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Frequently asked questions about igus® 3D printing

3D printing is a process a little like printing ink on to paper, except the process builds a three-dimensional object from a computer-aided design (CAD) model. It does this by adding material, layer by layer, which is why it is also called additive manufacturing. There are three key types of 3D printing. Fused Deposition Modelling (FDM), Selective Laser Sintering(SLS) and Stereolithography (SLA).

The terms ‘additive manufacturing’ or ‘rapid prototyping’ are often used as synonyms. When the 3D printing method is used to make components, material is added layer by layer – as the term ‘additive’ makes clear. This differentiates 3D printing from machining and cutting methods whereby material is removed in order to make components (subtractive method). This makes 3D printing very economical in its use of material as there is little or no wastage.

3D printing a part can take anywhere from 30 minutes up to 1 week, this is due to the 3D printer being used for this job, the geometry of the part, and the ultimate size of the part being printed.

Cost is relative. Filament, or materials, for 3D printing is one part of the full production cost. The methods in traditional manufacturing are considerably higher in cost than 3D printing due to the inevitable wastage from moulding and machining parts. In addition, by using 3D printing for prototyping, you can eliminate unnecessary overheads by preventing large amounts of waste material and tooling costs.

• Fast to manufacture from the moment the CAD is complete
• Manufacture with no minimum order quantity
• Easy to make changes and print another component. (ideal for prototypes and pre-production runs)
• High degree of flexibility in the manufacturing process. (You can try different materials and different print methods).
• Complex models can be created in shapes that would be impossible or expensive to produce.
• Lightweight solutions easy to implement by hollowing out parts.
• No tool or set-up costs

3D printing is now used in many areas of manufacturing. The possibilities are practically unlimited. Applications that really lend themselves well to the process are:

  • Prototypes
  • Small batch production
  • Trade fair models and concepts
  • Replacement parts where difficult or timely to source.
  • Architectural models
  • Research and science
  • Medical
  • Product design
  • Hobby model making
  • Food and Packaging
  • Automotive
  • Aerospace
  • Musical instruments

And many more…

igus® makes its 3D print parts from the high performance and highly tested iglidur® materials made from high quality plastics. In addition to long service life and self-lubricating, their properties include low coefficient of friction, low wear, and low absorption which are specific and beneficial to each application.

  • Plain bush bearings
  • Rollers
  • Gears and pulleys
  • Grippers
  • Racks
  • Linear bearings
  • Lead screw / drive nuts
  • Sliding elements
  • Integrated bearings and housings.

and all other parts that are optimised in terms of friction and wear

Fused Deposition Modelling (FDM) is a 3D printing method whereby a material such as one of our polymers is melted to create a 3D object layer by layer. Fused Deposition Modelling is an additive manufacturing method and is also referred to as the fused layer modelling method, Hence FDM or FLM. The plastic or metal material that is processed is called filament. Filaments are usually available in reels known as spools and two different diameters. 1.75 and (2.85mm) 3.00mm. Spools can be sold by weight or by material length.

The filament is heated to a liquid (plastic) state so that the individual layers of the model can be added through the nozzle of the printer head. The filament is heated accordingly and forced through a fine nozzle. This produces a thin thread of plastic, which is used to make layers that are placed one on top of the other to finally end up with a 3D component. Different materials require different settings. Nozzle temperature, bed temperature, and chamber temperature are three of the main variables that need to be set with a material.

Thanks to the expertise of igus®, their presence as a tribological specialist stands out for all types of moving applications; whether ordering in small batches or for a serial production requirement, igus® is able to ensure the application properties, how ever extreme or precise, are met with the appropriate polymer.

The igus® filaments and SLS powders for printing vary hugely in terms of their properties and specialities. Below is a list of some of the most popular 3D print materials, specific to certain industries and applications.

Filaments

I150 – food compliant filament, high resistance to abrasion

I180-PF – high resistance to wear, strength, available in black or white

J260 – maximum service life of Tribo-Filament, up to 120°C resistance

SLS materials

I3-PL – high resistance to wear, highly accurate details, good mechanical properties

I6-PL – abrasion resistance, very tough, specifically for worm gears

The two forms of 3D printer that igus® works with are:

SLS – selective laser-sintering

In SLS printers, a laser is used to sinter the powdered material (often polyamide or nylon) which aims at a predefined 3D space to bind the material together and produce a solid structure. This method is widely used for challenging projects, such as for medical devices like bespoke prosthetics. 

