After making sure the bed is level, adjusting the height of the first layer is the next step. To do this, place the nozzle over the center of the heated bed. Slowly lower the nozzle at 1mm increments until the nozzle lightly touches the glass. If the Z axis microswitch did not activate, raise the nozzle up and turn the height adjustment screw clockwise 1/4 turn. Now lower the nozzle again and repeat the process as necessary until the space between the nozzle and the glass is approximately the thickness of two pieces of paper. Do not become overly concerned with the height, just make sure that the nozzle DOES NOT hit the glass when it homes on the Z axis. After making your first print, you can adjust the height adjustment screw to dial in the perfect first layer thickness. Also keep in mind that the thickness of glass may vary from piece to piece, so it may be necessary to adjust height for different pieces of glass.
Getting Parts to Stick
Getting proper stick is a function of the following factors: 1) correct first layer height; 2) sufficient heat; and 3) properly preparing the surface.
Before going any further make sure the bed is level and the left/right adjustment is correct.
After leveling the bed, make sure the first layer is going down properly. In Slic3r, make sure that you are using at least two loops to go around the part (essentially to prime the hot end) and run the first layer at a slower speed than the remainder of the part (between 50-80%). Once printing, look closely at how the first layer goes down. The thickness of the first layer should be somewhere between a flat surface and a tube. Maybe the best way to describe it is as a pancake. If the bed is level, the thickness of the first layer should be consistent throughout the first layer. Another trick in the latest version of Slic3r is to increase the first layer percentage (to say 200%). Finally, on large parts specifying a "brim" (through Slic3r) also tends to prevent lift-off.
Heat is also an important factor. Too little heat and the parts will NOT stick, no matter what you do (for ABS). Too much heat, and the parts will stick well, but the sidewalls will have an hourglass shape (from heat warping). The heated bed is hardwired to the power supply. At 12 volts, the bed will get to about 110 degrees C. This value can be manipulated by adjusting the voltage on the power supply (be careful). The more voltage, the higher the temperature, the less voltage, the lower the temperature.
Finally, you must make sure that the surface is prepped. ABS will not stick to glass. The best solution we have found is to coat the glass with PET tape (or Kapton tape). When printing, make sure that the PET surface is facing up. Also, we have found that applying a thin layer of a mixture of ABS and acetone to the surface will further increase grip. Mix the ABS into the acetone so that the liquid appears cloudy. Too little ABS and the solution will not increase stick, too much ABS, and the parts will not come off.
Some will say that ABS should be printed at 220 C, some at 230 C. However, there is no simple answer. The best temperature to extrude will vary from manufacturer to manufacturer. Even then, different colors may have different ideal temperature settings. Generally, the hotter you extrude the filament, the stronger the part becomes. However, when you go too hot, you notice that the filament starts to get stringy and may start to smell pungent. You may also notice some bubbling. We build our parts at 240 C, with the exception of a few materials. While we can make the same parts at 220 C, the strength will be decreased. Any higher temp, and the stringing and smell would be unbearable. Bottom line-if you start to smell your print (other than the occasional fume), it's too hot.
Leveling the Bed
One of the common preconceptions about reprap-style printers is that they are a nightmare to setup. With AW3D, we have attempted to change all that. Follow these simple instructions, and in 5 minutes you will be set. As long as you don't move the machine around too much, these settings should remain and the bed should not need to be re-leveled. We regularly transport our printers and rarely have to re-calibrate them.
First, run the circle calibration file. If your bed is not leveled, you will notice that the circle has high and low points and that some parts of the circle stick to the glass and some do not (make sure you are printing on PET or Kapton-coated glass misted with a mixture of ABS and acetone).
If the left side of the circle is low and the right side is high, or vice versa, the left/right adjustment will be your first adjustment. For this adjustment, hold one of the flexible Z couplers and turn the other (they tend to rotate together because of the magnetic connection). Turning a coupler clockwise, will raise the hot end, while turning the coupler counterclockwise, will lower the hot end. Once you have made the adjustment, run the circle calibration again to see the results. Repeat until the left and right side print heights are the same (within reason).
Once the left/right adjustment is completed, you should adjust the finer adjustments located directly on the bed. As background, the PCB bed is connected to an upper rectangular aluminum frame which is connected to a lower aluminum supporting frame (that holds the lm8uu bearings and supports movement on the y axis). The upper frame is coupled to the lower frame with three bolts (for leveling, a fourth bolt would be redundant and only drive you crazy). The rearmost bolt is fixed (or "pinned"), so the only adjustments are the two spring-loaded bolts at the front left and right of the upper frame. Because the bolts are fixed at their bases, the only adjustment needed is to the top nut on either. By turning the but in (1/4 turn at a time), you will notice that the plate lowers on that corner and raises on the opposing diagonal corner. Adjust the nuts and reprint as necessary until getting an optimum circle. Remember, to adjust overall height, adjust the allen bolts on the left X bracket.
