3DE - 3D Printed Carbon Wrapped e-bike frame

Found this video series while doing some research, these guys are building a Lamborghini replica with Carbon fiber wrapped PLA, Looks like most of their panels aren't structural but seems as though the concept works
EDIT: I had a bit of a back and forth with the guys in the comments and they said they have since changed to ABS filament because it has a higher glass temperature
[youtube]LXx5P3yyFoA[/youtube]
 
Chambers said:
@BalorNG What kind of plastic did you use in your previous project? Any pics?

ABS plastic, carbon wrap, square taper crankarm in short length.
XU9Txd0h.jpg
 
Chambers said:
Found this video series while doing some research, these guys are building a Lamborghini replica with Carbon fiber wrapped PLA, Looks like most of their panels aren't structural but seems as though the concept works
EDIT: I had a bit of a back and forth with the guys in the comments and they said they have since changed to ABS filament because it has a higher glass temperature
[youtube]LXx5P3yyFoA[/youtube]

Yup, PLA, unless unnealed (major pain) will distort at merely 60 or C, which is easily achieveable in direct sunlight.
 
BalorNG said:
Chambers said:
@BalorNG What kind of plastic did you use in your previous project? Any pics?

ABS plastic, carbon wrap, square taper crankarm in short length.
XU9Txd0h.jpg

Thanks for the pic - Did this part fail in the end? How many layers of carbon?
Yup, PLA, unless unnealed (major pain) will distort at merely 60 or C, which is easily achieveable in direct sunlight.
I think I'm going to do a test with one of the parts I've already printed since I have them, Will change to ABS for rev B

Test will be as follows..
1. wrap the part inside and outside in fiberglass then Carbon Fiber (down-tube section)
2. Leave it in the sun for a week or until something happens (I live in a fairly tropical part of Australia) maybe with a weight or something resting on one of the sides for good measure

Should be interesting either way
 
I ran across an alternative to to ABS last year: ASA Apollox filament (Acrylonitrile Styrene Acrylate)

It is supposed to have less warping, good rigidity, low odor and better resilience to UV and water absorption than ABS.

https://www.formfutura.com/shop/product/apollox-2779?category=453

https://www.easy3dhome.com/apollox/

https://youtu.be/EzTVvT8Kmas

https://youtu.be/MHUNmaVW7mY

https://youtu.be/lCqwA1h3JV4
 
Chambers said:
Test will be as follows..
1. wrap the part inside and outside in fiberglass then Carbon Fiber (down-tube section)
2. Leave it in the sun for a week or until something happens (I live in a fairly tropical part of Australia) maybe with a weight or something resting on one of the sides for good measure

Should be interesting either way

Nothing interesting will happen but it’s still a bad idea. Too much weight with little long term strength from the PLA print. The way to get strength is either with a light sandwich-shell combination (airex foam core and the likes) that will last over time and temperature or to build strength with the carbon shell alone.

You can build a nice upper and lower mold half with PLA sections instead and vacuum bag the frame in halves, separately or together as a closed profile. It’s nice to just draw the design, print it and start laminating, avoiding the step of making the mold from scratch.
 
larsb said:
Nothing interesting will happen but it’s still a bad idea. Too much weight with little long term strength from the PLA print. The way to get strength is either with a light sandwich-shell combination (airex foam core and the likes) that will last over time and temperature or to build strength with the carbon shell alone.
In my head the plastic will be of little consequence once fully encapsulated (internal and external) but I could be very wrong - Since I already have some parts printed I will have a play around if only to satisfy my curiosity.

larsb said:
You can build a nice upper and lower mold half with PLA sections instead and vacuum bag the frame in halves, separately or together as a closed profile. It’s nice to just draw the design, print it and start laminating, avoiding the step of making the mold from scratch.
Yeah this is my plan B and actually what was originally in my head - Thanks for the input
 
LewTwo said:
I ran across an alternative to to ABS last year: ASA Apollox filament (Acrylonitrile Styrene Acrylate)

It is supposed to have less warping, good rigidity, low odor and better resilience to UV and water absorption than ABS.

https://www.formfutura.com/shop/product/apollox-2779?category=453

https://www.easy3dhome.com/apollox/

https://youtu.be/EzTVvT8Kmas

https://youtu.be/MHUNmaVW7mY

https://youtu.be/lCqwA1h3JV4
Thanks LewTwo, I had a bit of a read up on ASA last night after reading your post - seems promising.
 
If you’re wanting an optimised design (and you do since you’re paying for carbon) then the inside/pla/outside sandwich will rely on the pla for shell support and separation to stop buckling if you want it to be light. If you cannot trust the pla to do that (and you shouldn’t on long term) then it’s better to make a single shell with thicker carbon layering since this’ll be both stronger and take impacts better.
 
For those interested here's where the design is up to - 3DE 2 a.jpgI decided I might as well finish printing this test frame in PLA to get an idea of the design in real space ( I'll post some more pics later on)
 
Some pics...
 

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Quick update, I got a bit of fiber-glassing done on the PLA v1 this weekend. Conclusions: it's definitely possible to build a strong frame this way but probably much easier and tidier following standard methods with a two part mold...
 
Just a quick clip of a new Carbon Frame I'm Designing [youtube]Bg_gLKTSYpQ[/youtube] Similar specs to the previous one - this is just the initial conception - Cheers
 
Subscribed!

I've no idea what I'm talking about but... it may be possible to make 3d printed molds (using your current 3d models and substract operations) to create paraffine pieces, join them with heat and cover it with the composite. You can get out the wax if you want. If it works, this may speed up the creation of more frames.
 
trazor said:
Subscribed!

I've no idea what I'm talking about but... it may be possible to make 3d printed molds (using your current 3d models and substract operations) to create paraffine pieces, join them with heat and cover it with the composite. You can get out the wax if you want. If it works, this may speed up the creation of more frames.

That's very clever!
 
Compoundbike said:
.... hope it has enough Carbon to hold the Bike together.
If anyone figures out how to predict that without expensive finite element software then let me know.
 
LewTwo said:
Compoundbike said:
.... hope it has enough Carbon to hold the Bike together.
If anyone figures out how to predict that without expensive finite element software then let me know.

From what I've read a basic rule of thumb is the carbon should be the same thickness as if you were making it from mild steel.... so in the case of a bicycle that would be between 0.8 and 1.2mm thick in most cases (for the frame tubes, thicker for the BB etc) ...I will probably go 1.5 plus to err on the side of caution. Another guide is that the weight of the weave roughly eqautes to the thickness of the finished laminate by moving the decimal place e.g. a 210g twill will be roughly 0.21mm thick per layer.

Obviously there are other factors to consider like the direction of force / orientation of weave etc.
 
I was just watching some RC aircraft building videos, and a useful alternative to various common epoxies to put over carbon-fiber cloth is a type of rubbery glue called "goop" and thinning it with Toluene to make is more spreadable. He said it almost as hard and stiff as epoxy resin when it cures, but it's slightly more rubbery, and less prone to cracking on a crash.

https://youtu.be/3heh9swH2Zw?t=257
 
spinningmagnets said:
I was just watching some RC aircraft building videos, and a useful alternative to various common epoxies to put over carbon-fiber cloth is a type of rubbery glue called "goop" and thinning it with Toluene to make is more spreadable. He said it almost as hard and stiff as epoxy resin when it cures, but it's slightly more rubbery, and less prone to cracking on a crash.

https://youtu.be/3heh9swH2Zw?t=257

Interesting! Thanks
 
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