Max gets 1+2=<<1+2=3>>3 trains per year.
He repeats this for 5 years, meaning he gets 5*3 =<<5*3=15>>15 trains.
When this number is doubled by his parents, it becomes 15*2= <<15*2=30>>30 trains.
Since he already had 15 model trains, his total becomes 15+30= <<15+30=45>>45 trains.
#### 45