renatoa wrote: you can use a drinks shaker for such job,

Thanks for the input. The issue with drink shaker is the size (diameter). If it's small, not enough air volume can be moved thus making it inadequate for the roaster. My second choice before building the latest one was this pancake batter funnel which has 5 inch (12.7 cm) diameter at the top. It may work for 400g roaster but I wanted something bigger so I ended up with 7.5 inch (19.05 cm) diameter.