Archive for the ‘Tips and Tricks’ Category

smooth-on-xtc-3d-coating

One of the drawbacks of the FDM (FFF) 3D printing method is that the result of your printing is a model that is not totally smooth to the touch, you can see and feel the texture created by the layer by layer printing by extruding the thermoplastic material. The smaller the layer size the less noticeable the texture of the printed 3D model is, but it is till there and some people just want to get a smoother glossy or matte object as a result of their 3D printing. There are multiple solutions for smoothing the surface of your ABS or PLA 3D prints to make them look even better as a final product and not seem so much like they were actually 3D printed. The most commonly used approach seems to be the use of various solvents that can help you get a smoother look of the surface of different 3D prints, but you need to be careful with these as solvents might be dangerous to your health and if not properly handled you can also damage your 3D printed models.

One of the most commonly used methods for smoothing the surface of 3D prints made with ABS material is to use Acetone as it melts the ABS plastic and creates a smoother and glossy looking surface. The there are various ways for the application of Acetone for smoothing ABS prints that may produce varying results, so you might want ot try them all and experiment to see what works best for you and gives you the best results. Some people dip the model in acetone, some apply it on the model with a brush and some use Acetone vapors to melt the ABS plastic and give it a smoother finish. Regardless of what you use however you should be careful with Acetone and try to avoid inhaling and also be careful as Acetone is highly flammable. Another alternative to Acetone that might give you the same results for smoothing ABS prints is Methyl ethyl ketone (MEK), also known as Butanone, as some people report successfully using this instead of Acetone. Do note that Acetone and MEK do not seem to work well with PLA filaments like they do with ABS, so do not try them for smoothing PLA 3D prints!

For smoothing the surface of PLA 3D printed objects it seems that so far the best working solvent providing similar effect to Acetone for ABS is Tetrahydrofuran (THF). THF not only works for PLA like Acetone does for ABS, but it also smells similar and might be as dangerous as Acetone to your health if you do not properly handle it, so you should be extra careful when working with any of the solvents mentioned here. It is a wise idea to wear gloves and work in well ventilated area, so you will not be inhaling the fumes of the solvent you are working with, also be very careful when handling any of the mentioned solvents – Acetone, MEK or THF as they are all very flammable. Do note that Acetone is the easiest and most widely available solvent of the mentioned ones and you may have trouble finding or obtaining any of the others mentioned, so do check locally if they are easily accessible.

Another safer for handling alternative that is supposed to work with both ABS and PLA 3D print (as well as many others) is a special product dubbed as high performance 3D print coating called XTC-3D from Smooth-On. It has been getting some attention lately among the 3D printing community, though people are reporting mixed results after trying it out. The product is essentially an epoxy coating consisting of two liquids that are mixed together and then brushed onto any 3D print, the coating is supposed to self-level and wet out uniformly without leaving brush strokes. Working time is 10 minutes and cure time is about 4 hours and after that the XTC-3D should have cured to a hard, impact resistant coating that can be sanded, primed and painted. The problem with the Smooth-On XTC-3D is that it is not widely available, might be easier to obtain in US, but we could not find it available anywhere in Europe or a place to order it from that will deliver here, so that could be a serious problem. Other alternatives include priming and sanding the model and then maybe painting it or painting with PlastiDip rubber like coating directly.

pcb-build-plate-abs-printing

A few days ago we’ve tried using a perfboard build plate for ABS trick and we got very good results. Since then we have done some more experiments and cans hare our experience based on our printing efforts using ABS filaments over a piece of perfboard. We have created and printed a build plate base that was designed to house the perfboard we use for testing ABS 3D prints with in order to make it easier to swap the PCB build plate with the glass build plate we use for printing PLA. The idea was to have the two at the same height, so there will be no need to do a leveling adjustment when changing the build plates. This however was not too successful as the perfrboard build plate does need slight readjustment of the distance between the nozzle and the PCB for good prints.

abs-warped-vs-pcb-printed-non-warped

Finding the perfect level is still a bit of an issue, so the first two or three layers that we get printed of the object over the raft we use are not perfect, but there is still no warping. We even tried printing some PLA objects on the perfboard build plate and they worked just fine, so once you have the perfboard build plate installed and the extruder properly leveled for it you should be able to print with various materials, though with PLA filament it might be a bit harder to remove the raft from the perfboard. The only problem with the perfboard is finding a large enough PCB for prototyping with holes to cover the whole build plate that your 3D printer has. We are going to continue playing with the perfboard trick for printing ABS as we do have some more interesting ABS-based filaments to test printing with, though we do still prefer to work with PLA most of the time, unless there is something specific that ABS is better for.

abs-perfboard-printing

3D printing using ABS filament does have some specific requirements for the printing device, the most important of which is to have a heated buиld platform in order to prevent the printed part from warping up and to have it stick well to the base. Unfortunately not everyone has a printer that is capable of using ABS thermoplastic materials for printing as is also the case with us and our MakerBot Replicator 2 3D printer that is designed to support only PLA printing officially. That is precisely why we were looking for various things that may allow us to print using ABS filaments without the need to add a heated build platform to our Replicator 2 and we might have found a good workaround. We have stumbled across this idea and have decided to try it out – printing on a prototyping perfboard used for generic electrical projects. So we have found out some different perfboards and bought them to try out printing with ABS on them and our initial tests have produced very good results as you can see on the photo above. With that however there are a few catches that you should be aware of if deciding to try out this workaround, the important thing is that it works however.

abs-perfboard-printing-2

The trick that prevents the warping of the prints using this method are the holes of the perfboard where some of the filament gets in and thus, you need to print the models with a Raft however to get good prints that stick to the build plate. Do note that this solution has some drawbacks and other inconveniences that we’ve discovered while trying things out. First we had trouble finding big enough perfboards to cover our full build platform, so we have settled with the biggest ones we could find, but thiс means a more limited size for the prints using ABS. When we got the perfboards it has turned out that they are not perfectly flat and that can cause issues while printing, so we’ve used the flattest one to get better results. After inserting the perfboard on the build plate you will need to do a level adjustment as it will add something between 1 and 2 millimeters on top of the level you normally would use for the standard build plate oф the printer. You need to attach the perfboard well to the buиld plate so that it will not move during printing, but at the same time will still be easy to be removed when you need to get hte printed part off it and then you would need to clean the holes of the perfboard from the remaining material. The cleaning part is very important as the holes do the trick and if they are not cleaned after a print you may start getting the prints warping again, you can use a paperclip to easily remove the remaining ABS material. We are still playing with the ABS printing on perfboard, but things are really looking promising on the Replicator 2 based on the results we are getting, so stay tuned for more information based on our experience.


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