Forum - Recent Topics https://theopenexo.nau.edu/community/ Discussion Board en-US Fri, 03 Apr 2026 21:59:04 +0000 wpForo 60 Activation of the PID function https://theopenexo.nau.edu/community/motors-and-sensors/activation-of-the-pid-function/ Thu, 02 Apr 2026 19:03:17 +0000 Is it mandatory to install a torque sensor to enable PID control？

]]> wuyang https://theopenexo.nau.edu/community/motors-and-sensors/activation-of-the-pid-function/ Mechanical Testing for 3D Printed Motor Mounts https://theopenexo.nau.edu/community/mechanical-parts/mechanical-testing-for-3d-printed-motor-mounts/ Tue, 31 Mar 2026 09:27:32 +0000 Hi,

I am currently experimenting with and validating different 3D printing materials for the 3D Printed Motor Mounts. I was wondering if you could share what tests you conducted to validate your design using the Onyx filament.

I am specifically focusing on the hip ad/abduction block (both the hip and leg sides), as well as the motor-to-leg shell interface. What mechanical tests would you recommend for these components? Additionally, based on your testing and experience with OpenExo, what are the primary load cases acting on these parts?

Thanks,
Lauren

]]> laudew https://theopenexo.nau.edu/community/mechanical-parts/mechanical-testing-for-3d-printed-motor-mounts/ Using FSR, but the motor torque is not controlled https://theopenexo.nau.edu/community/motors-and-sensors/using-fsr-but-the-motor-torque-is-not-controlled/ Mon, 23 Mar 2026 03:20:29 +0000 Dear Developer,

We are trying to control a motor using FSR with the original v2.0 code. We have set the torque to 0.5 N·m via the SD card. However, when controlling the motor through the GUI, the output torque becomes extremely large and uncontrollable. Even after increasing the current limit of the adjustable power supply from 24V/2A to 24V/5A, the current hits the upper limit instantly. Could you please advise on how to resolve this issue? Thank you very much for your help.

]]> Huang_Enghong https://theopenexo.nau.edu/community/motors-and-sensors/using-fsr-but-the-motor-torque-is-not-controlled/ After we have completed the testing according to the assembly manual on the forum, we are ready to install the exoskeleton on the human body for testing. Could you please tell me what are the safe and effective steps to follow? https://theopenexo.nau.edu/community/firmware/after-we-have-completed-the-testing-according-to-the-assembly-manual-on-the-forum-we-are-ready-to-install-the-exoskeleton-on-the-human-body-for-testing-could-you-please-tell-me-what-are-the-safe-and/ Wed, 18 Mar 2026 01:02:29 +0000 After we have completed the testing according to the assembly manual on the forum, we are ready to install the exoskeleton on the human body for testing. Could you please tell me what are the safe and effective steps to follow?

]]> wangchu https://theopenexo.nau.edu/community/firmware/after-we-have-completed-the-testing-according-to-the-assembly-manual-on-the-forum-we-are-ready-to-install-the-exoskeleton-on-the-human-body-for-testing-could-you-please-tell-me-what-are-the-safe-and/ Elbow exo build guide? https://theopenexo.nau.edu/community/mechanical-parts/elbow-exo-build-guide/ Mon, 16 Mar 2026 21:37:52 +0000 There was a forum post related to a question about the elbow system that was mistakenly deleted (sorry!). 

Answer: We are currently working on the elbow build guide and expect to release it by the beginning of April. 