FDM – fused deposition modelling

In FDM printers, the filament is heated up and passed through a tiny syringe to deposit the material on the base plate according to the predefined 3D shape.

This method is mainly used for its main benefits of: cost effective, quick, good results. The materials used in FDM printers are also often much wider-ranging than those used in SLS printers.

The service life of igus® 3D printed parts is proudly guaranteed by our 130 trillion test movements occurring annually. During these experiments, we test the iglidur® plastics for coefficient of friction, wear, heat resistance, and many other relevant properties. Thanks to these rigorous tests, we are able to predict the life and wear rates for our polymers according to the applications they work in.

Required application properties can be obtained from all of our standard materials, such as higher and lower temperatures, contact pressure, water absorption, and many more.

The ESD feature means that the material is able to dissipate a build-up of static electricity caused by tribo-charging or electrostatic induction. This makes it hugely appealing for the electronics and packaging industry.

Absolutely. Although we can colour and dye our parts, it is indeed black which means it is more resilient to UV damage than if it was dyed.

Contact resistance 106 to 109 ohms * cm

3D printing parts is simple and can be manufactured after 3 steps:

  1. A CAD file is required to be transferred into a STL file format.
  2. igus® print the part is layers.
  3. The final object is cleaned and then if further work is required, i.e coating or polishing, this step is then completed.  

There are multiple industries that can use 3D printed parts. Recently we replaced a gear in a tractor which you can read more about here: https://blog.igus.co.uk/how-are-3d-printed-parts-used-in-real-life-applications/

This blog also gives you other examples such as the automotive industry. 

All iglidur® laser sintering materials are basically suitable, whereby the most suitable material can be selected depending on the requirement. iglidur® I3-PL is the most frequently selected and most cost-effective laser sintering material in the igus® 3D printing service.

Fastening threads can be printed directly from M6 or comparable dimensions. For this, the geometrical shape must be integrated in the 3D model. Alternatively, threads can also be cut or, in the case of heavily stressed or frequently screwed threads, thread inserts can be introduced. Please request a separate quotation for this.

igus®can provide components with threaded holes for trapezoidal or dryspin® lead screws upon request. Lead screw nuts for trapezoidal threads can be generated with the igus CAD configurators. For dryspin® threads, please contact your igus® contact person, as this is a protected geometry.

Appropriate mechanical reworking is possible. For machining on the lathe, the usual measures for unfilled plastics (e.g. POM) apply; here, a fixture may have to be made to prevent deformation of the component during clamping. Due to the increased wear resistance of the iglidur® materials, grinding is more demanding than with standard plastics.

For the smoothing of laser sintering components in the igus® 3D printing service, vibratory grinding and chemical smoothing are used. In vibratory grinding, the surface of the component is levelled with the aid of small wheels, thereby reducing the roughness. In chemical smoothing, the surface of the component is dissolved with the help of a chemical, thus smoothing the surface and closing it.

The vibratory finishing minimally removes particles from the surface and can, for example, anticipate the shrinkage of a plain bearing. It is a cost-effective and quick form of after-treatment, but is ineffective in places that the sliding bodies do not reach (e.g. inner edges, channels). The process is only suitable for smaller components with simple geometries.
The chemical smoothing process dissolves the plastic on the surface of the component. After the solvent has evaporated, a dense surface remains, while the untreated component always has a certain porosity, which plays a role in the use of lubricants, adhesives, compressed air as well as vacuum. This surface treatment produces even smoother surfaces than vibratory grinding, but also means a higher surcharge as well as a longer delivery time of the component of 9-12 working days.
Both surface treatments can be configured and ordered directly online in the iglidur Designer in the “Finishing” tab.

