lo_0l
-
Posts
129 -
Joined
-
Last visited
-
Days Won
10
Posts posted by lo_0l
-
-
Hey @sfsailboat, wanted to check in and see how your project is coming along? 🙂
-
12 hours ago, sfsailboat said:
Hi @lo_0l what products are you thinking will work well for a bed frame?
I was thinking you could actually use a size compatible with 80/20 as the connectors for it are much more common. Since anything aluminum needs to be anodized, you could use something like these nylon 3-way corner connectors and these nylon T connectors. You could also 3D print your own out of nylon, PETG, or a carbon fiber variant.
-
8 hours ago, richiewayne said:
I am fascinated with some of the cosmetic carbon fiber weaves and am looking to work on some projects that combine other functionality for a dramatic design. Much like the Pokeball video posted in the Cool Carbon Fiber Things thread.
I don’t have an immediate project, but am going through ideas in my head.
That's awesome! Tremendously looking forward to seeing your projects @richiewayne
You should check out this DIY composite curing oven that @John Kimball made a few weeks ago!
-
1 hour ago, richiewayne said:
Hi everyone. My name is Richie and I’ve been in the composites industry professionally for the past 12yrs. I’ve worked in both Aerospace and Marine, from phenolic prepregs to polyesters, honeycomb core to foam core, gelcoat to paint, part design, mold design, etc. With all that, I’m just now starting to build my own garage set up and build some hobby composites. I’m looking forward to getting some ideas from everyone and helping I’m with yours.
Welcome aboard! It's great to have you join us. What kind of hobby parts do you want to build?
If there are any subforums you'd like to see to support your efforts, please feel free to ask 🙂
-
Welcome to Composites Community @richiewayne!
-
Anyone here going to or at CAMX this week? 🙂
-
On 10/25/2023 at 2:04 AM, sfsailboat said:
Hi, I am looking to build a simple full size bed frame for a sailboat, 51" wide x 77" long x 3" high. What pieces do you recommend for easy assembly? I will place wood slats over the composite frame, and then the mattress on top of the slats.
Hey @sfsailboat! Welcome to Composites Community!
How much are you wanting it to look like a traditional bed frame? Do you want a brim to hold in the mattress you'll be using?
There are a few products that Rock West Composites has off the top of my head that would work well for making a traditional bed frame.
-
1
-
-
On 10/14/2023 at 6:42 PM, M Dulansky said:
Hi all! My name is Matt and I am going to take over for Sascha this week and delve into the construction of our testing rig and initial failure modes of our first few designs.
Intro
Throughout this project we used an MTS tensile testing machine located on campus at UC San Diego. This machine gave us extremely precise readouts of Force vs. Displacement that we utilized for our data analysis. The following image is a picture of a very similar testing machine to the one we used, we made various mounts for testing our specific coupons which I will discuss here.
Figure 1: MTS Tensile Testing Machine
1. Four Point Bending Test RigOriginally Sascha and I hoped to follow ASTM standard 393 for out of plane loading of Composite Sandwich panels, specifically the four point bending option. After machining the complicated geometry required by the specification we had the following result.
Figure 2: Initial Testing Rig
The bottom of the sandwich panel was then loaded with a similar setup, only with the two 60 durometer rubber contact pads spaced 22 inches apart instead of 6 inches. The goal of this test setup is to achieve compression failure in the top face sheet of the composite, which occurs from an excessive moment.
2. Initial Results
Using this setup we actually found that our coupons, made from 4 and 6 oz laminate fiberglass cloth were failure in shear due to the weak shear strength of the foam. This does not resemble the failure mode of a surfboard from out of plane impact so we needed to change our design. The following image shows the shear failure experienced by a sandwich panel from this test rig. The two parallel lines show the shear failure caused directly from the rubber contact pads.
