefully!
Don\'t be surprised if the manager prevents you from doing this --
Molds are expensive.
Some people like to remove resin from the mold with a painter\'s knife.
OMG must be careful if you choose this tool.
Planing the mold is not an option.
Seal the mold using the surface regulator of the water plant pre-inspection tool (or solvent-Based in FreKote B-15 or 700-NC).
This fills in the microscopic defects in the mold to make the surface smooth.
There are many steps to properly apply the surface regulator of the water plant pre-inspection tool.
Apply a thin pre-flight coating with lintfree cloth.
Rub in one direction. Wait 15 minutes. Stay awesome.
Apply a second thin coat.
After you put on this thin coat, use fresh lint
Clean immediately with free cloth.
Wait 15 minutes.
Apply a third thin coat.
Like the previous step, wipe it off immediately. Wait 15 minutes.
The book says we should seal and wipe for the fourth time and heal for 15 minutes at 180 degrees F.
We don\'t do that.
Experience said: \"We are finished.
The mold is sealed. \" Word.
Apply flash tape around the mold.
The flash belt leaves no residue and can withstand high temperature.
The mold is clean, sealed and ready for mold release.
Application for water plant (solvent-Based in FreKote B-15 or 700-
NC is also a good choice).
Spray the mold gently.
Wait 60 seconds and wipe with lintfree cloth.
Wait 15 minutes for mold release to solidify.
The front edge and the lower flap surface are sandwich panels containing core materials.
The behavior of sandwich panels is similar to that of I-beam -
The core is a middle.
Separate the two carbon fiber laminating materials.
This significantly increases the strength of the composite, while the weight increases slightly.
There are a variety of core materials, there are a variety of advantages and disadvantages
Please read the core material in Chapter 6 advanced composite manufacturing and repair points. The core (
We use honeycomb.
Need to be cut into size and chamfer at each edge (
See the stack completed above.
Honeycomb core is flexible and not easy to process (
We need to cut the chamfer or angle at each edge)
So there are some things we need to do to make it harder and more machinable.
We used two ways to make the honeycomb harder: 1629 A/B edge filler just like the dough for adults --
It is very light and fun to play.
Epocast 1629 is made by Huntsman and is a super
Low density, double
Component edge and void filler.
We use this to stabilize (aka potting)
Stability makes the honeycomb core harder so we can process the edges.
Mix a batch and start applying the edge filler to the perimeter using an putty knife.
Place the white polyester Peel layer on the surface of the table.
This ensures that the air escapes the cellular unit when Edge filler is applied.
Make sure the edge filler penetrates the entire honeycomb.
Flip the honeycomb and check the bottom to verify the correct application.
The edge filler has been fully applied to this core.
It takes about 10 minutes to do so.
The vacuum bag provides compaction pressure by removing air from the bag and allowing air above it (
Push the bag and the inside down
This compaction pressure helps shape the parts.
In this case, the upper and lower panels of the flaps are flat.
When the honeycomb edge filler combination is cured in the oven, the vacuum bag provides a uniform compaction pressure.
If placed in the center of the tool, the vacuum port will work best.
Expose the sealing tape in every corner.
This allows us to place the vacuum bag correctly.
This is very important.
A slight defect of the sealant brought to the interface of the polyethylene vacuum bag can lead to leakage, which may lead to insufficient vacuum.
Work vacuum bag and sealing tape with hand to ensure air-tight fit.
Use a lot of pressure to make sure everything is stuck together.
You will do this often and will get a lot of practice!
Take your time.
Don\'t be afraid to start over if the seal is insufficient
This is all part of your learning experience.
It takes a lot of patience and persistence to make composite materials. Never give up.
The integrity of the vacuum bag is very important.
Make sure there are no sharp objects in your work area to prevent accidental puncture of your vacuum bag.
Use the new razor blade to cut a small slit in a vacuum bag directly above the section of the femalebag connector. Insert thru-
Bag connector, rotating 1/4 clockwise.
Do not rotate completely clockwise as this will distort and squeeze the vacuum bag, causing a leak.
Connect the air hose.
Open the vacuum pump.
Set the pump to a vacuum of 10 inch to prevent the honeycomb core from breaking.
When the vacuum is attracted, you can now completely rotate through
Bag connector clockwise.
This ensures that the bag is flat and has a good seal at the connection.
Check the vacuum gauge.
Guarantee a vacuum of 10 inch.
Put the vacuum bag in the oven.
Curing time from oven. Remove bag.
Remove the blue flash tape.
Now look at the awesome solidified honeycomb edge filler.
It\'s flat and still very light (we used ultra-
Lightweight edge filler).
This honeycomb core is considered \"stable\" or \"potted.
The edges are rigid and can now be machined.
Before that, let\'s use another method to stabilize the frontier core.