Generally, printing at finer layer heights brings more details out of the 3D model. For example, if you have a complex shape such as an animal, you will see much more detail when using a .1mm layer height as you would with a .4mm layer height (4 times the detail on the Z axis). Things such as the eyes, ears, and feet, will be much more detailed along the z axis with the finer layer height. Remember however, that the finer you go on layer height, the better leveled the bed must be (new versions of Slic3r help compensate by allowing you to lay down more plastic on the first layer).
Before changing all your print heights however, there are several factors to consider. First, the general rule is that the maximum layer height for a given nozzle is 80% of the nozzle diameter. Therefore, with a .5mm nozzle (standard on AW3D v.5), your maximum layer height would be .4mm. Indeed, we print out the Gen6 cover at .4mm. The other parts however are printed out at finer layer heights, going down to .15mm for the herringbone gears (to pull out the resolution on the herringbone pattern on the Z axis).
Another consideration is print speed. With finer layer heights, each layer will take the same speed, however, there will be more layers for smaller layer heights. A .1mm layer height part will take 4 times a long to print as the same part printed out at .4mm.
Finally, when you go too fine on the layer height, the extrusion may simply be too slow to get accurate feed through the hot end. On the .5mm nozzle, the minimum layer height should be .1mm to achieve optimal results.
Getting the Best Prints
The key to getting the best prints is mastering your slicing software. Programs such as Slic3r convert your STL file into gcode. In Slic3r, you can change numerous parameters to achieve perfect printing. Customers are sometimes shocked that a piece that was previously virtually unprintable now comes out perfectly with only a few tweaks to Slic3r. The printer is very, very accurate, it is just a matter of giving it the proper inputs.
A good place to start is with relatively small prints. That way, you can quickly tell if all of your settings are correct. Start with a part that is approximately 2-4 inches in diameter that preferably does not need support. Open the Slic3r configuration provided with your printer that is labeled "Slow Parts" (or the equivalent). Slice the part with this configuration and then observe the print. If the part printed out great, there is no need to tweak, unless you want to change some of the parameters slightly to get a faster prints. Some things to keep in mind are as follows:
Speed - the slower you print, the less room for error. This does not necessarily mean error in the accuracy of the machine however. What we are talking about is error in the filament. Specifically, if you specify a slow speed for the perimeters (to get nice outer surface), but try to cheat a bit by specifying high fill speeds, the results are sometimes quite disturbing. You tend to see blobs in different parts of the print corresponding to location of the nozzle right after passing from a fill section to a perimeter. This happens because pressure builds up in the hot end during the high speed infill. When moving to a slower perimeter, that pressure spikes and you will see blobs corresponding to the spikes. To minimize this problem, be conservative in the differences between your infill and perimeter speeds.
Cooling - perhaps the greatest feature in Slic3r is to be able to control the speed of the print though the "Cooling" function. Specifically, if you were going to print out an object with an hourglass cross-section such as a trophy, without cooling your results would be disastrous. The problem is in the filament and the time it takes for the plastic to cool between layers. While the base of your trophy may print out well, when you approached the thin cross-section of the center portion, the plastic would not "set" before the next layer was printed. When the plastic "sets," it is cooling and decreasing in volume. If the plastic does not have time to shrink back down, the next layer will print into the soft underlayer and create a big mess. Things will not straighten out until the layer speed correlates to the time it take for the plastic to set. This is where "Cooling" comes into play. With cooling, you can specify a minimum layer time. We use 15 seconds and a minimum speed of 1mm/s to be safe. In application, now when the printer approaches the center section of the trophy, Slic3r will have altered the gcode to slow down the print speed such that the layer is printed in no less than 15 seconds. When the prints gets higher, you will notice that the print will start to speed up again once the area to print becomes larger.
On the Y axis, move the plate all the way to the back of the machine so that it contacts the y axis microswitch. Now, flick the y axis belt. You should hear a deep, chello-type frequency. If the belt is too loose, loosen the 13mm nuts that hold the threaded rod on the front of the machine. You should loosen a total of four nuts: two on the outermost ends of the rod, and one each on the supports that hold the smooth rods. With the nuts loosened, slide the threaded rod back and tighten the four nuts. Now recheck the tension on the belt and repeat if necessary.