Figure 3: Incorrect Failure Mode of First Testing Rig
3. Redesign
At this stage we understood that we needed to distribute the load from the testing machine in order to overcome the shear failure we experienced. The issue was that we were unsure how to overcome this because of the excessive deflection of the sandwich panel before failure. Eventually we decided to create a curved shell by which to press onto the coupon in order to distribute the load along the length of the coupon as it bends. After completing this we were able to get the desire failure mode we wanted, a singular buckle on the top face sheet of the specimen. The following images show both of these things.
Figure 4: Curved Shell Testing Rig Figure 5: Buckling Failure Mode
4. Conclusion
Through this process we were able to create an efficient testing rig, as well as determine the most effective testing methodology for the remainder of our designs. Look forward to next week where we start to dig into the various designs that we began implementing, and all the tribulations associated with each design. See you next week!
I'm not familiar with surfboard testing, but is the four-point method more indicative of the way someone's feet would naturally be positioned?
Also, is the goal of the coupons to test the resistance to a failure between the two sides or front and back?
Very cool! Thank you for sharing your project. Looking forward to more 🙂
-
2 hours ago, Mongo said:
Everything seems to be on the computer these days. I want to create a composite car chassis. Does anybody make scale models to use for load tests when they are designing a chassis? I want to put some chipboard (or other cheap material) in a laser cutter (or water jet) and build a scale model for testing its rigidity. Would there be any advantage to testing a physical scale model over a virtual model in the computer? Race teams still use a wind tunnel for scale models. Do they use the models for any other load tests?
Hey @Mongo!
I don't think so. From what I've seen modeling have gotten so darn good they rarely use full scale models. Though they do eventually test full-scale models to verify things.
I'm not sure that I'd use chipboard, but there are most definitely some materials you could take advantage of. I think the problem with composites for mainstream vehicles is cost/consistency right now. You're starting to see it more and more as they work out the kinks though!
Were you thinking of doing a full composite chassis or just partial?
-
5 hours ago, Mongo said:
@John Kimball I have been reading the scientific journal that you had posted in your previous comment. Where can I access all the supporting cited sources from the paper? There are 129 sources attached that I want to investigate and I don't want to pay for each publication.
Hey @Mongo,Within any paper you can usually copy the citation and right click and 'search for...' depending on your browser or copy and paste it into Google or your favorite search engine like below:
Usually, the source will pop right up 👍
-
These look like a great start @Anthony Fairhurst! With a couple of adjustments they should like great 👍
-
1
-
-
Cool project idea! This should look great! I've definitely seen some before like this on the bikes of friends 😀
You can buy these premade unless you're really itching for a project or have an odd-shaped exhaust. What kind of exhaust is this for? What shape is it?
-
How'd this one go @NightmareGoggles? Any pictures of the newest run at this?
-
On 9/13/2023 at 5:38 PM, Jeremy Senne said:
Some guys I used to work with did this back in the day:
Love it!
How long did it take to lay all of that up per set?
It looks pretty good! Was it done with a wet layup or prepreg?
-
1
-
-
24 minutes ago, Nell said:
Hello,
I have been working at a Composites company for 15 years but since I am in accounting, I haven't had much hands on experience, but my awareness of what can be done with composites has grown exponentially. I am so thrilled to be working at a company that not only provides solutions for the government and large companies, but also makes composites available to everyone through online ordering. I am excited to learn more about the everyday uses of composites through this online forum.
Welcome @Nell! It's great to have on board and a part of our community 🙂
Perhaps we can get some workshops going at some point and have you be a part of them!
-
19 hours ago, Shnorky said:
Hello,
My name is Mark, I'm from Arizona. I am very new to composites but also very interested in learning to make parts for my car. I have a 2022 Kia Forte GT, but there is not a lot of aftermarket support for it as with most Korean cars here in the states. I have ordered a couple of parts that are available but when talking to a couple of companies here locally 1 wanted $3000 for a spoiler and the other had no interest in the project. Either way, I have decided I want to push forward with some interior parts and will see how those come out before trying something larger like a spoiler.