The stability of the film adhesive ensures the flexibility of the honeycomb panel.
Unlike the upper and lower panels, we want the leading honeycomb core to be flexible.
The previous method was to stabilize with edge filler, resulting in a rigid honeycomb core.
We need a flexible honeycomb core for concave leading edge.
Hysol EA 9696 epoxy film adhesive is a film that will bond to one side of the cutting edge honeycomb core.
This will stabilize the core of the honeycomb so that we can process it.
Similar to the honeycomb core with edge filler, we need a vacuum bag with a honeycomb core with a film adhesive.
The film adhesive contains resin.
Time, temperature, compaction (vacuum bag)
The result is a flat honeycomb core with a film adhesive on one side.
The film adhesive is flexible, so the core is able to form a leading shape.
The blue flash tape in the cellular center is wrong.
There is no need to apply flash memory there.
The vacuum bag is similar to the core with the edge filler, we need a vacuum bag so things don\'t stick together and the resin flows (
More information about below)
There is also compaction pressure.
The steps described in the picture above: I know this is a lot, so let\'s talk about it.
The goal of the vacuum bag is three things above --
Don\'t stick together, allow the resin to flow, and the pressure will compress everything.
Don\'t stick together, if the plastic film is permanently stuck to our last part, then there is no fun.
We prevent this by stripping layers.
It\'s not sticky (
Made of polyester or Teflon)
It absorbs some resin. Polyester (white stuff)
Peeling well and leaving quite rough (matte)surface.
This is good for painting. Teflon (goldish)
It also peel off well, but leaves a smoother surface that is not very suitable for painting.
When the resin is heated, allowing the resin to flow, it becomes a liquid with a lower viscosity.
We want to control the rate at which it flows.
That\'s why we heat something slowly in the oven.
This is called the ramp rate and will depend on your resin (
Or film adhesive in this case).
When the resin on the film adhesive becomes less sticky, it flows and attaches to anything closest to it, or in this case, slightly higher than the honeycomb wall.
When the resin heals it from a gas called a \"volatile substance.
For vacuum bags cured in the oven, volatile substances must be removed, otherwise they replace the resin and create gaps.
Combination of oven and vacuum (
This is a pressure for us)
The pressure is not enough to dissolve volatile substances in the resin (
Although there is a autoclave! )
So they need a way out.
This is the main function of the vacuum pump.
There are holes on the red perforated film, and air and resin can flow through it before the resin is absorbed by the white polyester Peel layer.
Because the polyester Peel layer absorbs too much resin, we use a perforated film.
The compressed air inside the vacuum bag makes the air above it (
7 psi sea level)
Push the bag and the inside.
Part of this shape.
Rigid aluminum molds or autoclave do the same, but there are various advantages and disadvantages (expensive).
Add a white polyester Peel layer.
This ensures that nothing is stuck together.
Seal and vacuum the bag.
The same principles apply-
Make sure the bag is airtight and placed across
Port connectors and vacuum.
Treat for 90 minutes at 250 degrees Fahrenheit.
See the data sheet above.
Remove the vacuum bag from the oven.
Both honeycomb cores are stable and ready for processing.
Consult the engineering drawings and mark the outer perimeter of the honeycomb.
Cut into a certain size using a band saw.
Set the band saw to the right angle and machine chamfer.
Core pile with edge filler.
Aircraft flaps use 3 k 70 plain carbon fiber with Hexcel f700 resin system.
Cut the required materials using engineering drawings and/or templates.
We use pre-dip carbon fiber-
Use the right amount of resin.
The pre-dip contains a curing resin, so it must be kept in the refrigerator (-10 F)
Slow down the speed of chemical crossing
Its shelf life is limited and the time above freezing must be carefully recorded.
Cut carbon fiber with a sharp tool knife.
Place the first layer in the ready cutting edge mold.
It is very important to work carbon in place with a finger or plastic scraper.
I know it sounds simple, but it can be a very difficult step and the rush maker will skip or do it incorrectly.
Take the time to make sure the carbon follows the exact outline of the mold.
View the completed sample parts, double check all the curvature and plan accordingly.
First, place the carbon at the lowest point of the mold and work up.
It will take you 10 minutes.
Once again, take your time.
We are working on a very high performance section and detailed work is essential.
First of all, we need to do something called debunking.
Laminated on the mold with a vacuum bag.
We need to do this for each layer in the mold.
Your efforts will be rewarded.
Let\'s make another vacuum bag!
The picture above is the first step.
Vacuum bagging always comes back to the basics --
Do not stick airflow and compaction together.
Don\'t stick together, we put the mold on the mold, so the thickness will not stick to the mold. Done.
Next, place the red perforated release film on the top of the first carbon layer.
There are holes in this, allowing air to flow to the vacuum pump.
