FAQ

You will need:

  • 3DLabPrint digital 3D files
  • 3Dprinter
  • PLA filament
  • RC equipment (links provided in our airplane userguide)

 

Printing guide/FAQ

Introduction

Please see the PDF/VIDEO user guide prior to printing our models. Our Forum contains many useful informations as well. We’re using some specific features in our STL files resulting in possible errors in some CAD / slicing software. This is intentional result of extensive development to achieve desired strength to weight ratio.

Print

Our STL files are designed especially for Simplify3D slicing software. Factory files for Simplify 3D are included in downloaded packages. CURA or MatterControl provides satisfactory results as well and we provide respective config files in our bundles. Slic3r software is not supported except the completely redesigned P-47 Thunderbolt Slic3r version.  Please check our Facebook or Forum for recent informations.

Included Gcodes are 100% compatible with Prusa i3 original printers (it should work with most i3 family and compatible printers as well)
Please experiment with temperature (for PLA in range 210-260) for proper layer bonding… Usually for thin wall printing we need higher temperatures than recommended by filament manufacturer compared to printing standard items.

Outlines/Perimeters/Shells

Most of the parts are printed with only one perimeter/shell thickness (0.4 mm nozzle gives the best results). Turn on thin wall detection for our slic3r version Thunderbolt. For a first few milimeters of the parts or exposed parts you can use separate process with two or more perimeters shell. Please see the VIDEO guide for more information about this.

Extrusion multiplier – amount of filament

Please experiment with extrusion multiplier. This is very IMPORTANT for successful prints. Increasing extrusion multiplier results in stronger parts with better layer bonding. However it increases the resulting weight of printed parts. Refer to optimal weights for each part in our PDF user guides to find optimal multiplier value. The multiplier value can vary depending on your printer and filament diameter. Value 1.02 usualy works fine, but sometimes we may need at least 1.15. Allways ensure your hot end is in good shape, gives steady flow and right amount of filament. Don’t forget to calibrate you extruder E steps and add measured filament diameter into slicing software.

Retraction

The Retraction value is very dependent on your printer and filament quality. For non-bowden (direct drive) extruders RETRACTION values of 0.7-1.5 usually works fine. Good starting point is 0.8 and if you find some oozing during the non print movement try increasing this value. For bowden extruders use values around 4-6 mm. Set retraction for all spots, not just for outer perimeters! In case of nozzle clogs due to molten filament in heatbreak, decrease the retraction value.

In case of under-extrusion at layer start point (after retraction), please check your hot end for issues. “Extra restart distance” value (if your slicing software has this feature) adds some extra amount of filament after retraction. Values of 0.05 – 0.2 usually works . Another option is decreasing the print speed, increasing the movement speed to reduce oozing and adjusting the temperature. Reducing the retraction speed to 15-20 mm/s or placing the parts on heatbed differently might help fighting the underextrusion after retraction as well. Sometimes a drop of vegetable oil applied on filament prior to print could reduce friction especially in bowden extruders.

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If you have tried everything with no success, you can try one last solution:

Change the bottom stock setting to the optimize start point setting. This option causes some minor blobs to airfoil, but helps with oozing the filament out of the nozzle and so on… (Simplify3D picture)

 startpoints

The last chance – if you use Prusa i3 clone printer and nothing works.

Your hotend/extruder is not able to print thin walls. Consider upgrading with  E3D Prusa i3 Upgrade Kit , you get 100% working Nozzle/Hotend/Extruder combination. Especially in case of cheap Chinese printers this could push your printer to completely different level.

titan-angled-web-1000x1000

In general if you already tried all settings, more than one PLA filament supplier and nothing helps, you will need to check your Nozzle/HotEnd/Extruder. Clear it, replace the nozzle, ptfe tubing or a whole hotend, or upgrade to better quality extruder.

And just one advice from Philipp Amann (thanks for sharing this):

I have done a lot of testing and discussing with other “printers” and we have found, that the cheaper (or in bad condition) printers cant realy cope with 0,25 layer strength and the necessary restart. When you reduce the layer to 0,2 it works perfectly, even with the cheap printer.

This is 0.25mm layer

This is the same S3D profile with 0.2mm layer…

Bed adhesion

The very crucial part of success is proper first layer adhesion. The first layer must be properly flattened (squished) and it’s essential to decrease the first layer printing speed. Try to find the best sweetspot of your first layer height. For better strenght of printed parts and better bed adhesion is vital setting 2 perimeters for the first 1-3 mm of print. You can use separate process in Simplify3D. In other slicing software you could at least increase the width to 130-150% and reduce speed for the first layer. HEATED BED is highly recommended.

If you’re printing on glass, we have great experience with ultra strong hairspray. On clean, degreased glass apply the hairspray, let dry and scrape with razor blade to create matte surface. Heat up to 60°C.

PEI, kapton or other special bed surfaces works good as well. Without heated bed you can use some PVA glue stick like KORES and add some skirt outlines with 0 mm offset. The most difficult parts tending to warp due to poor bed adhesion are the trailing edge of wings. You could add some pads to these parts to increase adhesion.

 

Temperature/Print cooling

Temperature of hotend varies with each material. Try to print as hot as possible with print cooling fan OFF. (while keeping the hotend heatbreak fan ON). Molten plastic flowing from hotend should be able to melt again the previous layer, so it makes a solid bond. Fit as many parts as possible to the bed to let the other parts cool down and gain some strenght before the nozzle gets to the same spot. For PLA the range is 200-260°C. 230°C is a good starting point.

Filament

During our developement process we found PLA gives the best results. Any standard quality PLA is ok, however the final quality of print depends on combination Filament/Extruder/Hotend. Some colors of filament, due to coloring additions, gives different strenght of the resulting parts. Please experiment and find the best possible attributes suiting your need. Less translucent filaments are easier to paint, reflective colors are less prone to warp on direct sunlight.

Another possibility is to use PETG, however the result is more flexible, less brittle and more temperature resistant. Again it needs more temperature and retraction tuning.

ABS is not very suitable to print our planes due to temperature shrinkage during cooldown. You may be able to print using an enclosed printer and keeping the cooldown process very slow. Feel free to experiment.

We’re using PLA – Plasty Mladec (suplied by Prusa3D)

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Printers

The recommended build volume is 200/200/200 mm. Most of our planes fit 195/195/150 mm or 250/120/150 mm. The bigger the better. Heated bed is highly recommended.

Smaller Spitfire MkXVI comes with a version fitting the 150/150/150 mm build volume.

Recommended nozzle size is 0.4 mm. With a bit of extrusion multiplier tuning the range of 0.35 – 0.5 nozzle size could be used as well. Allways check the proper weights according to the PDF user guides. Direct drive extruders are prefered, however bowden printers are able to print our planes as well. The hotend and nozzle are the most important parts of the printer to achieve satisfactory results. Check their condition on regular basis as the thin wall printig is very sensitive to proper and steady flow of molten filament.

Please do calibrate your X/Y/Z steps/mm and ensure your axis are not skewed. If you have some disproportions in your printer, you won’t be able to assemble the plane properly.

Remember: There are many FFF/FMD printers on the market nowadays. Most of them should be good enough to print our model aircrafts. If it has sufficient build volume, heated bed, 0.4 mm nozzle and quality hotend/extruder, you’ll be fine.

We use Prusa i3 Original printers (supplied Gcodes works 100%), Makerfarm and we also tried some cheap Chinese Prusa clones (somehow it worked, but maybe extra upgrades are needed for better print results. Everything depends on individual printers)

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