3d Printing, Making

3d Printing – working with PLA and making the first layer stick

Printing with PLA is pretty easy (or at least it’s supposed to be) – apparently it’s even possible to print on a cold printer bed. It’s easy for experienced users of 3d printers – but for beginners, there’s a big learning curve where everything is hard before it is easy.

Printing the first layer

The big thing everyone struggles with is trying to get the first layer to correctly stick to the print bed. I found that 185C was the best temperature for the printer hot-end.

Painter’s tape

One technique commonly recommended is to stick a layer of painter’s tape on the print bed. (I used masking tape – this is slightly different but it’s cheap and widely available.) This makes it easier for the molten PLA to stick to the slightly rough surface.

I found this technique to be ok for small prints – for example, for objects that are a few cm wide. But for objects bigger than that, I found it either didn’t stick well, or it warped.

Also, I need to change the tape after every one or two prints.

Heated bed at 60C

Using the heated bed helped a lot to reduce warping for larger pieces – but I still found that once the height of the piece got above 10mm or so, the part still warped away from the heated bed.

10mm Brim

A brim is an extra band of plastic which is printed around the bottom layer of the object being printed. (It’s called a brim because it looks like the brim around a hat.) The reason for printing this extra band is to increase the amount of surface area in contact with the bed, and therefore increase how well it’s attached to the bed.

Sheet of glass clipped to the heated bed

A lot of people find that this helps with PLA adhesion – I didn’t find that it helped or hindered me that much. However, it was useful to have something which was easy to clean and remove from the heated bed.

BuildTak Print Surface

I bought some BuildTak adhesive surface from Amazon and attached it to my glass plate. My experience is that the first layer sticks unbelieveably well to this. One thing that caught me out on the first print was that my print head was too close to the bed (despite warnings on the packet that it was better to start too far away and lower the head). The printed part stuck much better than expected, and basically I really struggled to detach it after the print finished. The solution was to put the part (still attached to the glass) in the freezer for 15 minutes, and because of the different rates of contraction of glass and PLA, this made it pretty easy to remove the printed part.

Summary

Printing with PLA is easier once you have some experience of working with 3d printers, but for a beginner it can still be difficult. I found useful ways of making the first layer to stick are:

  • BuildTak surface;
  • Heated bed at 60C;
  • 10mm brim around the printed object.