Welcome @Shnorky (Mark)! Great to have you aboard with us 🙂
I know what you mean about a lack of parts. I have a 2021 Crosstrek and (would you believe it?) there aren't a lot of carbon fiber parts available either. I've resorted to wrapping my mirrors with carbon fiber vinyl for now. I have been thinking about making some real CF mirror covers, but I just don't have the time right now. Perhaps over the holiday break this winter I can convince @John Kimball to come out, defrost, and guide me through it.
What kind of interior parts do you want to make?
-
11 hours ago, John Kimball said:
I’ve always wanted to have real composite curing oven in my work shop. I only work in small objects, so an economical small curing oven has been out of the question. I decided to buy a the smallest toaster oven I could find on the Brazilian rain forest site and settled on a cheap ($54) oven with a dial thermostat.
I was pretty pleased with it, but it had some issues that kept me from trusting it.
1) it had 4 burner units. This can cause extreme heat on the surface of the part which can flash cure prepreg and even melt the vacuum bag.
2) The heat was wither On or Off, no ramp rate or easing to the temperature that prepreg really needs.
3) It required you to use a 60 minute timer to operate it. This is annoying because most cures are over 2 hours.
4) I also want to use it for a warming oven to cure paint and speed cure adhesive. This oven could only go as low as 130ºF, so it was still a bit high for my liking.
5) It got pretty hot on the outer shell when heating and caused the room to heat up and was kind of dangerous in my opinion.
With all that in mind and after some research, I decided to “modify” this cheap oven into something a little more usable for my needs.
I started by replacing the dial thermostat with a simple PID temperature controller with solid state relay (SSR) and a toggle power switch to bypass the silly timer. There was plenty of room inside for some simple electronics. I also added ceramic insulation to the areas that would allow. I also eliminated the 2 top burners to slow down the heating process. The remaining 2 burners are more than enough to heat the tiny space.
It was at this point that things started spiraling out of control. I realized that I wanted to control the power to the heaters even if the controller was powered on, so I added another switch. The SSR was mounted to a heat sink, so I figured it probably got pretty hot, so I mounted a small cooling fan to the back of the oven to provide some circulation while it’s running. It was running great, but it still got pretty hot on the outside, especially on the bottom. I found some heat deflection material that insulates with a very thin layer and put that on the bottom and the back of the unit. The PID allowed me to set a temperature and it would climb to that temp and then hold there. I thought I would be satisfied with that, but alas, I wasn’t. I found another PID controller that was programmable for ramp and soak for up to 20 different programs. A gold mine. and it was affordable. I also needed a way to monitor the temps of the part, so I added some internal thermocouple receptacles to the interior with connections on the front panel for easy readings.
This is where almost done turned into start over and, oh yeah, I’ll need vacuum in there. More research. I found a small vacuum pump about 4” x 3” x 1.5”. Perfect. It only pulls 20 in/Hg, but that will do for my projects just fine. so I bought a small vacuum gauge, some high temp vacuum hose and a few fittings and got back to building the oven properly. I added another switch to control the vacuum pump and mounted the vacuum gauge. I also added some more heat deflection material to the interior to keep it more efficient. I covered the glass with the insulation, so I also covered the glass with a carbon fiber plate to make it look a bit more finished.
Next I needed some small vacuum ports for my tiny hoses and parts, so I fabbed a couple of them from some brass fittings and washers.
The controller is fantastic. It can be tuned to the oven or even a mold or part in the oven for optimal heat control. It also has Bluetooth, so I can use my phone or iPad to program, control, and monitor cure cycles.
All said, I spent about $250 to build the final version. Considering that a small lab oven could cost much more than that, I’m pleased.
This is awesome! What a cool project!Is the heat in the oven distributed fairly evenly after removing the other heating elements?
-
1
-
-
1 hour ago, NightmareGoggles said:
Hello all,
I am currently trying to make a bistable composite using the paper below as reference.
https://core.ac.uk/download/pdf/187093671.pdf
The current layup I am using is B6-a, and my setup is as follows.
