Carbon Fiber Compression Mold

Show off your prints!!!

Carbon Fiber Compression Mold

Postby pyronaught » Wed Jul 13, 2016 7:19 pm

Let me just say I have new respect for PLA. The mold set below was printed in MakerGear black PLA with 80% infill. They are hollow inside with a 1/2" wall thickness. I am using them to press 10 sheets of carbon fiber in a hydraulic press down to a 3mm wall thickness with a fiber to resin ratio of about 65/35. These parts are holding up to a whopping 9000 pounds of compression force without cracking! I'm real curious what the limit is before they crack, but don't want to ruin a mold to find out. It takes three printers a full 24 hours to make a mold set, then there's several hours of sanding involved on top of that. The molded part tuns out great though, and is super strong. I tried to vacuum bag the same part for comparison and it didn't even come close to the quality of the compression molded part, and vacuum bagging is a bigger pain to prep and extract the part from afterwards. The part just pops right out of the compression mold with minimal waste materials (no perf sheet or breather cloth required and all excess epoxy can easily leave the part). So here's yet another cool thing you can do with a 3D printer!

mold_press1.jpg

mold_press2.jpg

mold_press3.jpg

mold_press4.jpg
Experience is what you get when you didn't get what you wanted.
User avatar
pyronaught
 
Posts: 669
Joined: Mon Dec 01, 2014 8:24 pm

Re: Carbon Fiber Compression Mold

Postby jimc » Thu Jul 14, 2016 2:05 am

thats great. what kind of epoxy are you using for the lamination? also what are you using for a release agent? wax, frecoat, liner? looks like i see a plastic release liner there and also some wax paper or something?
User avatar
jimc
 
Posts: 2884
Joined: Wed Apr 09, 2014 11:30 pm
Location: mullica, nj

Re: Carbon Fiber Compression Mold

Postby rpollack » Thu Jul 14, 2016 2:38 am

very cool!
User avatar
rpollack
 
Posts: 443
Joined: Wed Apr 09, 2014 9:01 pm
Location: Beachwood, OH

Re: Carbon Fiber Compression Mold

Postby pyronaught » Thu Jul 14, 2016 4:46 am

jimc wrote:thats great. what kind of epoxy are you using for the lamination? also what are you using for a release agent? wax, frecoat, liner? looks like i see a plastic release liner there and also some wax paper or something?


I'm using lamination epoxy, I can look up the company name if you are interested. Since these parts are not for show and are just for joint structures, I'm using a plastic liner for the release agent. The wax paper is just to catch the epoxy that is squeezed out of the mold so that it doesn't drip all over everything. I do wax the molds just in case something gets through, but thin stretch tape of the kind used for wrapping palettes of boxes works really well for release. The molds are a lot of time and effort to make so I don't want to risk screwing one up from something sticking to it. With the entire male mold wrapped in the film I never have to worry about epoxy touching it and it just pops right out of the mold with zero effort after curing. I just roll a couple of turns onto the male mold, then put a sheet of peel-ply over it in order to texture the inside of the part since it will be getting glued to another similar half that fits inside and sandwiches carbon fiber tubes in place. After the layup I put a couple more layers of the film over that so that the outside is glossy. There are still tiny wrinkles, but they are pretty small and nobody will ever see these anyway. These gussets are super stiff yet still light at around 150g. This is the best results I've ever had working with carbon fiber.
Experience is what you get when you didn't get what you wanted.
User avatar
pyronaught
 
Posts: 669
Joined: Mon Dec 01, 2014 8:24 pm

Re: Carbon Fiber Compression Mold

Postby jimc » Thu Jul 14, 2016 4:55 am

nice job. you dont have to bother with the name of the epoxy. i keep it here in 5 gal pails. i was just wondering if there was something special you were using. making molds like this is something that has been on the back of my mind. i just havent needed any special carbon or fiberglass parts for quite awhile.
User avatar
jimc
 