On the X axis, move the X carriage all the way to the left of the machine so that it contacts the x axis microswitch. Now, flick the x axis belt. Like the y axis adjustment, you should hear a deep, chello-type frequency. If the belt is too loose, loosen the 13mm nut and bolt on the right X bracket of the machine. With the adjuster loosened, slide the adjuster to tighten the belt and tighten the adjuster (don't over tighten). Now recheck the tension on the belt and repeat if necessary.
Getting Started With Airwolf 3D Printer Slic3r Configurations
Here is your Airwolf 3D Printer Quick Guide to Slic3r Configurations
What is a Config?
Slicing can be a little daunting at first and it is easy to get lost in the world of Slic3r settings! For your convenience we have included several configuration files for Slic3r 7.2b to get you started with your 3D printer. Version 7.2b is stable and very user friendly-the newer versions tend to perform better, but are best left to later, once you have mastered the basics. A Slic3r configuration file is also called a "config" file and is a 3d printer profile that you can load and it will automatically populate all of the settings in Slic3r. This type of file has an ".ini" extension. Please refer to the easy to read chart at the end of your 3d printer user manual entitled "3D Printer Slic3r Configurations". If you look at this chart of parts, you will see that the parts are individually identified and then grouped together by "plate". They are grouped as such because certain parts have similar optimal 3D print settings. For example, some parts can be 3D printed very fast such as parts with many straight lines and without many complex curvatures (plate 5), while other parts should be printed very slow to reach higher resolution, such as the gears.
Selecting the Right 3D Printer Slic3r Configurations
If you take a look at the folders in your flash drive, you will find the following folder: STL GCODE SLIC3R CONFIG\Slic3r Config
As of 01/21/13, the configuration files are as follows:
Gearset .25mm .5 nozzle - Setting to slice "Wolf Plate 4" which is comprised of mostly gears. These parts need to be super strong and very solid. This configuration file calls for .25mm layer heights, at a slow speed with a nearly solid (85%) infill.
Gen6 Cover .4mm .5 nozzle - Setting to slice "Wolf Plate 5" which is comprised of the cover for the circuit board on your 3D printer. This is a setting for fast, non organic parts without too much fine detail that can be 3D printed with a thicker (.4mm) layer height.Gearset .25mm .5 nozzle - Setting to slice "Wolf Plate 4" which is comprised of mostly gears. These parts need to be super strong and very solid. This configuration file calls for .25mm layer heights, at a slow speed with a nearly solid (85%) infill.
Slow Parts .25mm .5 nozzle - Setting to slice smaller parts at a .25mm layer height. Slower than above, but fast enough to 3D print out decent-sized parts at a good pace.
Standard .25mm .5 no - Setting to slice "Wolf Plates 1,2,3" which is comprised of most of the parts on the 3d printer. This is a workhorse setting for quickly processing several objects at once at 35% fill. We have recently started using a higher fill percentage (50%) for even stronger parts. Only use this setting once you have mastered printing and are comfortable that the bed is level and the first layer height is correct.
Very Precise .2mm .5 nozzle - - Setting to slice any part accurately. These are the same speed settings as the Gearset configuration, but the infill has been reduced to .35% to save time. Use this setting to start with as it causes less pressure buildup in the nozzle and is less prone to jamming the extruder if the first layer height or bed level is not correctly set.
Loading 3D Printer Slic3r Configurations
Open up Slic3r 7.2. Then select "load config.." A window will open up and you will select a configuration file provided on your flash drive. Once loaded, it will populate all of the settings in slic3r and voila! You are ready to slice.
When slicing a unique part, take a look at your Airwolf 3D printer first and identify a part most like your unique model. You can use the suitable config file and customize it to suit your needs! Once you have the hang of the basic Slic3r settings, you are ready to move on to the next wiki topic "Slicing 101 Effects of Layer Height on 3D Printed Parts" to read up on intermediate slicing techniques.
Download Airwolf 3D Printer Slic3r Configurations
You can also download your Airwolf 3D printer Slic3r configurations below.
[box type="download"]DOWNLOAD FILES HERE. Has this information been useful? We appreciate your feedback. [wpdm_file id=40][wpdm_file id=39][wpdm_file id=41][wpdm_file id=42][wpdm_file id=43]
Available downloadable files: Configuration files for Airwolf 3D Printer V.5 with .5mm nozzle[/box]
A word about Slic3r: Slic3r is free software, developed byAlessandro Ranellucci with the help of contributors and community. Please consider a donation (more about donations).You can download the Slic3r software here.
Apply PET film on 3D printer glass
This is how the team at Airwolf 3D applies PET film to 3d printer glass plates
What is PET film and how does it affect 3D printers?