Due to the integrated solid lubrication, igus® plain bearings also function in a vacuum. Depending on the application, the maximum permitted gas release on the plastic component must be reduced to a minimum. Due to the higher density, the laser sintering process is recommended here rather than the FDM process. The gas release of laser sintering plastic components can be reduced by first drying and then infiltrating the parts. Both can be offered by igus and carried out directly during production.

igus® has so far been able to gain experience with components produced using the laser sintering process. It is known that untreated components do not have a high gas tightness. Gas tightness can be significantly improved by an infiltration process or by chemical smoothing, which has already been confirmed by customer feedback. However, the gas-tightness always depends on the wall thickness; the thicker the wall, the more gas-tight the component. For components produced by filament printing, a lower gas tightness can be assumed, therefore the laser sintering process is recommended here.

igus® does not offer coloured laser sintering powder. Due to the increased effort involved in changing materials, the production of laser sintering components generally involves the subsequent colouring of the components instead. It is also possible for components made of iglidur® materials. Over 20 standard colours are available and special colours are also possible. The tribological properties of the material can be affected by colouring.
The iglidur® tribo-materials are basically white (iglidur® I6, I10), yellow/beige (iglidur® I3) or anthracite/black (iglidur® I8-ESD). For black components, iglidur® I8-ESD is sometimes the better choice compared to coloured components, as the component is through-dyed and the delivery time and part costs are not affected. As a result, the black colour is also more weather-resistant.

No, because it, like some others, only allows the use of proprietary filaments.

Filaments from igus® are available in diameters of 1.75mm and 2.85mm. Some 3D printers require 3mm diameter filament. In practice, this refers to the diameter 2.85mm, so it should be used synonymously. Therefore, the igus® “3mm filament” can be used on printers that require 2.85mm or 3mm filament.
Only the high-temperature filaments (iglidur® RW370, A350 etc.) are so far only available in 1.75mm.

The dimensions of the filament spools can be seen on the product pages in the shop.

igumid P150-PF is a fibre-reinforced material, which has a much higher stiffness and strength than the tribofilaments.

Depending on the tribofilament, various (water-)soluble filaments, such as PVA, from different third-party suppliers can be used. For filaments such as iglidur I180-PF, I190-PF and J260-PF with a higher processing temperature, a suitable support material for higher temperatures should be used if necessary (e.g. Formfutura Helios).
An alternative are so-called “breakaway” support materials, which can be easily removed by hand after 3D printing. For some tribofilaments, e.g. iglidur I150-PF, PLA is also suitable as a support material, which can be removed manually without much effort after printing.
For the high-temperature tribofilaments (iglidur RW370, A350 etc.), we are unable to make a recommendation at the moment.

For the tribofilaments, igus® offers the adhesion promoter for tribofilaments as well as the adhesive films , which can be ordered in the shop. The adhesion promoter is applied as a liquid to a printing surface (e.g. glass) and serves as an adhesion medium as well as a release aid when the plate has cooled down. The film is glued onto the printing plate and provides improved adhesion. Only the adhesion promoter is suitable for Ultimaker 3D printers.

The rule of thumb is a drying temperature that does not exceed the maximum application temperature of the plastic, but also does not damage the plastic reel. For filaments on matt black plastic spools max. 70°C, on transparent spools max. 90°C and on glossy black spools (high temperature filaments) max. 125°C with at least 4-6 hours drying time.

Post-processing steps such as mechanical finishing (drilling, turning, milling) and the setting of thread inserts is also possible for components made using the FDM process. Feel free to contact us if you need support for your application in this regard.

In addition to the tribofilaments, a range of other filaments, such as a flexible material (TPU) and other materials, are also available for the multi-material 3D printing service. Please contact us if you are interested.

Some filaments can form a material compound due to their molecular composition. Many others cannot be easily combined with each other, so that a form-fit connection should be constructed here. 

No, not at present. But it is quite conceivable that there will be a tribo-resin in the future. In the SLA and DLP processes, photopolymers are processed whose specifications can still change considerably after processing, especially due to the influence of UV radiation. igus is actively researching to solve it.

If a 3D model exists and there are no legal claims from the original manufacturer, this is possible. For commercial customers, igus® offers to rebuild defective components. Private customers have the option, through our cooperation with repair initiatives, to have the component reconstructed and manufactured. For simple parts such as plain bearings and gears, the igus CAD configurators can also be used

Not at this time.

Yes and no. Modified plastics have a very high resistance compared to metals. With a specific resistance of approx. 1×107 ohm x cm, iglidur I8-ESD is in the range of “antistatic dissipative”, but not really conductive.

