Even though Tinkercad was shutting down I decided to finish out the Jerry Can model and then move on to some other tool. Printing with a Shapeways or Sculpteo service is different than printing with a desktop 3D printer one might find in a home. The printing process is completely different in the ways that it creates the models and, in general, the materials it uses to print a model in. Most home printers use ABS and or PLA to print their models. The print head goes around and around to lay down each layer of the plastic to slowly build up a model. These printers have somewhat predictable results.
The printing services use a powder and that is fused with a laswer to create their models. When you create a model to be printed you have to keep these things in mind. You can’t create a model for Shapeways and then print it on your home printer. You can create a model at home and expect it to work with Shapeways. Why is that? When you create a model to be printed on a Makerbot or something similar you have to create support structures and or orient the model so that it is supported while it is being printed.
At Shapeways there is a big box of powder that your model is formed in. These models always have complete support during the printing process. At the end they simply blow away all of the excess powder that wasn’t touched by the laser.
The software that comes with a Makerbot will assist you in creating a hollow model with a structure to support the walls or other parts. This is a great way to conserve materials. Shapeways prints the model you send it. If it isn’t hollow already then they don’t make it hollow for you. This is a very important point to consider when using the services vs. using a home printer.
For example: The NATO Jerry Can model wasn’t hollow initially. It wasn’t overly pricey but I knew it was too high for that small of an item to be attractive to a potential buyer. I decided to try to make the NATO Jerry Can hollow and see if it had any reall effect on the price of the printed model.
I started with trying to figure out where to put a hole and how to make the model hollow. If you remember, I am still using Tinkercad at this point. I had to copy and paste the body into itself, make it smaller, and delete it. This left a cavity of roughly the same shape as the can body. I made a hole on the bottom of the model and planned to include a plug to close the hole. This seemed like a good idea but I felt it wasn’t exactly what I should do.
I then realized that I had the filler/pour cap on the top of the can that I could separate from the main body and turn into a plug.
After that was a success I had to make a structure inside the can to support the walls. The method to saving money on these models is to use as little material as possible while keeping your model stable and looking correct. Shapeways has minimum values for wall thicknesses which you have to meet before they will print a model. This is a great thing because they kind of have a build-in system that helps avoide bad prints. Of course they can’t do anything about a bad model design.
I elected to go with a simple perpendicular oval structure that would support four sides of the Nato Jerry Can.
This accomplished what I needed to do so I could now see if it made any real change to the pricing. After I updated my model on Shapeways I was shocked to find out that I had cut my cost to print by 60%!!!! That was massive difference for just making the model hollow! This would set me on the right path for future models to save as much money and material as possible without sacrificing the model structure or quality.
It is a good practice to print your models before selling them. You can work out any defects or issues you might have BEFORE a customer buys it. This was the first test print:
I was very pleased with the result. I found out that my dimensions were a little off so I had to widen my model and that test print was just as good as the first one and correct. I could now move on to more models and prints. But first, I still need to find a new tool to work with!
You can see the NATO 20L Jerry Can 1/10 Scale model on Shapeways.