Note that I have two red perforated releases of 0.
5 \"center overlap.
This allows the perforated release film to move when pressure is applied.
Fix the edge of the perforated release film with flash tape.
Air flow places two white polyester stripping layers on the top of the Red perforated release film.
This layer will serve as a \"breath \".
This provides extra space for air flow.
Tape edge with flash memory.
Place the flash tape around the mold.
Apply sealing tape to the top of the flash belt around the mold.
This should be a continuous sealing strip.
As you approach a change in direction, tear off the adhesive backing and move on in a new direction.
Compaction the vacuum bag we are using does not stretch, so we need to add expansion joints or \"folds\" in the tension area of the high vacuum bag \".
Folds are folds of extra vacuum bags usually 3 \"high (
If the fold is 3 \", it is easier to make.
The area of high vacuum bag tension appears in the curvature of the mold.
In this model, folds are required for the lower left and lower right curves.
See the notes in the picture.
Connect the vacuum pump and debulk for 15 minutes under a 20 inch vacuum.
This presses the thickness of the mold.
It is necessary to borrow three more times, so we will reuse this vacuum bag.
Remove the bag on one side and put it on the other.
Carefully raise the breathing and stripping layer and check the first layer of your compaction! Boom.
This is a fairly extreme geometry for carbon, so we start at the pro level of bat. Sweetness. You can do it.
Repeat the steps of the first and second layers.
The next layer of carbon is called \"double \".
The multiplier, while combining with the honeycomb core, provides additional support for the edge of the cutting edge.
We need extra thickness (plies)
Because this cutting edge is connected with fasteners.
The picture shows multiplication.
Layups and dunks.
Whoo hoooprep is a honeycomb core with a film adhesive through a slight grinding film adhesive with a red Scottish bright color.
Place the honeycomb core with the film adhesive in the center of the mold and place another layer of film adhesive on the top.
Take the time to carefully study the film adhesive around the honeycomb core. Debulk, dude.
This honeycomb core with a film adhesive looks like it was stripped off.
Add a booster to the perimeter of the honeycomb core with a film adhesive.
Doublers will not extend to the top of the mold as this will be trimmed from the last part.
Add the last two layers of carbon at a time.
The work on each floor should take 10 minutes.
Take your time. Don\'t rush.
Debulk is not needed because we will make our last vacuum bag!
Cut 5 pieces of white polyester cortex and place it like this.
Through overlapping edges. 25\".
Remove the old vacuum bag and attach a new sealing tape to the perimeter.
Place a perforated release film.
For ease of expansion, I should cut this perforated release film into two pieces. My bad.
Add a layer of breathing.
This allows air and volatile substances to escape the composite while providing compaction pressure.
Make sure that the final vacuum bag does not fall off any holes from the stock roll and make the final vacuum bag.
Add a thermocouple
Place folds in high curvature areas.
Use a flowmeter, meter, and sound leak detector to make sure there is no leak.
The curing part of 250 degrees Fahrenheit is 90 minutes.
It should be 2-
8 degrees Fahrenheit per minute.
The speed of slope descent should be 2-
8 degrees Fahrenheit to 150 degrees Fahrenheit per minute.
This baby looks good!
Carbon is treated in place one by one and paid off. . . . big time.
If we don\'t do all the work, the carbon layer will separate with the pressure applied.
This leads to the \"bridge \"(i. e.
The laminate does not lean correctly on the mold).
Bridging creates a resin pool because the laminate is removed from the mold and eventually results in defective parts.
The leading weight is less than 1 pound and can hold at least 200.
That\'s why the carbon fiber composites are so great and why we went through all the trouble! So sweet. So awesome.
Makes spar very similar to the frontier-
Put each layer of carbon fiber into the mold to make sure it fits the profile of the mold and peel each layer off.
It is very important to emit carbon into the corner.
Take the time to learn how the fabric is stretched and work it in place.
Once all layers are unsealed, it\'s time to make the final vacuum bag.
Spar will solidify in the autoclave, so there will be some difference in the vacuum bag.
Place a white polyester Peel layer.
I should have two instead of one, with a slight overlap in the middle.
The white line is the line of fiberglass.
These strings will help evacuate air or volatile substances (if any)
Laminate from composite materials.
It\'s called string breathing.
Next, apply a layer of blue High Temperature Solid release.
Strip the surrounding solid release tape with flash tape.
This ensures full sealing of the entire laminate.
This autoclave cycle will pressurize the laminate to 60 psi with nitrogen at a temperature of 260 F.
The parts manufactured in the autoclave have a low air hole rate (
Air and volatile voids are minimized because the pressure either forces them out or dissolves them in a solution)
This allows better compression performance.
The white fiberglass line extends beyond the solid layer, allowing for a small amount of air and resin (if any)
Leave the laminate.