The tribofilaments iglidur® RW370-PF, A350-PF and J350-PF are fire-retardant according to UL94 V-0. iglidur ®RW370-PF also fulfils the EN45545 standard for railway vehicles. The laser sintering material iglidur® I3 fulfils the FMV SS 302 or DIN 75200 standard for vehicle interiors. The certificates can be downloaded from the “Downloads” tab on the product pages in the shop .

The laser sintering materials iglidur® I and iglidur® I10 as well as the tribofilaments iglidur®–I151-PF and A350-PF are approved for food contact according to FDA and EU 10/2011. The certificates can be downloaded from the “Downloads” tab on the product pages in the shop.

Tests with iglidur® materials in rotating and pivoting applications under water have shown that especially the laser sintering material iglidur® I8-ESD is well suited for it, as the wear rate in this environment is very low.

In the weathering test (8 hours each of irradiation with UV-A as well as 4 hours of condensation at 50°C for a total of 2000 h / ASTM G154 cycle 4), the laser sintering materials iglidur® I3 and I6 proved to be relatively resistant, with a change in the flexural strength of about – 20%, and the tribofilament iglidur® I190-PF with about – 40% as the most resistant to weathering effects such as UV irradiation.

The chemical resistance of the tribofilaments and laser sintering materials can be viewed in the searchable lists in the “Technical data” tab on the product pages in the shop or in the iglidur Designer in the materials under “More information”

No, you only achieve food conformity by combining it with a clean 3D printing process. It is important to use clean print nozzles when 3D printing food-safe components, for example. In addition, either no adhesive (glue) or a food-grade adhesive should be used.

Components printed with food-compatible iglidur® materials have a food-safe surface, so that no additional coating is necessary. It applies to the 3D printing materials iglidur® I6, iglidur® I150, iglidur® I151 and iglidur® A350.

If there is prolonged contact between the plastic component and food, this increases the chance of migration of plastic particles. Therefore, it is important to check the food compliance declaration for the maximum permitted contact time. It may vary depending on whether the FDA or EU 10/2011 declaration is considered.
The ambient temperature of the application also plays a role. The higher the temperatures, the shorter the contact should be. Parts made of iglidur® I6 are suitable for a maximum 2-hour contact with food at temperatures of up to 70°C (according to EU regulation 10/2011).

It is not recommended to produce food compliant components in multi-material printing together with other, non-food grade materials, as mixing of the materials cannot be completely ruled out. The support material should either be food grade or the same material should be used as support material.

The settings should be chosen in the slicing software so that the surface of the object is as dense as possible. Among other things, this is achieved by lowering the printing speed and adapting the line width to the nozzle diameter. This allows unevenness in the component surface and reduces gaps in the cover layers.

Basically, all parts that come into contact with the filament should be free of residues. This applies in particular to the extruder sprocket and the pressure nozzle. In addition, a clean print bed is imperative. The glass plate should be cleaned and the use of either no adhesive or a food grade adhesive is recommended.

You do not need a lubricant for 3D printed gears made of iglidur® polymers. The gear already contains lubricant.

Unlike the situation for bearings, wear is not the biggest problem for gears. For gears, the question is when the teeth will break off. That determines a gear’s service life.

Tolerance depends on part dimensions. Parts up to 50mm have a tolerance of ± 0.1mm. Parts larger than 50mm have a tolerance of ± 0.2%. These values apply to non-reworked parts.

For the dimensioning of the fit on your shaft, it is necessary to know how torque is transmitted and what mechanism is used. If the shaft is 10x10mm, for example, a tolerance limit of 10.1mm would work for your gear.

There is a small advantage if you do not consider the printing volume.

iglidur® FDM materials are good for bearings and other wear-resistant parts. Gears made of our laser sintering materials have a much longer service life.

Yes, you can buy the filament online. Pay attention to the processing instructions, since many of our filaments require closed and/or high-temperature printers

 

 Our minimum wall thickness is 0.7mm. If we need to, we can go as low as 0.5mm, but we normally recommend a minimum of 0.7mm.

We have tested many gears made of various POMs and other machined gears such as PPT, but the results were not better than those for POM in any respect.

