Layering thickness

How do you know if the first layer is the correct height and the following layers are the correct heights. Is there any document that show what a first layer bead should look like, how thick and how tall it should be. When you extrude some filament should it be one long straight string or is it ok if it curles up. What should you look for in a print to determine how fast you can print, how hot the extruder should be, how hot the bed should be. I,m getting some blobs in printing some of my part, should this be expected. How do I know if my extruder is too low, it prints OK, just not sure if it is the best it can be

 

As a general rule, if the 1st layer is sticking...I dont mess with it It may be a little high or low for what some would call "perfect," but so long as the print sticks the 1st layer height makes no real difference. I personally prefer a lower more squished layer over a too high layer because a layer with less than good adhesion to the bed may let the print loosen an hour into the print.

The filament curling will depending on a lot of things like temperature, but curling is normal and makes no difference since your laying it down a fraction of a mm past the head anyway.

You really need to play with temperatures for your particular printer and filament. There are too many variables to be able to tell you what the perfect temperature should be, but a little online googling will give you some basic information on what many consider good 1st layers and what small defects are caused by too hot or too cool, too fast too slow...but its a lot like a recipe, changing one thing may necessitate changing other variables too. You may need to print hotter if you printer faster, you may need to print slower with some filament than others.

I can only say that if you have a good sticking 1st layer, you are 95% of the way there.

 

Thanks for the feed back.