5 Things to Check before 3D Printing
1. Build Plate Is Leveled and Cleaned
Leveling a build plate is extremely important as it can drastically affect the quality of your first layer. A leveled print surface can produce a print surface that is comparable to the top layer of a print and in the case of a glass build plate, a leveled build surface can result in a surface finish that is smooth and glossy. For higher end 3D printers, bed leveling is mostly done via some kind of sensor, most commonly a magnetic or a capacitive one. However, even with the sensor, there still has to be some kind of calibration when it comes to setting the distance between the nozzle and print bed, but once that is done, you are well on your way to producing a decent first layer. For lower cost 3D printers that comes without a bed leveling sensor, it will be necessary to check on all 4 corner points of the print bed and then subsequently checking on the centre of the print bed. In most situation, you’ll find the centre of the print bed slightly lower than the 4 corners. If that is the case, there are several things that you can print to support the middle section of the print. One such object is a wedge jack where you can slot it underneath the centre of the print bed and then adjust the height accordingly. You can find free designs of such wedge jacks for more popular printers like the CR-10 on Thingiverse.
2. Correct Print Settings
Especially in a 3D printing service bureau, where one operator is in charge of several prints, confusion with printing settings often happens as there can be many settings to check for each print model.
Checking the right temperature setting for the nozzle is set for the materials is always one of the most important setting to check. Using the temperature setting of PLA to print ABS can be catastrophic as it will cause the extruder unit to clog as the temperature used to melt PLA will not be enough to fully melt ABS. Next is the temperature of the print bed, if your 3D printer comes with a heated print bed. It would be recommended for most materials to employ the use of a heated bed. Materials like ABS will warp severely if the temperature of the heat bed is too low. Printing PLA with on a print bed with a temperature that is too high will cause the first few layers of PLA to soften and if the temperature is high enough, the PLA might even peel off or shift around the print bed.
- Correct Printer Settings
If you are printing using different printers with very different hardware, for example, print bed size and nozzle diameter, it is important to check this setting before you send your models over to the 3D printer. Printing with a nozzle diameter that is set too low will cause your printer to clog up as it is trying to extrude more than what it can handle. Printing with a nozzle diameter that is set too high will result in under extrusion. For print bed settings, not setting it right will cause your printer to print at the wrong position. The printer will also attempt to drive the extruder or the bed out of the print bed if the bed is set too large, and this will cause stress to your stepper motors and if it were to continue, your stepper motors might burn out.
- Resolution of the 3D Print
In most cases, getting the resolution of your 3D print wrong will not result in any permanent damages to your printer. However, it can cost you the quality of the print and unnecessary print time. Some materials might not be suitable for resolutions that are too high as well, like Nylon for example. It is encouraged for Nylon to be printed at the default resolution of 200 microns. Printing flexible filament like TPU or TPE at too low a resolution like 300 microns is also not recommended as they get stuck easily when the extruder tries to push out too much material at one go.
3. Color and Material of Filament is Correct
Checking the color of the filament is important. You do not want to print in the wrong filament color and having to reprint for the client again. It can be especially time consuming having to reprint a large print.
Getting the materials of the filament correct is especially crucial. Just like print settings, having the temperature settings wrong can be disastrous. Filament of different materials can be easily confused as most materials, when dyed, looks pretty much the same. It is therefore helpful to have some kind of label for spools of different materials. Most filament spools should already have sticker labels on the spool but in the event if the spool does not have a label, you can cut a piece of the packaging label and tape it down onto the spool. Most packagings will also contain information on the optimal printing temperature range.
4. Extruder Unit is Cleaned
The impact of a dirty nozzle or extruder unit might not show up immediately as dirts continues to accumulate at the extrusion point. When sufficient dirt gathers to form a partial or full clog, it might be too late to salvage as you are already halfway into the print. A partial clog can be hard to detect as it might not show up consistently on all 3D prints and if a partial clog is being ignored consistently, aggregation of materials might make its way up to the cold end of the extruder unit making it extremely hard to clean or sometimes rendering the entire extruder unit dysfunctional.
There are many way of cleaning an extruder unit. For both bowden and direct drive extruders, it helps by cleaning the drive gear first before making your way to the hot end. The drive gear can be easily cleaned using brushes with harder bristles or metal bristles. With the drive gear cleaned, you can then make your way down to the hot end of the extruder. Cleaning the hot end often involves 2 phases, cleaning it when it is heated and when it is at room temperature. Start by cleaning it when it is at room temperature by using a brush with hard bristles. Brush the exposed surface area of the heating block and the vicinity of the nozzle. When most of the dirt or particles are brushed off, you can proceed on with heating up the hot end. To remove the rest of the particles and dirt on the exposed area of the hot end, simply heat it to around 160℃ – 180℃ and repeat the same brushing steps but taking note that your brush is made with metal bristles this time. This should be able to remove all of the dirt and particles that are on the exposed area of the hot end. Next, depending on the type of plastic that is most commonly use on the particular printer, heat the nozzle up to the corresponding temperature that is use to print that particular type of plastic. When the nozzle is at the heated temperature, use a wire that has the diameter as the nozzle size and insert it into the nozzle. Repeat the motion of pushing and pulling until the wire feels smooth when it is being inserted into the nozzle. Finishing this step should get your extruder unit cleaned and ready for the next 3D print.
5. Adequate Amount of Bed Adhesion
Most FDM 3D printers comes with a heated bed nowadays as it helps greatly with print adhesion. However, there are still times when the 3D prints has too little contact surface with the bed surface or when the prints contains many sharp corners that might not stick as well to the print bed. This is often a problem that, if not checked before 3D printing, will only see its consequence later in the print. It is important to go to the preview of your slicing and examine the first layer for sharp corners or minimal contact surface. If either one is present, then it is important to apply aid for bed adhesion. If your first layer shows sharp corners, it helps to apply some glue stick to the area where the corners would be. This will help to prevent the peeling effect experienced when 3D printing with most materials. When 3D printing a model that has little contact area with the print bed, it is important to apply a thin layer of glue stick over the printed area as this will prevent the print from lifting off the surface. When printing with ABS, the above steps would still apply but instead of glue stick, you have to replace it with ABS juice.