Some things to consider: If you want to use a core, you need to think about how you are going to trim your part, cut holes etc. because you don’t want to expose the core. If I was doing this DIY in my garage… I would plan out an Option A which didn’t include a core, only laminate layers & Option B, which includes a core. Work out how each option would need to be built and see if you really need the core.
If you want to use composites I think your first triangle shape bracket would be do-able, and definitely the easiest of the two. But remove the cutouts so it’s one solid piece with just the two mounting holes. You might have to redesign it to have more material around the holes - much more if you want the core material to go right around the holes as well. But I wouldn’t try that myself… I would just have the core in the middle of the part and build up extra layers of laminate around the holes. For the edges you might be able to make a lip that comes out at 90º, if that would be suitable for your usage. Even a small amount of lip would add probably a lot of strength to the part. Have a search here for the car ramps that DDCompound built - they’re basically an upside down “U” shape.
For your 2nd part with the 3 tabs, well… anything is possible, but for a DIY garage job I can see that being a lot of work and needing to be produced as multiple sections and bonded together. Probably much, much easier and cheaper to just go aluminium on that one. Find an engineering shop that will cut the pieces and weld the tabs, job done. At least that is what I would do. Unless I wanted to turn it into a real project and didn’t need the part for at least a year or two!
Hope that helps some.
