Flex3Drive FAQs

What is Flex3Drive?

Flex3Drive is a range of light weight, high precision performance filament extruders for 3D printers. They have been developed and designed over several years and proven by hundreds of users around the world.

Flex3Drive utilises flexible driveshaft technology together with a high gear reduction in the print head to allow a precise direct drive functionality without having to carry a heavy stepper motor on the precision axis of your machine.

Flex3Drive also comes with a solid warranty.

Will the Flex3Drive fit my 3D Printer?

The short answer is yes.

We have a significant range of different Flex3Drive designs to fit all styles of printers which caters for most of the manufacturers on the market today. A lot of our work is focused on the various installation requirements of different machines aswell as design of the Flex3Drive assemblies themselves.

Please the links on the side bar menu for more information

What are the main benefits of the Flex3Drive?

The combination of lightweight, small size and high gear ratio mean the Flex3Drive offers a range of significant benefits such as:

  • The small size and low mass means a lighter smaller carriage.
  • The lightweight means there is less inertia
  • Less strain on the axis moving the printhead around the printing area of the machine.
  • The high gear ratio presents a greater (or finer) control resolution per mm of material being extruded
  • Lower torque loading on the motor results in lower motor driving currents allowing the motor to run for extended print times without getting warm or hot. The motor remains at room temperature
  • Lower current settings mean the stepper motor moves in a smoother manner between steps and is less inclined to skip steps due to over heating or excessive mechanical load conditions
  • A combination of the above factors also contribute to the elimination of ringing or ghosting whereby a wave pattern can be seen when accelerating away from corners.
  • High quality prints can be achieved with standard 8 bit electronic control systems and low cost stepper drivers such as the commonly used Arduino platform and Pololu 4988 stepper drivers.
  • The high gear ratio allows greater filament control at lower layer heights - print sub 50 micron layer heights smoothly.
  • Refined motion control curves on the E axis improve the acceleration and deceleration characteristics during both print time moves and retraction operations with less likelihood of stripping filament during retract intensive prints.
Will the Flex3Drive work with my Electronics?

Flex3Drive will work with any electronics on the market today. This does not mean it will work with your current settings which will have to be changed via the firmware. Sometimes this will also involve removing or adding a jumpers on the actual board to adjust microstepping rates if not controlled by firmware.

We provide hard settings for different firmwares and you can find out more information by following the links in the sidebar menu or click here to go straight to the setup page.

Will my hotend fit the Flex3Drive?

Yes. We cater for all the popular hotends on the market today. If you have a hotend or configuration that we dont currently serve, we will happily carry out any necessary modifications to an existing design to meet your needs

Does the driveshaft twist and cause innacurate extrusion?

No. The drivesahfts we use are not standard flexible shafts and are extremely resistant to torsional deflection. A special construction of the shaft using multi strands tightly wound in both directions around a solid spring steel core results in a very durable and accurate driveline component.

The 40:1 gear reduction acts to reduce the physical load on the shaft to within its specified operational limits. Under extreme conditions, very slight twisting of the shaft can occur, which translates to less error than a single skipped microstep. This error is also not cumulative as would be the case with skipped steps, but instead comes back into phase as the excessive load condition ceases.

We also understand accidents can happen, problems can occur or other components may fail which in turn may damage the driveshaft. These situations are extremely rare.

Due to our extensive torture and destruction testing (HALT) we are confident in our product and cover the entire driveline with a no quibble guarantee. Should your shaft become damaged or break, we will replace it. We will also work with you to try to understand the factors surronding the failure so that you can resume reliabale trouble free printing.

Why use a 40:1 gear ratio?

In the early days of our development of the Flex3Drive we tested different gear ratios inlcuding 20:1 30:1 and 50:1. Whilst we understood the pros and cons of these different ratios we wanted to find the optimal ratio by testing them to see the results in real life.

To summarize the effect, we found that 20:1 and 30:1 would result in too much strain on the flexible shaft causing it to weaken and lose its torsional stiffness, and eventually fail. This gradual failure affected print quality by creating artifacts as a result of a delay in transmission of torque from the motor to the extruder mechanism.

This became even more evident when we ran at moderate print speeds over 60-70mms with a 30:1 ratio and learnt that 30:1 was inadequate when running at higher volumetric flow rates.

