3D Printing

I recently bought myself a reprap prusa i3 3d printer from a company called hictop. This was a build it yourself kit and the assembly process was needless to say interesting, the instructions were incredibly useful and detailed. However it lacked detailed English instructions and as such often during assembly I placed parts in the wrong origination. Overall the build process was very success and I managed to get a print out on my first test.

I soon found that the build plate is a tricky thing, as getting the first couple of layers of a print to stick to the bed is not easy. However I tried the following technics until I found something that worked for me:

  1. Brushed the build plate down with sanding paper to add imperfections in the metal, this is meant to help plastic stick, However it made little to no difference.
  2. Changed the heat bed temperature to find the bed sticking temperature, I found around 55c is pretty good, But still most prints would fail.
  3. Used hair spray, found this to be amazing at making the prints stick, however it leaves a messy residue on the bed and needs reapplying every print.
  4. Tried applying normal masking tape to the bed, though this works well I was still seeing a lot of failures.
  5. Switched to painters tape, which is a blue coloured version of masking tape with a slightly different surface which really helps the plastic stick. However I found that if the temperature of the heat bed is too high the tape gets smaller and smaller during prints which means you constantly need to reapply. As such I experimented and recommended having the bed temperature between 35-45c. However I was still experiencing 1 in 4 prints slipping on the bed causing failure.
  6.  Finally settled on a combination of using painters tape on the bed and spraying the tape lightly with hair spray before each print. I found this helps the plastic stick as well as providing the tape will a small protective layer, meaning the tape lasts twice as long.

In additional to the above I tried experimenting with supports, which is adding additional plastic supports to the first few layer to ensure the print does not come lose a slip later on. There are two common types of support. A brim, which adds a small layer around model, giving it more surface area to stick to. This is easily removed by cutting of the excess material after a print. The second is a raft, which as the name suggests prints a platform underneath the print area, which is easy removed afterwards by slowly pulling it off the bottom. However I did find with rafts, if the printer is not calibrated properly the model may get very stuck to the rift and become impossible to remove. Both supports are useful but they add time to print, I personally prefer rafts however I have opted to only use these technics when having problems printing a specific model.

One thing that was bugging about the printer was that filament was scrapping on the top of the printer, sometimes causing it to break. I thought this would be a good starting point for learning a little 3d design, I had used autocad before but I really hate designing things in 2d space and would prefer manipulating objects in 3d. I stumbled across an online 3d editor called tinkercad made by autodesk, this allows you to work in 3d and export directly for printing. I quickly put together a clip that would attach to the 8mm pole of my printer.

2015-12-19 16.34.55 2015-12-19 16.35.02

I’ve uploaded my design to thingiverse http://www.thingiverse.com/thing:1212083

I hope my experience with the hictop prusa i3 helps someone 🙂

 

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