The general rule for 3D-printed or polymer bearings is: if the application and load are not very great, the parts can be made of polymer. This rule also works very well for parts printed in 3D. But if the load or surface speed is very high, there comes a point at which the application will work only with a metal part running against a polymer part. At a certain point, it is better to have a metallic shaft because it conducts the heat from the tribological system better. Then the smaller gear should be made of metal because it is always the one with the greater load. The larger gear can be made of polymer, so the system remains without lubrication.

Both gears can be made of polymer and our service life calculator used to determine the point at which the system stops functioning well. There will be a point at which polymer gears no longer function well because the load is too high.

 No, it doesn’t. The solid lubricants are not affected by the heat. The same is true for injection moulding and bar stock materials, which also experience intense heat briefly during the manufacturing process without losing their self-lubricating properties.

Metallic gears can handle higher loads that polymer ones can. If you have a metal gear that is reaching the limits of what a metal gear can do, you cannot replace it with a polymer gear. That would require a gear three or four times the current size. But if the metallic gear is not at the limit of what metallic material can do, you can, of course, replace it with a polymer gear, and then you have a system that requires no external lubrication and for which you can receive any type of gear very quickly. You can use our service life calculator to determine whether this is the case for your application or not.

Sintered material is fairly rough, but smooths quickly during use, and the roughness does not impair the printed part’s performance.

Worms made of hard anodised aluminium are especially well-suited to high loads. However, suitable worms from the igus® 3D printing service made of the material iglidur® I3 are sufficient for normal loads, since such worms are remarkable for their great strength. The great advantage here is also freedom of design, since even complex, rare worms such as globoid screws can be printed in 3D, quickly and at low cost.

Worm wheel and worm gear design requires precise harmonisation of tooth flank geometry. This is necessary for transmitting the intended torques and ensuring that the flanks are wear-resistant and abrasion-resistant. Simple, economical manufacturing processes for one-off productions and small series are important if the design is to be transferred to computer and 3D printing systems, making it commercially attractive.

 

A worm wheel is generally used in a gearbox’s output. Traditionally, it is made of a copper-tin alloy. This material exhibits excellent emergency running properties in conjunction with steel components. This is an important point in favour of using metal worm wheels when a great deal of heat is generated or high torques are transmitted. Worm gears made of metal are also often integrated into the cooling and lubricant circuits. In many cases, a worm made of hardened steel is used with a worm wheel made of a softer material, such as brass or bronze. But self-lubricating polymers are increasingly being used for worm wheels.

Basically, polymer gears are suited to dry running without lubricating oil – this allows worm gears printed from iglidur® to run without lubrication. The user enjoys great advantages, since maintenance costs and downtime are much lower when worm wheels made of high-quality polymer materials are used. 3D printing production is more flexible for design engineers than the milling of gears from metal or polymer. Worm gear geometry can be absolutely optimised in the former, whilst compromises must be made in the latter. The optimised geometry means that it takes longer for play to develop in polymer worm gears than in milled gears. Surface pressure and abrasion are greatly reduced thanks to large contact areas.

The most important advantages are wear resistance, impact resistance, inherent elasticity for reducing surface pressure, especially great resilience, self-lubricating properties, corrosion resistance, quiet operation, freedom from maintenance and good emergency running properties. The most important criterion is the polymer in use. Special materials are remarkable for great abrasion resistance and toughness, high-precision, detailed surface creation and extremely long service life in worm wheel applications.

 

iglidur® I6 is a laser-sintering material that was specifically developed for worm wheels. In addition to the general advantages of all iglidur® polymers, such as wear resistance and lubrication-free properties, iglidur® I6 is remarkable for its especially great sliding capacity, which optimises worm wheel functionality. The idea for the development came from our robolink robot arm design engineers. In testing, worm wheels manufactured from iglidur® I6 proved many times more wear-resistant than other 3D printed polymer worm wheels. Plastic worm wheels are suited to industrial use only if high-quality polymer is used. Earlier tests with PLA and ABS were unsuccessful, since the high coefficient of friction caused the components to wear relatively quickly. That is why new polymers with the desired properties were developed. Special designs for high temperatures or the food industry are available. Wear tests for these materials show that they are very abrasion-resistant. The material data for iglidur® I6 can be found here.