Posts: 2884
Joined: Wed Apr 09, 2014 11:30 pm
Location: mullica, nj

Re: Carbon Fiber Compression Mold

Postby pyronaught » Thu Jul 14, 2016 5:28 am

I've been playing with that Raptor PLA "dishwasher safe" filament from MakerGeeks since it seems to have ideal qualities for making these and I eventually want to use thermoset epoxy and heat cure them. The problem I'm having with it is that it warps almost as bad as ABS. It's really strong stuff though, I hope I can get it to stay down. I'm experimenting with heat dissipation methods on the corners, since if you can keep the corners from peeling then nothing else will peel up.
Experience is what you get when you didn't get what you wanted.
User avatar
pyronaught
 
Posts: 669
Joined: Mon Dec 01, 2014 8:24 pm

Re: Carbon Fiber Compression Mold

Postby willnewton » Thu Jul 14, 2016 7:45 pm

I used to use a fair bit of MGS epoxy for carbon fiber and Kevlar molding. It is a fantastic epoxy and low odor as well (amine-free).

I made a hotbox from foam sheeting and light bulbs with a Ranco temp controller. It was no problem to post cure at 120° F.

I used to make hundreds of competition RC glider parts for sale this way for years if you have any questions.

Cool tools!
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. http://forum.makergear.com/viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/about
User avatar
willnewton
 
Posts: 438
Joined: Wed Apr 09, 2014 8:32 pm

Re: Carbon Fiber Compression Mold

Postby pyronaught » Sat Jul 16, 2016 4:10 am

willnewton wrote:I used to use a fair bit of MGS epoxy for carbon fiber and Kevlar molding. It is a fantastic epoxy and low odor as well (amine-free).

I made a hotbox from foam sheeting and light bulbs with a Ranco temp controller. It was no problem to post cure at 120° F.

I used to make hundreds of competition RC glider parts for sale this way for years if you have any questions.

Cool tools!



I see a lot of guys doing vacuum bagging over PLA molds for making RC parts, but never came across anyone doing compression molding. The nice thing about compression molding is you can really put one hell of a lot of force on the layers to squeeze them together. I have a mold set I could not use because they changed the part after I had already printed the molds for it, so I used them to do a crush test to see how much the PLA could take. This was just standard PLA with a 12mm wall, no PLA+, Raptor PLA or anything fancy. I went as high as 10 tons on the gauge, which is 1800 lbs pushing the two parts together and they STILL didn't break. The only damage was the press plate on the bottom started crushing an indentation in the bottom mold since the mold was slightly larger than the plate. Even that damage would not occur if the plate was bigger than the mold that is sitting on it. I think the part that would eventually fail would be the side walls of the female mold. There should be a point where they just buckle, but it is so far beyond the working pressure that I don't have to worry about ever hitting that point.
Experience is what you get when you didn't get what you wanted.
User avatar
pyronaught
 
Posts: 669
Joined: Mon Dec 01, 2014 8:24 pm

Re: Carbon Fiber Compression Mold

Postby jimc » Sat Jul 16, 2016 4:16 am

ive never done a compression mold myself but dont you end up with a situation where you are just squeezing all the epoxy out of the laminate making for a dry layup?
User avatar
jimc
 
Posts: 2884
Joined: Wed Apr 09, 2014 11:30 pm
Location: mullica, nj

Re: Carbon Fiber Compression Mold

Postby pyronaught » Sat Jul 16, 2016 8:14 am

jimc wrote:ive never done a compression mold myself but dont you end up with a situation where you are just squeezing all the epoxy out of the laminate making for a dry layup?


You can control how much epoxy you squeeze out by how much pressure you use. So if you measure the weight of the carbon fiber in the part and then weigh the finished part, you can figure out your fiber to resin ratio and adjust the pressure to make it what you want it to be. A hydraulic press ram holds its position, so it wont keep extending as the contents compress the way an air ram would.
Experience is what you get when you didn't get what you wanted.
User avatar
pyronaught
 
Posts: 669
Joined: Mon Dec 01, 2014 8:24 pm

Next

Return to Printed Object Showcase

Who is online

Users browsing this forum: No registered users and 2 guests