Hey everyone. This is Matt from IC3D and I am going to explain to you the importance of proper first layer squish and how to achieve it.
First layer squish is the amount that the first layer of your print is pushed into the build plate. More squish will produce a flatter first layer that has more contact with the build plate, but less Z height. Less squish will produce lines that look like noodles.
In FDM printing, part warping and poor adhesion to the build plate, are problems that plague 3D printers.
I have found that setting a proper distance between the build plate and the nozzle remedies most of the warping problems that I have had.
You can often tell how well the build plate has been set by looking at the base of the part after it has been pulled from the build plate.
The shiny section shows places where the plastic has been pressed into the build plate. The rest of the first layer, is not contacting the top of the plate.
I try to make the majority of the base layer lines shiny, but I still want to be able to make out the different lines from each other.
Here are the results of under squish, shown on the left; over squish shown on the right; and a good amount of squish, shown in the center. You can see that the under squish is very warped and has separations between the strings of filament. The over squish is too flat and has raised ridges between the strings of filament.
There are also many machines out there that lack very flat build surfaces, which makes leveling properly impossible. Make sure that this is a huge consideration when purchasing a printer, as it will save you a lot of time and headache in the future with part warping.