Hackberry portal Forum HACKberry Q&A Troubleshooting Finger Movement Problems.

This topic contains 5 replies, has 3 voices, and was last updated by  Hiroshi Yamaura 3 years, 7 months ago.

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  • #1158

    Hello,
    I have completed building the Hackberry Exiii (Thanks for the CPU and Hardware Kit Satima in Colorado Springs!), however, I have the following problems:

    1) The “Middle, Ring & Little” fingers do not always fully extend when the Index finger does.

    2) The “Thumb” does not move when I push the “Thumb” button.

    Nothing is obstructing the movement, and I’m not sure if it’s a servo positioning problem or if there is something else wrong. Please explain how to do the following steps in the assembly section so I can troubleshoot the issue:

    1) Set servo motor’s degree at pre-set index extended degree in the Arduino program.
    – 写真のように“HbPalmBase03”に“Servo motor Large”を取り付けます。 サーボモータを取り付ける前に、Arduinoを接続した基板等を用いて、人差し指の角度を伸ばした時の角度に設定します。

    Also, Do I calibrate the servo’s to 5 volts or 6 volts?

    Also, Is there some way of troubleshooting the Thumb to see why its not moving when I push the Thumb button? Every time I turn on the hand, the thumb moves a millimeter, but the button does not work.

    I would appreciate some help at this point. It is 99% complete, and I’m almost ready to help someone with your excellent work. Thank you, for all your help.

    #1159

    Hiroshi Yamaura
    Keymaster

    Hello,
    Congratulations for completing assembly!(We also want to say thank you to Tima)
    I’ll answer your question one by one.

    1) The “Middle, Ring & Little” fingers do not always fully extend when the Index finger does.

    First, please make sure your fingers can be moved without friction.
    If there are frictions, enlarge the shaft hole or polish that part until they can move smoothly.
    Then, make sure the linkage connected to little finger is fixed to the top of servo horn.
    Since servo horn has many holes, the linkage sometimes be fixed to wrong holes.

    View post on imgur.com

    Next, temporarily remove the servo horn from the servo.
    You can move the servo to extended position using Arduino without servo horn.
    After moving the servo, set the servo horn with little finger extended.

    Maybe your problem will be solved but if you still have the problem,
    You can adjust the servo movement from Arduino sketch.
    The angle of the servo is defined at 66 and 67 lines.
    https://github.com/exiii/HACKberry/blob/master/HACKberry-software/HACKberry_v1/HACKBerry_v1/HACKBerry_v1.ino

    You will find the statement

    int middleMin = 100;//extend

    int middleMax = 15;//flex

    You can adjust the position and the range of little finger movement by changing this value.

    I’ll answer other questions later.

    #1162

    After adding a polyswitch (I assumed you did), I wonder if you tried to run the servo before installing them in the hand to see if it works. Sounded like loose connection somewhere? The electronic kit and the servos were tested and proven to be working before being sent out.

    #1163

    Hiroshi Yamaura
    Keymaster

    2) The “Thumb” does not move when I push the “Thumb” button.

    As Tima said, please check whether servo moves properly or not before installing.

    Please explain how to do the following steps in the assembly section so I can troubleshoot the issue:
    1) Set servo motor’s degree at pre-set index extended degree in the Arduino program.
    – 写真のように“HbPalmBase03”に“Servo motor Large”を取り付けます。 サーボモータを取り付ける前に、Arduinoを接続した基板等を用いて、人差し指の角度を伸ばした時の角度に設定します。

    Simply connect the PCB, the battery and servo. Then, turn on the switch. The servo motor large will go to extended angle.
    The processes are explained in the following page.
    http://exiii-hackberry.com/dw/doku.php?id=how_to_assemble:socket02

    Also, Do I calibrate the servo’s to 5 volts or 6 volts?

    As for calibration, that voltage will not affect the position of servo motor.
    It just affect the torque.
    We recommend you to use 5[V] because it is safer but if you need higher torque, you can use 6[V].
    It is in the ranges of rating voltage.
    https://www.pololu.com/product/1058/specs
    http://www.emaxmodel.com/es08md.html

    #1172

    Hello,
    Thank you Hiroshi, and Tima. I tried your suggestions and found out that when I loosened the circuit board, the middle, ring and little finger started working. I guess the circuit board was to tight, and caused connection problems. I also set the servo horns better and got better results.

    The thumb now moves once when I press the button, but, it does not move when pressed a second time. I believe I have cold solder connections on the switches, so I will re-solder them and test them. I will let you know what happens.

    Also, my friends are were very excited when I showed it to them, especially my friend who was shot and lost the use of his arm from the shoulder to his hand. He has some movement in his fingers but that’s all. I would like to help him with a EXO Skeletal system that could help him use his arm one day, so keep on developing your ideas!

    Again, thanks, for all your help!

    #1173

    Hiroshi Yamaura
    Keymaster

    I guess the circuit board was to tight, and caused connection problems.

    I experienced the same problem. Please make sure the reset switch of Arduino Micro is not pressed by DC-DC converter.

    動作のフリーズについて

    In that case, you can add tiny plastic fragment to prevent it.

    動作のフリーズについて

    I would like to help him with a EXO Skeletal system

    Sounds great! There are many exoskeleton projects using 3D printer.
    http://www.roboticstrends.com/article/3d_printed_hand_exoskeleton_simplifies_rehab/3d_printers
    I think HACKberry’s sensor system can be combined with some of them.

    Thank you for the update.

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