Printing in PLA on my Makerbot Replicator 2 with a raft is pretty reliable. There are a few problems with this though:
- I waste extra filament on the material to print the raft.
- Printing the raft gobbles up a lot of extra time for the print.
- Getting the model detached from the raft can be really tough (this is the biggest problem by far).
So printing without a raft can be a good thing! The problem is getting the first layer to stick! Here are a few tips I have found helpful at this time:
- Put a nice even layer of blue painter’s tape on the build plate.
- Make sure you properly level the build plate.
- Sand the surface of the blue painter’s tape with sandpaper.
- Wipe down the surface of the blue painter’s tape with rubbing alcohol (this was important, before I did this parts of the print would not stick).
- Set the printer’s print speed way down (notice how it prints the first layer of the raft real slow — 30mm per second). — note due to improvements in Makerbot’s software, this step is no longer needed.
This did it for me.
Of course setting the print speed real slow causes the print to take a whole lot longer. I wish Makerbot would change their Makerware software so that if you printed without a raft it would automatically print the first two layers really slow then print the remaining layers at the speed set by the user in Makerware.