- I have a custom oven which reaches 225 C for 4 hours.
- I have a brass tube 1 inch in diameter
- I wrap my layup around one third of the tube in order to get a third of the tube.
- My fiber glass is +45/-45, 300gsm (couldn't find 200gsm)
-
I have experimented with the following layups (From outside to inside)
- 0.5 PP/300 GF
- 0.5 PP/2x300 GF
- 0.5 PP/3x300 GF
- I have ptfe coated glass fabric paper sandwiching both sides of the layup with a tight winding of heat shrink tape to hold it all together and apply compression in the oven
The problem I am having is that almost all of the composites I have produced have ridges from the tape where they did not compress fully or enough and thus the plastic is not fully impregnating the fiberglass at some places, leaving me with a composite that is not fully bistable in some parts. If anyone has any suggestions on how to fix this, or even general suggestions relating to my process, or perhaps even somewhere I could get these manufactured for me, I would greatly appreciate it.
Hey @NightmareGoggles! Welcome to Composites Community 🙂Do you have any pictures that you can provide?
-
Apparently they make carbon fiber welding helmets!
You can grab a Carbon Fiber Pancake Welding Hood from CMR Fabrications:
-
On 8/12/2023 at 6:58 AM, Jacky974 said:
Hi all,
I’m from Quebec City, my dream is to build a full body car in CF 😍
I’ve more than 10 year in experience in video Youtube ahah, I don’t start ever … so shy lool.
I’ve start with resin table.
hope to have more helpful in this forum and to help you too.
Jacky
Welcome aboard Jacky! It's wonderful to have you be a part of our Composites Community 🙂
-
1
-
-
8 minutes ago, codyb407 said:
Thanks! So far for infusion tutorials I've found AJ Hartman's videos extremely helpful. As far as overlays or skinning, I've watched so many from so many different creators I couldn't tell you lol.
I know what you mean, there's SO much different stuff out there. I wish someone had videos/classes + a project kit.
-
1
-
-
9 minutes ago, codyb407 said:
As mentioned, I'm Cody and I'm extremely new to all of this, but I'm OBSESSED with carbon fiber!
I've been watching tons and tons of videos from wet method "skinning" to infusion methods using molds. I'm trying to take in as much information as I can before I place an order to give it a go on some interior parts from my vehicle.
The first method I'm going to try is going to be wet "overlay' or "skinning", just to get a feel for using the material, and mixing and using epoxy as I've never worked with anything like that before. Eventually learn every method and pick what works best for me, and possibly make a little side gig out of it. (Friends & Family to begin with of course).
I was going to order my first pieces of the puzzle off of amazon, as I want to start small.
If anyone has any suggestions, tips, or pointers, they would be appreciated!
Thanks, and happy Compositing!
-Cody Ball
Welcome @codyb407!
It's great to have you aboard! What composites videos have you found to be the most helpful?
-
I'm curious @Mongo, is there a particular reason you want to use Ekoa®? I've seen a lot of interest lately so I'm curious why you're looking to use it as opposed to something like fiberglass.
Do you use Ekoa® much or at all currently?
-
On 7/22/2023 at 7:52 AM, Sean Bovey said:
Hello, I run the Materials Testing/Destructive Testing department at an aerospace manufacturing facility. We primarily work with carbon but also see a reasonable amount of fiberglass. Our facility also supports a Silacone department where we produce aerospace hoses. My team tests it all. I took over the department about 2 years ago. Im responsible for all of the materials/materials testing QE duties for our Quality dept. Primarily seeking to network with experts in the industry but I may be able to support others to some small degree as well. I was handed the Calibration department about 1 year ago and very much still getting my feet wet in that area. I really appreciate the opportunity your forum presents.
Welcome Sean! It's great to have more people aboard!
How long have you been working in composites all together?
DIY curing oven
in Equipment
Posted
Would you mind sharing a Google Doc or something? 🙂