Hi all, I am pretty new to 3d but even more new to MoI.

I have some questions about boleans. For a test i tried to create a car-tyre with the profiles cut out of the tyre as geometry.

Let's say that i wanted to creat a tyre like the picture below.
I made the following steps:

1 I created a half tire wich I can mirror when it's done.
2 I created the profiles of the tyre as geometry wich i want to cut out of the tyre with a bolean command. (i think i have to use the merge command here so I can cut out the outer profiles and keep the inner profiles in the tyre)
3 I try the bolean command and it doesn't work. When i select one little profile piece and the base tyre it works for some of the object. But i think it's strange that for other objects it doesn't works.

My questions:
Q1: Is it possible to merge a bunch of objects (the little profile pieces Let's say 40 of them) with one base object (the base tyre geometry) by using one time a bolean command ?
Q2: When try to bolean 1 object at the time from the base tyre it works for some of the object but for other objects wich are basically identical only located on an other place on the tyre it doesn't work.
Q3: Should I use the merge command ? because the differance command will cut a hole and ik want to keep the profiles on the inside of the tyre.
Q4: When i try to union or join theprofile pieces it doens't works

THNX in advance
PS: Sorry for my bad english, I tried to explain myself the best I can, but it is a little hard for me in English.