DanBog

This is a great idea, I actually have a longer piece of OSB that I can use for this, it'll also help me drill at the same distance for all my shelves.

My walls are made of concrete and AAC. Until now, I never really needed much precision. However, my holes are never parallel or straight. I’ve got some floating shelves that I need to attach. I figured I’d put together a jig like this guy from YouTube (though upon rewatching, I noticed he’s only using glue). As I was trying to drill through these boards, I realized that I’m not very good at measuring accurately through wood also. I feel a bit overwhelmed by this. It can’t be that hard; many people do it. Now, I’m just sitting here, looking at the shelves and waiting for ideas on how to install them without them being crooked.

Thank you all, I should have indeed used another type of bearing, will know better in the future. I placed two of mine back to back and it's... decent, still drops a little but maybe because they're cheap Chinese bearings £5 each. Another issue is that some of the wooden joints have started to squeak, and I’m not sure what to do about it. It’s hard for me to identify the exact location and reason for the squeaking. I probably need to take it all apart and apply some silicone to the joints, but I'm tolerating it for now. Yes, the cats use the wheel for walking. They don’t run on it because once it gets going, it’s difficult to stop. I guess they don’t like the idea of having to anchor themselves for their lives.

I was looking at this 'tutorial' but I don't understand how they did it https://imgur.com/gallery/4UqgBA5#EP1nn5Z

*I apologize in advance for the way I write because English is not my first language I've got a UCF 205 bearing on the wall identical to the one you see on the outside wheel. Since this is a DIY project and I don't know anything about bearings (and apparently the shops in my area also don't) I realized late they are unusable because they allow a play/slack/clearance, like mixing in a pot, they're built so that the shaft is sustained on both sides and that keeps it horizontal. Not in my case, as the wheel is so crooked that it scrapes the back wall. I am at my wits' end after in the building process I cut a piece of my finger and had to get it sewed back on. I had a talk with an online store that tried to sell me the same bearing claiming it's fixed. And today I went and talked to all 3 shops that sell bearings and one of them tried to sell me a bearing for x4 the price claiming mine has that play because it's made in China. The other stores said there are no fixed bearings of this type. An ugly solution is to get two more and place them back to back, but now my conexpands are too short to pass through two such bearing and I need longer ones and to drill in another place, only to make everything uglier and heavier. I am taking a break from this project for a few days to avoid a stroke, but I welcome any helpful ideas you might have to finish this.