I am looking to start the mobile base of my InMoov. There are a huge number of different materials available to use. I am contemplating Carbon Fiber and Aluminum. Does anyone have experience with these two materials that would be willing to give some pointers (mainly on the carbon fiber end)? I think my base will be either 18"x18" or 24"x24". I wonder what the strength of the base would be with Carbon Fiber and what thickness of carbon fiber I should use to hold say 50 lbs of SLA batteries when the base is being supported by 4 sides by maybe 1" aluminium square tubing? The frame would be aluminum and the motors would be mounted to aluminum. I guess my question is how thick of a CF sheet would I need and should I go with a honeycomb fill in the CF or a solid CF sheet? I have a friend who can weld really well so I am thinking about having a welded frame.
This is an area that I know little to nothing about. I hope to find some advice or else it's going to be trial and error. This could get really expensive.
I had a friend make some car parts from carbon fiber. He started with a foam shape that he carved with a knife and Dremmel. Then he made a fiberglass mold of the shape.
Finally he used a putty to fill in any cracks in the fiberglass mold.
Once that was dry and ready, he laid the sheets of carbon into the fiberglass mold to make the object.
It did take a day for one piece - but it was worth it. I watched him do it - well, drank beer and watched him work... And even though it was time consuming, it wasn't a lot of work if you don't rush.
I had helped my ex-father-in-law build speed boats for a summer a while back. I have worked with fiberglass but not carbon fiber. I am trying to decide if I just make the base out of aluminum or try a newer technology. I have time before I am at that point but my brain doesn't stop working on what's next... It can be a curse,
I know that welding aluminum is a pain at best so the frame may end up steel. IDK at this point. It looks like the base of my inmoov will probably weigh more than the top, but I guess that is a good thing for stability. If I went CF, I might have problems with it being top heavy.
There is a lot of research to do for sure. I wish I was better on the fabrication side of robotics but there is an opportunity for me to learn.
Thanks DJ
You could buy a roll of Carbon Fiber based material for your 3D printer and make some sample parts and see if they would meet up to what you need.
I have a roll ($70), but have not used it yet.
I can say my drive shaft is made out of carbon fiber, and it has been used/abused behind a lot torque and knock on wood, no issues.
I think it would look great done in carbon fiber, and if its too light, you can always add weight balance to where ever it may be needed.
I've done fiberglass and carbon fiber. Most carbon is just for looks because of the attractive weave pattern. Carbon fiber is just graphite mesh fibers and resin , and vacuum cured. I've done aluminum cloth as well which looks super cool. When searching for materials use graphite as a search term instead of carbon...
The number one thing you want to consider is cost of your tools and waste material when working with carbon fiber. You will need a good vacuum pump and large vacuum bags to "pressure cure" the carbon. This packs fibers tightly together and squished out excess epoxy. I have 120 dollars in my dual rotor robovac
Generally speaking you will mock up your part in other materials like wood , plastic or foam and then create a mold that you can later cast your "real carbon fiber" parts from.