3v motor gearbox housing

This is a first attempt at making a gearbox and is far from perfect. It's very noisy and not that smooth. I used parts I had lying around and the gears and motor were part of a kit I got from amazon.

Non Printed Parts:

• 1x 3v mini DC motor
• 1x 1 worm gear
• 3x spur gears around 20mm (outer diameter)
• 1x 2mm shaft cut to 19mm long
• 1x 2mm shaft around 30mm long
• 4x m3 x 10mm screws

Only the top spur gear needs to grip the shaft, with the other 2 spinning freely.