Ok so I added holes on the arms for the shelf boards to slide into like how there is on the bottom of the main part. I also deepend the holes that were on the main part for the shelf boards because I realized that theres was nothing to hold them in place from behind and it would’ve been really unstable.
To add extra stability I also added a “spike” on the arm to keep it steady horizontally and so that it wiggles around less and added another hole on the main part to acccomodate for this.
And then finally I made this thing attached in the picture I don’t know what to call it but its purpose is to keep the arms in place so I guess its function is sort of like a screw. This part alone doesn’t do anything by itself, I’m gonna make another part that you put inside of this part and then twist to create that joint which hopefully won’t come apart easily. And yeah thats pretty much it.