Due to its minimal KNEX usage (55 pieces) i have decided to make 2, as i play my Uke in more that one place.
I imagine this will hold other small instruments but i have not tested this.
Step 1: Get your Parts
1 Way : 6
Orange Ladder : 2
Yellow 5 way: 6
3D 2x 4 way : 2
3D 2x 7 way : 4
3D 4 way + 7 way : 4
Green (16mm) : 10
White (32mm) : 4
Blue (54mm) : 5
Yellow (86mm) : 6
Red (128mm) : 4
+some form of spacer.
+optional padding (detailed in last step)
I used 55 knex pieces + padding
Step 2: Building the base
Step 3: Building the raised platform
Step 4: Join those parts!
Your main structure is now complete
Step 6: Coming along good now
At this point the Ukelele should be able to stand in the stand, but i find the back rest too flexible, The following steps will make it a bit more rigid.
Step 7: Extra rigid pieces
It should now hold your ukelele firmer
Step 8: Ukelele Comfort
On the side rails i have sewed some felt around them.
Where the ukelele touches on the front and back rests i have added some sticky backed felt pads, I have also put some on the base to make it softer and slightly grippier on floors.