DC motor won't run - how to increase strength of coils?
There are a few obvious things to fix here:





Use better bearings!  That large diameter just rubbing against what looks like a plastic sleeve must have significant friction.  Cut the red pipe shorter and have something much thinner come out the ends.  Even a nail sticking out going into a nylon eyelet with a little bigger inner diameter than the nail should be lots better.  A drop of oil in each bearing would help too.

You should be able to give the shaft a quick twirl with a finger, and have it take a few seconds to coast to a stop.

You need field magnets.  A motor works due to magnetic forces between the rotor and the stator.  You have magnets on the rotor, and they seem to be commutated, but there is no magnetic field for these magnets to experience force against.

Since you are commutating the rotor, you only need fixed magnets for the stator.  Properly placed permanent magnets would work.

Make sure your rotor magnet arrangement makes sense.  This is a particularly poor picture because we can't see the rotor magnetic arrangement.  The simplest would be three electro-magnets spaced equally apart.  The picture looks like there are two at right angles.  That by itself is not a good strategy.  Perhaps the two you show are 120&deg; apart and a third one is hidden.  That would be OK, but again, your picture does not make that clear.

Make sure your commutation is correct.  Once you have proper stator magnets, you can check this by slowly rotating the shaft and feeling when the rotor tries to pull in what direction.