The main reason for breathing is to provide a path for air and volitales (
It releases gas when the resin is cured).
Depending on your resin system and environmental conditions, you may or may not produce volatile substances.
We used a layer of 10 breaths in a 60 psi autoclave.
Under this pressure, the respirator is compressed to the thickness of the paper towel. . . .
Very thin but not enough to breathe and remove volatile substances.
Remove the flash tape around the mold and apply the sealing tape.
Make a vacuum bag and insert two
Bag connector and vacuum.
This bag has two ports because one port vacuuming and the other is used to monitor the pressure.
Check for leaks using meters.
There can be no leakage in the bag and a vacuum must be kept.
Cured for 90 minutes at 260 degrees F, the ramp rate is 5 degrees per minute.
Take out the vacuum bag and check your parts!
We will make these two parts appear magically.
They contain edge-stable honeycomb cores that are easy to manufacture compared to the front and spar.
Compistes cut well with a band saw and easily polished, but special bits are required to use the router.
A great choice for McMasterCarr carbide router bits.
Trim each composite part using a trim template.
I would rather do it with a CNC machine or robot arm.
Tools are very important when making composite materials.
Investing in good tools will ensure consistency of parts and higher production.
Test to install your parts in the fixture.
We use the adhesive to connect the upper panel, the lower panel, and the spar together.
Apply a uniform layer of wax and an immediate buff.
Wait 10 minutes before applying the second coat.
Apply for three coats.
Because we are going to use fasteners, there is no need for adhesive at the front end.
Place the flash in the area where the potential adhesive is lost.
This will help us to remove the excess adhesive after curing.
Hysol has a good guide for surface preparation. Read page 176 -
179 The key points for the repair of advanced composite materials what the surface looks like before preparing the surface.
Pay attention to the texture.
There are three options for preparing composite surfaces for the adhesive
180 sandpaper, Red Scotch whisky, or sandblasted.
Make sure the resin is worn, not carbon fiber.
If your dust is black then you need to remove the carbon fiber.
The picture display surface is ready. It is shiny.
Wipe the prepared surface with lintfree cloth.
Use the fresh side of the cloth every wipe.
The surface is clean when the cloth is clean.
Test the energy of the worn surface by adding water and keeping the parts at 30 degrees.
The water should cover the prepared surface evenly.
Don\'t do this in your actual section, do it in the sample section.
If this test is performed, please re-
Motivate the surface by gently polishing the surface with sandpaper and wiping it clean.
Read page 179 for advanced composite repair and design points, we used Hysol EA 9309. 3NA adhesive.
This thing works well.
For specifications, see the data sheet above.
Wear clothes that you don\'t care about when you play with these things.
Read page 186 for key points in repair and design of advanced composite materials. Cleco-
Style clips put things together nicely.
Appreciate your role
High speed and low feed are used when processing composite materials. Use brad-
Point carbide drill bits for carbon fiber composites.
Use the template to drill a hole in the leading edge and insert the hole clamp.
Drill another hole on the other side and insert an extra hole clip.
This ensures that the template remains in place while drilling.
Drill baby, drill.
Try not to get the drill off and break the only Brad-
Point drill is available.
You lose calm. . . . totes for real.
Align and clamp the leading edge with the rear edge.
Use the holes on the front edge to match the holes on the back edge.
Use the hole clip to fix everything down.
The carbon fiber composite uses a 130 degree sink.
The composite is thin so we need additional drafts.
There are many fasteners and systems for connecting composite materials.
We used the Click key fastener.
American aluminum Huck Fasteners are also very popular.
See the data sheet above.
This is a connection to two-part adhesive.
The mixing tube is great.
They are easy to use and ensure repeatability.
It is essential to control the manufacturing process.
Pass the CB200 adhesive through the mixing tube and discard 2 inch of the length of the mixing tube.
This ensures a full mixing of the adhesive.
Don\'t remove the mixing tube if you don\'t use all the adhesive!
Put the whole component into the refrigerator.
When needed again, remove the old mixing tube and install a new mixing tube.
The surface of the composite is prepared by grinding the resin with red Scottish bright color.
This is ready for the surface of the adhesive.
Read page 176 -
179 in the essential elements of advanced composite repair, we will use something called a nut plate.
Specifically, this is an 8 floating nut board.
Use the CB200 adhesive and plug-in.
Repeat for all holes.
When cured, the adhesive becomes green.
Pull the orange tabsDo over. torque! Weigh the part.
Weigh 1233 grams or less than 3 lbs. Amazing.
This is the best engineering and human intelligence.
This flap will withstand the power of thousands of pounds before it fails, weighing only a few pounds.
Let\'s go to Mars. . . .
Or build a great plane. I\'m in.
Thanks for reading.
Of course I enjoyed the trip and shared my experience with you.
Do cool things