We also found that at 30:1 ratio one had a lower extrusion control resolutio when running at ultra fine layer heights. 40:1 was found to be the ideal ratio in terms of load, speed and resolution across the board, as well as staying within the operational torque limits of the driveshafts.

Is there a twisting force on the end effector when used in a Delta printer?

The short answer is no. Due to the high gearing and the fixed PTFE outer sleeve the rotational torque of the driveshaft does not have a twisting counter effect on the end effector.

How does the Flex3Drive fit the end effector of my Delta style machine?

When working with Delta printers we supply a new end effector or an adaptor plate that fits your effector.

What motor do you recommend?

You can use any low inductance Nema14 or Nema17 motor. Motors we have tested include the SY42STH38-1684A or 17HS15-1684S that work very well. Also if preferred there are pancake style 17HS08-1004S or 17HS10-0704S stepping motors. We recommend using www.omc-stepperonline.com as your source due to their worldwide availability.

What materials can I print with the Flex3Drive?

Any. We have tested our extruders with a very wide range of the different materials currently available and have not found any that cannot be used.

Does the Flex3Drive work with both 1.75 and 3mm filament diameters?

Yes. Nearly all variants within the Flex3Drive range are available in both 1.75mm or 3mm versions with the exception of the Ultimaker products, and the Cyclops variant of the Chimera/Cyclops product.

Equally, if you choose to convert your machine from 3mm to 1.75mm or the other way, you can simply print the parts you require to convert the Flex3Drive from one to the other.

It is important to note that the reason for having different versions for different filament diameters is that the centreline of the filament is in a different position by around 0.8mm, and to maintain reliable operation it is important to keep the precision of the assembly.

Is there a dual filament Flex3Drive?

Yes we have several dual drive models including units that work with dual JHead / E3D and similar hotends when wishing to use a single material together with a support material. A 2into1 design specifically for the E3D Chimera / Cyclops hotend from E3D is also available. Additionally we have another slimline dual filament hotend due for release that provides a compact 2in1 mixer nozzle within the footprint of a standard JHead hotend.

How do I set up my Flex3Drive?

There are an infinite number of potential deployment configurations when all things such as motor specification, stepper driver type, machine voltage and other factors are considered. Therefore it is not practical to advise a specific set of "numbers" for some parameters, however we have a detailed description of the best tuning process that is very easy to follow and can be completed in a very short amount of time.

We also provide hard values for the various firmwares that populate our landscape along with recommended installation points for the motors on different printer designs.

Please follow the links in the side bar menu for software and mechanical installation support.

Where should I position my extruder motor?

One thing to consider when installing a Flex3Drive is the new location of the extruder motor. For cartesian machines, this can be on the gantry, mounted to the opposite end from the X axis motor. For Delta printers, this can be on the back of one of the uprights at approximately half way of the Z build volume. For XY gantry machines, we suggest at the back of the machine to one side or in the middle.

Please visit the Installation Tips section in the side bar menu for more information.

Will the Flex3Drive work with Flexible Filaments?

Yes. The fully contained filament path will prevent filament from escaping, even if it is 1.75mm flexible filament which is effectively like pushing string uphill.

Is the Flex3Drive Open Source?

We have deliberated over this most important of questions. Our plan is to to release downloadable stl files of our extruders in the near future. Unfortunately for reasons we can not elaborate upon, we will not be releasing files just at this time as it would damage the hard work and effort we have put into creating our products for you.

Some of our files will be released in relation to ancillary printable parts required for the installation of the product and to provide a greater range of installation options.

Additionally some of the parts we produce are unique and not available anywhere else, being produced from our own injection moulding tools. Other parts need to be made on a CNC machine. If someone attempted to make their own version with our designs, they would most likely have an inferior product.

Furthermore our drive-shafts are unique and not available anywhere else, as they are produced to our specification. Standard flexible drive-shafts are not sufficient in this application. If someone attempted to make a Flex3Drive using our designs, with their own components they will end up with an inferior and troublesome product.

We hope to counter the downside of not releasing just yet, by providing an exemplary product, with excellent after sales support, installation documentation, and a solid warranty on our products.

This situation is only temporary, and we hope you understand and continue to support us.

We produce 3D Printers, can you design a Flex3Drive specifically for our machines?

Yes absolutely. In doing so you will also have full rights to the work we produce for you whether you want to go open or closed source with those designs. If you wish to know more please contact us via the contact page.