To get an add-on you need to add the total amount of the add-ons to your pledge

Click the blue button (Manage your Pledge) this will take you through to your pledge page for this kickstarter. On this page you will see both your pledge level chosen and also underneath this the amount you have. Change JUST the amount and then click the blue button to the right (Change your pledge). This will keep your pledge intact but also add funds for the add-ons.

Hi Dtoner

All our models are delivered as STL Files and are designed to be printed on a 3D Printer. Home 3D printers start about $300US.

I would go for a printer that has at least a 150 x 150 x 150 build volume and uses PLA filament

The best value for money printer at the moment is the Prusa i3 MK2 http://shop.prusa3d.com/en/3d-printers/59-original-prusa-i3-mk2-kit.html

Then you will need Filament, which is the plastic that the printer uses to make the models, It's about $25 per kilo

Once you have that, its a simple matter of downloading the files from our website and them printing them. Your printer will come with software that will allow you to scale the models and set the quality of the print before printing.

Our Help section on our site also has more information http://www.printablescenery.com/knowledgebase