]]> Zachary Lerner https://theopenexo.nau.edu/community/mechanical-parts/elbow-exo-build-guide/ After the test is completed, assistance cannot be provided. https://theopenexo.nau.edu/community/firmware/after-the-test-is-completed-assistance-cannot-be-provided/ Fri, 06 Feb 2026 09:25:27 +0000
Hello, regarding this open-source project, we assembled it based on your open-source materials. The steps for using the upper computer to conduct motor calibration are all normal. However, when we tried to use it directly, this exoskeleton device was unable to provide any assistance for human walking. We also removed the comment before the #define HEADLESS statement in the code, but it still didn't work. May I ask how this situation should be resolved? Do you have any programs that can directly assist in this matter that you could share?
]]> wangchu https://theopenexo.nau.edu/community/firmware/after-the-test-is-completed-assistance-cannot-be-provided/ After assembly, there is no power assistance. https://theopenexo.nau.edu/community/software/after-assembly-there-is-no-power-assistance/ Fri, 06 Feb 2026 00:44:02 +0000
Hello, regarding this open-source project, we assembled it based on your open-source materials. The steps for using the upper computer to conduct motor calibration are all normal. However, when we tried to use it directly, this exoskeleton device was unable to provide any assistance for human walking. We also removed the comment before the #define HEADLESS statement in the code, but it still didn't work. May I ask how this situation should be resolved? Do you have any programs that can directly assist in this matter that you could share?
 
 
]]> wangchu https://theopenexo.nau.edu/community/software/after-assembly-there-is-no-power-assistance/ i can not read SD_card.The debug output reads: "SD.begin() failed https://theopenexo.nau.edu/community/firmware/i-can-not-read-sd_card-the-debug-output-reads-sd-begin-failed/ Tue, 03 Feb 2026 09:28:34 +0000 i can not read SD_card,i need your help.
SD.begin(SD_SELECT) allways return false(Parselni.cpp: line 73 )
We know that SD_SELECT in the program is assigned the value of BUILTIN_SDCARD, and we tried to find the definition of BUILTIN_SDCARD. We learned that this value is not defined by the user but is inherent to the Teensy board. We added a print statement and found that BUILTIN_SDCARD is 254, and the CS pin in the SPI setup reads 3.3V instead of 0V. So far, we don't understand why SD.begin(SD_SELECT) returns false. This makes it difficult to proceed with our replication work because we cannot read the SD card's configuration parameters. Are there any solutions?

]]> huang_EnHong https://theopenexo.nau.edu/community/firmware/i-can-not-read-sd_card-the-debug-output-reads-sd-begin-failed/ MIT mode？ https://theopenexo.nau.edu/community/motors-and-sensors/mit-mode%ef%bc%9f/ Sun, 01 Feb 2026 14:06:46 +0000
Hello, I’d like to confirm whether the motor is operating in MIT mode when the exoskeleton is running.
 
Per the user manual for the AK60v1.1 motor, a motor configured to MIT mode via the host computer requires a specific CAN command to be sent to it before it can be activated. The relevant excerpt from the AK60v1.1 motor’s user manual is as follows:


Special CAN Commands
 
  • Enter motor control mode: {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFC}
  • Exit motor control mode: {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFD}
  • Set the motor’s current position as the zero point: {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFE}
 
Note: When controlling the motor via CAN communication, you must enter the motor control mode first!



However, I don’t seem to have found this specific CAN command in the OpenExo code. When I was replicating this project, the motor failed to rotate. Do you think this might be the underlying issue? I look forward to your response. Thank you!
 
 
]]> wuyang https://theopenexo.nau.edu/community/motors-and-sensors/mit-mode%ef%bc%9f/ Ankle build cable crimps https://theopenexo.nau.edu/community/mechanical-parts/ankle-build-cable-crimps/ Mon, 26 Jan 2026 21:17:45 +0000 I am following the ankle build guide, but I am stuck on the last steps of using the cable crimps to secure the steel cable through the pulley (image attached). In the BOM, the only cable crimps listed are McMaster 3914T11. However, it seems too small to be able to fit both ends of the cable through. I was wondering if the cable crimps that were referred to in the guide are different from what's listed in the BOM or if I am looking at the wrong BOM. I would appreciate it if you could let me know the product number. 

]]> delta https://theopenexo.nau.edu/community/mechanical-parts/ankle-build-cable-crimps/