pet weelchair

this is a dog wheel chair made to be parametric
for dog from 10 to 30 kg
wheels bought here:
http://www.ebay.it/itm/251338195142?euid=318afdcc582d4caab1ffe8766c368240&bu=43147744162&cp=1&sojTags=bu=bu

and aluminium ( 20x10 mm ) from hobby shop