NEW Application for robolink in low cost sorting

Our customer PROFACTOR from Austria ( has shown a new low cost sorting solution at MOTEK show in Stuttgart. They use our robolink joint arm RL-DQ-RBT-5532S for this task. The arm uses a CPR control unit (

For further questions about the complete solution please contact Mr. Helmut Nöhmayer from PROFACTOR (

NEW robolink “gantry” unit 5+1

in older posts, I presented our current solution for pick+place of e-chain parts. Cycle time of 5-6 sec/pick is the most critical issue (we can not operate much faster due to missing stiffness of the igus arm). We now solve this issue by using our arms on drylin rails, in addition we use 2 units to feed one mounting unit.

Result: reduction of cycle time!

We expect a final cycle time of 2,5 sec with this “5+1” unit (or better 2x(5+1): 2 drylin carriages and 2 pcs roboolink arms with 5 DOF). We will present the new mounting unit in operation at SPS show in Nürnberg by the end of NOV. Sales price for total 12 DOF unit will be BELOW 10.000,- € (detailed pricing will be announced at SPS show). We use BECKHOFF control parts here.

Video of first test runs….

Output Encoder for RL-D / RL-S

We supply 2 options of encoders for our joints / joint arms.

Option 1 (our Standard before HMI 2017): Motorencoder plus Ini switch for 0-point reference on the joint output (PRT bearing)

Option 2): Output encoder on the PRT bearing of the joint. This is our own development, we use a magnetic ring plus Encoderchip on the output with an aditional magnet and Hall Sensor as reference point. Please find attached a description of the output encoder attached in GER and ENGL. Advantage: less cables, higher resolution, more accuracy for the arm.

DOWNLOAD section:

output encoder DEU: RL-D Sensorik Doku (#3)

output encoder ENGL: RL-D Sensors Dok (E #3)

strain wave gear (RL-S) vs. cycloid gear (RL-C)

The strain wave gear is available as a product in the size RL-S-17 and RL-S-20. RL-S-30 is a prototype and still in development.

The cyclo gear can be an alternative in future and is not available as a product yet. The sizes 17 and 20 are currently in development.

Both types of gears contain a coaxial in- and output axis (different from RL-D worm gears), they consist of three similar components:

  • An outer (static) toothed ring
  • An inner toothed ring (rigid in the cycloid gear, flexible in the SWG)

  • A drive (an excentric in the case of the cycloid gear, the wave generator in the SWG)



strain wave gear with flexible inner ring                  cycloid gear with excentric ring



RL-D different versions, pricing

We have defined 3 different quality standards for our robolink D joints and I want to explain the background of this issue. The 3 qualities are:

  • “low cost”,
  • “standard”,
  • “high end”

The main performance differences are stiffness, friction, precision (reverse play) and on the other hand cost. For size -20 and -30, the price difference between low cost and high end is ~factor 2, for size -50 it is ~factor 1,5. standard version ~ in the middle.

The high end version contains of our lubrication free worm gear with worm wheel made of iglidur J and worm shaft made of aluminum (hard anodized), it has ball bearings for the axial shaft load and for the back side (only version 102). The outer bearings are our PRT-01-xx (= high end rotary table made of aluminum with sliding elements made of iglidur J). Housing and inner connection parts are made of moulded plastic parts (our RN33), screws and nuts are stainless steel.

Most parts of the standard version are the same, but the back side has a sliding bearing (iglidur J) instead of the ball bearing (only version 102) and the PRT itsself is version PRT-02-xx-AL, which is a low cost version of PRT-01-xx. It has more plastic parts and thus is much lighter. Compared with PRT-01 is is a bit less stiff and a bit less precise. In a performanmce comparison of the to joints, we see no big differences for most applicaations as long as we do not get to the limits.

The low cost version of our RL-D in comparison contains a moulded plastic worm shaft and sliding axial bearings instead of the ball bearings. Also the PRT is not build with an aluminum outer ring but a moulded plastic outer ring (PRT-02-xx-LC). Friction is higher and precision worse than our “standard” version. It should be used only for “easy applications” as for example hand adjustments.  



For size -20 and -30, all versions are available. For size -50, only version “high end” is available, as PRT-02-50 is yet under construction. We will have it in ~OCT 2015.