Airwolf 3D printers applies a polyester film (PET) to the borosilicate glass plate before shipping out with a new 3D printer or 3D printer kit. We have found that ABS adheres to PET better than Kapton and it is more durable than Kapton, resulting in better part stick and less tears to the printing surface.
One of the PET products that we like to use is a 200mm wide strip of PET adhesive green tape that is approximately 0.06mm thickness. This particular product is sold on a roll and has no backing (liner). This is a high temperature resistant film which is often used as an electroplate mask shield during a wave solder process on PCB .
We apply this film to the glass using a "wet" method, which is similar to applying tint to a car window. The benefit here is that this is a good method for beginners, as the wet film is much more forgiving and can be manipulated and repositioned during application. The downside is that the film will need to "cure" for at least 10 hours, during which time the moisture will evaporate and the PET will adhere to the glass well. If you use the glass too soon, you run the risk of forming bubbles under the PET film when the glass is heated up.
What parts and tools are necessary to apply PET film?
We recommend the following parts and tools:
• Glass plate (very clean)
• Fine mister bottle (or spray bottle) with water
• PET roll (200 mm)
• Hard installation foam (or credit card)
• Sharp blade (or exacto knife)
• One paper towel
Follow these steps to apply PET film to your glass plate
What follows are the steps we take in applying a wide strip of PET using the "wet" method.
Step one: Unrolling the PET film
Have all of your tools readily available within an arm's reach. You will not have time to stop and go to look for something later as this is a swiftly performed procedure. Start off by finding the edge of the PET roll and then peel up a 1" flap. Adhere this flap to the edge of a table and use your foam to press the PET into the table, ensuring a good stick. (Don't worry about removing the film later, as this is a medium tack adhesion and typically comes off with moderate effort and does not leave a residue.)
Next, you will peel off and unroll enough film to cover your glass, about 11". To do this hold the roll with both hands and swiftly pull it down and away from the table in one strong, quick movement. Do not stop and start during this step, because this will leave a mark or crease at your stopping section and this may result in air bubble or lines in your PET film. It is better to unroll a couple of extra inches than to fall short. Gently release the roll and let it hang in this position momentarily.
Step two: Position the PET film onto the glass
Get your glass plate and apply a fine mist of water ensuring that it is completely saturated. Try not to touch the printing surface as hands can leave a residue which may prevent proper adhesion. While lifting up the roll and film, carefully place the wet glass under the film and line it up with the glass. Once you are satisfied with the placement, hold the glass in position and use your blade to cut off the roll of PET film, leaving a 1" flap. Then cut the other end of the film (closest to the table edge), again, leaving a 1" flap. This will release the glass and now it should have a 1" flap of PET on both ends.
Step three: Applying the PET film without air bubbles
Lay down the glass on a clean surface and lift one of the corners of the film about half way to the center. Hold the film up and away from the glass at a 45 degree angle and use your squeegee to press the film down and to remove any air bubbles. Work your way from the center of the glass to the corner. The center of the glass is the most important and if you see any air bubbles, it is best to pull it back up while it is wet and try again.
Next, pull up the film from the opposite corner and repeat. Do this until all of the water and air bubbles have been worked out of film.
Step four: Trim the PET flaps
Next, use your sharp blade to trim the two flaps. You will want to hold the blade against the edge of the glass and bring it in slightly so that it is at a 45 degree angle. Airwolf 3D glass plates are custom fabricated with a "pencil cut" edge, a type of beveled edge. Cutting the PET at an angle prevents the possibility of a loose flap, which might result in the film curling up later on your 3d printer glass.
Next, place your glass on a paper towel and once again use your squeegee to press out the edges and work out any residual water.
Remove it off the paper towel and set it aside on a dry, flat surface to dry for at least 10 hours before using it on the heated bed of your 3D printer. Do not leave objects on top of the surface as this may leave an imprint on the film.
WATCH INSTRUCTIONAL VIDEO HERE. Has this information been useful? We appreciate your feedback.
Watch instructional video to apply PET film [/box]
Final notes and resources:
These are instructions for applying this particular width and thickness of PET film. There are many other widths and thicknesses which may require different methodologies, such as a dry application.
You can find this PET film on ebay here eBay PET.
Airwolf 3D printers will soon offer thicker sheets of PET with a liner. We will announce the availability of this new product on facebook.
You might also purchase PET film sheets (with a liner) from Airwolf 3D printer customer, Terry at this ebay listing.
Are you looking for borosilicate 3d printer glass? You can purchase it here, in our webstore.