If you have ever tried to print a model with a very shallow angle, you may have encountered the problem of holes in the top of your print. This can happen when the printer tries to bridge a large gap with very little support from below. The filament may sag or curl up, creating gaps or bumps on the surface.

There are a few ways to overcome this problem and get a smooth and solid top layer for your 3D print. Here are some tips that you can try:

• Increase the number of top layers. By adding more layers on top of each other, you can fill in the gaps and create a thicker and stronger surface. You can adjust this setting in your slicer software, usually under infill or shell options.
• Increase the infill density. By increasing the amount of material inside your model, you can provide more support for the top layer and prevent it from sagging. You can also adjust this setting in your slicer software, usually under infill options.
• Increase the print temperature. By increasing the temperature of your nozzle, you can make the filament more fluid and easier to bridge gaps. However, be careful not to increase it too much, as it may cause other problems such as stringing or oozing.
• Decrease the print speed. By decreasing the speed of your printer, you can give more time for the filament to cool down and solidify before moving to the next position. This can reduce sagging and curling and improve the quality of your print.
• Use a cooling fan. By using a cooling fan, you can blow air on the filament as it comes out of the nozzle and help it cool down faster and retain its shape. This can also reduce sagging and curling and improve the quality of your print.
• Rotate or tilt your model. By rotating or tilting your model, you can change the angle of the surface and make it less shallow. This can reduce the amount of bridging required and make it easier for your printer to handle.