my post rather informative...
since all gear made of nylon, or some similar plastic on this lathe, i think aluminum is suitable... i was thinking to cut of corian...
also the sdpi website has ready gears, but those only 6mm thick and this lathe has 8 mm thick gears...

thank you for link, in the recent days i discovered many similar site... i found one item i might buy that is the longer bed... theirs longer by 4 inch...

the gear, i felt no comfortable with the 21... still it is just a very substitutive solution... very possible i have to shift for a larger lathe, which ones are has better solution like this mini lathe...